Home Forums Hunting & Shooting Express Rifles and Big Bores Only 45-70 in an 1886 45-90?

This is the first I’ve read that Browning 1886 rifles were fitted with a slow twist barrel. Admittedly that was something I had never checked but assumed the twist to be a 1 in 20” twist. The two Browning 1886 rifles I had shot superbly with heavy bullets. In fact I rarely use anything lighter than 400 gr. Anyhow I went and dug my Browning 1886 out of the safe and checked the twist using a tight patch. As near as I could determine it has a 1 in 20” twist.

I believe some of the barrels fitted to Miroku 1885 rifles in 45/70 and 45/90 (mainly heavy round barrel BPCR versions) were 1 in 18” Badger cut rifle barrels.

The tight barrel dimensions and the SAAMI throat (ie no throat) does make for difficult chambering of some jacketed and cast bullets in the Browning. For years prior to its introduction in the Browning, Marlin and Ruger had produced 45/70 rifles with a short throat, longer than what they do now. That’s what bullet producers were used to making their bullets fit. The 300gr pills generally weren’t a problem fitting the Browning 45/70 chamber. I suspect this is what made people come to the conclusion that the Browning won’t accept heavier bullets.

My browning 1886, which was reamed from .45-70 to .45-90, is definitely 1:20 twist. It shoots .45-70s no problem and remarkably accurately - much more accurately than the factory sights can take advantage of.

Question for the 1886 owners:

I just purchased a new Moriku 1886 Deluxe in 45-70, what I want to find out is if the actions are the same for the 45-70 and 45-90, IE: do they lengthen the 45-90 version or make any internal changes? I measured mine and bolt face to breech face while fully open is almost exactly 3". Can somebody with a 45-90 please measure theirs to see if its any different?

Thanks!
577Nitro JES

May I ask what are your objectives?
If all you want to know is can you fire 45-70 ammo in a 45-90, the answer is yes.

The actions are "the same" in terms of length and parts. Conversion consists of a re-chamber, and then running a .45-90 dummy though and seeing if there's anything around the loading gate, shell lifter etc. that needs a little tweaking for the larger round. The resulting rifle should feed and shoot both rounds up to a 2.75ish OAL in both rounds.

I do believe some of the factory Miroku .45-90s may come with slow twist barrels, which is not desirable IMO. Others definitely are 1:20". I'm not sure other than testing how to tell which is which. I think all their .45-70s are fast twist.

Thank you Sir! This is exactly what I was looking for. I'm thinking about re-chambering in either 45-90, or a long throat 45-70 so I can use 500gr bullets without seating them so far down.

his is the first I’ve read that Browning 1886 rifles were fitted with a slow twist barrel. "

ME too. I will not believe it until someone does a test and proves it.

All the talk of 500 gain bullets in the .45/70 takes me back to a time of unlimited culling deer sized feral game in which anything went, including 500 grain Hornady's which I tried in the SS version of the Marlin 1895. Long before Stainless Marlins were available, The SS version had 22" barrel, half length magazine and a rounded pistol grip and lever.

The cartridges hand loaded to seat to the cannelure were too long to cycle through the action but loaded singly without issue. They also killed feral goats with utter reliability though interestingly demonstrated far less flesh disbursement that did the .458 Winchester handloaded with Hornady solids at the time.

Loads tried included:

50gn IMR 4064 = 1491fps
48gn AR2206 = 1434fps (There is a 2206H version today which is a modified burning rate sold as H 4895 in the US)
45gn AR2207 = 1576fps (Sold in the US as H 4198)
46gn Rel 7 = 1584fps
50gn Rel 12 = 1439fps

Interestingly, best accuracy came from 44gn of AR 2207 which generated 1550fps.

That would be some great data to try with 480-gr DGX or FN cast bullets in the Winchester 1886,
loaded to 2.78" and works through the action of the .45-70 Gov't., 1:20" twist, 20" barrel.
My 1885 from Browning/Miroku has a 1:18" twist, 28" barrel.