.3215 bullet in a .3215 bore

[dougk]

I am going back and forth with some one on the bullet size for a .3215 bore  this is the average of 3 measurements of the distance from grove to grove.  I believe the bullet should be .321 a friend thinks the bullet should be .3215.  What is the best bullet size?
 
thanks
 
Doug

[us920669]

Just my opinion based on 40 years of fooling with oddball cartridges: With something that big you could go a little under to a little over,  maybe .001 to .0015, but best is probably right on the money.  What is the cartridge?  Lead or jacketed?

[dougk]

is an 8x72R from Suhl Germany in 1936.

The bullet is a Norma Alaska.

[pastorp]

I asume thats a jacketed bullet so I would size to match bore diamiter but not over.    If it was cast I like a couple thousands over.
 
Regards.

[us920669]

I probably should have cautioned you about going over with a jacketed bullet, especially if it is a hard jacket. Or just do it and realize that pressure will be higher and adjust the load accordingly.  You mentioned an average reading.  Could it be that the bore is not perfectly round?  That's not unusual in older rifles and really not something to worry about.  A good cast gas check bullet at .322 might be best, but that would be custom ($). 


The Hawk Bullet Company makes a line of "Dead Soft" jacketed bullets well suited to irregular bores, as they slug up or swage down with ease.  My old catalog shows a 170 gr at .321.  Performance on game is excellent.  They have a web site, but products are not cheap.

[dougk]

here is a picture of the Norma Alaska

http://www.grafs.com/retail/catalog/product/productId/11512

[us920669]

Well, I like the shape and the weight - they are a bit on the fat side.  It's the old 8 m/m compatibility problem they always warn you about.  I'm sure you have pondered it at length.  You could probably use a slower powder, and not too much of it, just accept the fact that it's not going to be a barn-burner.  They are pricey little devils.  You could get a mold and a sizer and make the perfect bullet for that classic rifle until the cows come home.  It would be a big plus if you ever decided to sell the rifle.

[dougk]

I am having someone make me up 100 rounds.  This one was a challenge.  Lucky the gun was at the smiths and he was able to determine the exact bore diameter.