Pin Gage for revolver cylinder throats - plus or minus?

[Elric]

Now that I've found the 1917 Auto Rim revolver (looks to be original cylinder), I'd like to check the throats and see what they are. Not looking for a gajillion pin set, just good enough for .450 to .460

Does it matter to get a plus set or a minus set? Seems like the same level of accuracy, size plus, or size minus...

 

[waco]

If I’m not mistaken, people prefer the minus sets.

 

[Brad]

Minus!
If you want to really get wrapped around the axel you get them in .0005 increments.
I figure that if a .453 is a snug fit and a .454 won’t go then I can safely assume the throats are .453+ and just use a. .453 bullet.

I am less concerned at purchase with exact size than I am in weeding out throats larger enough to be an issue. Too small can be fixed easily enough but it isn’t so easy to put metal back.

 

[Elric]

I half-adzed measured a sized bullet, maybe .453, but what happened with the crimping?

It looks like the original cylinder, the small number stamped on the rear face of the cylinder looks early 1900s-ish. Old man had moon clips and Hornady 45 Auto cases, but I'm goin for the bern... The barrel is from the early 1990s, so it most likely is of modern throat and bore dimensions...

Pretty sure who did the work, he was steeped in the 1850s-1920s and a lot of other stuff. Could hold a thousandth on a clapped-out Rockwell-Delta lathe... Wonder if he's still around...

 

[RBHarter]

I had 2 1918 vintage and both had .453 +-.0003 for all 6 holes . The "newer" one is of mid August 1918 the Army assumed management on 8/17/18 and increased production by some 50-75 guns a day depending on working days . The minimum fit parts were the first victims of the increased production . Both of those appear to have been hand fit to zero slop but who knows for sure without a letter it may have been shipped to an arsenal and stored for 40 yr then went to Moe's bait shop and slept in a drawer for another 50 yr . But it may have been used a lot and sent back for an overhaul in 82' also .....

 

[Outpost75]

FWIW all three of my Colt New Service revolvers in .455 Eley, .45 ACP and .45 Colt produced from 1914-1920 all have .455" cylinder throats

My M1917 S&W and 25-5 both had .457! which is why I sold the 25-5 and recylindered the 1917, having John Taylor fit, line-bore and chamber a Model 29 .44 Magnum cylinder to .45 Colt with .4525" throats.

 

[CZ93X62]

I had a late-70s-made S&W Model 25-2 in 45 ACP that had 'generous' throat specs as well--on the order of .455"-.456". A few years ago Glen Dye (AKA Gopher Slayer) and I met with a lady concerning 5 of her late husband's S&W Model 29 examples from the 1970s. We did pin gauging of throats on this bevy of otherwise VERY NICE revolvers. Out of a total of 30 throats, 1 was .432", 2 were .434", and the rest were .433". It should be noted that in SAAMI drawings .433" is the upper limit of "on spec" measurements. Alrighty, then. I guess such generosity was a feature of N-frame S&Ws of that era.

Nicely enough, a S&W Mountain Gun in 44 Magnum of more recent making had .431" throats (and shot wonderfully), and my new PC 625 in 45 ACP throats will admit a minus .0002" pin of .452" and the .453" pin is a no-go.

 

[Catshooter]

I had a Smith 25 with the .456 throats. I found a 454424 mould (not a 452) that dropped 'em at .457. Shot those as cast very well. Didn't like .452 at all.


Cat

 

[358156 hp]

My original S&W 44 "Mountain Revolver" had .434 throats and a .430 bore. This was back in the days that custom moulds, sizers, and the like were not readily obtainable. Tom had pretty much opened Accurate, and I ordered a mould that dropped what I needed. Chris at Latesmith supplied a proper sized Star Die (which I still have), and I started making ammo. Then I found one last issue, my crimping dies all swaged down the front (driving) band of the bullets. I bought every die on the market at the time and couldn't get around the issue and sold the revolver, cautioning the new owner that it doesn't like cast bullets. He was happy with it and jacketed bullets, and I sold off the mould, but nobody wanted the oversized Star die. Now days I could simple lap out the LEE 44 mag collet style crimp die and be done with it.

 

[Charles Graff]

My Colt 1917 runs .455 in the throats.

 

[Gary]

Boy Charles, you certainly have some fantastic handguns.