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r.erichsen
11-18-2011, 09:53 PM
While looking over custom barrel blanks while planning a custom barrel out for an HK build, I was struck by the options for various calibers. In considering a build for another CETME (my "Modelo G" plan will remain 7.62x51mm) I thought about calibers based on the .308 case, both lighter and heavier than .308. I haven't made any final decisions and the plan is still very early, but I'm very interested in a light .243 build with a handy length.

Several calibers are grouped into the .308 Winchester family:

.243 Winchester *
.260 Remington *
7mm-08 Remington
.308 Winchester
.338 Remington
.358 Winchester
** Technically 7.62x51 mm is part of this family, but since there are dimensional differences in the case I've left it out.

I disqualified the calibers from .30 cal up immediately (though a .358 CETME is intriguing). The more I thought about it, the more interesting a .243 Winchester build became. Though smaller in bore, CETME was clearly interested in trying to do something very similar with it's low pressure 7.62x40 and downloaded 7.62x51 CETME ammunition. When I compared some of the (if somewhat unreliable and highly variable information on the subject) CETME loads to that of a moderate .243 Winchester with 100 grain projectiles, interesting parallels appeared. The 7.62x51 mm CETME round fired a 112 grain aluminum cored projectile at 2700 FPS (though I've read numbers as high as 125 grain, perhaps a later or specialized loading @ 2500 FPS), both with lower ballistic coefficients than most of the longer, heavier 6 mm bullets used in the .243. A fairly moderate .243 will fire it's 6 mm 95-105 grain projectile at 2700-2800 FPS from the same barrel lengths. From an energy perspective, a close match. If a 60 degree LP was used for these lighter CETME loadings, and a 50 degree for the 7.62x51mm NATO loadings, it stands to reason the Modelo A and early Modelo B 60 degree would be well suited to the .243 application.

Cutting and chambering a barrel blank to .243 won't be any more costly or expensive than any other caliber and the throat area can be made tight so that the bullet just nips the rifling of the barrel when seated. The cost of .243 ammo is roughly the same as .308 (both of which are more costly than 7.62x51 mm NATO surplus, but thats true of milsurp in general). Reloading is also comparable to the .308 with projectiles per 1000 somewhat less costly and brass slightly more costly, it's a wash. As calibers go, I really like the .243 (.260 Remington was my next choice, but it's not as cost effective unless I commit to reload) and it should make for an interesting experiment.

Has anyone built a CETME in a lighter .308 based or similar chambering and if so, care to share your experiences?

Many thanks,

R

jbruney
11-18-2011, 11:11 PM
You have definitely caught my interest and you've already compiled a good deal of info.

HKILLER
11-18-2011, 11:13 PM
i like your idea i thing ptr made a 243 cal ptr 91 model for a short time.

Noskov
11-19-2011, 02:34 AM
i like your idea i thing ptr made a 243 cal ptr 91 model for a short time.

They did, there was one on gunbroker for a while but think it finally sold or the seller decided not to re-list it. At least you could still use standard G3/CETME mags with the rifle too.

jbruney
11-19-2011, 06:41 AM
This is good to follow if you do it because I have some dies in this caliber....If it works out well for you there could be one in my future. I don't mind at all following someone's blazed trails on these projects....anyway I have and love the round. If you invent this wheel I'll put my sled on it and it'll become a cart.............Good luck with this. Godspeed.

holescreek
11-19-2011, 10:49 AM
I wonder if that means that PTR might have some barrels left? That could save someone a ton of headaches.

HKaltwasser
11-19-2011, 11:39 AM
i like your idea i thing ptr made a 243 cal ptr 91 model for a short time.
I always wanted one of those PTR91 .243's. Seems like a great caliber in this platform.

r.erichsen
11-19-2011, 02:03 PM
I always wanted one of those PTR91 .243's. Seems like a great caliber in this platform.

Why wait? Build one!

The only parts that are unique for the .243 caliber are the barrel and the correct locking piece for the bolt head. Holescreek is making locking pieces for CETME (and a few for HK now or so I've heard) in various shoulder angles leaving only the task of getting someone like Jayson over at IGF to cut and chamber a barrel blank, and then someone like Kenny Hart from over on HKPro to flute the chamber. Everything else remains unchanged.

As mentioned, the Modelo A and early B have a locking piece shoulder angle of 60 degrees. I think this is probably a good starting point. A 55 degree might be more ideal for "heavy" .243 operating higher pressure loads. I found what I consider to be the most accurate information on the original 7.62x51 mm CETME load:

"Jacketed spitzer bullet of 112.5 grains (7.25 g) weight, a brass or steel case of 151 grains (9.7 g), for a muzzle velocity of 2493 fps (760 mps)." NOTE the steel case reference. I've heard that the Spanish made use of steel for many types of ammo - it works pretty well in DRB and it's interesting it wasn't more common. "The construction of the bullet is particularly noteworthy. The CETME bullet has a 90/10 brass alloy (gilding metal) jacket, with a plastic nose filler for the first third of the bullet, and a lead antimony core. That is to say, the bullet jacket is not filled with the lead core, but has what might be considered a lightweight ballistic tip (not unlike the kapok tip in the .303 British service round). This cartridge, adopted in 1957, remained the standard Spanish service round for the next twenty-five years." The lead "plug" at the base of what is a largely plastic tipped and plastic cored (no aluminum core as I've seen reported, likely from an earlier project with the 7.62x40 mm and 7.92x33 mm projects that were abandoned) bullet, would cause the bullet to be very unstable on impact causing early yaw. An interesting design and more advanced than the earlier .303 Enfield design.

Once the barrel is pressed and the correct bolt gap is established, you could drill the cross pin hole and have your .243 CETME (or HK with proper locking piece), or press out the barrel and press in a barrel of a different caliber. Not as "modular" as some rifles, but at least within the .308 family, it's a locking piece and a barrel for each.

If the exterior profile of the new .243 barrel matches the OE 7.62x51 mm barrel profile, the barrel is automatically "medium-heavy profile" but still fits the same triple frame as what would be a "light profile" in .308/7.62x51 mm.

If it goes well I might do another in .260 or 7 mm-08, both of which have superb flat shooting, light recoiling characteristics.

1) Barrel blank (not really a "match" barrel, but good) $140
2) Cut blank, thread muzzle, bore and ream chamber $245 (Jayson from IGF is one of the better sources)
3) Flute chamber for positive extraction $175 (Kenny Hart, though he's busy and hasn't been posting much this year on HKPro)
4) Locking piece - unwanted/unloved 60 degree LPs from the older Modelo B and earlier Modelo A, $15-30, a custom made LP can be bought from Holescreek for about $75

Regards,

R

WildBillCody
11-19-2011, 02:17 PM
This was a topic years ago, IIRC there was someone who built one in 22-250. The hard part is getting the flutes cut in the chamber, not changing the caliber.

r.erichsen
11-19-2011, 02:27 PM
WildBillCody,

Other than Kenny Hart, do you know of other folks that do chamber fluting?

R

HKaltwasser
11-19-2011, 05:14 PM
WildBillCody,

Other than Kenny Hart, do you know of other folks that do chamber fluting?

R

I don't think Kenny does fresh flute cuttung. He will cut correct spec for out of spec(flute deepening) PTR's but I don't think he does fresh ones. RCM would do a group order but I don't think they'd do a single barrel. You might give BRAVO5 a call. He might do one or a few for ya. After this thread ,I tracked a few PTR91 .243's down just to see what prices are at. around 900.00-1,200. They're still out there, I'm just not quit ready to buy at this point. I'd like to build one but I'm still collecting tools.

GeorgiaG3
11-19-2011, 06:49 PM
I don't think Kenny does fresh flute cuttung. He will cut correct spec for out of spec(flute deepening) PTR's but I don't think he does fresh ones.

That's what I thought. There's a big difference between filing down preexisting flutes and flat out carving new ones. Honestly, I would think that anyone who has the tooling for turning down a barrel blank, would also have the tooling for carving out flutes.

I can't be sure on that (Hell, I've never even used a lathe) but it would seem anyone with a lathe would have tools or be able to get them for cheap.

WildBillCody
11-19-2011, 06:52 PM
Nope, Sorry, That was awhile ago. IIRC they were EDM cutting them.



WildBillCody,

Other than Kenny Hart, do you know of other folks that do chamber fluting?

R

holescreek
11-19-2011, 07:32 PM
I would love to see some that were edm'd! We had a pretty good discussion on fluting a year or two ago here back when I started into fluting my barrels on my CNC mill. I actually started thinking seriously about making a home ecm (not edm!) machine to chamber flute. ECM is electrochemical machining and there is virtually no electrode wear. The trick is that the electrode must be advanced incrementally so that the arc gap remains constant. Problem for me is I'm just a machinist, not an electrical engineer. There is a good (if poorly done) video on youtube showing a very simple ECM process done on a drill press. It's all about control of the gap.

I think that a smart fella (without a CNC) could figure out a way to make a hand shaper with a reciprocating cutter that followed an enlarged guide plate with the profile of the cartridge on it. Or maybe just use some kind of spring tensioner to maintain constant pressure on the cutter as it was pulled through the chamber. That way you could control the start and stop points. Put the barrel in an indexer to rotate to each flute and go to town.


I would think that anyone who has the tooling for turning down a barrel blank, would also have the tooling for carving out flutes.



Chamber fluting isn't really complicated but it is very time consuming and requires specialized tools and holders that can't be bought. Besides my home made CNC mill and custom tool holders I bought a used Deckel SO cutter grinder to make the very tiny carbide cutters necessary to cut the flutes. On an average barrel when everything goes perfectly I still have about 5 cutter changes due to wear. The fastest time I ever fluted a chamber when everything went perfectly was around 4 hours. The longest time and most cutter changes was a stainless barrel that ended up at just over 10 hours (IIRC) because I had a heck of a time getting the cutter geometry right for the steel type and kept breaking the tips off the cutters.

r.erichsen
11-19-2011, 08:08 PM
I don't think Kenny does fresh flute cuttung. He will cut correct spec for out of spec(flute deepening) PTR's but I don't think he does fresh ones. RCM would do a group order but I don't think they'd do a single barrel. You might give BRAVO5 a call. He might do one or a few for ya. After this thread ,I tracked a few PTR91 .243's down just to see what prices are at. around 900.00-1,200. They're still out there, I'm just not quit ready to buy at this point. I'd like to build one but I'm still collecting tools.

Buying to own is always easiest (and usually cheaper) but I'm all about the thrill of the build, solving new problems as they arise, looking for new challenges as my skills improve and I learn more.

R

jbruney
11-19-2011, 08:11 PM
It's been some years but I always detested machining SS..It just plain sucked and left particularly nasty shavings...The only advantage to that material is corrosion resistance and high temp tolerance...Besides properly maintained firearms should have no corrosion issues..Sorry for the short rant my crankiness brought on, but that material and memories just.............small splinters that don't have the decency to rust away under your skin..magnets are useless on most.

WildBillCody
11-19-2011, 08:15 PM
I would love to see some that were edm'd! We had a pretty good discussion on fluting a year or two ago here back when I started into fluting my barrels on my CNC mill. I actually started thinking seriously about making a home ecm (not edm!) machine to chamber flute. ECM is electrochemical machining and there is virtually no electrode wear. The trick is that the electrode must be advanced incrementally so that the arc gap remains constant. Problem for me is I'm just a machinist, not an electrical engineer. There is a good (if poorly done) video on youtube showing a very simple ECM process done on a drill press. It's all about control of the gap.

I think that a smart fella (without a CNC) could figure out a way to make a hand shaper with a reciprocating cutter that followed an enlarged guide plate with the profile of the cartridge on it. Or maybe just use some kind of spring tensioner to maintain constant pressure on the cutter as it was pulled through the chamber. That way you could control the start and stop points. Put the barrel in an indexer to rotate to each flute and go to town.



Chamber fluting isn't really complicated but it is very time consuming and requires specialized tools and holders that can't be bought. Besides my home made CNC mill and custom tool holders I bought a used Deckel SO cutter grinder to make the very tiny carbide cutters necessary to cut the flutes. On an average barrel when everything goes perfectly I still have about 5 cutter changes due to wear. The fastest time I ever fluted a chamber when everything went perfectly was around 4 hours. The longest time and most cutter changes was a stainless barrel that ended up at just over 10 hours (IIRC) because I had a heck of a time getting the cutter geometry right for the steel type and kept breaking the tips off the cutters.

Perro was involved in that I think, the 22-250 one...

r.erichsen
11-19-2011, 08:26 PM
I would love to see some that were edm'd! We had a pretty good discussion on fluting a year or two ago here back when I started into fluting my barrels on my CNC mill. I actually started thinking seriously about making a home ecm (not edm!) machine to chamber flute. ECM is electrochemical machining and there is virtually no electrode wear. The trick is that the electrode must be advanced incrementally so that the arc gap remains constant. Problem for me is I'm just a machinist, not an electrical engineer. There is a good (if poorly done) video on youtube showing a very simple ECM process done on a drill press. It's all about control of the gap.

I think that a smart fella (without a CNC) could figure out a way to make a hand shaper with a reciprocating cutter that followed an enlarged guide plate with the profile of the cartridge on it. Or maybe just use some kind of spring tensioner to maintain constant pressure on the cutter as it was pulled through the chamber. That way you could control the start and stop points. Put the barrel in an indexer to rotate to each flute and go to town.



Chamber fluting isn't really complicated but it is very time consuming and requires specialized tools and holders that can't be bought. Besides my home made CNC mill and custom tool holders I bought a used Deckel SO cutter grinder to make the very tiny carbide cutters necessary to cut the flutes. On an average barrel when everything goes perfectly I still have about 5 cutter changes due to wear. The fastest time I ever fluted a chamber when everything went perfectly was around 4 hours. The longest time and most cutter changes was a stainless barrel that ended up at just over 10 hours (IIRC) because I had a heck of a time getting the cutter geometry right for the steel type and kept breaking the tips off the cutters.

I read through that thread with great interest and realized quickly the effort would make little sense to attempt to duplicate. It would take several months of experimenting to do what I probably will only ever do 2 or 3 times - if that many. ;)

As a last resort, I'll preserve the opportunity to destroy several perfectly good barrel blanks - add that to my list of the growing pile of serviceable firearm parts I've mangled in the last 11 months (with many more to follow)!

R

Lalvis
11-19-2011, 09:56 PM
I think a 22-250 CETME would be something cool!:Smile_glasses: Way better than the 5.56 c93

GeorgiaG3
11-20-2011, 07:52 AM
Can anyone direct me to this thread about chamber fluting?

Sounds pretty interesting...

WildBillCody
11-20-2011, 09:12 AM
The one I'm talking about was years ago, maybe even on Gunboards.

holescreek
11-20-2011, 10:53 AM
Can anyone direct me to this thread about chamber fluting?

Sounds pretty interesting...

Here's one of them:
http://www.militaryfirearm.com/Forum/showthread.php?17254-Chamber-fluting-in-the-home-shop&highlight=chamber+fluting

r.erichsen
11-20-2011, 04:43 PM
In discussion with Holescreek I think I can take one item off the list (the locking piece) by going the HK internals route. Far more LPs to work with and a backup plan of sorts if finding 60 degree CETME LPs proved more difficult than I might have originally anticipated. The benefit is also the ability to more easily replace and spare up on LPs which may or may not be easy going the CETME route.

I'm going through HKweaponsystems and other forums for folks who have fluted chambers in order to get a list of those who have, those that have offered this as a service and those that are either too busy or or jaded to do so for this project.

My expectation at this point is that the fluting would be exactly the same as the 7.62x51 mm chamber up to the beginning of the case shoulder. At that point it will be tapering more rapidly for the necked down .243 case and that's where the real fun would begin.

It will probably take at least a few weeks, if not a few months, to find a potential "fluter" for this project. If that falls through, I'll have to work out the degree wheel and template to do it myself with hand tools.

Wish me luck,

R

GeorgiaG3
11-20-2011, 10:29 PM
Would it be possible to make a barrel insert for the 7.62 that allows you to change between the two cartridges like is done with the .22?

r.erichsen
11-20-2011, 10:42 PM
Would it be possible to make a barrel insert for the 7.62 that allows you to change between the two cartridges like is done with the .22?

I would have safety concerns given the pressures. You can get away with those .22 LR conversions with their skinny tubes and lightweight chamber inserts because not a lot of energy is involved and even if it burst you'd have the chamber of the outer 7.62x51 mm barrel to contain the destruction.

.243 runs at pressures that range from 40K to 53K+ PSI - quite a lot higher than a .22 LR. There is also the question of how you would go about securing a chamber insert for .243 given that only the portion of the shoulder up is different from .308/7.62x51.

I'm going to contact Bravo 5 and RCM about a .243 bore barrel with flutes and see what they have to say. Thompson-Contender made the barrels for PTR and they might be another option - they made the .243 bore barrels used in the PTR .243 rifles so it stands to reason unless PTR has an exclusive contract for anything remotely HK (possible, but unlikely) TC might produce, they might be able to make me something as well. Obviously they have fluting equipment around.

R

r.erichsen
11-21-2011, 12:25 PM
So far I've compiled a list of possible barrel fabricators who could help me on this project:

TC (Thompson Contender?) which I saw in relation to making barrels for PTR - I must have the wrong TC, they said they don't make barrels, they just finish pre-chambered barrels by cutting to length, reprofiling and crowning them. Can anyone confirm if there is some other "TC" and if so, a full company name?

RCM (Rim Country Manufacturing) - they told me they don't do custom work, at least for the general public.

Urbach (Urbach Precision) - phone number just obtained, no email available, I'll try to find out today

Bravo 5 - still waiting for a response by email.

One of these folks should be able to take a barrel blank in chrome-moly and fabricate me a proper barrel, I hope. ;)

R

HKaltwasser
11-21-2011, 03:00 PM
So far I've compiled a list of possible barrel fabricators who could help me on this project:

TC (Thompson Contender?) which I saw in relation to making barrels for PTR - I must have the wrong TC, they said they don't make barrels, they just finish pre-chambered barrels by cutting to length, reprofiling and crowning them. Can anyone confirm if there is some other "TC" and if so, a full company name?

RCM (Rim Country Manufacturing) - they told me they don't do custom work, at least for the general public.

Urbach (Urbach Precision) - phone number just obtained, no email available, I'll try to find out today

Bravo 5 - still waiting for a response by email.

One of these folks should be able to take a barrel blank in chrome-moly and fabricate me a proper barrel, I hope. ;)

R

I think BRAVO5 is gunna be your best bet. Urbach is retired and won't likely respond to you. People have been trying to get ahold of that guy for years. It seems that Gordon Miller of HKspecialists has priority with M. Urbach. He won't be cheap either but he's the best at what he does too. Thompson center barrels may be able to help but I would give them your specifications on the flutes. They're the one's that did the shalow flutes for PTR(although with provided specs by PTR)
Another place you could try is Green Mtn. Barrels. I know they've done some HK/Cetme barrel runs for century.

r.erichsen
11-21-2011, 06:57 PM
I think BRAVO5 is gunna be your best bet. Urbach is retired and won't likely respond to you. People have been trying to get ahold of that guy for years. It seems that Gordon Miller of HKspecialists has priority with M. Urbach. He won't be cheap either but he's the best at what he does too. Thompson center barrels may be able to help but I would give them your specifications on the flutes. They're the one's that did the shalow flutes for PTR(although with provided specs by PTR)
Another place you could try is Green Mtn. Barrels. I know they've done some HK/Cetme barrel runs for century.

HKaltwasser,

I hadn't heard Urbach was retired. Shucks - scratch that one off the list. I'm down to Bravo5 and possibly "Thompson Machine" (Holescreek gave me that on Calguns forum). Regarding Thompson Center/Thompson Contender (http://www.tcarms.com/customShop/barrels.php if that is who you are talking about), I already contacted them and they told me they don't make barrels at all - they just finish them on the lathe. They order barrel "blanks" which come pre-chambered and rough profiled, which is a pretty complete blank by most standards. They declined to confirm or deny if they ever did work for PTR, but if they did, there is an unknown, unnamed barrel producer upstream of them that is actually "making" the barrels. I have no reason to doubt the product manager I contacted that they are not a barrel producer, so my search continues. I suppose like most firearms companies, Thompson Center just acts as a middleman and control the barrel drawings for any of the barrels they sell or use in their assembled weapons, specializing in their part of the business and outsourcing the rest. I don't really know where the TC connection came from with JLD/PTR, but at this point it is thoroughly debunked, unless there is some OTHER Thompson Contender/Thompson Center that actually makes barrels and I just can't find them.

I had not heard Green Mountain ever made an HK barrel for anyone, Century or otherwise. Interesting. Unfortunately I'm in fairly regular contact with Dennis P over there for AK barrels and he's made it clear to me in the past that a min order around there is 100 barrels, no custom one-offs, etc. etc. Anything not in the catalog or online is a custom job carrying the 100 barrel minimum, a credit application and the usual stuff to become a wholesale customer. They were off the list even before you mentioned them, unfortunately.

I hope my heroes over at Bravo5 haven't taken the week off so I can get an answer on using blanks from other manufacturers. Holes mentioned on the Calguns thread I started that he was under the impression that even Bravo5 is just a barrel finisher and don't actually manufacturer anything (the barrels are pre-chambered and fluted before they get them, paraphrasing a bit). I hope thats not true, but we'll see.

R

holescreek
11-21-2011, 07:25 PM
Perro will probably know which "Thompson" it was that did the PTR barrels. No matter who it was you are going to be looking at a heck of a setup fee for one barrel of an odd caliber. Probably best to start figuring out the best way to do it yourself.

HKaltwasser
11-21-2011, 08:42 PM
HKaltwasser,

I hadn't heard Urbach was retired. Shucks - scratch that one off the list. I'm down to Bravo5 and possibly "Thompson Machine" (Holescreek gave me that on Calguns forum). Regarding Thompson Center/Thompson Contender (http://www.tcarms.com/customShop/barrels.php if that is who you are talking about), I already contacted them and they told me they don't make barrels at all - they just finish them on the lathe. They order barrel "blanks" which come pre-chambered and rough profiled, which is a pretty complete blank by most standards. They declined to confirm or deny if they ever did work for PTR, but if they did, there is an unknown, unnamed barrel producer upstream of them that is actually "making" the barrels. I have no reason to doubt the product manager I contacted that they are not a barrel producer, so my search continues. I suppose like most firearms companies, Thompson Center just acts as a middleman and control the barrel drawings for any of the barrels they sell or use in their assembled weapons, specializing in their part of the business and outsourcing the rest. I don't really know where the TC connection came from with JLD/PTR, but at this point it is thoroughly debunked, unless there is some OTHER Thompson Contender/Thompson Center that actually makes barrels and I just can't find them.

I had not heard Green Mountain ever made an HK barrel for anyone, Century or otherwise. Interesting. Unfortunately I'm in fairly regular contact with Dennis P over there for AK barrels and he's made it clear to me in the past that a min order around there is 100 barrels, no custom one-offs, etc. etc. Anything not in the catalog or online is a custom job carrying the 100 barrel minimum, a credit application and the usual stuff to become a wholesale customer. They were off the list even before you mentioned them, unfortunately.

I hope my heroes over at Bravo5 haven't taken the week off so I can get an answer on using blanks from other manufacturers. Holes mentioned on the Calguns thread I started that he was under the impression that even Bravo5 is just a barrel finisher and don't actually manufacturer anything (the barrels are pre-chambered and fluted before they get them, paraphrasing a bit). I hope thats not true, but we'll see.

R

The last time I talked to BRAVO5 about PSG1 barrel, they said they were waiting on blanks so they could finfish them out(chambered and fluted or maybe just fluted, and mayby they just profile). I may be just guessing at alot of this. I had wrote them awhile back, again asking if they could chamber and flute a Lothar Walther barrel for me and never heard back. A call may be the best confirmation . Fluting has always been the hang-ups on the DRL rifles. Not too many that will do it without large runs.

As far as the Green mtn. goes, from what I understand they did all of or at least some of the c93 barrels. There again, I don't know what part of the procees they were involved in.

r.erichsen
11-21-2011, 09:41 PM
Perro will probably know which "Thompson" it was that did the PTR barrels. No matter who it was you are going to be looking at a heck of a setup fee for one barrel of an odd caliber. Probably best to start figuring out the best way to do it yourself.

You're probably right Holes. I'll probably buy a couple of roughed out blanks, a cheap one I will likely ruin experimenting and a good one I actually plan to use. According to Kenny it took him about 4-5 hours to hand flute a chamber, I think your ECM idea is interesting but may take a bit longer to work out than just getting in there with triangular diamond coated files after making the template for the cuts.

R

HKaltwasser
11-22-2011, 01:22 PM
Perro will probably know which "Thompson" it was that did the PTR barrels. No matter who it was you are going to be looking at a heck of a setup fee for one barrel of an odd caliber. Probably best to start figuring out the best way to do it yourself.
They're advertized as coming with Thompson Center barrels.

Otis61
11-22-2011, 04:43 PM
Did you check Rim Country Manufacturing?

r.erichsen
11-22-2011, 04:59 PM
They're advertized as coming with Thompson Center barrels.

The response from Thompson Center didn't confirm or deny they ever worked with PTR, but they did say they don't manufacture barrels per se. I'll talk to someone else after the holiday to make sure the initial response wasn't a classic failure to communicate on my part or theirs. UPDATE: TC does make barrels, but are unwilling to discuss details for PTR or any other customer.

R

r.erichsen
11-22-2011, 05:01 PM
Did you check Rim Country Manufacturing?

Affirmative, I responded to that question a few pages ago. RCM does NO custom one-off work of any kind - you better have credit approval and a large min order of barrels if you want to work with RCM, because the general public is not who they cater to.

R

Blackwing
01-15-2012, 11:24 AM
RCM caters to Adam at HKPARTS.NET and that is it. They signed an exclusive for him to sell all of their HK style anything stuff. They make barrels at his request.

r.erichsen
01-15-2012, 01:47 PM
Good to know. Maybe if I can convince Adam to order 100 .243 barrels I might be able to buy my one. Somehow I don't see much likelihood unless Adam is buying in much smaller quantities.

R

r.erichsen
07-23-2012, 12:13 PM
My unfluted heavy sporter 20" .243 barrel is on route back to me and the .358 barrel is somewhere in profiling process. It's a lot less exciting than a barrel that is more or less guaranteed to work, but that's the digs with custom calibers on custom barrels. Having excluded EDM as a practical method, manual fluting is the next most likely alternative. Building an ECM machine would probably eat up the remainder of the summer and does not appeal to me.

R

holescreek
07-23-2012, 01:05 PM
Didn't you get that manual fluting jig?

Lalvis
07-23-2012, 01:11 PM
Don't forget the 22-250 is also in the 308 family! That would be interesting to say the lest

r.erichsen
07-23-2012, 01:58 PM
Didn't you get that manual fluting jig?

Kenny wasn't ready to part with it yet. I just sent him a PM to ask him if he had finished his multi-caliber HK 11 yet.

R

r.erichsen
07-23-2012, 01:59 PM
Don't forget the 22-250 is also in the 308 family! That would be interesting to say the lest

Someone on Weaponsguild did it, but I can't find the thread. I understand they got away with an unfluted chamber, but I have none of the details if that is true or not. 22-250 is .250 Savage based, not part of the .308 Winchester (which sprang out of the .300 Savage) family.

R

holescreek
07-23-2012, 03:51 PM
Someone on Weaponsguild did it, but I can't find the thread. I understand they got away with an unfluted chamber, but I have none of the details if that is true or not. 22-250 is .250 Savage based, not part of the .308 Winchester (which sprang out of the .300 Savage) family.

R

I've never heard of it being done, at least not in the last 3 years. Never heard it mentioned in that time either.

r.erichsen
07-23-2012, 03:55 PM
I've never heard of it being done, at least not in the last 3 years. Never heard it mentioned in that time either.

7-8 years ago is what I've been told. Must be deep in the Prexis archives.

R

3333fps
12-20-2013, 03:22 AM
I tried building 3 different HK91's with no flutes through the years. I tried a 308, a 243 once, and wildcat. I tried polishing the chamber, to help extract. The problem will always be failure to extract. It is my understanding that failure to extract was an original design flaw with this type firearm. The original design wouldn't extract. The chamber flutes were a fix for that. EDM is is a pain, but it is really the way to go. I tried a rig with micro diamond cutters, no luck, the consistency was bad.