Need help with 45/70 bullet size.

[bslim]

I just purchased a Browning BPCR Rifle in 45/70. I've tried several loads in it, but haven't found the right one yet. I slugged the barrel with a 360" cast bullet and found that all of the rifleing shows up well, but contact with the lands is only 3/4 of the way around the bullet. Is this normal and will the bullet expand enough when fired to seal up? Thx in advance for your help.

[knifemaker]

It sounds like you may have a larger then normal groove dia. in your barrel. Get a larger slug, such as a egg shaped fishing sinker that you can buy at any store selling fishing gear. Use that to slug the barrel. I would not be surprised if your barrel groove dia. is .461 or .462 based on what you said above. Also use pure lead to slug the barrel not a bullet alloy. when you slug the barrel, do not use calipers to measure the slug for barrel groove dia. use a mike instead as they are more accurate for the average person to use.

[bobthenailer]

My Browning bpcr in 45/70 shoots cast bullets sized @.459 dia excellent .
Browning uses Badger match barrels on the BPCR

[MT Chambers]

I agree, if it's a Badger barrel, .459" should work, in my gun that's the size to use!

[bslim]

The barrel is half round/half octagon with an "NP" stamped on the barrel close the the receiver. Is there any other way of knowing if this is a Badger barrel? Thx.

[fouronesix]

It would really surprise me if it has a groove diameter of .460 +. Most modern higher quality barrels, and your Browning barrel should be, run pretty close to right on spec. That would be .450 bore and .458 groove. As already advised, try re-slugging. Lube the bore really really well first with a patch saturated with oil and use a slightly oversized tapered soft lead slug. Do it a couple of times to be sure. Carefully measure straight across the grooves. If you measure a .458-.459 groove, I'd try something like the RCBS 405gr GC bullet of fairly soft alloy, maybe BHN 10 sized to .459, lubed with a fairly soft lube and pushed to something like 1200 fps. 4759 or 5744 are good powders for the purpose. No crimp needed for these type loads in a single shot.

[bslim]

Thanks for the advise guys, I'll re- slug the barrel as per above and start from scratch. I do have a 405 grn. RNFP bullet mold from Accurate Molds. It's not Gass Checked. Will this be a problem if I only push this bullet to 1200 FT/SEC?

[fouronesix]

It's not Gass Checked. Will this be a problem if I only push this bullet to 1200 FT/SEC?

Hard to say. But the way to find out is to load a few and shoot them. If you have leading or accuracy problems with those powders and those velocities (pressures), a filler might help. Many, many, many threads on correct use of fillers for lighter, smokeless powder loads. Fillers are not wads. There are incorrect ways to use fillers. There are misconceptions about fillers.

[High Desert Hunter]

Are you shooting smokeless or black? Like everyone else, I would have a hard time believing a Browning BPCR would have a groove diameter over .460, but it could happen. If you are shooting black, I would cast my bullets soft, I have found they work much better than the alloy I use for smokeless loads, even the loads that I am trying to duplicate BP velocities. I also don't seat and crimp the way I do with smokeless, I tend to let the throat finish seating the bullet, and have found this to shrink my groups.

[mpmarty]

I shoot all weights of cast in my 45/70 and never use a filler or a check. No problems up to more velocity than I can stand. Average for 400gr cast is around 1750 with 3031 powder. Look up the load data in a manual as I don't post load info online.

[Guido4198]

My Browning 45/70 BPCR LOVES the NEI Badger-Browning bullet. 30:1 drops 491 gns. sized .459. Lube with SPG or Emmert's. If you want to shoot blackpowder...here's what has worked REAL well for me: 67 gns. ffg with a .030 veg. overpowder wad. C.O.L. 2.65 or so. Those rifles have a short throat. Compress the powder with a compression die and seat the NEI bullet all the way in...no grease grooves showing. I've only used WLRM primers. Others may work as well or even better..I don't know. With blackpowder...develop a consistent wiping protocol to use between every shot, or use a blowtube, to control the fouling. Out to 200 yds, from a good rest, the precision is so good it's kinda boring. One BIG hole.
ENJOY..!!

[44man]

That sounds good and I have to look at the boolit mold. The Browning is not easy to get shooting because of shallow rifling. Mine likes a .460" boolit and the Rapine Gov boolit shoots fair. It does not like the Lyman 405 gr, most measure .457" and way too many molds are too small.
The gun needs treated like micro groove.