Reaming 45 Colt NV cylinders

[nonpcnrarn]

I didn't want to hijack another topic so I will ask it here. As a matter of course I automatically send Blackhawk or Vaquero cylinders to be reamed to a uniform 0.4525 inches. I have 2 NVs in 45 Colt. I had heard that the cylinder throats of the NVs in 45 Colt were more uniform. Has anyone found this to be true? I don't have the ability to accurately measure the cylinder throats of the NVs and don't want to send them in if it isn't necessary. They will probably be used for CAS shooting where hitting a 16" x 16" target at close range is the accuracy requirement. I have the larger framed guns for trail/hunting use. Has anyone found the cylinder throats of the 45 Colt NVs to be way off in size or out of round?

[paul105]

I had two .45 New Vaqueros -- on one, all the cyl throats were undersized and CAS reamed them to .4525. Two or three of the throats were undersized and oblong or eggshaped on the other one.

You can use bullets to check for undersized throats -- If a jacketed .452 will pass thru the throats, they probably are OK and don't need to be reamed.

FWIW,

Paul

[44special]

If I were you, I'd take a sample of the bullet you plan to shoot in the guns, and try passing it through the throats. If they pass through snugly, then don't worry about the numbers.

[Frank V]

Nov 15, 2009 16:16:32 GMT -5 44special said:

If I were you, I'd take a sample of the bullet you plan to shoot in the guns, and try passing it through the throats. If they pass through snugly, then don't worry about the numbers.

This is a quick check that I use too!
Frank

[Aggie01]

My New Vaquero shoots like a house afire with kooz cast 255's and herco or unique. No throat work done.

[dale53]

I don't have a New Vaquero but DO have a new Bisley SS BlackHawk .45 Colt/.45 ACP Convertible. Both cylinders needed reamed. Further, two friends also each got a new one just like mine and THEIRS required reaming also. All six cylinders were undersize. I reamed them a uniform .4525".

With that evidence, I would suspect STRONGLY that your New Vaqueros are probably undersize, also. Just do the "bullet check" to satisfy yourself before sending it in.

Dale53

[wickerbill]

Haven't got a NV yet, but last year I came to the conclusion that with the number of 45 cal blackhawks I had, it was more cost effective to just buy a reamer. I did and I have been very happy with my decision ever sense. I have also done several cylinders for guys in my gun club. I did theirs for free, because I figured that I had saved money by buying the reamer instead of sending off all my cylinders.
Bill

[joej]

I’m just curious as to why a lot of folks ream to 4525, as opposed to 4520, when using 452 sized cast bullets. I think BFR 454 Casull and 45 Colt have bore diameters of 451 and cylinder throats measuring 4520.

[nonpcnrarn]

Nov 16, 2009 10:27:59 GMT -5 joej said:

I’m just curious as to why a lot of folks ream to 4525, as opposed to 4520, when using 452 sized cast bullets. I think BFR 454 Casull and 45 Colt have bore diameters of 451 and cylinder throats measuring 4520.

I believe it is to let the bullet bump up to obturate the barrel. You don't want the bullet to be undersized starting down the bore because it was swaged down by the cylinder throat. It is better to have a lead bullet that is slightly oversized vs slightly undersized. If it is undersized then you get powder gasses escaping around the bullet, melting it and depositing lead on the bore.

[joej]

Understood, just didn't know why 4525 was better than 4520 with a 451 bore.

[wickerbill]

Nov 16, 2009 10:27:59 GMT -5 joej said:

I’m just curious as to why a lot of folks ream to 4525, as opposed to 4520, when using 452 sized cast bullets. I think BFR 454 Casull and 45 Colt have bore diameters of 451 and cylinder throats measuring 4520.

We are talking about Rugers in this question. Ruger 45 cal cylinders are notorious for being bored under sized. The goal of a lot of cast bullet shooters is to put a 0.001" bigger than bore size bullet down the barrel. The reason for reaming the cylinder throats to .4525 is to make sure we don't squeeze the bullet down more than needed. Hope this helps.
Bill

[J Miller]

Nov 16, 2009 10:27:59 GMT -5 joej said:

I’m just curious as to why a lot of folks ream to 4525, as opposed to 4520, when using 452 sized cast bullets. I think BFR 454 Casull and 45 Colt have bore diameters of 451 and cylinder throats measuring 4520.

joej,

From what I've read, and been told, the .4525" throats have proven to be optimum for .452" lead bullets. The .452" throats is supposed to optimum for .451" to .452" jacketed bullets.

With my OM BH which has .4525" throats, I can't tell the difference. Lead and jacketed perform equally well in it.

Joe

[joej]

Thanks, I wasn't aware that the 4525 throats worked better for 452 cast bullets. I thought 4520 was more than sufficient for a 451 bore. I have a Smith with 4515 throats and it shoots cast bullets pretty good. It can't shoot as well as my BFR, so I was toying with the idea of reaming to 4520 but now if I decide to ream, I'll go to 4525 and see if there's an improvement with cast bullets.

[dale53]

I have sized my .45 caliber bullets to .452" for many, many years. The .4525" dimension allows .0005" clearance to use long bullets without cylinder throat interference. My .45 Colt Convertible would not allow me to even seat my .45 ACP reloads in the ACP cylinder before they were reamed (I use mostly SWC's seated with a small portion of the bullet extending from the mouth of the case). When the cylinder throats are the correct size (.4525") then that portion of the bullet extends into the throat properly aligning the bullet with the throat. If you try to put a .452" bullet in a .452" cylinder throat you can get an interference fit - that's too much of a good thing.(:>().

That's one reason - the other reason is that my Dave Manson reamer comes in at the size of .4525"...

FWIW
Dale53

[carl]

Nov 17, 2009 1:00:19 GMT -5 dale53 said:

That's one reason - the other reason is that my Dave Manson reamer comes in at the size of .4525

FWIW
Dale53

You took the words right out of my "keyboard"!

Carl