So just started to do some load development for my MAS49/56, Using horn 150FMJ and h4350.

Anyone have any experience with loading for the mas semi autos? What powders and bullets have you used? Not much out there for the SA MAS lots for the MAS36.

I started load work with 41gr and went up to 44gr, wont lock back on the mag so now i am going to work up to 47gr and see what it will do. Just looking for reliable function an good accuracy. I will say the loads are @ 2100-2300fps so far and very accurate maybe 5" for all charges @ 100yd from bags.

*As a precaution if someone uses this as a helpful note use cci 34 primers due to the floating FP in the SA mas series of rifles*

After this the AG42b will be next for load development, then the Vennie FN.  

First off, the 4350's are far too slow for this rifle.  Your bolt will slam back like a ultra slow powder for a Garand.  Your trigger finger WILL feel the sting.

Most of the 7.5 reloading data out there is not meant for this rifle.

Guys are usually using a 4895 class powder for this rifle, but I think it is a bit too slow.  I tried 3031 and moved on to 4198, probably a closer match to what French ball is loaded with. Way back when, I recall reading French posters recommending 4895 Vectan equivalents.

Still working on mine.  I'll get back to it with decent bullets instead of the awful 147 gr FMJ's I bought cheap and stacked deep.  The stuff I have loaded ready to go is dated 2011.  My next real go with this rifle will be with M2 type 150 grain bullets and 3031 or 4198 powder.

I have some ammo loaded with my favorite light bullet, the Speer 125 jph with 40 grains of 4198 in RP 6.5x55 brass and 9 1/2 primers.  Sights set to 400 for use at 100 yards.  I found all my Chronograph stuff in one place and will try it out.

Yeah, with the standard firing pin CCI34's are the only primer to use.  That floating firing pin looks like a truck axle.  I made a lightweight firing pin of 1144 stressproof for it.

French ball ammo is the gold standard here, like Swiss ammo for the K-31.  Get some and use it as a benchmark.

I've had my 49-56 for several years. I use Hornady data (8th edition) as a guideline.

Here are a couple things you should know.

1) Many of these rifles are fresh from arsenal rebuild. When I started shooting my hand loads I "thought" I was having issues with function. The fact is the rifle's and the magazine's Parkerizing was still very fresh and was slowing down the action much like a new AR acts. After a few trips to the range and some oiling my failures to feed and to lock back stopped.

2) These rifles like to throw brass into the next county. If you haven't made a way to catch your brass you either need to or get an adjustable gas valve. A guy on Gunboards forum sells them. It's an easy install and does not permanently alter the rifle. With it in place you can totally control your ejection right down to single shot if you wanted.

3) These rifles are very hard on soft point bullets but it doesn't seem to effect accuracy much out to 200 yards.

My rifle shoots very good. It has one quirk. It shoots the first round about 3 inches low and 3 inches left. I haven't been able to figure out why but if I'm shooting clay pigeons at 200 yards and reload before emptying the magazine it continues to shoot dead on. If I empty the mag and reload the next round will be low left.

With a 4x optic I can compete head to head with my son shooting a 12x12 swinger at 200 yards (off hand). In fact he complains that I have a distinct advantage using the 4x optic while he's using NM iron sights and his M1A "Loaded" I really can't argue that either.

I don't push my rifle to it's top end potential I load it strictly for best accuracy.

After I check my load files I will post some of the powders and bullets I use.

The ammo I have loaded now has a commercial 150gr .308" FMJ, WC-844 powder and CCI-34 primer. Unless you have one of the firing pin mods only use CCI-34 primes. The 49-56 is notorious for slam fires. Including PPU factory ammo.

One more caution: I don't know what dies you are using but Lee dies for this cartridge are very tight. That is they grossly undersize the brass. This undersizing is in the diameter of the case at the shoulder. This topic has been discussed extensively on the reloading forum at Gunboards. Other brand dies are much better.

I've discussed this personally with Lee. Their dies are made to minimum spec. The problem is the 49-56 being a military rifle is chambered kinda loosely.

If you are using Lee dies and you find that your overall case length is growing over .020" when you re size this is a result of the over sizing. At that rate or growth you will be having head separations in only 2 or 3 cycles if not before.

To further clarify. If you find that after sizing your brass is .015" to .025" over the trim spec, this is a problem.

I actually used a (fired from my rifle) French military casing and lapping compound to lap out my Lee die. My brass now grows less than .010" when sized. This growth closely matches what other people are experiencing with RCBS and other brand dies. My finished case dimensions also are much closer to what the other brand dies are too.

More later.

Motor

I checked my load files. I've used:

H-4895

IMR-4895

IMR-4064

H-335 / WC-844

130gr, 147gr and 150gr bullets. Several types.

The best soft points I've used as far as not being mangeled when automatically loaded is the Remington 150gr pointed core lock. This bullet has jacket all the way up to the small diameter exposed lead tip.

I haven't tried any plastic tipped bullets in it.

As a side note there is a commonly used trick to making the trigger pull a lot better too and it doesn't alter the rifle in any way or involve changing any parts.

Motor

Thanks motor i was wondering if you were the same motor on gunboards. Thanks for all the info, i will def have to check this last round for the length issues you brought up. I am using Lee dies.

So lets go back to the powder, i choose H4350  based on the rifle being DI and using 6.5creed AR data.  Why would it be to slow if it works in a large frame AR?
Not being argumentative genuinely interested why it is not a viable. I have some 4064 so i will work up some loads with that also and shelve the h4350 for now.

I'll look at the Hornady manual again to see if they list any loads using either 4350.

4350 is just kinda slow for this size casing with 30 caliber bore. It may work ok but you'll likely have to use more of it just to get the same performance you would get from smaller charges of a faster powder.

Plus you'll be burning a lot of it in the air out in front of the muzzle.

Although the 7.5 is a little larger than .308 Win in capacity it's maximum pressure is much lower.

Maximum loads shooting 150s is only around 2600fps.

Motor

so i sat down tonight and checked my fired rounds from sunday, i decapped and measured 12. The average growth was .013" for all 12.  All the cases stayed under the max OAL after sizing so i beleive i am GTG in that department.

Also sat down and loaded 12rnds with 4064 .

Ill try to get them shot before i head out to the long range on friday and actually do some testing to 200yds

It's a little confusing. The measurement you want to compare is the length the brass was before you fired them and now after you re sized.

The fact that you are still under maximum length after sizing is a very positive sign assuming you were likely at "normal" trim length when you loaded them last which would be about .010" under maximum.

The 4064 should work good it's just a pain to dispense. I use my Chargemaster when using it.

Motor

I just checked my Hornady manual (8th edition).

The maximum load listed for IMR-4064 is 44.4gr

I use 41gr IMR-4064 with 147-150gr bullets.

There are no loads listed using either 4350 with 150s but there is data for W-760 which is close to 4350 in burn rate.

Anyway I thought I should let you know about the IMR-4064. It looks to me like you are starting at maximum which isn't a good thing.

Hornady lists 2600fps as maximum with 44.4gr IMR-4064

The starting load is just 38.1gr

Motor

Thanks for the heads up motor i actually realized my mistake when i went to load them tonight i loaded 40-43gr of 4064.

Empire just had a few of these rifles in stock so I picked one up. How are they on brass? Please post results OP. I have all the mentioned powders in stock collecting dust. Bought for Garand but stuck with Varget in that.

I haven't had to retire any casings yet. I'm very likely in the neighborhood of 5 cycles but until I fixed my Lee die I was neck only sizing.

Yes I know you're not supposed to neck only size a self loading rifle but I test chambered each casing before loading and made sure the CCI-34 primer was below flush.

As mentioned above the biggest problem with these are the distance they throw brass. If you don't use an adjustable gas valve you NEED to make some kind of catching or blocking device.

Expect good accuracy. My rifle with 4x optic will shoot groups that would satisfy any whitetail deer hunter. It would of course with the battle sights as well but it's much easier with the scope.  

One drawback to the scope is you need a high cheek rest.  

Motor

Got my 49/56 tonight. I am hugely impressed. Really like the weight and balance.

Only have a handful of empty cases so I am going to do the unthinkable and use factory ammo for first go around. Seems ammo is not much more expensive than new brass. Just like boxer mosin rounds.

Got a set if Lee die. Might return but I think I will just try setting them up using a headspace gauge making sure I am not over sizing.

If it doesnt work, I may order a CH4D trim die anyway and use that to full length size like most of my other rifle rounds.

Any errors in my ideas?

I actually got out Friday between storms and shot my reloads. Ended up settleing on 43.5gr of 4064. Worked flawlessly and was very accurate. Roughly 2-3" @ 100yd.

On the note of dies I am using Lee dies and my brass grows .013" after sizing. I'm starting to notice the sizing is becoming harder after 3 firings.

Not showing any signs of case issues but I'll be ordering an rcbs set to try out. I got the Lee dies for $20 so no huge loss to me.

I've been using the same 30 pieces of brass for development and testing just to see how much abuse the will take.

Shoots fantastic and functions well. Will be Shooting a match with it on the 29th.

Good info. Thanks. I plan to anneal the brass so that should help keep it alive longer.

The problem I and others had with the Lee die isn't related to head space. It is the diameter at the body/shoulder junction. Measure one of your fired casings at this point then measure it again after you size the casing.

Another thing to pay attention to is when the casing is entering the die. If you feel contact and sizing beginning with only about 1/2 of the casing in the die this is the shoulder diameter being sized. The shoulder diameter should never be the first point of contact in a full length sizing die.

Be careful shooting factory ammo. The 49-56 is known to slam fire Privi ammo.

I you guys can't find the thread on Gunboards that covers the die issues let me know and I'll post some shoulder diameter dimensions that may help. Measure the factory ammo too so you have something to compare to.

Motor

Ran my 49/56 yesterday with 100 Serbian rounds. Everything ran flawless. Cleaning cases now. Will anneal later.

Impressed with accuracy. Love the peep sight.

Thinking I may just buy the CH4D trim die tomorrow and use that for sizing if they have one. M die for opening mouth when I load.

Anyone try cast bullets? PC?

Thoughts on replacing firing pin with a light weight one or this? https://murraysguns.com/product/mas-4956-firing-pin-kit/

I have read positive reviews on the firing pin mod. Guys report being able to use standard primes without issues. This is something I've considered but haven't done. My first 1000 CCI-34s cost me $53 but within the last year I picked up another 1000 for less than $30 at a gun show so I'll be good for a while.

I haven't tried my powder coated cast bullets in the 49-56 yet but I do shoot them from my 1949 Santa Fee (A commercially sporterized M36 made very likely in 1949). I do gas check these.

The fallowing is speculation based on my experience with the powder coated cast bullet:

If you use a pointed design (like the Lee 160gr 2R) cast to about 15bhn, powder coat and gas check I think you would have a decent chance of getting a load that will work in every way.

I have not examined the difference in port size between the factory gas cut off valve and the adjustable one made and sold by Gunboards member "starmetal" but if one has a larger opening than the other you may be better off using the larger one. This will allow more gas of course and maybe help cycle the action with a lighter load.

BTW: I didn't know the Serbian ammo was boxer primed.

Motor