Reloading for AR 10

[force0311]

Hi guys,

First of all, thank you for all of the knowlege that you share. Great info. I have an entire reloading setup coming to me (I'm a green horn). I'm spent countless hours researching fl sizing dies versus sb dies. I plan on reloading lake city brass and have come to one conclusion. If the brass fits correctly into my L.E. wilson case gauge, then i should not have any problems with the round chambering in the rifle.... Is this correct?

[Jimro]

You can assume that, but it isn't always the case.

Case length gauges often don't measure the expansion at the base of the brass, so if you have a tight chamber in your AR-10 you might need to get small a base resizing die even if the case length is in spec.

You'll find out pretty easy if you start having problems getting your reloads chambered or they get stuck in the chamber.

Jimro

[force0311]

Thanks Jimro!

[Slamfire]

Case length gauges often don't measure the expansion at the base of the brass, so if you have a tight chamber in your AR-10 you might need to get small a base resizing die even if the case length is in spec.

I agree. I also use small base dies for my gas guns because of this issue.

There are those who don't believe you need to use small base dies for Garands, M1a's or AR10's. I am going to try to show how it could make a difference.

Recently I shot my newly rebarreled M1a in a local reduced course match. I think I was the only Dinosaur shooting 30 caliber on the line. This rifle has a Barnett barrel and the commerical chamber dimensions are smaller than the standard military rifle. I am able to tell the difference when sizing brass for this rifle, compared to sizing brass from my FAL. The FAL has such a huge chamber that it is very difficult to small base size those cases.

I have 308 and 30-6 gages, cut by Gene Barnett which are a little out of the ordinary. He cut these gages with his chambering reamer. Standard cartridge headspace gages are cut with a special reamer that is wide in the middle. A standard cartridge headspace gage measures length, not “fatness”. A reamer cut headspace gage will show you if the case is too long and too “fat” for that chamber.

I have a number of 308 small base dies, and I still have my Lee standard die.

I sized a number of my match cases in the Lee die. All of them dropped in the reamer cut case gage. So, if you said you don’t need small base dies, you would be correct most of the time.

So now I had to scratch around trying to find cases that would prove my point.

These two cases are once fired range pickup brass that I found in my brass box. I had to go through about 20 cases before I found a set of really ballooned cases. On the right is the Barnett reamer cut gage.






If you notice one case has completed dropped into the Wilson cartridge headspace gage, while the other has not dropped into the Barnett reamer cut gage. This shows how much they have swelled up after being fired. Must have been a big chamber.

The second picture is of the fattest of the group after sizing in with Lee Die. I trimmed the thing to make sure that the case neck did not interfere with the throat in the gage.




Hopefully you can see that the case did not drop all the way in the case gage. At least on its own. It would have taken a good hard push to get that base all the way in.





This is after resizing in my RCBS small base die. I could not find the RCBS box, so the case/gage are sitting on a Redding small base box. However, that little additional sizing removed the interference fit.




Sometimes cases are so ballooned that even a small base die won’t reduce the case to factory dimensions. It all depends on the chamber the round was fired in.

I know it is extra effort to size cases with small base dies, if you use a good lube like Imperial Sizing wax or RCBS case lube, the effort is somewhat reduced. Still for all the extra bother involved in sizing with small base dies I'll do it for my Garands and M1a's. With those rifles I don’t want any resistance to chambering, I don’t want any delay to bolt closure. Because as the bolt stops and the lugs are turning, that darn free floating firing pin is just tapping the heck out of the primer.

Now just two weeks ago, a shooting bud of mine was having jams with his AR10. He was using Dillion carbide 308 dies, which sufficiently sized the LC brass he had, for width, but he was not using his Dillion case gauge properly. At the range, we had to dismantle his AR10, because we could not get the bolt closed on one of his rounds. I separated the upper from the lower, then we played a game of bash the charging handle, to get the round out of the chamber. His cases were so long, from base to shoulder, that we could not get the rifle to reliably chamber his rounds. This was also true of his 308 M700. Once we got to his house, and I adjusted his die, so it sized cases to gauge minimum, we had no problems with chambering.

Also, don't load to reloading manual maximums. They are way too high for these gas guns. For example, I recommend a maximum load of 42.5 grains IMR 4895 with a 150 grain bullet, and 41.5 grains of IMR 4895 with a 168. Bud was loading 44 grains with a 168 and having extraction issues. He got that load from a manual, which is tailored for bolt guns. Once we got his issues straightened out, he went back to the range and was firing sub MOA groups, and the rifle functioned each time.

[force0311]

Thanks slamfire! So i will get a jp enterprise reamer case gauge and i should be good to go. If i'm using a reamer case gauge (that measures both diameter and length) then there should be no need for the wilsone case gauges!

[force0311]

I just saw something amazing. Have you guys seen/used a slotted case gauge made by sgeridan engineering?

[force0311]

That's sheridan engineering.

[Slamfire]

That's sheridan engineering.

I had never heard of them till your post. I think these gauges are a great idea.

[On Deck]

So maybe this is why first round chambers, fires, but will not extract??

Using 550B & Dillon full length 308 dies set. And my second batch of reloads chamber, but FTF's by light primer strikes - puts just a dimple in the CCI primers.

And they all passed the Wilson Case Gauge test - go figure!

[Nitescout]

I`m surprised someone hasn`t mentioned the RCBS Precision Mic PN 88329.

This tool is the best way to tell what your chamber size is...I know they`re all
supposed to be standard. but they don`t always leave the factory the same size as the Wilson, or other brand go/no gauges.

I purchased one of these when I was having chambering Issues in a rem 700 in .308. The chamber was too tight!!! I had to remove about .005 from the top of the shell holder to get the cases to go in to the die deep enough to chamber.

Now that I have a new M1A, this tool gets to check each resized case to make sure they will chamber.. It really measures your fired cases accurately. I was surprised to find most factory ammo is .010 to .020 under size. using current
dated LC 15 GI ammo, some come out of the chamber .001 over size to .002 undersize. There is also a loaded round tool included in the kit to measure for best seating depth. I hope this helps.

[Sharkbite]

Quote:
That's sheridan engineering.
I had never heard of them till your post. I think these gauges are a great idea.

I use Sheridan gauges in 556, 300blk and 308. I consider them essential in checking loaded ammo.

The "slotted" version allows you to not just check the ammo, but to see WHERE its out of spec if it dosent fit.

I have never had a round that passed the guage and then would not chamber.

[Tomas]

force0311:

First off, Semper Fi! I was 0311, then 8541.

You were given some great advice here.

However, I have been reloading for .308s (bolts, Galil, Scar H, M1A and AR 10) and have never had to use any of the specialized tools they mention. I use RCBS FL dies, Dillon case gauge, CCI 200s, etc. A pretty vanilla set up. I have loaded for near 25 years now, and fired in excess of 20,000 .308 rounds through the various rifles listed, and never had any of the problems mentioned in the other posts.

I'm not saying, at all, that they are not smart, experienced reloaders...clearly they are and are giving sound advice.

I just think that you can start without all the worry, and move to the more specialized tools as you need them. SB dies stress the brass more at the base, and you get less re-loads. I retired mine for that reason and went back to my FL dies. I like the idea of the Sheridan dies, but $60 is a lot for one.

Address problems as they arise, you'll go broke and crazy preparing for every possible contingency. It's not rocket science...resize, trim, chamfer, kill the primer crimp, prime (seat 'em deep) and load...then go shoot!

[Slamfire]

SB dies stress the brass more at the base, and you get less re-loads.

I did not see that. I took one set of 308 Win brass 23 firings , and I shot them in a M1a. I lubricated these cases before firing, most of the time paste wax rubbed on the outside, but there were times I left on the RCBS water soluble lube. Lubricating the cases prevented case head separations, which occur typically less than 10 reloads, sometimes four reloads, in Garand mechanisms.


These cases were mostly sized in a small base die. I don't remember when I quit using a standard Lee die, but for the majority of their shooting life, these cases were sized in an RCBS small base die. Cases fired in a FAL are next to mine shot in my M1a. The FAL cases lost their case heads in only a couple of firings. None of my cases show the slightest bit of sidewall thinning. I retired the cases because the primer pockets started to get large, and I did not want a dropped primer causing a malfunction in NRA rapid fire. Shooting an alibi always hurts my score.


I bought a Sheridan gage in 308 and 30-06. I love gadgets like this. I was good to see that my small base sized 30-06 Garand ammunition dropped right in, not merely a sized case, but a loaded round.

[Nitescout]

Slamfire, Good on you!!!

I`m glad to see someone else likes to cut away cases to check for web thinning.

It`s good to see good records being kept on cases. and magic markers (sharpie) to write data on cases.

It`s good to see that someone else uses GI brass in their reloads...I used to make my 7mm/08, and 243 cases from LC Match cases...since GI brass is thicker and heavier, powder charges need to be reduced when working up a load. You`ll also get necks that are too thick, and need reaming to keep the neck tension uniform.

[Slamfire]

I`m glad to see someone else likes to cut away cases to check for web thinning.

It was important to determine if I was having any sidewall stretch as I shot these rounds. With the exception of the 22 reloaded, 23 times fired case, all of the sectioned cases had neck splits or body splits. These happen as the case work hardens.

It`s good to see good records being kept on cases. and magic markers (sharpie) to write data on cases.

I segregate cases by case head and the number of times reloaded. I often note if the pocket has been reamed, the trim length, primer, etc. Since I found that gun powder deteriorates, now I write the date loaded, and make an attempt to shoot the oldest ammunition first.

It`s good to see that someone else uses GI brass in their reloads...I used to make my 7mm/08, and 243 cases from LC Match cases...since GI brass is thicker and heavier, powder charges need to be reduced when working up a load. You`ll also get necks that are too thick, and need reaming to keep the neck tension uniform.

For the M1 Garand and the M1a, LC cases are the best you can use. IMI used to make some outstanding cases, have not seen them in a while. LC cases are heavy, case hardness appropriate for the mechanism. And the primer pockets hold up, unlike Federal.

I have not tried to neck down LC, but I have necked up to 35 Whelen. Works fine.