Is it ok to shoot 45-70 in an 1886 45-90?

Sort of like shooting a 22 short in a 22 LR chamber, I'd think. You might be better off shooting light loads in your 45-90, if you're going to do it a lot. I'd be glad to consider trading my 45-70 1886 for your 45-90

Was the rifling twist the same for both cartridges? IIRC the 45-90 was designed to shoot a lighter bullet faster. But I am getting to an age where I clearly remember something that never happened.

The 45-90 was built for express loads in the 1886 partly because the 1886 had a limited OAL and the Sharps version was too long for the 1886. I recall the 1886 had a slower twist. I believe it's the same case as the 45-2.4, but the 45-2.4 had a faster twist than the 1886.

I was thinking about trading for one, but it seems like alot of trouble. I already have High Wall in 45-70, so I was hoping it was ok to use those rounds in this.

It is.

I've wanted a 45-90 in an 1886 for quite a while, but have been too cheap to put up the coin, since 1886 45-90's go for a lot of money. I have a Miroku "1 in 500" 1886 in 45-70 that's pretty (and heavy) that I'd consider as a partial trade.

Yup do it all the time in my 1886

I had an original '86 .45-90, they had a 1 in 30" twist. New ones are the same as the 45-70's. I shot a box of Remington 405 gr trapdoor loads through it once, grouped well enough for 100 yard hunting.

With the right bullets you can load and cycle 45/70 cartridges loaded to 45/90 length in your 1886 in 45/70. I can in my Browning 1886 in 45/70. This gives you the best of both options. 45/90 performance potential using 45/70 brass.

You need bore riding cast designs with a longish nose that have a crimp groove in the right place or, alternatively, use a Lee FCD to crimp in place.

Why don't you just use the right case and be done with it?

If you can seat the bullet out pretty far in a 45-70 chamber that would be outstanding. Ive often thought that i wanted a 45-90 but i dont think id be gaining much of anything. Ive already got an 1886 45-70 Extra Lite , 450 Alaskan Extra Lite, and an big old heavy octogon 1886 45-70. I really need to play with seating depth on those 45-70 rifles

45/70 chambers have no throat to speak of, so you need to select bullets carefully if you want trouble free feeding and function.

By way of example in the link below you will find a pic of various bullets - some are loaded to 45/90 length that do feed in my Browning 1886 in 45/70. This shows how versatile a 45/70 can be in an 1886 platform. The chamber is a stock no throat 45/70 chamber.

https://levergunscommunity.org/viewtopic.php?t=71103

What Fotis said (yes) + 1.

My Miroku/Winchester 1886 45-90 TD has taken a lot of game with factory 300 grain .45-70 ammo at 1800 + fps.



Most of my handloading has been for .45-90 loads for Africa and other special purposes.

Obviously, it is prudent to clean the chamber after shooting much 45-70 ammo.

I did it years ago in an original 1886 45-90, worked fine but had to clean the chamber before shooting 45-90 loads.

I have to be honest and admit I forgot about the 45/90 in the 1886. But; what I have read here does ring true and jog my memory. All except the part that compared 45/70 and 45/90 to 22LR and short. No, wrong! AFAIK, the over all total cartridge length for 1886 ammo in 45/70 and 45/90 is the SAME. There is no power increase. It is much more like 22long and 22 long rifle. That is a difference in bullet weight.

They always said you can shoot 45/70 in a 45/90 Winchester. It must be ok with 405 bullets.

Trading an original 45/90 to get a 45/70, OMG, rethink that idea!! Nobody cares about a Miruko 45/90 but a real Winchester 45/90 is a big deal. It used to be the 50/100 was the big deal. Nobody can afford those any more, so today best most can hope for is 45/90. Now we are talking collector bragging rights. No practical gain in one 45 over the other.

As for Miruko, if they want to get my attention, for the $$$ involved, they should do a 50/100 or stay with 45/70.

Yes, but why would one do that? Sort or like running regular gas in ones Maserati

Making a long story short--- I bought the Miroku Winchester 1886 .45-90 TD because I planned to experiment with heavy big game loads for Afrika and wanted the security of knowing it was up to the job. both mechanically and weight wise WRT handling recoil. It weighs 9.5 pounds empty and once I learned how mount the crescent butt plate, it has never bruised me.

Ironically, the 450 grain bullets at 2150 fps loaded by Grizzly Cartridge never generated enough pressure to be a concern. The 1886 can handle way more pressure (and heavier bullets) if needed.
Since the 450 grain North Fork and Punch bullets performed as planned on the ele and buffalo, we concluded the is no need for heavier bullets or higher velocity.

Insurance comes with a price in weight and $.

Keep in mind the original Winchester 1886 in 45-90 had a different twist then the same rifles in 45-70. The 45-70s could use bullets up to 500 grains. The 45-90 was limited to 300 grain bullets in the era they were made. I don't know how the newest Miroku rifles are twisted, but in 1986 when Browning re-introduced the M1886 they were chambered in the 45-70 but twisted slower like the 45-90s were which is why they shot 300 grain bullets very well, 350s OK and 400 poorly as a rule. 500 grain bullet would impact sideways at 25 yards I has 2 of them and they were definitely "light bullet rifles"


I have been told that Winchester addressed that problem (After the joining with Browning) and the the new Winchester 1886s are twisted 1-18 instead of 1-30, but I have not proven that to myself yet, so take it as hear-say for now,.

My more recent Model 1886 Winchester .45-70 lever action "Short Rifle" from BACO/Miroku
has a 20"-long round barrel and 1:20" twist.
I slugged it and found a groove diameter of .457".
It will handle cartidges up to 2.800" COL, loading through the gate, feeding from the magazine.
The Hornady 480-grain .458" DGX Bonded can be loaded, crimped on the factory cannelure, for COL 2.785" in .45-70.
Since it is .450" diameter and smaller ahead of the cannelure, it works fine in the no-throat SAAMI .45-70 Gov't.
Just like JFE said about selecting cast bullets for bore-rider noses.

If using the steel-jacketed .458" DGX in the .457" grooves,
just for fun I might push them through a .457" LEE sizer and leave the lube on them
before loading, with a wax paper, milk carton, or playing card wad over powder.
For hardcast, FNGC, powder-coat-painted bullets in similar smokeless loads I would size them to .459" bearing with bore-rider nose.
No need for a .45-90 that way.
That even kills my desire for a .450 Alaskan.

BTW the BACO Winchester 1885 High Wall .45-70 Gov't. has a groove diameter of .457" also, but 1:18" twist, 28"-long octagon barrel.
That one is a 2010 model year.

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.