I've got a MAS 49/56 in .308 that has wroked fine with commercial loads before but is having some trouble digesting my handloads. I'm getting lots of FTE and in some cases, the bolt doesn't even open at all. I'm thinking the culprit might be in the powder I'm using in my handloads as opposed to whatever is used in the Winchester stuff I bought from Wally-World.

I've tried IMR 4064 in a few different powder weights (the highest being 44 grs.) and none were successful. I'm thinking of using H380 and seeing if that works.

I guess I'm going for opinions here: is H380 significantly slower burning than IMR 4064 that it could generate enough gas to operate the rifle? Is there a powder that might work better than either one?

i use RL-15 45.5 with 150s either one of yours should do very well, just find the sweet spot

quote:

Originally posted by asmith80:
I've got a MAS 49/56 in .308 that has wroked fine with commercial loads before but is having some trouble digesting my handloads. I'm getting lots of FTE and in some cases, the bolt doesn't even open at all. I'm thinking the culprit might be in the powder I'm using in my handloads as opposed to whatever is used in the Winchester stuff I bought from Wally-World.

I've tried IMR 4064 in a few different powder weights (the highest being 44 grs.) and none were successful. I'm thinking of using H380 and seeing if that works.

I guess I'm going for opinions here: is H380 significantly slower burning than IMR 4064 that it could generate enough gas to operate the rifle? Is there a powder that might work better than either one?

IF your problem is insufficient gas pressure at the port to operate the action, you need to increase your charge of IMR 4064, NOT go to a slower powder. H380 is much slower than IMR 4064, and is, as you may know, a ball powder that meters through a powder measure MUCH more accurately than IMR 4064 does. But 7.62X51mm NATO ammunition operates at 50,000-52,000 PSI. So rifles designed for this ammunition are built to function reliabbly at pressures approaching this level. Since IMR 4064 is entirely satisfactory operating the M1 and M14 rifles, I believe your 44-grain load is still too light to work your rifle's system (IF you are using 150-grain or lighter bullet. I believe if you had seated a 180-grain bullet on top of that powder charge, the gun would work!!)

Since you didn't say what bullet weight you used with 44 grains of IMR 4064, I cannot comment on the correctness of that load.

IF your load is NOT OPERATING the action properly due to lack of pressure, AND you are using bullets of 150-grain weight or less, what I would do is to increase the IMR 4064 charge about 0.5 of a grain at a time, up to as much as 48-50 grains MAX., test three rounds with each powder charge level, and stop increasing when you get to a powder charge level that WILL function the gun. You know-"work up slowly"! IF you are using 165-grain bullets, stop working up at 46-48 grains, and IF you are using 180-grainers, 44 grains of IMR 4064 should be enough!

I would NOT change powders yet!

El Deguello,

What you just said makes a lot of sense. The handloads I was using were 155 gr. bullets. I had also tried commercial ammo (Sellier abd Bellot, I think) which was 150 gr. and I had the same problems. I just checked the box for the Winchester stuff that DID work and, lo and behold, it was 180 gr. soft points.

I'll give the heavier bullet a try before I go buying up more powder.

Ok, just got back from the range with some new loads. I Loaded up IMR 4064 in 44.5, 45.0, 45.5, 46.0 and 46.5 gr. increments. The 44.5 weight cycled the action just enough to fling the cases out, but not enough to reset the hammer, which is what I expected.

The 45.0 weight cycled every time (I had only loaded 3 rounds, tho). I thought that since that weight worked fine the heavier charges should as well but with the heavier charges I couldn't even get the action to cycle at all. What gives?

I've got some 180 gr. bullets I'm going to try with a lighter charge and I'm going to load up more rounds in the charge weight that worked just to make sure it wasn't a fluke, but what could be the reason the other charge weights didn't work?

Starting to run out of ideas completely with trying to get this thing to work. I've tried heavier charge weights in my handloads, heavier bullets, lubing all the moving parts, checking the chamber for roughness and burrs and I'm still only getting partial function (few stovepipes, but mostly not even opening enough to reset the trigger). I did notice the clip that holds the pin on the grenade launcher lever has gone missing and the pin was drifting out, but even after pushing it back in place and staking it down as best I could at the range, I still couldn't get it to function.

If anybody has any more ideas or even the name and number of a gunsmith that would know how to fix it, I'm all ears.

There some interesting information at the link below that might be applicable to your particular problem.

http://en.wikipedia.org/wiki/MAS-49