Micrometer seating dies

[cimmaronkid]

Do any of you use micrometer seating dies? I compared the same load using a standard RCBS seating die, and then using a micrometer seating die, and could tell no difference in group size from my 22-250 varmint rifle. Trouble here is that the rifle has a Hart Heavy Benchrest action and a Hart stainless benchrest barrel and am wondering if the rifle is making up for the standard seater. What do you guys think? By the way, this gun shoots around a .254 ctc group at 100 yds on a good day.

[Norton]

I never used those , But I would think if you were carefull with the OAL and load data on the RCBS loaded round, it would be the same. So it must be you, not the rifle or the dies. You did it right both times, with both sets of dies. Don't the micrometer dies just make seating simplier and quicker to change seating depths ? Correct bullet seating is what I have always found to be the hardest part of reloading on auto pistol rounds. Seating the bullet in the belled out mouth on certain rounds such as 380 is a big Pain. Post a pic of the rifle if you have not all ready.

[NavajoNPaleFace]

I've never used the mike dies so I can't speak of the differences.

I use standard RCBS and Redding dies and between the two I prefer Redding.

If I am tedious I can set the dies up to generally get +/- .005" on OAL or COL.

Even with mike dies this OAL can fluctuate some merely by the fact that although bullet shapes within the same lot number and item number are nearly identical there are slight diffferences with ogives, actually bullet curves, etc. and the Redington dies have a "hollow" bullet seating plug unlike the slightly cupped shape of the RCBS and with the Reddington seating plug the bullet goes up inside the plug. The distance and where it meets the ogive depends on which hollow the plug has since ther are varying amounts of "hollow" plugs Reddington can supply. Is that confusing?

With that ever-so-slight difference in bullet shape in relation to the bullet seating plug there well may be a slight variance on the OAL outcome.

Also, if you were to take different cases and microscope the base you might see some that are perfectly flat or some that are on a very slight angle not detectable with normal vision. That has an effect on the caliper readings.

So, in the scheme of precision round building I would think that standard dies are comparable to mike dies. Are they comparable when it comes to ideas of "extreme precision" rounds...I dunno.

I'm sure others (such as anal retentive bench shooters and match shooters) might have a differing opinion but that is my "shade tree" thoughts on it.

Now, if I were to become a match or bench shooter searching for the ultimate in accuracy I may well try the mike dies but for now I am happy with what I have.

I wish I could submit some of my drawings on how I see the differences in OAL occurrances as I envision them but I hope I can make some verbal sense. Probably not, though. :D

[cimmaronkid]

Understand exactly what you are saying. I am trying to justify the purchase of several Micro seater dies and can't see the justification in the price. I shoot a lot of prairie dogs, but don't need that last .001 reduction in group size as I don't think the PD will ever be able to tell the difference. Unless I were to go to some form of arbor press, I don't see the advantages either. I was just wondering if you guys thought they were worth the money for what supposed benefit you got from them. By the way, here is a picture of my rig.

[86thecat]

If we're talking about the same dies, it's not that they're more accurate but they can be adjusted in exact increments. If you seat the first round and col is .043 too long just dial the knob down .043 and col should be exact. Once distance to lands is known you can load up rounds in known steps to test accuracy without a lot of fiddlin'. Saves time developing loads before a dummy round is made up for each type of bullet.

[woofert]

cimmaronkid,

I’ve never used the micrometer seating die but I do have a way that gets very close to the same thing.

You’ll need to know the threads per inch on the seating stem, most are 10 x 24 tpi.

On the seating stem, use a black sharpie and put a dot on one side at the top, under the slot for the screw driver.

On the top of the seating die body itself mark a cross with the black sharpie with the lines of the cross intersecting in the center of the die, 90 degrees from each other, I use a centering head from my combination square.

Re-assemble the die, note the location of the black dot on the seating stem and seat a bullet, then measure for COL.

Lets say your COL is 0.178” over.

If your seating stem has 24 threads per inch (10 x 24) than each complete rotation of the seating stem equals 1/24th of an inch or 0.0416” and each line on the die body equals 1/4th of a rotation or 0.0104

4 complete rotations of the seating stem equals 0.1664” plus ¼ turn of the seating stem equals 0.0104 so you have move the COL 0.1768”

That puts you with in a couple of thousands of an inch to what you want, then it’s just a matter of fine tuning the seating depth to get what you want.

Hope this wasn’t to confusing but it’s worked pretty good for me.

Woofert

[Seattlefungus]

I agree with 86thecat, If you are using a progressive press with different types of bullets and crimps, it allow for more consistant control on the end product... Unless you did like I did, and use a Dillon and just bought multiple shell plates and dies. Set each for the common crimp for the bullet type. So when I want to change caliber or bullet, I swap the shell plate. (Cause I'm lazy and had money momma didn't know about)...

[4 brigada]

Hi,

I use the micrometer seating dies for .308 and 7.5 Swiss only. Find it easier as not all the the chambers have the same jump, most of my rifles are .308 so the different bullets, 175 sierra hpbt , 168 A max and 175 berger VLD also have different seating depths. Its a time saver for me, and Im pretty retentive on loading but I believe what ever works dont mess with it

[arnaiz]

I got the micrometer stem for my Hornady 308 win dies....and use twice before store it years ago.
You will do same with less costs and work with standard dies.
You will learn soon how long down the dies with 1 setter die stem screw, with half, 1/4 and so....keep such money for powder

[pigpen]

As someone has all ready said, the micrometer seating die is just for use as a ref. when reloading to make sure you seat the bullet to the same depth & have a uniform OAL. In my opinion, as long as you use calipers to measure OAL, you really wont need the micrometer seating die.

[Norton]

Anyone tried the micrometer adjustment thumb screw for the RCBS powder dispenser? that looks like it might be worth it.. I do not like useing the standard set up. But it's a bit high at $35

[woofert]

Anyone tried the micrometer adjustment thumb screw for the RCBS powder dispenser? that looks like it might be worth it.. I do not like useing the standard set up. But it's a bit high at $35

Norton,

that is one extra do-dad that I'm glad I got.

when ever I get a new can of powder and work up loads I stick a piece of masking tape on the can and record the micrometer setting and what weight of that powder it throws.

It makes getting back to the charge weights I want easier when switching between powder.

one improvement I made on mine was to use some cold blueing on it to make the body real dark black and then used some white model paint to high lite the markings, just dab the paint on the markings, let it dry a little and wipe off the excess.

Woofert

[wonderwolf]

I thought the mic seaters are more for mulitple weight bullets. I've put thought into getting a seater mic for my forster match set. Cause I load 60's ,77's and 80's and it would be nice to just look up the number from the my notebook and run the stem to that number instead of having to sacrafice a peice of brass to try and get it right the first time.


Thoughts?

[woofert]

I thought the mic seaters are more for mulitple weight bullets. I've put thought into getting a seater mic for my forster match set. Cause I load 60's ,77's and 80's and it would be nice to just look up the number from the my notebook and run the stem to that number instead of having to sacrafice a peice of brass to try and get it right the first time.


Thoughts?

wonderwolf.

I would think that that would work, you’d just have to make sure that the bullet seating die is mounted in the press the same way each time you use it, maybe one of those die nuts with a set screw to lock it onto the die body.

What I have done in the past with different bullet weights in the same caliber is to make up a dummy round with no powder or primer and seat the bullet to the COL I want, that way the seating die location in the press isn’t critical.

Just screw in the seating die and lock it in place with the die nut, back off the seating stem and run the dummy round up into the die, then screw the seating stem in until it makes contact with the bullet.

Woofert

[Seattlefungus]

Norton & Woofert, I came across a set of those micrometer powder charge die for Dillon. I agree with Woofret. best damn gadget I ever bought!! When you check the powder charge dropped in a casing, no measurable difference in weight no matter how long you've been pulling the handle. I got mine of ebay and bought eight at 20 apiece for the different die and shell plates. makes it a snap to change calibers and bullets weight to charge.