Bore Slug Request: 32" 45-70 Barrel for SB2

[jkpq45]

Hello All,

Not sure if the 32" 45/70 barrel is the same for the SB2 and Buffalo Classic series--but can anyone tell me what the land and groove diameters are for these barrels?  Surely someone has run a slug from the breech and muzzle ends and put a mic to it.  I understand the barrel is 1 in 20" twist as well per the FAQ.

Thanks,
jkpq45

[Catshooter45]

jkpq45,
 
No one can tell you the size of your barrel.  They all vary.  The only way to tell is to measure it.  Sorry, it is what it is.
 
 
Cat

[jkpq45]

I'm actually trying to plan the next project and considering sendoff to "the mothership" for either the .410/45 OR the 45/70 @ 32".

A lot will depend on how these bores mic out--if it's in the neighborhood of ~0.458", my ship may be sunk.  If it's in the 0.454" to 0.455" range, there's still hope.

[quickdtoo]

What Catshooter said, doesn't make much difference what our barrels slug, the SAAMI spec is .450" bore and .456" groove, tolerance is .002", just depends on when the barrel was made in the life of the tooling. I've dropped .452" bullets thru most of my 45-70 barrels(7 of em), some will drop part way thru and stop mid bore. FWIW, all H&R barrels are slightly tighter at the throat end by ~.0005" because they aren't stress relieved before they're turned.

Tim

http://www.saami.org/PubResources/CC_Drawings/Rifle/45-70%20Government.pdf

[gcrank1]

It is your throat dia. that is really more important for lead bullet shooting. Use the largest dia. slug in the case that will still chamber up and extract cleanly. My guess is your desired dia. is too small if you really want to hit the target and not have leading issues.

[quickdtoo]

What he said, I have no problems chambering .459" and .460" cast in my 45-70 H&Rs.  Size em in the bore when fired..... so to speak! 

Tim