what is the diameter of a large pistol primer?

[BlindJustice]

I have a 1894 Marlin in 45 Colt. I measured a bunch of
HP bullets width of the HP and the Barnes XPB 225 gr. is
.260 inches - would this be safe in a tubular magazine?

If not I guess you could put one in the breech for #1 and
also have one as the first one in, last one out of the magzine
and load the rest of the magazine with the Leadhead 225 gr. TC=BB
at the same velocity for same POA.

 

[Ol` Joe]

I believe they are 0.210" but I would need to measure one to verify it.

Keep in mind the 45 Colt is a rimmed cartridge and the bullets tip will not be consistantly on center with the axis of the magazine tube. I`d contact the bullet maker and get his opinion on useing them in a tube mag.

 

[BlindJustice]

Yeah, I thought about the 'tip' of the cartridge as it
lies in the tubular magazine.... Isn't there some stuff used by
gunsmiths - dip the tip of the bullets in it and put em in the magazine
Empty the magazine and check to see what the HP bullet touches.

 

[BlindJustice]

I had a friend come over with Calipers and he verified
the .210 dia.

Oh, and he also measured the extra thick .45 Auto RIm at
0.0755 inches and the blackpowder era .45 Colt is .0500

 

[BlindJustice]

It is 0.210 dia. of a large pistol primer.

OH, FYI - seems a .45 Colt has a rim of about
0.050 thickness, the .45 Auto RIm is 0.0755 of an inch.
-