New guy on your forum with a few questions

[Krinkov762]

Hey guys, although I'm new to this forum I'm not new to gun building. I've banged together a slew of AK's and AK variants over the years and thought I'd try something a little different by cutting my teeth on a Cetme C build. I've been researching info here regarding the in/outs, bolt gap, cocking tube gap etc.

I bought an unused NOS cast stainless Century receiver from a friend a few years ago and it's been collecting dust until now. My first question is regarding the interference I'm feeling when I drop my bolt/bolt carrier through the receiver. It hangs up ever so slightly and may wear in ok but I believe it would be ideal if it slipped effortlessly through. If I drop it in sharply it will drop through... however, if I drop it gently through it usually hangs up and stops about 2/3 of the way through. If I shake it, it will come through... so there is only a slight and annoying interference. I've filed a bit on the rails which improved matters... but still experiencing a slight drag. I don't notice any burrs or flashing getting in the way. Secondly, Can anyone here shed some light on the cast stainless Century receiver's rear sight boss? Is there a different sight that is normally installed on a stainless cast Century receiver other than the one supplied in the parts kit? I'm looking at a threaded boss and a machined flat area. The Cetme C rear sight in the parts kit is welded to the receiver chunk and needs to be demilled... removed and placed onto the flat spot & welded in place...correct? So what is the raised threaded boss for? Btw, I was looking at parts on the AOA website and discovered a sight that may work in lieu of the original in the parts kit. Click this link and tell me what you think? It could be removed easily and might fit perfectly on the flat machined surface and you gain windage adjustment. https://armsofamerica.com/special-du...r-sight-combo/

Thanks!

[scottz63]

Welcome!

More knowledgeable people on this subject matter will come along to help you, I'm sure.

[holescreek]

The slight interference is probably coming from the bolt locking lever. Try pulling the bolt head out (away) from the carrier to simulate rifle function with the rollers released.
All of the cast stainless Cetme receivers I've seen photos of show cast Cetme paddle wheel fins.

Does the rear sight area look like this? https://www.robertrtg.com/store/pc/H...TE-27p6307.htm

[Krinkov762]

The slight interference is probably coming from the bolt locking lever. Try pulling the bolt head out (away) from the carrier to simulate rifle function with the rollers released.
All of the cast stainless Cetme receivers I've seen photos of show cast Cetme paddle wheel fins.

Does the rear sight area look like this? https://www.robertrtg.com/store/pc/H...TE-27p6307.htm

Yes sir, it looks very similar.

[WildBillCody]

Welcome, it sounds like you have a G3 receiver not CETME
g3castrec.jpg


, the CETME cast rec look like this:
cetmecastrear sight.jpg

The original sight base was separate and welded on:
Cast CETMErearsight.jpg

On the G3 as well, which is the base Holes showed you. On the cast receivers the rear sight bases were molded in.

There have been many people who have replaced the G# and CETME sights with other types of peeps. Not sure that Ak sight would work, the notch would be too big cause now it's 8" closer to your face.

Plus you to think about zeroing issues, the HK sights are fixed front moveable rear. The CETME are fixed rear, moveable front. What kind of tripletree you got?

As far as the sticking problem goes another thing to look for is if someone tightened up a scope mount on it too tight it can actually cause the sides of the receiver to bow in.

[WildBillCody]

About the slickest rear sight setup I have seen other than the standard HK sight was a AR-15 A2 sight base that had the elevation peg removed and some how attached to the rear of the receiver, not sure if it was welded on or screwed on, but it looked like it would work. Of course you would have no adjustability for elevation, other than what you set the zero to and use it like a battle zero.

[holescreek]

So you get the best of both worlds. A great cast stainless steel receiver that takes G3 sights built with low cost Cetme guts.

Use 309L rod to join the steel components to the stainless steel receiver. The rest of the build is standard Cetme stuff.

[Krinkov762]

Welcome, it sounds like you have a G3 receiver not CETME
g3castrec.jpg


On the G3 as well, which is the base Holes showed you. On the cast receivers the rear sight bases were molded in.

There have been many people who have replaced the G# and CETME sights with other types of peeps. Not sure that Ak sight would work, the notch would be too big cause now it's 8" closer to your face.

Plus you to think about zeroing issues, the HK sights are fixed front moveable rear. The CETME are fixed rear, moveable front. What kind of tripletree you got?

As far as the sticking problem goes another thing to look for is if someone tightened up a scope mount on it too tight it can actually cause the sides of the receiver to bow in.

Oh, I didn't realize there were two different rear sight options on Century cast receivers. I stand corrected. I have the G3 style receiver. I tried to download a pic of mine and had trouble. I don't know enough about the differences in the tripletrees so I wouldn't know how to answer you on that. I'll try again to download a pic or two.

My receiver says:

Made in USA
Century Arms Inc
St Albans VT
CAI-3 .308 (7.62mm)

[WildBillCody]

The cast receiver is really the way to go much stronger IMHO.

The HK has a slot on the side, the sight is a stamped piece of sheet metal held in with a pin.
new-us-triple-frame-front-sight-tower-hk-g3-91-hk33-33k-4.jpg

The CETME has a threaded post that is offset and screws in from the top, with a little set screw in the front to lock it in place.
cetmefront sight.jpg

Like I said one set of sights zero from the front, the other adjust from the rear.

[Krinkov762]

Sorry about the large pics: