Help with actual bullet size of Czech 76.2x25

Polish-Jack

Polish-Jack

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I have a M57 with an oversized barrel and looking for appropriate ammo for it. As it happens I have a chance to buy some surplus Czech ammo and an wondering if anyone can has any that can pull a bullet and do an actual measurement.

I've tried Chinese and Russian, but they are on the small side.
 
Depends on how oversized your barrel is. Have you slugged & miked the tube? The nominal size of 7.62x25 Tokarev bullets is .307 & Czech ammo is fitted with
that size. An option that should work fine in the M57 is to use 30 Mauser (7.63x25) ammo which uses .308 diameter projectiles.
 
Suther said:
Im confused. Are you saying you'd like to find 7.62x25 that happens to have bullets that are 40thou+ bigger than normal?
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Yep. I figure that if a Zastava makes a factory new M57 with a barrel that measures .312 there must be a cartridge somewhere that measures. 310 or. 311.

I'm looking for it because when I shot Russian or Chinese cartridges through it that have bullet sizes of .308 and. 309 I literally can't hit the barn door with it. I'm hoping that bullet size is the issue as I've never shot a Tokarev that was not accurate. I really don't want this factory new pistol to be a lemon.
 
Polish-Jack said:
I'm hoping to find a surplus cartridge that will work with this gun so I don't have to reload it. These things savage the brass on the way out.
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That's not going to happen. Militaries are very much set on getting their ammunition manufactured to strict plus or minus tolerances.

.005 over standard is way to much for them to bother with. I would suggest you look for a replacement barrel.
 
Polish-Jack said:
Yep. I figure that if a Zastava makes a factory new M57 with a barrel that measures .312 there must be a cartridge somewhere that measures. 310 or. 311.

I'm looking for it because when I shot Russian or Chinese cartridges through it that have bullet sizes of .308 and. 309 I literally can't hit the barn door with it. I'm hoping that bullet size is the issue as I've never shot a Tokarev that was not accurate. I really don't want this factory new pistol to be a lemon.
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Sounds like something is seriously wrong with your barrel. The only instance I can think of where 5thou over bullet size is not considered a major issue is with Lee Enfields, particularly ww1 vintage ones with well used bores.

I can't see how a pistol made in the late 50s at the earliest would have a barrel that far out of spec and not be considered a lemon.
 
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I am not familiar with mil-surp type handguns, but have messed with a few mil-surp rifles. Regarding that bore size - was that diameter taken from a slug that went all the way through that barrel, or just in and out at the muzzle? The reason that I ask - I have found several rifles with the muzzle end one or two inches (or more) worn down from sloppy use of pull through cords or cleaning rods - rubbing against side of bore at muzzle and increasing diameter - get a different diameter, on those, depending how you get a slug. Was wondering if same can happen on a hand gun?

EDIT: so re-thinking that - cleaning rod wear increases "bore" diameter - never seen one worn down to the bottom of grooves - it would be the groove diameter that one gets on a slug - bullet to be similar to groove size, not bore size. So my question was likely "out to lunch"...
 
bearhunter said:
That's not going to happen. Militaries are very much set on getting their ammunition manufactured to strict plus or minus tolerances.

.005 over standard is way to much for them to bother with. I would suggest you look for a replacement barrel.
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The CIP states the bullet diameter is supposed to be 7.90mm, which is .311. That's why I think Zastava made the barrel .312.
 
Potashminer said:
I am not familiar with mil-surp type handguns, but have messed with a few mil-surp rifles. Regarding that bore size - was that diameter taken from a slug that went all the way through that barrel, or just in and out at the muzzle? The reason that I ask - I have found several rifles with the muzzle end one or two inches (or more) worn down from sloppy use of pull through cords or cleaning rods - rubbing against side of bore at muzzle and increasing diameter - get a different diameter, on those, depending how you get a slug. Was wondering if same can happen on a hand gun?

EDIT: so re-thinking that - cleaning rod wear increases "bore" diameter - never seen one worn down to the bottom of grooves - it would be the groove diameter that one gets on a slug - bullet to be similar to groove size, not bore size. So my question was likely "out to lunch"...
Click to expand...

I slugged the barrel all the way through, muzzle to chamber. It's also a new old stock man manufacture from the 90s.
 
Suther said:
Sounds like something is seriously wrong with your barrel. The only instance I can think of where 5thou over bullet size is not considered a major issue is with Lee Enfields, particularly ww1 vintage ones with well used bores.

I can't see how a pistol made in the late 50s at the earliest would have a barrel that far out of spec and not be considered a lemon.
Click to expand...

The barrel seems to be in CIP spec. Bullet is supposed to measure .311 according to them.
 
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