Question after slugging the bore?

[oneMOA]

This is a bullet/rifle question and I hope on the right forum. My newly aquired Browning 1885 BPCR in 45-70 will be fed a diet of smokeless, at least for awhile. Since the bores are supposed to be consistant on these rifles, and most bullets available on the web are sized at .458, I have ordered a few to test. Yesterday I slugged the bore and found it to be .4585. It has been my experience with commercial cast bullets, that they are not perfectly round, so I was not surprised when I measured a few of the .458 sized bullets I ordered.

In the past my experience with cast bullets has been with pistol bullets, shooting USPSA and Cowboy Action. Pin point accuracy is not a requirement in these games and so I was not concerned with inconsistant bullet dia. I am concerned with the accuracy of bullets for my Browning BPCR. In my research on loads for these rifles, the BP shooters want soft bullets. The smokeless shooters want a more hard cast bullet, even when loading down to 1100 to 1200 FPS. I'm wondering if I should be buying .459 sized bullets? I haven't begun any ammo testing as of yet, but I'm just wondering if I'm wasting my time with these commercial bullets. Would I be trying to put lipstik on a pig?

oneMOA

[Themoose]

onemoa,

I haven't had a 45-70 for years, but remember that the cast bullet from softer lead will expand(obturate) and fill the grooves when using black powder. I shot a C-Sharps using bullets I cast from the Lyman Postell mold and fired them unsized and was very pleased with the accuracy out to 500 yards. I think that I used a 30:1 ratio of lead to tin. If you are going to buy your bullets instead of casting them, you would want to pay attention to their alloy composition. I think that if you check out the suppliers such as Buffalo Arms they will provide that info on the bullets they sell. Hope this helps... Have fun with your rifle.

[largom]

My 45-70 boolits drop from my RCBS and LBT molds at .460. I shoot them as cast, unsized lubed with FWFL. Accuracy is great in 5 different guns.

Larry

[Nobade]

In your other post you mention AA5744. I would try a few of those commercial bullets with about 25 grains of it and see how your new rifle shoots. If it's not accurate or leads the bore, then think about some granular filler. I wouldn't use that with 5744, but if you have any medium rifle powder like 3031, 4064, 4895, etc. then about 1/2 to 5/8 full case of it plus enough cream 'o' wheat to make a compressed load is usually beneficial to making a complete gas seal and getting commercial bullets to perform reasonably well. Might be worth a try if they don't work by themselves.

BTW, welcome to the forum!

-Nobade