Good heavens, .450 throats in a .45 colt!?!?

[Cornbread]

I bought a Ruger Blackhawk convertible the other day in 45 colt/45 acp and the cylinder throats are .450 on both cylinders. I guess that must be in spec for jacketed bullets? The forcing cone is cut at 18 degrees it looks like, so I took it to my local smith who is thankfully one of the best in the country to have the cylinders reamed out to .4525 and the forcing cone done at an 11 degree angle and nicely polished up afterward. Is this common in convertibles or did I just get a really tight one?

[boatswainsmate]

I recently bought one of these and had the same issue. I had mine reamed out to .4525. I don't know about the forcing cone.

[5Shot]

I have one like yours - Cylinder is hair under 0.452", and the barrel has a definite constriction at the threads. Heading off to a smith shortly. Gonna have the barrel shortened to 4-5/8", flush with the ejector rod housing, while it's there.

I recently bought one of these and had the same issue. I had mine reamed out to .4525. I don't know about the forcing cone.

[MT Gianni]

Yep, you don't even need to read the rest to know the brand. That is the reason several shops have a full time business making correct cylinder diameters .

[Guesser]

My Ruger 45/45 convertible had one throat that slugged .442. In 12 chambers only one was .450 or .451. I reamed all 12 out to .4525.
Worked miracles with accuracy.

[DougGuy]

Late model Rugers are running .4505" ~ .451" and I have pinned out a cpl rollmarked Bisley cylinders @.450" even. This is about typical. You will have to go back to some 70s and 80s production to find larger throats and then when you do, they are .454" and .456" go figure!

If anyone needs help with cylinder throats, send a PM or check out the link in my sig..

[Cornbread]

OK well it sounds like I'm definitely not the only one then. I'd rather have them under than way over because I can get under fixed pretty easily. Way over I'd have more of an issue with. We'll see how it shoots when I get it back. I didn't even bother trying to shoot it first with cylinders that tight I'd just get frustrated and lead the gun. I'd rather get it back nice, and enjoy shooting it the first time vs being frustrated with it the first time out.

[DougGuy]

I'd rather get it back nice, and enjoy shooting it the first time vs being frustrated with it the first time out.

Very true! About the only other thing the Ruger needs besides throats and forcing cone, is taking one leg of the trigger return spring off and letting it hang loose under the grips.

The bottom line is this.. Dry fire the gun at a target or point of reference, and see if you can dry fire it and hold the sights motionless as the hammer falls. If taking one leg of the spring off helps, but doesn't quite let you hold it perfectly still, swap in a Wolff 30oz. trigger return spring, and try it, then try it again with one leg of that Wolff spring hanging off. You should now be able to drop the hammer with zero movement of the sight picture. When you get to that point, live fire will be really good.

I don't do anything to my sear/hammer arrangement in the Ruger revolvers, I find that taking the trigger return spring tension down far enough to dry fire with sights motionless, lets what little creep there is in the trigger act like a dbl set trigger. Mine takes up the creep, then stops, then the next most smallest amount of force you add to the trigger, fires it. You know exactly when the gun is going to fire, it's very consistent and dependable and I wouldn't change that for nothing.

[Tar Heel]

My Ruger Vaquero (original) has cylinder mouths of .450 and a bore of .451 (very bad)
The NMBH has cylinder mouths of .452 and a bore of .4505 (good)
The Cimarron Arms 1873 (Uberti) has .454/.451 diameters and
The Uberti 1873 has .454/.450 diameters.

I can only surmise that Ruger has such small mouths and bores because the vast majority of shooters shoot factory jacketed bullets at .451 inches and the guns are more accurate with those dimensions and factory ammo. We, the black sheep of the shooting community, who use alchemy and sorcery to make our bullets do require different dimensions on our cylinder mouths and bores.

[MtGun44]

Yep, I reamed my BH convertible .45 to .452 for both. There is an old thread
on it in the gunsmithing section. It would probably be very accurate with jbullets
at those dimensions. Mine was .450 and .449 with pin gages.

Bill

[Tar Heel]

I'm going to run the Vaquero up to DougGuy in the morning. That's the worst one and the only one which can actually be corrected without new barrels (or cylinders).

[Silver Jack Hammer]

Didn't even need to open the thread to see what brand of gun you were going to talk about. Colt man here, but as a Colt man I can remind you it's a lot easier to have too tight dimensions and have to open up your cylinder throats than it is to have to buy a new cylinder and have your new cylinder re-cut to proper dimensions and fitted. That's what I've had to do with a Colt. I had a cylinder burst during re-cutting. That's life. But as a Colt man I can say my most accurate .45 Colt is my Blackhawk.

[Tar Heel]

Living only about an hour away from DougGuy, he was gracious enough to allow me to come to his workshop today and bring the Ruger Vaquero in for cylinder mouth reaming. As mentioned before, this revolver, an original Ruger Vaquero, had a bore of .451 and cylinder mouths of .450".

Doug started with opening the mouths to .452 and after polishing with his proprietary polishing tool, the mouths were mirror smooth and plug gauged at .4525” each. Doug does all the reaming by hand by the way so he “can feel the tool work.” All of the requisite shims, pilots, and other needed accoutrements were employed to ensure the mouths were aligned and concentric with the chamber axis.

Doug implored me to also have the forcing cone cut to 11° to accurize the revolver for my cast bullets and I have to admit he didn’t have to bend my arm much to allow him to proceed. I was never a fan of the factory forcing cone on either the Vaquero or the Blackhawk revolvers. Macro photographs I had taken really displayed the tool marks and roughness of the factory forcing cones so any improvement that could be made, was a “no brainer” to me.

Again, all the requisite pilots were installed and the forcing cone was cut by hand. Doug’s attention to detail was exceptional as was his attention to small matters like placing a towel under the cutter to prevent shavings from migrating into other parts of the revolver or lying inside the tool creating “grit” in the cutting surfaces. After cutting and polishing the forcing cone the difference was clearly evident to me. See the attached “before” and “after” pictures.

After seeing the Vaquero, I showed Doug the Blackhawk having cylinder mouths which pin gauged out using .452 gauges rather well. Doug said “watch this” and proceeded to clean the chamber mouths with the .452 reamer. Shavings were present despite the pin gauge use. The Blackhawk now sports .4525 chamber mouths and an 11° forcing cone as well.

I can’t wait to get these guns to the range and see for myself how much of an improvement has been made. If you have been a fence sitter about getting your chamber mouths reamed and made consistent for your cast bullets, do yourself a favor and get your cylinder to Doug for reaming. I was very impressed with his slow demeanor and attention to detail. As an old-school person myself, I’ll vouch for his craftsmanship since I have seen him work.

By the way, this is not a paid public service announcement. I wrote the man a check for his work today and was pleased to do it. I’ll pay for craftsmanship any day. There are scant few of them left.

The highlight of the day was when Doug said to me “Forcing cone? Now you actually have one.”

Attachment 116566 Attachment 116567

Attachment 116568 Attachment 116569

Attachment 116570 Attachment 116571

[SharpsShooter]

Late model Rugers are running .4505" ~ .451" and I have pinned out a cpl rollmarked Bisley cylinders @.450" even. This is about typical. You will have to go back to some 70s and 80s production to find larger throats and then when you do, they are .454" and .456" go figure!

If anyone needs help with cylinder throats, send a PM or check out the link in my sig..

I have one of those. The cylinder throats in my three – screw were . 4525" out to . 455". I have mine reamed to .455". Once that was done, the accuracy was amazing.

SS

[Dan Cash]

Un Godly tight throats and constricted barrels are what give those guns the humped up constipated look.

[DougGuy]

Well Tar Heel LOL thanks for such a glowing review of the afternoon's work! Hadn't expected that..

I am anxious to see how these shoot as well, because now I can FINALLY SAY that I have seen not one but TWO .45 caliber Ruger single action revolvers, with absolutely ZERO thread choke! The threaded area in these revolvers is undetectable from the inside of the bore. The pilot for the forcing cone reamer, and the .442" pilot out of my .45 ACP chamber reamer kit both passed from muzzle to forcing cone in each barrel, with absolutely no change in tightness or tension the entire length of the barrel. Even the rollmarked warning on the sides of these two are faint and not very well impressed on the outside, the results of this are no distortion inside the bore behind the rollmarks. Unbelievable. And the same feller has TWO that are that way!! Rarely see one like this in dozens of Rugers, let alone two. Lucky guy that Tar Heel, very lucky..

These two got exactly what I feel is the best and simplest accurizing for a Ruger. I have said it many times, all that is necessary to bring these SA revolvers into being the best you can make them for the buck, is 1.) Consistent, even, and round cylinder throats, sized at .4525" ~ .4527" but all 6 matching in size, 2.) forcing cone cut to 11° (polishing optional) and 3.) PMTJ, Poor Man's Trigger Job by taking one leg of the trigger return spring off and letting it hang (and/or swapping in a Wolff 30oz. spring). This is dependent on the revolver not having a measurable thread choke.

After that, it's up to the shooter how meticulous they are at the loading bench, and how well they can shoot the gun.

Hopefully you will have two very fine shootin' sixguns, either of which will easily outshoot the both of us!

One gun, the NM Blackhawk, had a cylinder that had been remarked on the front from the factory, you could see how they scratched through one set of numbers and renumbered it a second time. This one had what appeared at first to be .452" throats, but the .452" pin gage would start in the throat but not go the rest of the way into it. The factory had made bellmouths of these cylinder throats somehow, but it did clean up with the .4525" reamer and the hone. And this was sold as a new gun. Hmm.... Fixed now..

Glad to be of assistance to you today sir, and thanks for the work and also the kind words here, it is greatly appreciated!

[Moonie]

my NMBH 45/45 convertible had throats ranging from .450-.451. Now they are all .4525.

[9.3X62AL]

My BisHawk 45 Colt came OEM with 2 throats at .448" and 4 at .449", grooves are .452". After mucho gymnastics, I honed the throats to .453" and now get excellent accuracy with .454" bullets. This is my sole example of the many revolvers I own or have owned that I have taken tools to in this manner. The barrel has no discernable thread choke.

[Tar Heel]

The best group of the day today was with the Blackhawk shooting KTSWC bullets. Note that these bullets are sized to .452 and I am sure that leaving them as cast at .453 and lubing with a 454 sizing die will tighten the group. This is a 24 shot group at 25 yards. It's right at 2.5 inches. Load was a 255 RCBS KTSWC over 5.0gr TiteGroup, set into Starline brass and sparked with a Federal 150 LP primer.

Now I have made brass available to see if the larger bullets will fix this group. This Blackhawk shoots at least 6" high with the rear sight bottomed out. I think Ruger put the wrong sight blade in this gun.

Attachment 116707

[9.3X62AL]

5.0 x Titegroup is a fairly mild, low-velocity load. Get that SWC running in the 900-1000 FPS ballpark, and there is a good chance that hits will strike lower on account of barrel time/recoil arc dispersion dynamics.