Miroku Winchester 1886 Short Chamber

[riverrambler]

I purchased a Miroku Winchester 1886 Deluxe chambered in 45-70 manufactured in 2020. I also purchased hardcast bullets from MBC in 405grn WNFP and 300grn WNFP. Looking at several manuals with similar bullets the data shows an average of 2.55" OAL ranging from 2.53" to 2.59". However my bolt will not close on the shortest OAL for these bullets. My understanding is that the barrel was designed for shooting jacketed bullets. So I purchased a Hornady OAL gage and bullet comparerator set. The measurements I'm getting touching the lands are 2.164" @ the ogive and 2.446" OAL to the bullet tip for the 300grn WNFP and 2.152" @ the ogive and 2.439" OAL to the bullet tip for the 405grn WNFP.
Would it be safe to load these bullets to these specs providing I don't overly compress the powder?

[John in WYO]

Not knowing you or your shooting and reloading background is, I’d have to see your loaded rounds to better understand what may be going on. I’m not sure I comprehend what the issue is. Maybe a short throat?

I’m not familiar with the bullets you bought, but surely they function if seated and crimped in the crimp groove on the bullet(?).

Good luck…

[M-Tecs]

Take a sharpie and blacken the bullet and the front of the case to identify were and why you have contact. It could be too little flare scraping the bullet and leaving a ridge of lead. I could be the flare not being removed enough.

Or it could be the bullets are seated out too long. If that is the issue that would be a short throat not a short chamber. The case volume of the 45/70 is very large so seating the bullet deep enough for a short throat will not create any pressure issues. That being said Trail Boss should not be compressed. I do not use Trail Boss in the 45/70 but that is the only powder verse volume that I can think of that would have possible compression issues in a 45/70.

What powders are you using?

[veeman]

I have 2 Browning 1886's, one rifle and one SRC. Both will not chamber Berry's Plated 350 FN bullets. Haven't had anything else not chamber. The Browning's are notorious for short throats. I would suspect your Winchester, made by Miroku, same as the Browning's, has the same problem, short throat. Funny how those same Berry's bullets shoot great in my Uberti 1876 45/75.

[riverrambler]

I'm using Varget and Accurate 4350. My mistake, I meant short throat.

[riverrambler]

Yes I believe the issue is a short throat.They wont crimp in a groove so I'm using a Lee Factory Crimp die. Been reloading since 1992 in various handgun cartridges and 444 Marlin. New to reloading the 45-70

[NSB]

They DO NOT have short throats. What they have are throats made to SAAMI specs. I’ve owned three of these guns (1886 and 1885’s) and had all of them reamed out to a longer length. I took them to Turnbull for CC treatment and some other work done. They’re the ones who told me that if you measure the chamber and compare it to SAAMI, it’s right on. Everyone else makes their chambers longer knowing that a lot of bullets with a blunt ogive won’t chamber. When I picked the guns up I asked how much they lengthened the chamber. It was lengthened to what they use for best results and that was .250”. All three of these guns are superbly accurate. My High Wall will do five shots under an inch at 100 yards and feed everything. Take your gun to a competent gunsmith and have a reamer run into the gun and lengthen the chamber. Then you can use whatever you want to shoot.

[Gunlaker]

I've owned a few of these rifles. Some bullets don't fit the throat such that they can be loaded to the normal length listed in the reloading manuals. One bullet that worked in them was the Remington 405gr and I'm pretty sure the Speer 350gr ones were fine. I don't think the Speer 400 grainers could be loaded to the crimp groove of full length brass. In the end I shot cast bullets out of mine anyway. All of the 405-450gr bullets I tried worked perfectly.

Chris.

[NSB]

I shoot Rem 405g JSP in my guns. So far they’ve been the most accurate by far. The 45-70 with those bullets is the least fussy gun/cartridge I’ve ever owned. About any powder in any loading manual will shoot good-excellent groups. Too bad Remington decided to quit offering that bullet. I’m sitting on about 1,500 of them, so I’m set for a long time.

[M-Tecs]

I shoot Rem 405g JSP in my guns. So far they’ve been the most accurate by far. The 45-70 with those bullets is the least fussy gun/cartridge I’ve ever owned. About any powder in any loading manual will shoot good-excellent groups. Too bad Remington decided to quit offering that bullet. I’m sitting on about 1,500 of them, so I’m set for a long time.

I love that bullet for accuracy. I have about half of what you have.

[Milky Duck]

the hornady leverlution CASES might be your friend here,they are 3-4mm 1/8th??" shorter than the normal cases so projectile/boolit seated to same depth INSIDE case might solve your issue.
I use the shorter cases with smokeless and origonal longer cases with BP.... I sure dont have seating issues as rifle was chambered with a boring bar set on correct angle and chamber made long because we could.