45-70 short throat

[HuntinandBanjos94]

I have a buffalo classic and I was wondering, if I was going to ream it out, how far would I have to ream the throat out to shoot the 535 grain lyman postel and the beartooth 525 grain piledriver? My rifle has a short throat so I highly doubt they'll chamber without the throat being reamed out.

[quickdtoo]

The only way to know for sure is make up a dummy round and chamber it to see how deep the bullet has to be seated to fully chamber, or use a tool and a bullet to see what COL will work, see the simple COL guage in the FAQs. There's no way to know for sure if you don't actually have the bullet you want to use so you can check it, chambers vary a lot, what works in one won't necessarily work in another.

Tim

[quickdtoo]

I thought I shot or gave all my 525gr Piledrivers away, but I still have a few, I tried one in two of my un-throated 45-70 barrels, one chambered at 2.520" and the other at 2.515", both hard into the lands which is fine for cast bullets in an extractor barrel, on an ejector barrel it won't likely eject a loaded round. The GBO 45-70 throater is loaned out right now, but it should be available in a couple weeks.

Tim

[HuntinandBanjos94]

that's what I figured I'll just have to try it and see what needs to be done.

Thanks,

Travis

[keith44]

My Handi rifle shoots the Lyman Postell just fine (with a dose of IMR 3031)  I have a dummy round with that projectile somewhere.  If you want to know the exact length. I remember the postell having a reduced diameter (or bore riding) forward section (between nose and forward driving band).  I lightly crimped the bullet into the case on this band and had no chambering issues with the as issued chamber.

[gcrank1]

It really all depends on the ojive of the bullet, as alluded to above by some that fit. Not all bullets of the same, or similar weight, are created alike.

[brad925]

i am shooting a Lee 405HB in my B.C. OAL 2.608 and thats snugged up to the bore.

[bikerbeans]

My 45-70 BC ain't got a short throat anymore.    I throated my other BC with a 45-120 chamber reamer.    
 
I was wondering if you got a little carried away with the throating reamer would you end up with a gun that would be good for "breech" seating for BPCR or would you just need to a rent a 45-90 chamber reamer? 
 
Throater will be on its way back to WA this afternoon.
 
BB

[quickdtoo]

FWIW, Ben, who donated the .458 throater, used that reamer to rechamber his H&Rs to 45-90, although I don't understand how since the widest point on the throater is .460", a loaded round is much bigger than that at the neck, so I suspect he got a bit of wobble doing it by hand that would allow the longer round to chamber.

Tim

[gcrank1]

In a true beach-seat chamber the cartridge part is still the same as in a normal chamber, then it is reduced in dia. forward to the bullet dia. (ie. groove dia. + .0005" of the rifling) so there is no transition for the bullet to have to pass though. Some of these throats are tapered, rather than cylindrical, as in a typical ballseat. The lubed bullet is pushed into the throat and sits just a bit in front of the cartridge, which is primed and charged, and often capped with a card and/or lube wad. As you can see, this lessens the opportunity for the bullet to do anything but drive true into and through the bore.
Some have had decent luck by breech seating a cast lead bullet, of the right size to fit the normal chamber throat, but oversize to the bore groove dia. I have successfully done just so with the standard H&R 38-55 chamber and a shortened, fire-formed case to sit behind the bullet with the bit of clearance to the bullet base.