M1A load help, please.

[Silvercreek Farmer]

I'm going to attempt a functioning CB load for the M1A. I've read Bruce's thread and this is what I have so far:

1x fired Lake City brass (fired in subject rifle) full length sized in RCBS X Die.
Trimmed to RCBS specs, chamfered/debarred and Primer pockets reamed
Lee 170 RNFP cast from ACCOWW, powder coated, gas checked and sized to 309
CCI Large Rifle primers
A bottle of IMR 4064

From what I found, Bruce never used anything heavier than 150 grains with 4064. Any ideas for a starting load? 25-26 grains? Any risk of SEE with 4064?

[Outpost75]

I would defer to Larry Gibson on specific loads for reliable function of the M14/M1A.

In the .30-'06 about 36 grains is about the minimum to reliably cycle the M1 Garand with a 160-grain bullet.

In the 7.62 NATO/.308 Win., I would start at 30 grains of 4895, 4064, RL15 or Varget and use a 1 grain Dacron filler, about a 1/2" square of 1/4" thick quilt batting, tucked loosely into the case neck, such that its final position is determined by the location of the bullet base when seated. This should give about 1850-1900 fps in the M1A and cycle the rifle reliably. I would not reduce 4064 below 50% of case capacity under any circumstances, even if a filler is used.

Without filler you are OK down to 75% of case capacity with 4064, and 60% with 4895, RL15 or Varget. At these levels a 1-grain Dacron filler, NOT pushed down upon the powder, but tucked loosely into the case neck, will improve ballistic uniformity.

With these reduced loads the above powders and loads will be safe with bullets up to the #311299, if properly sized to fit your rifle.

[Silvercreek Farmer]

Thanks!

[Larry Gibson]

I've not really used a lot of 4064 for many years in my M1A/M14s and none with cast bullets. Even back then I preferred 4895 for use with match bullets and cast bullets. However, that's not to say 4064 won't work with your cast bullet in your M1A.

I suggest the following;

1st is to find the point of functional reliability. To do this you may use "cull" bullets with minor defects. I suggest starting at 25 gr IMR4064 and working up in one gr increments to 31 or 32 gr. A 3/4 to 1 gr Dacron filler should be used. Load 3 rounds of each increment.

Using this method will save you time and some frustration. No need to shoot for group or even chronograph, functional reliability is the goal here. Load the 3 rounds of each increment into the magazine (easily done with magazine in the rifle and bolt locked back) one at a time and shoot each round one at a time. What you're looking for is for the bolt to fully come to the rear and lock back with each round.......thus the need to only load and shoot one round at a time. The load at which the bolt locks back with all 3 shots is the starting load minus 1/2 gr. In other words if the bolt locks back on all 3 shots of the 28 gr load then 27.5 gr is your "start load" with your bullet, cases, primers and 4064 in your rifle.

Once you know the start load then load from there 10 rounds each in 1/2 gr incrementally increasing increments to 34 gr. Then it is time to shoot seriously from the bench for group and to chronograph if you want best accuracy. Test at 100 yards if you plan on shooting at longer ranges. When accuracy really starts going south you will know the load is past the RPM Threshold for those components. With the best group(s) load 3 additional 10 shot test strings of each to confirm accuracy testing one of the test strings at the longer range you intend to shoot at.

[Silvercreek Farmer]

Thank you for all the information, gentlemen. I might try to track down some H4895, I was just trying to work with what I had, as the closest powder source is 50 miles away. Are there any other better candidates than 4064 if I can't find the H4895?

[Larry Gibson]

Let's nnot rule out the 4064 until you try it. It's going to be like a very, very slow lot of IMR4895 is all. Just because I never used it before doesn't mean it won't work just fine.

[Silvercreek Farmer]

Sorry Larry, the 4064 results will have to wait. I was able to find a lb of H4895 not too far out of the way of another errand so I picked it up. I'll start with that and save the 4064 for jacketed. I figure the all the suggestions will still apply...

[Larry Gibson]

Same suggestions apply.

[beemer]

Thank you for all the information, gentlemen. I might try to track down some H4895, I was just trying to work with what I had, as the closest powder source is 50 miles away. Are there any other better candidates than 4064 if I can't find the H4895?

I have wondered if there was a source in Morganton, where do you find your powder. There are two sources between Conover and Taylorsville and two in Wilkes Co. Wal-Mart in Taylorsville has a very limited supply, maybe 5-6 kinds but have a fair selection of bullets and RCBS dies and such. The best selection around is H G & H just off 16 and ED & Dale's in Wilkes. Like you said all are probably 50 or so miles from Morganton.

Dave

[Silvercreek Farmer]

HGH was my go to, but I'm rarely up that way. I forgot about Not Just Fishing, but they are high. Bows and Ballistics may have some if they are still around. Academy also has a handful of powders, but not 4895. I've haven't looked in Lenoir in a while, but still around 30 miles. Asheville is the other way and may have a few places, but I was headed to Charlotte, so I stopped in at Gander outdoors in Gastonia. I'm sure there are better prices to be had elsewhere, but gas and all. I was surprised that Shooters Express in Belmont didn't carry anything.

[Silvercreek Farmer]

Dad called on short notice and wanted to shoot the M1A, so I just loaded up 20 rounds at 30 grains for some casual shooting. Without trying too hard, I put 10 rounds into 4 inches or so at 100 yards, which would be consistent with many of Bruce's 50 yard groups. Ejection and lock back was perfect. I did bear down and shot 5 rounds of Federal ball ammo as well as I could, for a 3 inch group, so it looks like the cast will certainly shoot pretty close to the limits of my eye and the rifle. It'll be fun to see what it will do with proper load development. I also loaded 10 over 10 grains of Promo. Probably had 9 in 3 inches with one opening the group to 4 or so. Ejection, albeit by hand, was also robust. Looks like I'll be chasing brass either way! Predictably so, the light loads were around a foot lower than the 4895 loads but also 6-8 inches to the right. Any explanation for the change in windage? There was a light, intermittent breeze, but I don't think it would have made that much difference.

[Larry Gibson]

"the light loads were around a foot lower than the 4895 loads but also 6-8 inches to the right. Any explanation for the change in windage?"

Lower velocity is why it hits lower and longer barrel time allows the barrel to recoil slightly more to the right.

[Silvercreek Farmer]

Any thoughts on the need to anneal case necks with the X-Die/Lyman M die?

[Larry Gibson]

Never found a need to anneal even after 20+ loadings with LC or other US M80 cases.