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Discussion Starter · #1 ·
I have a E.German Mak. and have measured the groove diameter at and between .3661 to .3664 I don't know how that measures against the standard Makarov pistols. If any knows what the correct diameter should be would you post it. Please, I am getting ready to shoot some lead bullets thru it and just would like to be in the safe zone.

fknipfer1
 

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here is an example of the mn91/30 lands and grooves definitions...





I have a E.German Mak. and have measured the groove diameter at and between .3661 to .3664 I don't know how that measures against the standard Makarov pistols. If any knows what the correct diameter should be would you post it. Please, I am getting ready to shoot some lead bullets thru it and just would like to be in the safe zone.

fknipfer1
 

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Discussion Starter · #6 ·
I measured the groove diameter of my Makarov and my P-83 and they measure Makarov .3661 to .3664 and the P-83 measures from .3671 to .3674. There is over a .001 of an inch difference. Us old rifle guys for accuracy when we shoot cast bullets we measure our groove diameters and size and shoot a cast bullet .001 over our groove diameters. Like the Makarov has a groove diamater of say .36625 average. We would shoot a sized bullet of .36725. Not being a pistol reloader because of no interest I am now starting to reload pistol cartridges because I now have my CCW license. My cast bullets are averaging between .3648 to .3650 I bought them finished. Is this to much clearance for in a rifle that much difference a bullet would keyhole or have no accuracy at say 100yds. Does the distance of say 25yds even matter and what kind of a clearance woud you require.
I was shocked when someon said they had not heard of groove diameters, they are bottom of the barrel (the complete bottom below the lands.
Or did I read it wrong.
 

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Your bullets seem right on at .365.

Here is the case / bullet dimension standard:

SpecificationsBullet diameter9.27 mm (0.365 in)Neck diameter9.91 mm (0.390 in)Base diameter9.95 mm (0.392 in)Rim diameter9.95 mm (0.392 in)Rim thickness1.00 mm (0.039 in)Case length18.10 mm (0.713 in)Overall length25.00 mm (0.984 in)Rifling twist240.00 (1 in 9.45 in)Maximum pressure160.00 MPa (23,206 psi)
 

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Discussion Starter · #10 ·
I just loaded ten rounds of 115gr Cast LFN with 2.6grs of Unique (very light) gotta start somewhere. Kept the cartridge long .970 for safety purposes let you guys know how they did, if it doesn't rain going to Chonograph them at 10'. I have a correction for the first ten feet so I should get some good data. Lotta room left in the case for powder. I put a new 21# recoil spring in my Mak to keep it safe. May no be enough round to eject the spent case.
 

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The way I understand things is that: reloader slugs the bore, measures groove diameter and then picks the bullet that is 0.001 larger than groove diameter.

All these question about groove diameter is what non reloaders ask. They ask because they do not get to choose their bullets.
 

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Well, to paraphrase that, I guess the question is: "Has anyone slugged their bore"?

I have not. I don't try to make a bench rest round with 9x18. It would be informative to have a post of slugged bore measurements.
 

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Discussion Starter · #13 ·
Well one thing you can do is to find out if you barrel is oversized and worn out. I always try for accuracy and not speed no matter what I load. If you don't want to do that its fine with me but I like to find out everything I can about my pistols. I have a 9mm 16" Marlin camp rifle and I slugged it to find out what size lead bullets to use. You don't slug for JHP or FMJ's just lead.
 

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Well one thing you can do is to find out if you barrel is oversized and worn out. I always try for accuracy and not speed no matter what I load. If you don't want to do that its fine with me but I like to find out everything I can about my pistols. I have a 9mm 16" Marlin camp rifle and I slugged it to find out what size lead bullets to use. You don't slug for JHP or FMJ's just lead.
Soviets gave manufacturing documentation to East Germany. You have what Soviets gave East Germans.
 
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