Lee C312-155-2R recipe for .308 Win

[darrowj]

Folks,

I'm fairly new at casting for rifles. I have an M1A and a C312-155-2R mold. My intention is buying the C312-155-2R was to use it with my AK. I have and it worked great. So I decided to take the next step and try cast boolits with the M1A. I've experimented. Shot about 300 rounds through it with cast. Broke down the rifle for cleaning and found not leading in barrel or gas system. Pretty sweet.

I do still have trouble with proper cycling. I've been using the Lyman manual to guide me, but there is no solid reference for the mold I'm using. At the moment I'm seeing 22/25 rounds fire, eject, and feed a round. On those 3, average, problem rounds pull the trigger and no joy. The firing pin strikes but does not ignite the primer.

I've experimented with the various recipes. Mainly by changing the COAL and increasing Powder charge by a grain at a time.

Here is the last I tried:

IMR 4198 - 24 grains (25 round batch with 1 grn Polyfill and 25 without - no difference seen)
COAL 2.710
Federal 210 primers
Winchester Brass
BHN 20
Gas checked
Sized to .311

Any hints or experiences to share?

[Larry Gibson]

Read Bruces work on cast in the M1A in this thread; http://castboolits.gunloads.com/showthread.php?t=3558

Larry Gibson

[darrowj]

Read Bruces work on cast in the M1A in this thread; http://castboolits.gunloads.com/showthread.php?t=3558

Larry Gibson

Thanks. I did read it. His post on this forum is the reason I started casting for my rifles. It was very eye opening and informative. I did not find specific information about the mold I'm using in that post. This is not an emergency call for help or anything. Just looking to see if anyone else has done this before and recommendations. I'll keep at it in any case.

[bruce drake]

"On those 3, average, problem rounds pull the trigger and no joy. The firing pin strikes but does not ignite the primer."

This sounds more like several potential issues in your reloading and not the boolit/powder combination.

What case resizing lube are you using? I found that if I used Hornady Oneshot or one other other spray resizing lubes, that sometimes the excess lube from the neck would migrate down and render theprimer inert.

Are your primers seated fully? A primer that isn't fully seated will often push forward when a firing pin strikes it and not cause an ignition. Once properly seated those cartridges usually fire on the second strike.

And if the primer is fully seated, an inconsistent resize of the shoulder of your case can cause the same fault. If you don't resize the shoulder of the cartridge case properly, sometimes the strike of the firing pin will just push the cartridge forward without setting the primer off on the first strike. This occurs when the shoulder is pushed back from the standard by a sizing die that is cranked to far down and it pushes the shoulder back. And easy test for this is to compare a fired case's shoulder with one of your unfired "duds" if the shoulder is lower in the "dud" you'll see the issue easily. if not, pulled the calipers or ruler out and measure the difference and see it that way.

Ok,

That's 3 possible answers to your click-no boom issues.

That LEE 155gr is a good weight for a M1A or any other 308WIN chambered rifle. It is one of my favorite lead bullet molds. I use it for my T99 Arisakas, a No. 4 Enfield, a Winchester P14 Enfield, a Mosin-Nagant Type 44, a 7.62x39 Mauser, a 308 WIN Mauser and a M-1 30-06 Garand rifle.

Bruce

[darrowj]

What case resizing lube are you using? I found that if I used Hornady Oneshot or one other other spray resizing lubes, that sometimes the excess lube from the neck would migrate down and render theprimer inert.

Are your primers seated fully? A primer that isn't fully seated will often push forward when a firing pin strikes it and not cause an ignition. Once properly seated those cartridges usually fire on the second strike.

And if the primer is fully seated, an inconsistent resize of the shoulder of your case can cause the same fault. If you don't resize the shoulder of the cartridge case properly, sometimes the strike of the firing pin will just push the cartridge forward without setting the primer off on the first strike. This occurs when the shoulder is pushed back from the standard by a sizing die that is cranked to far down and it pushes the shoulder back. And easy test for this is to compare a fired case's shoulder with one of your unfired "duds" if the shoulder is lower in the "dud" you'll see the issue easily. if not, pulled the calipers or ruler out and measure the difference and see it that way.

Ok,

That's 3 possible answers to your click-no boom issues.

Bruce

I do not think is is the resize or the primer seating. I say that because before I started reloading cast boolits with the M1A I was reloading with store bought FMJ heads. I think I shot around 600 - 700 rounds that way. Using IMR 4895 according to the Hornady (and other manual I cannot remember) and the same box of primers. Same brass as well. With FMJ heads I did not encounter any problems.

I spot check my 308 reloads using a case gauge. I bought the Dillion gauge. here. I found that it works well and checks these measurements you mention.

With the cast reloads I do see a small dimple on the primer when it fails to fire. Looks different when I look at those that did fire. As in smaller dimple.

I suspect that there is not enough energy to fully cycle the rifle. My question to the cast boolits community was really what powders and amounts as well as what COAL have folks used with the mold?