Question about two Ruger Old Model Blackhawk 45 Convertibles

[rhino72]

I'm hoping someone here might know the answer to this. I have a circa 1972 Old Model Blackhawk 45 Colt/ACP, 4 5/8", that my dad bought in 1973. I have both cylinders for it.

Today I bought a c. 1971, 7 1/2" Old Model 45 Convertible at the local pawn shop for $275 - feeling pretty happy about that; however, it only came with the ACP cylinder.

My question is, could I shoot this new gun with my other gun's Colt cylinder, or are they matched to the gun? I don't see any markings on the cylinders indicating they were matched to the gun (or don't know what to look for), and when I put the Colt cyl. in the 'new' gun, it seemed to cycle fine. But, I don't know how to check 'timing,' and don't want to use the "shoot it and see if it blows up or spits lead out the sides" method.

Thanks for any help!

[BwBrown]

Some of the convertibles had serial numbers on the cylinders matching the frame they were mated to. Just for the fun of it, I would try:
First to see if the cylinder will even fit into the frame - there were some variations in the pin boss of the cylinders.
Second, if it fits into the frame with no end play, see how it ticks - indexes and locks each chamber. Are there stiff spots in the rotation...
Third is to determine if when locked, each chamber is actually in line with the barrel. There are gauges for this, but the human eye with good lighting has an amazing ability to center (that's what makes peep sights work) and see out of round, etc.

All this before getting anywhere near a loaded round.

If in doubt at any point, have them checked out by a good pistol-smith. They are only a year apart - there is always a chance they'll interchange.

[rhino72]

Thanks for the info, BwBrown!

The 45 Colt cylinder fits in the new gun, no problem, and 'ticks' just fine. No tight spots or other weirdness. Seems to lock up tight. If anything there's a barely perceptible bit more end play than the ACP cylinder, but actually less end play than the first (4 5/8") gun. I'll see if I can find a bright light and do a visual check of chamber alignment - not sure how to check that precisely.

[pietro]

.

Cylinder timing in any revolver is professionally verified via the use of the proper size "range rod" inserted downbore from the muzzle, with the hammer cocked, to determine if the tight-fitting (to the bore) range rod will enter each/every chamber from the front.

If it does, the cylinder's timed right.

The poor man's version is to peer down the unloaded gun's barrel with a strong light, with the hammer cocked over each chamber - if even a small sliver of chamber mouth is seen (to one side or the other), the chamber and/or cylinder is out of time, and would most likely side spit gas/debris from the cylinder/chamber mouth(s).




.

[rhino72]

Thanks, pietro. I did just that with a bright LED flashlight, and it seems good. I compared it with how it looked with the ACP cylinder and saw no difference. I cycled through all chambers and watched each come in to alignment at fully cocked, and they seem good. May try firing it off a rest with a light load and a string tied to the trigger next :smile:

[MT Gianni]

You can always send it to Ruger for an "original" cylinder. There is so much to love about shooting acp's in the blackhawk. Most are more accurate than the Colt.

[rhino72]

MT Gianni, I agree. I just started shooting Lyman 452460 200 gr. over 4.7 gr. of Green Dot in the 4 5/8" gun (1st ACP load ever, just got the dies the day before yesterday). I shot a 5-shot group during lunch yesterday, off my back deck, and was pleased. 25 yards, braced against the deck rail. They chrono'd at about 825 fps. I think I am an ACP-in-the-Blackhawk convert now.
155921

[ReloaderFred]

Both of my New Model Blackhawk .45 Colt/.45 acp handguns are more accurate with .45 acp than with .45 Colt. And cheaper to shoot, too.......

Hope this helps.

Fred

[Poygan]

My experience is the same as Fred's. 452488 is my boolit of choice.

[Larry Gibson]

Put the 45 Colt cylinder in the revolver. Find a gunsmith or machinist with a set of pin gauges. Use the gauge that is just a slip fit in the bore. Let it slide down and if it goes into the cylinder throats go shooting.

Larry Gibson

[rhino72]

Thanks guys - for now I'll just shoot it with ACP, and probably have it gauged by a machinist if I decide to shoot the Colt cylinder in it. The only reason I would need it, really, is if I decided to take it hunting and needed a little more oomph with a heavier bullet and a 'Ruger only' loading. Other than that, it's just for a fun gun.

[Char-Gar]

Long before range rods and pin gauges were available, cylinder alignment was checked by looking down the barrel with the hammer cocked. Light came through the firing pin hole in the frame and with a little experience, you can see if the cylinder lines up with the barrel. It really isn't all that hard. It helps if the barrel and cylinder charge holes are clean.

[DougGuy]

If there is no excessive end shake, and the barrel cylinder gap is within .004" to .008" and you can look down the bore and see good alignment, you are good to go.

Check your cylinder throats with the boolits you intend to load. For best results with cast, the boolit should enter the cylinder throats with a light drag. If they won't go, then the throats are down sizing your boolits when you fire them. Rugers are notorious for undersized and uneven cylinder throats. It's not a safety issue, but having the throats sized half thousandth over boolit diameter and having them all even will shrink groups quite favorably.

[rhino72]

The alignment does look good when sighting down the barrel, cocked with a bright light. At least as good as the ACP cyl that came with it. I'll try slugging all the chambers three cylinders (or spring for a set of gauges) and see what I come up with. I'll also check endplay with some feeler gauges.

I just shot a 25 yd. 5-shot group off the back porch, and it shoots great (the aforementioned 4.7 gr. Green Dot/452460 boolit). My group was right at an inch for 4 of the shots, but unfortunately I pulled the 2nd shot in the group of 5, and it ended up 5 inches to the right of the other 4. Sorry the pic is rotated 90 deg to the left, and I messed up the boolit holes a bit when I peeled it off the target.

If my cylinder throats are undersized and/or uneven, how do I remedy that? In a former life I worked in machine shops (sort of a jr. machinist/peon) and am fairly handy with tools, though I mostly do woodworking now. Is this a gunsmith-only project, or could I obtain a reamer and do it myself?

Thanks again for all the info and input!

155930

[McLintock]

One thing you might want to keep in mind, those Old Model Ruger 45 Convertibles are both highly collectable and sought after by Ruger collectors. If they letter from the factory as being shipped as convertibles, the 4 5/8's is valued at $955 in collectable condition and the 7 1/2 is valued at $845. So shoot them, but take a little extra care when doing so.
McLintock

[rhino72]

I knew they were prized, but didn't know they booked for that. So sounds like I did ok at $275 for the 7 1/2, even considering the missing Colt cylinder?

I grew up shooting the 4 5/8, as my dad bought it the year after I was born. He traded it off in the 90's to a friend of his, to my dismay. I contacted his friend a few years ago, and he graciously traded it back to me for a Marlin XL7 in 25-06, plus some ammo to go with it. I guess I came out on top on that deal, too!

[DougGuy]

rhino72 I ream a lot of cylinders and also barrels for members on this forum and a couple others and also for those who contact me through the facebook page in my sig. Send me a PM to get started. You send the cylinders and you get them back fairly quickly, with .4525" throats all matched, which is about perfect for .452" boolits. And yes you can still shoot jacketed through them without issue if you want.

The worst thing people do, is try to save money by using a chucking reamer which has no way of maintaining center, OR they think that for the cost of the Brownell's solid nose reamer they can save money by buying one reamer and doing all their cylinders. In thought, this works. In the real world, that solid nose reamer is .003" to .005" smaller than your existing throats, which is totally unacceptable. I think they have a .447" nose and you can imagine how sloppy that would be in a .450" or .451" throat. The reamer just starts cutting wherever it picks up a cut and it will follow that all the way through and about half the time you can turn the cylinder over and see an eyebrow of what used to be the original throat, on one side of the new throat because the reamer cut so far off that it ran out that far. Seen this happen a few times..

If you want your gun to shoot to the best of it's ability, the reamer needs to be fitted with bushings that are in half thousandth increments so you can pick the tightest one and since Ruger is also nortorious for having several different sizes of throats in the same cylinder, I have had a couple that used 3 and 4 different pilot bushings just to maintain a snug fit in the throats. By now, with 5 bushings, you are at approximately 2.5 or 3x what I charge to do one cylinder.

[rhino72]

Sounds great, DougGuy - I'll PM you soon.

[McLintock]

On the 7 1/2" with only the 45 ACP cylinder, if it is a lettered convertible, since the ACP cylinder is the one with the last 3 digits of the serial number on it, any OM 45 Colt cylinder that fits it in both the barrel/cylinder gap and end shake areas will make it whole again. They are occasionally on places like Rugerforum, Ebay and Gunbroker if you watch them closely. Checking for the 3 digits is an easy way to see if it might letter as a convertible. To get those values they have to rate 95% or better condition wise, but even if they don't, they're still worth a good amount. I've got both models with original boxes they came in and about 98% condition, great guns for either the collector or shooter.
McLintock

[contender1]

rhino 72,,, you got a heck of a deal. Yes, those guns are very desirable to many, but as for values listed above,,, one thing to consider is "condition, condition, condition."
I own several factory OM convertibles, and they are valued at $600-$1000. Good solid shooter grades command the $600-$650 range. An OM 45 Colt cylinder may cost you $100-$150,,, but it'd be worth it according to your purchase price. Measure the OAL of the existing ACP cylinder & look for one like that.
Interchangeability of cylinders is usually a non issue to where MANY of us who collect OM Rugers buy spare cylinders all the time,,, knowing they will time right up.

[tigweldit]

Also know that if you send an "old model" back to Ruger, for any reason, they will do the transfer bar safety up grade to it. Even if you tell them not to!

[contender1]

tigweldit is correct. Plus,,, Ruger won't build an OM spare cylinder anymore.

[rfd]

how to the nmbh converts compare to the older models? was thinking hard on getting one in 45c/45acp w/5.5" barrel as i already load for a 1911.

[Dale53]

rfd;
Everyone has their preferences, of course. However, I really like my SS Bisley .45 Colt/.45ACP Convertible. As Doug stated, my Convertible came with undersize cylinder throats. I was trained as a machinist and borrowed a reamer kit made for the task, complete with pilots. After the job, using either cylinder with appropriate loads, the revolver will shoot under an inch at 25 yards off a bench.

These revolvers are a very useful piece in most every way. I did have my pistolsmith do a trigger job and free spin pawl.

Dale53

[rfd]

thanx for the scoop, dale53 - what's the deal with the undersized cylinder throats? why are they sold that way, rather than do 'em right from the get-go?

[Dale53]

There has been a number of theories advanced. I suspect that tool wear is the real answer. At any rate, since the factory, no doubt, uses factory jacketed bullet loads, they would shoot accurately enough to pass. No manufacturer seems to be really interested in how their products work with home cast bullets and reloads.

That said, after i finished reaming my throats to .4525", my combination shoots so well, i am actually GLAD my revolver required a bit of work. I got a "Custom" performing revolver for just a bit more than production revolver. That's exactly what anyone who sends a cylinder to Doug will end up with. That's nothing but good!

FWIW,
Dale53