reloading 50 bmg for M3HB

[bubbapug1]

I have 300 AMAX 750 grain 50 bmg bullets. They are much longer than a normal bullet, but they have a long major (0.510)section I can crimp with. I was wondering if anyone has loaded the amax 50 bmg bullet for use in a M3 and what the OAL was to get the bullet to work properly.

Does the fact that this bullet will be seated so deeply to maintain an operating OAL effect pressure? I do the same with my 223 loads to fit the amax bullets in the magazines of the AR's and they function fine and shoot wonderfully accurate.

The length of the major section (0.510) of this A-Max bullet is almost 1" long (0.94)

The start of the major section is around 1.5" back from the tip. I can seat that bullet that far in and still get a good crimp. I have to do the same thing with my 223 loads and it works fine...but I know 223 and 50 bmg are two different animals.

I am sure seating a bullet so far into the case HAS to increase pressure however, and I do see in some manuals they require extra OAL, but not that extreme in the case of the 223.

I am not sure how fast that bullet will let lose, and how fast the pressures build, but I know it has to be constant with boyles law...

Bottom line is, I don't want to blow up my M3

Any suggestions?

 

[ChrisGarrett]

Re: reloading 50 bmg for M3HB

That bullet isn't meant for heavy duty machine gun barrel chambers, I'm pretty sure, but there's only one way to know if you can seat it to acceptable depths and that's to use the dummy round method and see where your lands are exactly. That will give you an idea of your ammo's COAL for that combo and in that chamber.

Take a fired case, dent in one edge of the mouth, so it'll hold an AMAX in place, take a bullet and insert it just barely into the mouth so it's stuck, but not deeply, take a dry erase marker, a candle or a Sharpie and mark/soot the bullet and then carefully insert it into the chamber and gently close the bolt.

Gently open the bolt and remove the case, if the bullet's stuck in the lands, tap it out carefully with a rod and insert it back into the case mouth up to the line where the ink is scraped away. Measure the COAL and go from there.

Also, it's called the 'bearing surface', that straight part of the bullet's main body.

Chris

 

[bubbapug1]

Re: reloading 50 bmg for M3HB

Thanks...I will do as advised..

 

[Lt. Arclight]

Re: reloading 50 bmg for M3HB

You won't even get close to the lands.The bullet is not to be crimped and will more than likely get driven into the case as the gun cycles.

Realistically the most accurate projectile for an M2 or M3 would be AP and that would only be marginal over ball ammo.

 

[M4-Pilot]

Re: reloading 50 bmg for M3HB

Hey bubbapug, check your PMs