Troubles with 45 Colt, Miroku Winchester 1873

[Float Pilot]

I just obtained a new Japanese made Winchester 73 in 45 Colt. It has a 20 inch barrel

I tried 9.0 grains of CFE Pistol which is supposed to be around 13,000 psi. Using Star-line brass, a Win stan/mag primer and heavy roll crimp into some mystery 250 grain rounded flat point cast bullets with a beveled base. They are .452 to .453.

This load averaged 1120 fps from the 20 inch M-73 and 900 fps from a 5.5 inch Uberti SAA.
But it was still a 1.5 inch to 2.o inch groups at only 25 yards from the rifle. Over a sandbag.
The same load shot a 2.5 inch group from the 5.5 inch SAA off hand.

NOTE: My original 1892 in 38wcf will shoot cloverleafs at 50 yards with hand-loads if I use jacketed bullets. So it is probably not me.

The next load was 8.0 grains of Unique into the same brass and primer.
This load averaged 1,082 fps from the 20 inch M-73 and only 780 fps from a 5.5 inch SAA. And this was even worse at 2.0 to 2.5 inch groups at only 25 yards. It did shoot a 1.5 inch group from the SAA at 25 yards.


While both these loads are not wimpy, bit had a lot of gas escaping back down the side of the case in two revolvers and in the rifle. So I am not obtaining a good gas seal. SEE PIC

So any ideas why I am still experiencing gas blowing back down the cases at these velocities? Any thoughts on a better load?

I want to try annealing the case mouths to make them softer and also some .454 or .455 slugs if I can find a few to try as an experiment.

 

[BigBore45]

slug the bore.. also what twist rate is the rifle? You have to get a good gas seal. so maybe work up with the Unique load. It should be closer to 850-900 FPS out of the pistol @ max load.

my old win 94 in 45 colt with 20" barrel shoots 2 1/2" groups at 100 yards with ruger only loaded 250 grain keith style bullets. It is not very accurate with cowboy action loads. i think if i recall correctly it shot a 6" group at 50 yards with some 250 gr. RNFP at 1000 FPS.

that 1873 action will NOT handle the ruger only loads.

 

[Float Pilot]

The rifling twist rate is listed as being 1 in 26. Kinda slow....
And get this,,, I just slugged the grooves and they are 0.452.5
No wonder my .452 and 453 bullets just skidded down the bore.

 

[Kruff]

The chamber may be a bit oversize. I load 8 gr. of Unique with a Cast 255 gr FP for my Rossi M92 with a 16" barrel and get no smoking on the cases at all. Velocity averages 1100 fps.

 

[CraigC]

I couldn't get away from that with my Miroku `92 .45Colt until I reached "Ruger only" levels.

 

[BigBore45]

The rifling twist rate is listed as being 1 in 26. Kinda slow....
And get this,,, I just slugged the grooves and they are 0.452.5
No wonder my .452 and 453 bullets just skidded down the bore.

there it is.... you can order un sized bullets or cast and get a sizer to .454

i wuld still run max loads in it to seal the chamber and get the rpm of the bullet up as much as you can.

 

[Float Pilot]

MAX LOAD is a relative concept here. The Model 1873 action is pretty weak and 14,000 psi is max.

 

[Don McDowell]

12 grains of bludot
18 grs of 5744
18 grs. of 2400,
or even jump your unique load to 9 grs.
And get ahold of some decent 454 bullets.

 

[GooseGestapo]

My Win M94 in .45 does something similar. Being a very strong action, I can get away with upping the charges a tad.
I mostly use Universal. By upping the charge to 8.2gr from listed max of 7.8, I'm able to get the cases to maintain obturation till the bullet clears the barrel, which significantly reduces sooting of the cases, and gas blow by into the action and my face.

Re: the bullets. Sounds like the accuracy problem is partially related to the sooting/blowback. The pressures aren't enough to obturate some "hard" bullets to your "generous" bore.
Get some (or cast yourself) some softer bullets, and use a black powder substitute. The faster pressure rise will better seal the cases, and obturate the bullets.

The problems you are having is that you are trying to use modern components intended for "high pressures" in an Old tech weapon.
Btw: I prefer Magtech brass as it's the thinnest I've found. It expands and seals at the lowest pressures. Starline is great brass, IF, you're loading Ruger ONLY loads. Thinner brass is better for "standard" loads. PMC is thick, too. Remington and Winchester more like the Magtech, but slightly thicker.
.454" bullets, if the loaded rounds will chamber, will help a lot. But combined with thick brass like the Starline, might not chamber.
There are several cast bullet vendors that offer bullets intended for your application.
Shop around...

Added; F.P.; I'm a CFI, CFII, MEI: SEL. Trying to talk my wife into another Alaska adventure to include getting my SES Comm with you. Of course, we'll do a bit of shooting, hunting, fishing, loading, and casting when not flying or swapping tales/jokes/lies around a Fire...!

 

[Float Pilot]

GooseGestapo

Well here you go. A few teasers. You know I also have a guest pilot cabin.....


https://www.youtube.com/watch?v=ECMBh-XvxZ4

https://www.youtube.com/watch?v=33E9_qQysoo

https://www.youtube.com/watch?v=CuktyiILdEg

 

[Float Pilot]

Well still no 454 bullets yet.
I found some old .452 Keith style 250 grain SWCs and squeezed them a little in a vise until they were .453.
They were a wee bit softer and had a good flat base instead of a beveled base.


So being desperate to get out of other chores I ran out to the range again.
Groups at 26 yards. Rifle rested on sandbag. The 5.5 inch SAA was modified weaver stance leaning against a bench.

18.0 grains AA-5744
20in Rifle = 1,055 fps (1.5inch grp) 5.5 in pistol= 796 fps (2.0 in gp)

9.5 grains AA #5
20in rifle= 1,000 fps (1.25 inch grp) 5.5in SAA= 740fps (1.0 in grp)

10.5 grains HS-6
20in Rifle= 1,050fps (1.30 in grp) 5.5in SAA= 800fps ( 2.25in grp)

Still lots of gas blow back along the case wall. BUT, just a flat base seems to help with the rifle barrel, so I'll bet some .454 slugs will really work out.

 

[MEHavey]

Go get some 44-40 brass and gently expand the neck to 45. You will never have blow-by again.

 

[Float Pilot]

I found some old 1970s vintage Winchester brass out in my shop. It has been awhile since I have seen that particular coffee can.
It is a lot thinner in the mouth.
I have some .454 slugs on order. Hopefully I will get them in before the crazy time of summer kicks in.... When flying and cabin rental season are in full swing I can never get enough sleep, much less hand-load or go to the range.

 

[ArchAngelCD]

In stead of trying to find .454" bullets try using softer bullets. You didn't say but I'm guessing your bullets are 18 BHN, try .452" 12 BHN bullets and you just might fine a very accurate load for your rifle.

 

[Float Pilot]

From the new 1873 Win chambered in 45 colt

WOW 2 tenths of a grain and a heavy crimp made a HUGE difference.

.454 Diameter hard cast bevel base 250 grain RN FP ( Dardas)

8.8 grains CFE Pistol: WW Brass, WW primer.

20in Rifle 1095 fps ( 2.75 inch group)..


.454 Dia hard cast 250 grain. RN FP

9.0 grains CFE Pistol. Star Line brass, WLP Heavy roll crimp 1.595 col

20in rifle = 1,160 fps average. (0.75 inch at 25 yards)

 

[RecoilRob]

When reloading the cases, only size down far enough to hold the projectile and leave as much of the body as is...and it'll help keep them cleaner. My Taurus Thunderbolt is bad like this and will tie up after a hundred or so 'cowboy' level rounds as gunk gets blown back through the action with every shot. Partial resizing leaves the case better centered in the chamber and greatly reduces the pressure needed to expand and seal so they stay cleaner as does the rifle.

 

[Malamute]

This is the subject of some discussion elsewhere, both Cascity and castboolits forums have had information about the sooty cases and different loads and bullets for 45 Colt rifles and specifically the 73s.

Besides using 44-40 cases, some guys are annealing their 45 Colt cases to get a better chamber seal. Your old cases will probably help also. The cases I first had for 45 Colt were thinner than what I see today.

1873 section,

http://www.cascity.com/forumhall/index.php?PHPSESSID=q62rh8n8pdt9rqfftm6ship302&board=109.0

http://castboolits.gunloads.com/goo...-8859-1&q=45+colt+rifle+loads&sa.x=10&sa.y=12

 

[Float Pilot]

I have been annealing the cases as of late, in a cake pan with water while I heat the mouths with my torch. This Miroku still has a pretty loose chamber but it works a little better. My last post on this thread showed that I finally found a load that works with cast lead, by adding 2 tenths of a grain and using a heavier crimp.
I am pretty happy with that new CFE PISTOL POWDER in the few chamberings I have played with.

 

[Steve S.]

My Miroku 24.25" Grade I likes 6 grains of Titegroup under a 250 grain LFN - just put 10 rounds thru it about a week ago at a benched 50 yards (getting ready for deer season) and all the rounds were touching at 2" high (I use a tang sight). This rifle just did not like Unique but seemed to instantly like the Titegroup - I had to experiment a little to find a good load combo.

 

[Float Pilot]

I tried 6.2 grains of Tight Group and it was OK from my rifle accuracy wise, but it was rather slow in the velocity dept. I was seeing between 990 to 1010 fps.
My SAA's really liked it though.... I was seeing right at 830 fps from my 5.5 inch and 800fps from my 4 -3/4 inch Colts.