[Paul Jenkins]

Gentlemen,
I am new to this forum and have a new to me M1A. The rifle shoots great & functions great. The problem, if it is one, is that after every fireing with Fed. Gold match cases I get .010 to .015 stretching after resizing. I am thinking the exspander
is pulling the case out? The rifle and reloads shoot so well, I am reluctant to change anything. I am loading 41 grs. IMR 4895, 168 HPBTM, O.A.L. 2.800"with Fed 210M primers. Best grps, 3/8", 1/2" at 100 yds. everyting under 1" except when I pull one.
Is this normal? I am F.L. sizing. Is that required for an auto? I fear I will be seperating cases soon.

 

[Bowhntr6pt]

Do you lube the inside of the case neck?

 

[Paul Jenkins]

No sir,
I don't like to lube the inside of a case neck because i thought it would be introducing another variable. But I guess a consistant lube wouldn't be any worse. I'll try lubing the inside & see how the accuracy goes. I guess I could add a few extra steps & reclean after resizing and then priming.

 

[Paul Jenkins]

Gentlemen,
Iv'e never had a stretching problem like this before. I have experienced some, but never this bad. This is with a Krieger heavy barrel.

 

[Bowhntr6pt]

No sir,
I don't like to lube the inside of a case neck because i thought it would be introducing another variable. But I guess a consistant lube wouldn't be any worse. I'll try lubing the inside & see how the accuracy goes. I guess I could add a few extra steps & reclean after resizing and then priming.

I'm not sure I follow you... you mean you don't clean the cases after you lube and size them?

I lightly clean my brass maybe an hour in the tumbler, lube and resize including the neck, trim if needed, then tumble them until really clean.

Then I prime and load.

 

[TheTinMan]

This should be moved to the Ammunition section...

Your accuracy sounds great!

You lube the inside of the neck with graphite powder and a brush - not regular case lube, just to be clear. Forgive me for stating what may be obvious.

The M14/M1A platform is really rough on cases. Most guys expect only 4-5 reloads because of case separation.

What sizing die are you using? My Hornady sizer stretches the cases at least as much as you are getting. I did find that dialing the expander ball out/down helped reduce the stretch a little bit. RCBS X-Die almost eliminates the need for trimming. Search the ammo section for more info on those dies.

I don't tumble my cases again after sizing, but I do wipe the lube off by rolling them in an old pillow case or some other available rag.

 

[Paul Jenkins]

Gentlemen,
I may be cutting corners to much. I will lube the inside neck walls before sizing & reclean after. I was surprised to see so much elongation. Never experienced so much with other chambers. Should enhance accuracy even more. That's what I care most.. I'm not a competitive shooter, I just get off shooting accurate rifles and this one is worth caring for.

 

[308 Shooter]

I put the expander rod in the drill and take a bit of diameter off the plug with fine sandpaper, this makes the plug a bit smaller and smoother making easier to pull through the case. It also makes for a bit tighter fit for the bullet, which isn't a bad thing either.

 

[panther308]

Sir,

How are you sizing ? have you tried to remove the expander ball ? what type of lube are you using ?

My suggestion would be to lube a case then FL resize with the expander ball in place then measure the case mouth ID it should be in the neighborhood of .305" - .306", you could also after sizing, trim the case and size again and measure OAL to see if the expander is pulling the case on extraction.

 

[KYShooter]

In my experience, case stretching with the M1A is the norm. When fired, the cases tend to bulge a little in the area close to the base of the case. When you resize, and squeeze that buldge in, the brass has to go somewhere and that is typically "up", making the case longer. With LC brass, you will only get about 3 good reloads before you start seeing cases separate. I typically go ahead and load the fourth time but those rounds are for practice only. With Federal cases, I'm afraid you can expect fewer reloads because Federal brass tends to be a little softer than LC or WRA cases. Carefully setting your FL die and lubing the inside of the case neck will help some but won't eliminate the problem.

 

[win308]

Federal Match brass has a reputation for being very soft. 20 ~ 30 years ago when once fired brass was plentyful, people would keep LC, WCC and RA 7.62 brass in their stash...but would happily give you FC or Federal brass if you needed some to get started. Today it's still the same...too soft for gas gun reloading.

The problem is, everyone is shooting AR's so 7.62 brass isn't plentiful anymore...and you have to use what you've got.....cases that are soft and stretchy if the headstamp is Federal.

 

[charlie98]

You may want to read up on loading for the M1a... I've heard about case head separations and, unfortunately, had one a few months ago... complete head separation on the 2nd loading. I currently use once-fired, processed military brass (although that may change) and I think I just got a bad case.

Now I check my cases with a bent paperclip, running it down the inside of the case to check for pending case separation or thinning. Like most of the others, the brass goes in the recycle bin after the 4th or 5th firing.

There is a lot more to loading for the M1a than is normally the case... case prep, powder selection, bullet weight, seating depth, primer selection and seating depth... the list goes on. If it's any consolation, your handload you list is right on the money... that's almost exactly what I load.

 

[RAMMAC]

Regardless of what the head space may seem to be, if you have actually measured it, it might be worth experimenting with adjusting the re-sizing die. If you are getting short case life using around 41 grains of 4895 (less than 4 reloads) then you might want to screw the die out a quarter turn or so and re-size a few cases and fire them until they develop that inside blemish that indicates they are stretching. It could be that you are bumping the case shoulder back farther than is necessary.

Just make sure you test fit the re sized cases (right after re-sizing and before you do anything else to them) in the actual chamber you intend to use them in. Drop the empty case in to the chamber and let the bolt fly home. Make sure that the bolt cams completely in to battery (take note of where the bolt roller is in relationship to the op rod rail, it should be very close to it or touching). Or drop the re-sized case in to a Wilson style head space and case length gauge.

 

[casebro]

Here's link to an ongoing thread http://m14forum.com/m14/103917-m1a-odd-headspace-question.html

 

[Larry Gibson]

Suggest you get the regular RCBS X-die. The SB die is not necessary. It ends the case stretching during sizing and you can get 20+ firings per case.

Larry Gibson

 

[dozier]

In my experience, case stretching with the M1A is the norm. When fired, the cases tend to bulge a little in the area close to the base of the case. When you resize, and squeeze that buldge in, the brass has to go somewhere and that is typically "up", making the case longer. With LC brass, you will only get about 3 good reloads before you start seeing cases separate. I typically go ahead and load the fourth time but those rounds are for practice only. With Federal cases, I'm afraid you can expect fewer reloads because Federal brass tends to be a little softer than LC or WRA cases. Carefully setting your FL die and lubing the inside of the case neck will help some but won't eliminate the problem.

I agree 100% with KYShooter above. Primer pockets enlarge after a few reloadings also. I shoot fed GMMs to use as a base line before using my reloads thru the chrony. Because of the limited number of reloads from Federal cases, I don't bother reloading it. dozier

 

[dprice3844444]

well,case stretching might also indicate that the action is moving too fast.might want to get one of those vented gas plugs from brownells like they use for the garand to shoot factory ammo.i notice when i shoot my bar at 550 instead of 350,it really stretches the cases

 

[Paul Jenkins]

Gentlemen,
Thanks for all the comments. Apparently I just need to be more careful in my case preps and realize the nature of the rifle. Sure am having fun with this tack driver.

 

[Hamstur]

Hey Paul,

What kind of resizing die are you using? If you're using a basic FL die, the neck outer diameter will likely be 0.330". Like it's already been stated, FC brass is soft which makes it stretch when sized.

The other issue is it's fairly thick -- I just pulled a FC round out and measured it at 0.338". I measured 3 pieces of fired FC brass and the OD is 0.344". A rule of thumb is you shouldn't downsize a case neck more than 0.010" because it causes the brass to stretch, strain & weaken. If using a basic die, this is what's happening.

I minimized stretch using a Redding Type S die with Ti-nitride bushings and a carbide expander ball -- this way I can select the optimal neck OD size & not having to use lube means the necksize is more exact.

Off the top of my head, the bushing I use for once fired brands are:
- RP & FC = 0.337"
- LC = 0.336"
- Win = 2 passes thru FL die --> pass 1 at 0.337", pass 2 at 0.331"

The set up is not cheap, but I went this route because I shoot an accuracy bolt gun.

Regarding your plinking load question, I've found my 18" Scout likes the exact same: RP or FC brass, 41.0 IMR4895, 168 BTHP, 2.800" COL. Accuracy is sub-MOA out to 200 yards and recoil is light. I don't like this load much past 200 yards and defer to the standard LC brass, 41.5 IMR4895, 168 BTHP, 2.800" COL otherwise.

Regarding your sizing question, FL sizing is a must for service guns. Neck sizing is okay for bolt guns because because the shell is stationary and fire-forms to the chamber.

 

[dprice3844444]

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