Miroku winchester 92 bore diameters

[IrishFritz]

A quick search of the archives didn't turn up the average bore diameters of the Miroku 92 357 and 44 mags. I'd like to pair up a handgun and a light rifle/carbine and would like to be able to interchange rounds between the two with "acceptable" if not optimal accuracy. So relative bore diameters between the handgun and the rifle become important. I think it might be hard to pair a S&W 29 with a Marlin 1894 in 44 mag, for instance. So, anybody help me out with those bore diameters and what might your thoughts be on my project? Thanks all, IrishFritz. P.S. I should have added I shoot lead bullets only.

[Buckshot]

............I can't speak to the two cartridges you mentioned as the only Miroku made Winchester I have is chambered in 45 Colt.

http://www.fototime.com/B655FB7E5A3EBD2/standard.jpghttp://www.fototime.com/745969169444B08/standard.jpg

I was told it was an 'Earlier' issue, but I'm not a student of them. All I can add is that the bore and groove is perfection at .444" x .452". The twist is what is normally encountered in revolvers at 16".

...............Buckshot

[Randy Bohannon]

My Win/Miroku 73 44-40 accepts a bullet @.430" at the reccomended O.A.L since modern replicas basically use the same dimension as .44 Rem. Mag. and interchange barrels between the two cartridges.To match up a revolver to the rifle you will need to measure the chamber mouth of each chamber of the revolver and see if any are close to rifles throat dimension and have them all trued up to be the same.It is easier/cheaper to have the revolver's chamber mouths evened up to match the rifles throat. DougGuy here does fabulous work on cylinders for reasonable prices.

[CamoWhamo]

I have 2 Win/Miroku 92's in 44-40 and both have a .431 bore. From that i assumed they used the same barrel as they do for .44 Magnum (SAAMI spec for .44 Mag rifle is .431).

The chambers are quite loose tolerance and I can chamber a round loaded with a .432 bullet in those rifles but the challenge was finding dies that would accept that large a bullet without swaging them down or squeezing the case mouth and causing bullet shaving.
For that reason i generally loaded them at .431 and they shoot ok.

I also have a Win/Miroku 1873 in 44-40 and the bore on that rifle is .430. The chamber is definitely tighter and only the more traditional shaped bullets chamber properly. I round loaded with a .431 bullet is a tight sliding fit and care needs to be taken with reloading them as any bulge means they won't chamber.
I have settled on .430 bullets (Accurate 43-220CC) as they chamber well and are very accurate. Ragged one-hole groups at 55yd.

[Randy Bohannon]

What Camo said.

[35 Whelen]

I hate to be "that" person, but it's GROOVE diameter in which we bullet casters are interested, not bore.

35W

[IrishFritz]

Thanks for the info guys. Indeed, I'm looking for the maximum diameter of the bores as measured in a barrel with even numbered lands and grooves from the bottom of the groove to the top of the
corresponding land: thats fairly easy to measure. In a barrel with odd numbered lands and grooves from the bottom of the edge of the groove to the opposite edge of the corresponding land, (I know the proper method is in v blocks with a dial caliper with the correct mathematic formula). I do understand that we want the diameter of the cylinder throats to be approximately identical or no more than .001" over the bore diameter of the handgun. At the same time, I'm looking to have the bullet diameter as it exits the handgun to be within a .002" of the bore diameter of the rifle. The point is to not have the bullet swaging up or swaging down excessively between the two guns. Until recently, I owned a mid 70's vintage model 29 that had a very tight .4292 bore diameter. My belief is that that particular hand gun would be impossible to mate with a current manufacture Marlin 1894 which by reputation run .433-.434 bore diameters. If indeed the Myroku's run @.431 .358 then I should be able to mate their rifle to a Ruger Blackhawk without too much trouble as Rugers tend to have rather generous manufacturing tolerance ranges (to say the least). Anyhow, thats my hope. Cheers, IrishFritz

[Walks]

Why I am always outside the circle, my old BROWNING 92 in .44Mag has a groove diameter of .4295, maybe the older guns were made with smaller bores. My 2 older NM Super BlackHawk's from the mid 1970's have .429diameter bores. My Earlier Production Super RedHawk from the early 1990's has a .430diameter.

My 1988 made WIN 94 20"bbl has a bore diameter of. 430, feel like I'm under bored.

[IrishFritz]

Thanks Walks, Well, I guess I'm going to find out as I've got a short rifle in 44 mag inbound about Wednesday. I will cerrosafe cast the bore and my hope is that it will be in the .429-.430 range as all of my molds cast .430+/- a bit and I don't want to have to get a custom mold. Unfortunately, all of my molds are SWC designs and my guess is they may not feed reliably, but I'll wait to see before spending money. If I have to buy a mold, then I'll opt for a RNFP with a wide meplat- probably gas checked and bore diameter as cast. (oh boy do I hate putting on gas checks) Anyhow, thanks for the info IrishFritz

[prs]

I realize this is an older thread, but I ran across it and see what appears to me to be some confusion regrading barrel diameters of groove VS bore. As published in AMERICAN RIFLEMAN:

"The dimension from the bottom of the groove to the bottom of the opposite groove is the groove diameter. When the gun is fired, a bullet is forced into the barrel under great pressure. ... There are two diameters in a barrel. The greater (major) diameter is the groove; the lesser (minor) is the bore." Mar 15, 2011

Odd numbered rifling grooves, and even ones too, can have groove diameter determined by adding 2X groove depth to bore diameter.

Good, bad, or ugly; forward chamber dimensions and case wall thickness should determine best bullet diameter.

That is how I figure anyway.

prs

[smithnframe]

I had one in 38 wcf that was the same bore diameter as my Uberti revolvers.