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Blackhawk lock-up

This is a discussion on Blackhawk lock-up within the Ruger Single Action forums, part of the Pistol & Revolver Forum category; How much wiggle when the hammer is cocked on a Ruger NM Blackhawk is considered too much? I've got 4 Blackhawks, a 1970's (first 2 ...


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Old March 4th, 2020, 03:49 PM   #1
 
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Blackhawk lock-up

How much wiggle when the hammer is cocked on a Ruger NM Blackhawk is considered too much? I've got 4 Blackhawks, a 1970's (first 2 years of the New Model), a 2000's model, and two 1980's models. The 3 newest ones have barely any wiggle to them when the hammer is cocked at all. The oldest one has noticeably more wiggle (about 2 standard pieces of paper thickness) but there is no evidence of leading or any issues of non-alignment when firing. Anything to worry about?



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Old March 4th, 2020, 05:34 PM   #2
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Montana09, First and foremost, Blackhawks are NOT precision firearms, in fact there is some intentional cylinder slack designed in that actually helps the gun to be more accurate. Here's the concept: The rear of the barrel has a forcing cone that literally funnels bullets into the bore. As a bullet exits the cylinder and starts into the forcing cone, it forces the cylinder to move vertically and/or horizontally until the cylinder throat lines up with the bore (thus the name "forcing cone"). This is called "cylinder-to-bore alignment" or C-T-B. Some revolvers such as a S&W DA are way more precision and have a "bank vault" lockup. If C-T-B alignment was perfect, you wouldn't need a forcing cone but as I'm sure you know, Rugers are far from perfect.

So what all this rhetoric means is …. it's perfectly normal to have some cylinder side play and even a few thousandths vertical play in a Blackhawk. If a gun is shipped with a slight C-T-B misalignment, it will loosen up after a box or so of ammo has been fired and will "shoot loose" a little, allowing the cylinder to align when fired. That's why some guns have more and some guns have less cylinder side play …. all depending on how they left the factory.

Revolvers should be tested in the same condition as when the gun fires. For Blackhawks, it means the hammer should be fully forward, not cocked. Chances are it won't make much difference because there's only one thing that secures the cylinder and that is the cylinder latch. If you remove your cylinder and grab your cylinder latch (located in the frame, directly above the trigger), there will be a little side play between the latch and the window in the frame. This is where cylinder side play comes from. Here' a photo that shows how you can reduce cylinder side play, however it assumes the gun's cylinder-to-bore alignment is good.



This picture shows a Blackhawk "belly up" with the grip frame removed. Note the pivot pin for the trigger and you will see an added shim washer between the trigger and cylinder latch. Most Blackhawks can use a shim about .010" thick but not more than .020" thick. By adding the shim washer, it will reduce cylinder latch side play and tighten up the cylinder. This also affects cocking the hammer because if the shim washer is too thick, the cylinder can't move far enough to allow the hammer to fully cock. I've done this modification on many Blackhawks, however some were pretty tight from the factory so the shim washer just wouldn't work.

Last is vertical cylinder play. It's harder to feel because it is seldom more than .002". You can get an idea by removing the cylinder then inserting the base pin. If you can feel any slack between the base pin and cylinder, you have vertical cylinder play. Again, this is actually part of Ruger's design. Belt Mountain makes base pins that are slightly oversized. They pretty much remove vertical play so it's a crap shoot …. does a Belt Mountain base pin improve accuracy (better C-T-B alignment), or does it make accuracy worse because there is not enough vertical play to correct C-T-B alignment? I very seldom try to correct vertical cylinder play because the gun will probably shoot better with the factory base pin.
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Old March 5th, 2020, 07:10 AM   #3
 
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Originally Posted by Iowegan View Post
Montana09, First and foremost, Blackhawks are NOT precision firearms, in fact there is some intentional cylinder slack designed in that actually helps the gun to be more accurate. Here's the concept: The rear of the barrel has a forcing cone that literally funnels bullets into the bore. As a bullet exits the cylinder and starts into the forcing cone, it forces the cylinder to move vertically and/or horizontally until the cylinder throat lines up with the bore (thus the name "forcing cone"). This is called "cylinder-to-bore alignment" or C-T-B. Some revolvers such as a S&W DA are way more precision and have a "bank vault" lockup. If C-T-B alignment was perfect, you wouldn't need a forcing cone but as I'm sure you know, Rugers are far from perfect.

So what all this rhetoric means is …. it's perfectly normal to have some cylinder side play and even a few thousandths vertical play in a Blackhawk. If a gun is shipped with a slight C-T-B misalignment, it will loosen up after a box or so of ammo has been fired and will "shoot loose" a little, allowing the cylinder to align when fired. That's why some guns have more and some guns have less cylinder side play …. all depending on how they left the factory.

Revolvers should be tested in the same condition as when the gun fires. For Blackhawks, it means the hammer should be fully forward, not cocked. Chances are it won't make much difference because there's only one thing that secures the cylinder and that is the cylinder latch. If you remove your cylinder and grab your cylinder latch (located in the frame, directly above the trigger), there will be a little side play between the latch and the window in the frame. This is where cylinder side play comes from. Here' a photo that shows how you can reduce cylinder side play, however it assumes the gun's cylinder-to-bore alignment is good.



This picture shows a Blackhawk "belly up" with the grip frame removed. Note the pivot pin for the trigger and you will see an added shim washer between the trigger and cylinder latch. Most Blackhawks can use a shim about .010" thick but not more than .020" thick. By adding the shim washer, it will reduce cylinder latch side play and tighten up the cylinder. This also affects cocking the hammer because if the shim washer is too thick, the cylinder can't move far enough to allow the hammer to fully cock. I've done this modification on many Blackhawks, however some were pretty tight from the factory so the shim washer just wouldn't work.

Last is vertical cylinder play. It's harder to feel because it is seldom more than .002". You can get an idea by removing the cylinder then inserting the base pin. If you can feel any slack between the base pin and cylinder, you have vertical cylinder play. Again, this is actually part of Ruger's design. Belt Mountain makes base pins that are slightly oversized. They pretty much remove vertical play so it's a crap shoot …. does a Belt Mountain base pin improve accuracy (better C-T-B alignment), or does it make accuracy worse because there is not enough vertical play to correct C-T-B alignment? I very seldom try to correct vertical cylinder play because the gun will probably shoot better with the factory base pin.
Great info for us not near as familiar as you are with SA revolvers. Although I’ve owned them all my life I never got into the inner workings. Thanks for your knowledge and your willingness to share it.
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Old March 5th, 2020, 07:50 AM   #4
 
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Iowegan, thanks for this reply! I was just about to post something about this exact topic. I just bought a new Blackhawk 357 and the first thing I noticed was the cylinder play. Now coming from a Smith and Wesson 686+ (my EDC), you get spoiled because everything is top notch (IMO) and cylinder lockup and play is just like you said - like a bank vault.

So I ended up buying a Belt mountain base pin thinking I could tighten up the play a little. The base pin fit my cylinder fine, and the frame fine, but when I put everything together last night, it was an absolute pain to align the base pin w/ the cylinder. And when I did, I literally could not pull the base pin back out to remove the cylinder. I was like, screw this, I'm putting my stock base pin back in that functioned just fine.

And given that, last week at the range I was shooting the 10 ring consistently from 10+ yards. So I thought to myself last night that I could probably live w/ a little play in the cylinder especially if it wasn't impacting accuracy.

But awesome to know that the play is actually intentionally engineered into the construction of the Blackhawk. I'll be honest, I wasn't impressed by the fit and finish of the gun, but putting in a lighter trigger spring, dremeling down some obvious burs (poor QC to say the least), changing up the rear sight, and adding some new grips, - got it shooting one ragged hole at 10'ish yards. I'm a happy camper for now.
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Old March 5th, 2020, 10:57 AM   #5
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SAAComanche, Ruger SA's design reinforce a couple old sayings …. "The proof is in the pudding", "more is not always better" and "you can't tell a book by its cover" …. probably even more sayings apply. When you compare a Ruger Blackhawk to a S&W DA revolver (at least the older Smiths), you will note many differences …. some you can see, some you can feel, and some that may not trigger your senses …. like opinions.

Many people tend to "transfer technology", meaning they think just because one brand has virtually no cylinder side play, a tight B/C gap, virtually no endshake, or a light SA trigger pull that all other revolvers should have the same attributes. Fact is, Ruger's design is pretty darn accurate, even though the cylinder does the floppy chicken, B/C gaps are usually looser, endshake isn't as tight, and trigger pulls are harsher. One thing to note …. after thousands of rounds fired, the Blackhawk will be just as accurate (maybe more so) as when new, whereas S&Ws tend to degrade.

Last edited by Iowegan; March 5th, 2020 at 10:59 AM.
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Old March 5th, 2020, 01:52 PM   #6
 
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Absolutely. I didn't want to give up on this gun. I love single sixes, I love 357 Magnum, and I really like the heft of a Blackhawk. Made some tweaks and so far so good. Taking it out coyote hunting this weekend. See if I can't take a dog down at 20 yards with it!
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Old March 5th, 2020, 02:56 PM   #7
 
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Quote:
Originally Posted by SAAComanche View Post
Absolutely. I didn't want to give up on this gun. I love single sixes, I love 357 Magnum, and I really like the heft of a Blackhawk. Made some tweaks and so far so good. Taking it out coyote hunting this weekend. See if I can't take a dog down at 20 yards with it!
The blackhawk 357 is the best overall revolver in 357/38 I have used personally and will probably last beyond my lifetime. I had a Smith & Wesson loosen & wear in some areas at less than 5k rounds, did like the Smith gun and some features (mainly the short hammer pull design and trigger feel) as well as some of its looks. Smith just did NOT stand up to heavy use and I don't abuse them. Both are accurate but Ruger action easily smoothed if needed.
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Old March 5th, 2020, 04:45 PM   #8
 
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SAA Comanche which Belt Mountain Base pin version was it? I love their #5 style pin for convertible Rugers. I have it on my 45LC/45 ACP NM Blackhawk, my first 357/9mm NM Blackhaw, and my .22LR/22Mag Single Six. If you want I may be interested in taking it off your hands.

Thanks for the info Iowegan, I've taken them apart numerous times and fitted SBH hammers to all my NM Blackhawks, just never thought about adding a shim down there.
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Old March 5th, 2020, 06:55 PM   #9
 
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Hi Montana, it's their standard version with the lock screw. At this point, if the accuracy is not affected by the slight cylinder play, I'm not sure what the actual purpose of the oversized base pin is.
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Old March 5th, 2020, 07:39 PM   #10
 
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Ahhh I've not messed with that version. I like their #5 style because of it's shape; the hourglass shape it has makes it easier to slide in and out to swap cylinders between calibers. Also, aesthetically I like the looks of it personally.
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