BM59 gas block on Mini-G

[pkozak1]

What is the purpose of the BM59 gas block on the Mini-G? Is it for a more straight op rod, straighter push back on the action? Info curious? Any pictures? Thanks.

[jbkf1003]

It leaves more space between the oprod/gas cylinder and barrel, some people like that look, it also allows the use of an ultimak scout rail without modification to the rod or rail and allows the use of BM59 muzzle devices, of which there are several variants. I may be missing something as well.

Justin

[mxlmax]

Less bend in the op rod and you can use the BM59 bipod.

[Punch The Clown]

I can't believe John Garand didn't do it 25 years earlier. Much more practical design.

[ordmm]

I can't believe John Garand didn't do it 25 years earlier. Much more practical design.

I have wondered the same thing. That being said it seems every part of the design of the M1 seems to have had a purpose in the mind of the designer but unfortunately most are lost to the inventors and support staff passing. Sure would have made making op-rods a lot easier. The people at Beretta had the advantage of only having to product improvement rather than the total design from scratch.

[Corpsie]

I would imagine the bend in the op-rod allows it to act more like a spring which would help with durability

[mxlmax]

I would imagine the bend in the op-rod allows it to act more like a spring which would help with durability

Not a chance. Otherwise the M14 op rod world have been longer, thinner with more bend and no op rod guide. I would ask Tim if he has built a Garand with a BM59 GC and a straighted out Garand op rod!

[timshufflin]

Not a chance. Otherwise the M14 op rod world have been longer, thinner with more bend and no op rod guide. I would ask Tim if he has built a Garand with a BM59 GC and a straighted out Garand op rod!

No I have not.

[Shug]

One of JCG's considerations for the bent oprod might have been bayonet interchangeability with the 1903. A dropdown cylinder would have required a new bayonet design, or a muzzle device like the tricomp to mount the bayonet on.

A lot of the M1 Garand design was driven by legacy requirements, and it's been demonstrated that the Army Ordnance folks (a rather conservative lot) were heavily involved in the requirements process. Caliber .30 (30-06), is another example of a legacy requirement for the Garand, due to the large stockpiles of ammo left over from the Great War and commonality with the 1903, BAR, and Browning MGs.

[timshufflin]

All you'd have to do is put a bayonet lug on the bottom of the gas cylinder.

[Shug]

What about the bayonet's loop that goes around the muzzle, centered on the barrel axis? A lug under the BM59 gas cylinder would be further off-axis than the lug on a 1903 or Garand.

Sometimes guys who work requirements get stuck on little details like that and lose sight of the bigger picture during development programs. Just look at what the Army Air Corps did to the high-performance Bell XP-39 prototype that turned it into the dog that was the P-39. Some AAC requirements guy at Wright Field got fixated on coefficient of drag, and, voila, no external air scoops for turbo-supercharger or intercooler were allowed in the final design because they created drag, even though removing those features significantly reduced engine output, especially at higher altitudes.

[timshufflin]

What about the bayonet's loop that goes around the muzzle, centered on the barrel axis? A lug under the BM59 gas cylinder would be further off-axis than the lug on a 1903 or Garand.

Sometimes guys who work requirements get stuck on little details like that and lose sight of the bigger picture during development programs. Just look at what the Army Air Corps did to the high-performance Bell XP-39 prototype that turned it into the dog that was the P-39. Some AAC requirements guy at Wright Field got fixated on coefficient of drag, and, voila, no external air scoops for turbo-supercharger or intercooler were allowed in the final design because they created drag, even though removing those features significantly reduced engine output, especially at higher altitudes.

Well duh, I screwed that one up. Gotta be a way.

[Shug]

When you have access to a machine shop, there's always a way...

Anyway, the point I was trying to make before I drifted off on the tangent was sometimes designers/engineers get fixated on minor issues and lose sight of the big picture of the product's design. Overall, though, the Garand was pretty well fit for its intended purpose and operating environments, despite the oprod design.

[jbkf1003]

I'm sure you could get an M5 Bayonet to work, as it is just keyed for the gas plug and does not have a ring around the bore. It would just sit a little lower on the rifle. But the m5 was developed after the Garand, and reusing current bayonets probably was a design consideration. As Shug said, It's things like not having to purchase all new bayonets that make the difference between "America's most beloved battle rifle" and an obscure prototype lost to history.

Justin

1858

[koreanwargrandson]

the 500 lb gorilla that gets ignored is the original gas system of the m1. the first 4 years of the garands service life, till about 1940ish, the m1 was a gas trap. you couldnt do a drop down if you needed to trap the gas at the muzzle to push the op rod as the first 55k gas trap m1s did. once they went from gas trap to port and piston, sure, you could do a drop down, but you would have needed to make major changes in issue gear as mentioned above, as well as major production changes, possibly delaying the m1s universal field issue by a year, maybe two. considering global events in 1940, a delay in rifle production would have been unacceptable

[Punch The Clown]

the 500 lb gorilla that gets ignored is the original gas system of the m1. the first 4 years of the garands service life, till about 1940ish, the m1 was a gas trap. you couldnt do a drop down if you needed to trap the gas at the muzzle to push the op rod as the first 55k gas trap m1s did. once they went from gas trap to port and piston, sure, you could do a drop down, but you would have needed to make major changes in issue gear as mentioned above, as well as major production changes, possibly delaying the m1s universal field issue by a year, maybe two. considering global events in 1940, a delay in rifle production would have been unacceptable. Tim can rebend an op rod in a few minutes. I like Shug's theory.

[mxlmax]

. Tim can rebend an op rod in a few minutes. I like Shug's theory.

Punch,
I was thinking about how to configure a little different Mini-G. I already have a Baretta BM59 so a mag fed MiniG would be sort of a duplication.......I was originally thinking about a Mini G using one of Jim Thompson's SS 308 Wilson barrels and a drop down BM59 GC for something a little different. Now I am also thinking about a full length Garand using the 308 Wilson SS barrel and the drop down BM59 GC and a 3" brake just because. Who knows, maybe even a full length mag fed 308 SS barrel with a drop down GC (if Tim would do it) just for the he!! of it. Call me crazy.
Randy aka MXLMAX

[Punch The Clown]

Tim built a Garand a few years ago for "The Hawaiian". It was some odd length specified by the owner-something like a 21" barrel. Boy did it look good.