45LC Blackhawk question.

Help Support Ruger Forum:

tim81499

Bearcat
Joined
Jul 29, 2023
Messages
13
Location
wyoming
Posting from my phone so this could be messed up.

I just need to know what the size difference is between the 45 new and old models. I have a NM 45 convertible and the LC cylinder was missing. I bought one that claimed to be a new model. I had to take about 8/1000 off the front bushing to make it fit. It's extremely smooth and sweet shooting, seems better than the original was. I just need to make sure I have a NM cylinder before I start working the loads.

Thanks
 

contender

Ruger Guru
Joined
Sep 18, 2002
Messages
24,812
Location
Lake Lure NC USA
Welcome to the Forum!

In general,, when it comes to the NM vs the OM cylinders,, the cylinder boss is noticeably different. Not 8/1000.
I'd have to go & measure my NM & my OM to see how much different they are,, but the OM's have a shorter cylinder boss, vs the NM's. Often,, when matching up a spare cylinder,, a few thousands may need to be honed off. And sometimes there needs to be a shim or bushing to make one fit.
 

Johnnu2

Hunter
Joined
Jun 26, 2003
Messages
2,760
Location
NYS
I'm guessing that your question is about the strength of an OM cylinder vs. a NM cylinder (since, as you said that the fit and function is fine on the one you put in the gun currently)..? If so, my humble experience loading for my OM 45Colt cylinder, has been that the OM cylinders were STRONG. All normal loading precautions should be applied for either one.
J.
 

tim81499

Bearcat
Joined
Jul 29, 2023
Messages
13
Location
wyoming
Yes, thats pretty much it. I remember the Speer #9 manual saying something about not loading up the OM like you could the NM but i don't remember why. The book is 400 miles from me right now so I cant look it up at the moment. This is my 3rd Ruger 45LC, all new model and i had a very accurate load that worked well in the last two and yes it was a bit hot. Thanks.
 

contender

Ruger Guru
Joined
Sep 18, 2002
Messages
24,812
Location
Lake Lure NC USA
Kudos on getting things to work out. The OM 45's are a big favorite of mine. And the .45 Colt is just an excellent caliber that can be loaded to all kinds of differing performances.
 

gunzo

Buckeye
Joined
Sep 8, 2010
Messages
1,945
Location
Kentucky
The Speer #9 makes no mention of OM vs. NM strengths or cyl. diameters & actually shows a picture of a 4 5/8" gun they used too compare to a 7 1/2". The 4 5/8" is an OM when working up Ruger only loads. My #9 is first print Oct. '74.


Compare the OD's of the NM ACP cyl & the OM 45C cyl.
 

tim81499

Bearcat
Joined
Jul 29, 2023
Messages
13
Location
wyoming
The Speer #9 makes no mention of OM vs. NM strengths or cyl. diameters & actually shows a picture of a 4 5/8" gun they used too compare to a 7 1/2". The 4 5/8" is an OM when working up Ruger only loads. My #9 is first print Oct. '74.


Compare the OD's of the NM ACP cyl & the OM 45C cyl.
Hmmm, i read it somewhere. I thought it was in the 45 section for Ruget 45 and contender, im probably wrong. But thanks for looking for it.
 

gunzo

Buckeye
Joined
Sep 8, 2010
Messages
1,945
Location
Kentucky
Well Tim. I admit to not scouring the entire book, just both 45 Colt sections & missed it if it said that.

FWIW, My NM Large frame BH 45 Colt cyl. measures 1.730".
 

tim81499

Bearcat
Joined
Jul 29, 2023
Messages
13
Location
wyoming
Well Tim. I admit to not scouring the entire book, just both 45 Colt sections & missed it if it said that.

FWIW, My NM Large frame BH 45 Colt cyl. measures 1.730".
I'm kind of a reloading book collector. The Speer #9 was the first reloading book I bought in around 76. Since then, I've almost managed to collect the full series, even some of the early paperbacks. The #9 in my opinion is hands down the most educational of the bunch as far as bullet history goes. I've read it many times over and over. My first reloader was a lee loader, the 'hit it with a hammer' kind. I did all my 45 LC rounds with that loader way back then. The good old days.

My 45LC cylinder is inches 1.7" even and the 45ACP is 1.703" without my glasses. Bushing to bushing is 1.968" for 45LC and 1.968" for 45ACP. Before fitting the 45LC cylinder it was 1.976 bushing to bushing.
 
Joined
Sep 1, 2003
Messages
7,007
Location
Richmond Texas USA
Welcome to the Forum!

In general,, when it comes to the NM vs the OM cylinders,, the cylinder boss is noticeably different. Not 8/1000.
I'd have to go & measure my NM & my OM to see how much different they are,, but the OM's have a shorter cylinder boss, vs the NM's. Often,, when matching up a spare cylinder,, a few thousands may need to be honed off. And sometimes there needs to be a shim or bushing to make one fit.
Contender,
I may be having a brain fart or CRS, but isn't the main difference between the old and new 45 Colt cylinder. The old is a recessed cyl. and the new one is not which is the same difference as the 44 Mag Supers.
 

Hondo44

Hawkeye
Joined
Apr 3, 2009
Messages
8,013
Location
People's Republik of California
For purposes of reloading the old and new model 45 cylinders are the same strength for Ruger only loads. The exception are 45 cylinders for the new vaqueros and new model flattop Blackhawks because those cylinders are smaller in diameter because those models use the medium size frame. Only use load levels 1 & 2 in those smaller cylinders.
 
Last edited:

Johnnu2

Hunter
Joined
Jun 26, 2003
Messages
2,760
Location
NYS
I won't even begin to tell you how hot I loaded my OM Blackhawk 45Colt MANY MANY years ago when I was stupidly young; but, it was way off the charts. I wouldn't recommend it to anyone now that I'm wiser :))))))

YES, I MISS THOSE DAYS............ and I still have that same gun albeit we are both treated more gently now..!!!

J.
 

gunzo

Buckeye
Joined
Sep 8, 2010
Messages
1,945
Location
Kentucky
I'm kind of a reloading book collector. The Speer #9 was the first reloading book I bought in around 76. Since then, I've almost managed to collect the full series, even some of the early paperbacks. The #9 in my opinion is hands down the most educational of the bunch as far as bullet history goes. I've read it many times over and over. My first reloader was a lee loader, the 'hit it with a hammer' kind. I did all my 45 LC rounds with that loader way back then. The good old days.

My 45LC cylinder is inches 1.7" even and the 45ACP is 1.703" without my glasses. Bushing to bushing is 1.968" for 45LC and 1.968" for 45ACP. Before fitting the 45LC cylinder it was 1.976 bushing to bushing.
Tim, I honestly think you can move on & not be concerned with your cylinder diameter.. Be cautious & enjoy the gun to it's fullest.
 

tim81499

Bearcat
Joined
Jul 29, 2023
Messages
13
Location
wyoming
I won't even begin to tell you how hot I loaded my OM Blackhawk 45Colt MANY MANY years ago when I was stupidly young; but, it was way off the charts. I wouldn't recommend it to anyone now that I'm wiser :))))))

YES, I MISS THOSE DAYS............ and I still have that same gun albeit we are both treated more gently now..!!!

J.
My load was 23.5 grains 296 with a 260 grain Speer bullet and large pistol magnum primer. Speed checked at 1400 fps consistently. I shot thousands of rounds with that load. I think that's the reason I have carpal tunnel now. I doubt I load this one that hot. LOL
 

contender

Ruger Guru
Joined
Sep 18, 2002
Messages
24,812
Location
Lake Lure NC USA
Jim, yes,, that's also a big difference. But to just look at them, especially in pictures & such, it's often the easiest thing to look at the cylinder boss.
I guess I wasn't clear enough in my posting,, and should have included the recessed cylinder part.

I was focusing more on the fitting part,, !
 
Top