Thursday, April 14, 2022

Mise à Niveau

So, set the wayback machine for the summer of 2007, when I was still living in Knoxville, right after I left Coal Creek Armory. Having some spare time on my hands, I drove over to Nashville to spend a few days at Oleg Volk's place, hanging out and providing an eclectic selection of guns for photographic purposes.

The first morning there, Oleg and a few others were heading out to go do some shooting. Having just finished a good long stretch of six-day workweeks at an indoor range, I begged off. "I'll just chill here and read, if it's all the same to you guys. If you want to shoot anything I brought, feel free to drag it along."

Among the guns they elected to take was the MAS-49/56. I handed Oleg a couple boxes of Portuguese FNM-branded full metal jacket ammunition and told him to knock himself out.

He asked where to hold on the target at a hundred yards.

"How the hell should I know?" I replied, "I've had it a couple years, but never got around to shooting it."

I spent a pleasant couple hours in silence with a book, and when the crew came trooping back in from the range, Oleg had an unhappy look on his face and was nursing his right thumb.

"What happened?"

"The rifle tried to break my hand."

Yikes. The internet wouldn't be happy with me if I broke their photographer, no matter how indirectly.

It turned out that Oleg let the bolt fly forward to chamber the first round, and the rifle promptly slamfired, kicking up a gout of dirt a few yards in front of the line and pranging the base of Oleg's thumb with that big round nylon knob on the MAS charging handle.

A bit of research on the internets turned up the fact that this is what we would call a Known Issue with some ammunition, since the MAS has a large, heavy firing pin meant to deliver a healthy lick to a hard French military primer.

Y'know how the free-floating pin on an AR will lightly dimple a primer when you chamber a round? Same thing, but that's an AR firing pin up top and the MAS pin below...

The two solutions for this I uncovered at the time were to either have a 'smith lighten the factory pin, which seemed pretty iffy, or to track down one of a small number of titanium firing pins someone had allegedly made in unicorn-like quantities a few years earlier.

The importance I assigned to this task can be assessed by the fact that I finally got around to it last month.

I mused about it on Facebook, and Ian McCollum... because of course he would know ...recommended a spring-loaded rebounding pin from Murray's Gunsmithing in Texas, and said they had worked fine in his blasters. So I ordered one. (With my own money, Mr. Federal Trade Commission.)

The other day I went and installed it.

To do so, first you lock the bolt to the rear and remove the magazine, ensuring the weapon is clear.


Next you let the bolt go back forward. This step is important.


Now, look at the rear of the receiver. See that rectangular button doohickey? Put your thumb on the serrated top and press downward and hold it...


While holding that button down, grab the rear sight/receiver cover assembly, slide it slightly toward the muzzle end of the gun and then CAREFULLY lift it up and away from the rifle. Be careful here, because it is under a lot of pressure from the action spring. The spring will probably come away from the rifle along with the cover.


Next, pull the bolt carrier assembly to the rear and lift it out of the receiver...


The bolt will just drop out of the carrier. From there it's a simple matter of pulling out the old pin and replacing it with the new one.



Reassembly is pretty straightforwardly the reverse of disassembly. I will note that the "sproing factor" of that action spring is hard to overstate; that bolt and carrier assembly is small and light when you consider the power of the 7.5x54mm cartridge; it doesn't have a lot of inertia on its own so the spring is doing a lot of work. Getting that receiver cover back on with the spring all compressed back into its nest definitely takes all of both hands.

Now it's ready to use with Prvi Partisan ammunition and the thumbs of America are safe!

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3 comments:

Paul Chappell said...

Nice! Still kind of annoyed with myself for not picking one up in the 90's when I had my C&R and they were available. Looks quite nice!

Corey K said...

Hopefully you'll not let a further 15 years pass before trying it out yourself!

taylor said...

Somewhere in my box of "ammo for guns I used to own" I have a pack or two of surplus 7.5 French on stripper clips. Wonder if it's worth digging out and putting on gunbroker or the like? Pretty sure I have a box or two of commercial stuff for it as well.