When Ruger tightened tolerances of chambers on NMBH 45 Colt?

[Onty]

Would you please have info when Ruger tightened tolerances of chambers on NMBH 45 Colt?

Can that be established by serial number?

I know that some years ago Ruger made NMBH in 45 Colt with quite large chambers. See extract from excellent article "The .45 Colt - Dissolving the Myth, Discovering the Potential by John Linebaugh" https://www.johnlinebaughcustomsixguns.com/writings :

They are an engineering marvel but why they won't tighten up their tolerances and chamber proper size charge holes in the cylinder is beyond me. Ruger .45 Colt chambers are BIG. I have seen and measured hundreds of them and they are .486 to .490 in dia.

(*UPDATE- This article was written 25 years ago and the new Ruger Bisleys and Blackhawks that we measure now in 45 Colt caliber have EXCELLENT minimum dimension chambers “but tight” chamber throats. Read .451, these should be opened up to .453 for best results. Ruger got part of it right. Tight chambers stopped the brass stretch. JL, Jan. 2017)

I am considering one NMBH 45 Colt, 7.5", but hesitate to jump before knowing more. Seller is a gun dealer, and from my experience, they do not bother to answer. Otherwise, I will ask shop to measure chambers.

 

[Jackrabbit1957]

I think in some cases Ruger went too tight. Why not take a .45 bullet with you and remove the cylinder, drop the bullet in a chamber and see if goes through? Quick and simple test.

 

[Ohen Cepel]

On mine, most are not the same. 2 will drop right through, 2 stick about 1/2 way out and 2 will just peek out a bit. I think about getting them honed but haven't bothered.

 

[Onty]

I think in some cases Ruger went too tight. Why not take a .45 bullet with you and remove the cylinder, drop the bullet in a chamber and see if goes through? Quick and simple test.

Unfortunately, revolver is located from me about 12 hours straight driving. I don't worry about tight chamber mouth, like .450" or .451", that could be fixed. I worry that chambers where case sits are too big, like .486" or more. I don't like to have bulged cases, that tremendously reduces case life.

On mine, most are not the same. 2 will drop right through, 2 stick about 1/2 way out and 2 will just peek out a bit. I think about getting them honed but haven't bothered.

This is typical for Ruger, they used a tooling head with 3 reamers, and result were 3 different chambers (2+2+2). I had Bisley 357 Magnum, 7.5", that will make 3 distinguished groups 1" - 1.5", and whole group was 3", if I remembered correctly, it was more than 25 years ago. I sold it very soon, also, just too heavy for a caliber.

 

[SDGlock23]

It's been going on for many years, but that said the last Bisley .45 I had, which was recently bought, shot excellent right out of the box.

 

[mavracer]

I talked to Bob Stoddard whe he had a little gunstore in Medicine Lodge Ks, he used to be Ruger plant manager. According to him they changed the process when they brought out the new Vaquero and the mid frame flat tops and all of those would be reamed sequentially with a single bit. They phased in the process to the other lines shortly after that. I know the 50th anniversary Blackhawk was issued in 2005 IIRC my conversation was about 2008 and to my knowledge all production was using the new method then.
I would say anything newer than 2010 should be safe.
Although you can still run into tight throats but they'll all be the same lol.

 

[.308 Norma]

On mine, most are not the same. 2 will drop right through, 2 stick about 1/2 way out and 2 will just peek out a bit. I think about getting them honed but haven't bothered.

I think that's about what my .45 Colt Blackhawk (mid-90s) was like. I had the chambers reamed. It might have helped if I was a better shot.

 

[Anchorite]

Never. As long as Ruger gang reams their cylinders, they will always be out of spec. I check (and ream to clean up) all my cylinders. I then spec all my cast bullet diameters accordingly.

 

[mavracer]

Never. As long as Ruger gang reams their cylinders,

They haven't gang reamed single action cylinders for over 10 years.

 

[Anchorite]

They haven't gang reamed single action cylinders for over 10 years.

Thanks. I stand corrected.

 

[Onty]

@ mavracer;
"According to him they changed the process when they brought out the new Vaquero and the mid frame flat tops and all of those would be reamed sequentially with a single bit...
I would say anything newer than 2010 should be safe."

Thank you Sir, this is a tremendous help!

Now, is any list of serial numbers range sorted by year of production for NMBH?

 

[Ohen Cepel]

Now, is any list of serial numbers range sorted by year of production for NMBH?

This is a list up to 2015;
Ruger New Model Blackhawk Serial Number History

Or, if you have the # you should be able to look it up here;
Serial Number Lookup (ruger.com)

There is also a list for models prior to the first link I posted.

I have found Ruger to be pretty good on letting one put a date to things.

 

[Onty]

This is a list up to 2015;
Ruger New Model Blackhawk Serial Number History

Or, if you have the # you should be able to look it up here;
Serial Number Lookup (ruger.com)

There is also a list for models prior to the first link I posted.

I have found Ruger to be pretty good on letting one put a date to things.

THANK YOU SIR! This is exactly what I am looking for. With this tabulation and info about new method of production from 2010 mavracer provided, I have all info I need.

Just located two NM Blackhawk revolvers, one 45 Colt serial No. 47-26XXX, another 45 Colt / 45 ACP serial No 46-47XXX. So, from what I could see in tabulation, they were manufactured way before 2010. Considering John Linebaugh's statement " I have seen and measured hundreds of them and they are .486 to .490 in dia." , I am almost certain that these two are with large chambers.

 

[murf]

I bought my 45 cal Blackhawk new in April of 2000. all six chambers were .452" in diameter (till I reamed them all out to .4525"). was accurate before and after the reaming.

murf

p.s. serial no. 48-010XX