Problems with new Blackhawk 4 5/8" Blackhawk.

I took my new gun out to the range today for some bench resting of pet loads that my six inch GP100 and S&W 686 both like. This Blackhawk has a 4 5/8" barrel. The gun is not modified in any way yet. Before I took it shooting, I found that both .357" JHP bullets and .358" lead bullets will stick in the cylinder throats and cannot be pushed out with moderate pressure. So all throats are undersized.
My problems were:
1. Middling accuracy with known good loads. Loads use 158g JHP and 158g LSWC bullets over 10.5g of Blue Dot.
2. The base pin would not stay put. After every shot, I could not cock the hammer for the next shot until I pushed the base pin back in. It seems that under recoil, the base pin is able to push past the retaining latch and move outwards far enough to disable the action. If I try to make this happen by just pulling on the base pin by hand, it will not move far enough to replicate the failure. However, the base pin latch rides in a radiused groove on the base pin, so there is some back and forth slop.

Questions are:
Do you think it would help to to throat the cylinder chambers? I do have the correct reamer to do so.
Do you think my base pin latch needs a stronger spring, or does it sound like a different issue?

I'm reluctant to send the gun back to the factory if I can cure this myself.
Thanks!

Is this the only Blackhawk you own? If no, try the basepin from another BH.

If I owned the reamer, I would probably use it if I was not happy with performance.

Gator89 said:

Is this the only Blackhawk you own? If no, try the basepin from another BH.

If I owned the reamer, I would probably use it if I was not happy with performance.

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I currently own a 7 1/2" Bisley. No issues with it. I did ream the chambers on the Bisley.
UPDATE: while cleaning the gun, I found that I actually WAS able to pull the base pin out by hand without touching the base pin latch. I took the latch assembly apart and re-assembled it. I can no longer pull the base pin out by hand. It appears to me that the latch assembly was not fully tightened together. This problem MAY be solved.

I believe that I will clean up the cylinder, then ream it.

Ream those chamber throats, as that is what is causing poor accuracy. I don't understand why Ruger doesn't size them correctly before leaving the factory but that is what needs to be done to (most?) Ruger revolvers to get them shooting worth a darn.

I reamed all 5 of my .357's 3 Security Sixes, 2 Blackhawks. I used a .358" reamer. All 5 shot better. I like to load a coated cast bullet from Missouri Bullet Co. much improved!

daveg.inkc said:

I reamed all 5 of my .357's 3 Security Sixes, 2 Blackhawks. I used a .358" reamer. All 5 shot better. I like to load a coated cast bullet from Missouri Bullet Co. much improved!

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Yeah. I have also reamed my Bisley and GP100. With the right loads they are my most accurate revolvers. I shoot silhouette competitions with them. I am trying to get away from lead, so I concentrate on jacketed or plated.

Did you measure your throats with pin gauges?
That's the better way to judge tight throats.

contender said:

Did you measure your throats with pin gauges?
That's the better way to judge tight throats.

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No. I don't have pin gauges. But not much material was removed during reaming.

Pin gauges are not an expensive tool I feel is necessary to accompany a reamer set. If you have a ball micrometer,,, it can do the job too,,, but an out of round chamber isn't as easily noticed with a ball mic. A set of pin gauges,, .250 to .500 (get the "minus" type,) is under $100 from many places. If you are going to do more than one or two cylinders,,, well worth the investment.

At least the throats are UNDERSIZED so that we can ream them out. I recall the old S&W model 25-2 .45ACP with their .455"+++ cyl throats (supposed to be .452") back in the day. BUT, Ruger's QC should be improved, although with that the price would no doubt rise! Happy holidays to everyone!

I use a pair of pin gauges and also recommend them. That said, the simple push bullet go/no go seems to work too. Before reaming (.45 Colt), bullet would not pass. After reaming it does pass with finger pressure. Simple check. You just don't know how 'much' undersized or if drops through how much oversize.

After reaming the cylinder yesterday, I took the gun out to the range today and fired on a string of 4 successive targets. Twelve rounds per target. The first target results were pretty bad. Worse than yesterday. I was worried that reaming had actually degraded the gun, the opposite of what I intended. But with each successive target, results improved. For the last target, I first cleaned the barrel with a boresnake to see if fouling buildup was a factor. It shot a bit better after the boresnake than before, which is good news. It is now clearly shooting better than it did yesterday. But the darned base pin still slips out and hangs up the action.
I found a Wolff base pin latch spring that was in my parts box. I have installed it and it seems much stronger than the original. Maybe that will fix the problem. If not, I will ask Ruger to send me replacement base pins and latch parts. Cheaper than sending to to the factory.

Gun shot pretty well today in spite of unfavorable conditions at the range. Six rounds into 1 1/4" at 15.5 yards. Base pin did not back out. Looks like the extra power latch spring did the trick. Still, I'm a bit surprised that I needed it.

Belt Mtn base pin. One of them comes with an Allen screw to keep it in place. Good luck!
gramps

gramps said:

Belt Mtn base pin. One of them comes with an Allen screw to keep it in place. Good luck!
gramps

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Thanks, Gramps!
I contacted Ruger yesterday about the base pin issue. This morning, they sent me an entire new base pin latch assembly at no cost. The customer support rep said that he has heard of this problem a number of times, and that replacing the assembly usually cures it. He thought my problem might be the piece that blocks the base pin.
We will see. But anyhow, the problem is already solved with a stronger spring.
I am now enjoying owning this gun.

One thing not mentioned, is if you haven't shot much Single Action revolvers, they are harder to master and shoot well. The longer hammer fall time has it's affect. Grip hand placement, grip hand strength also... I mention this because I see you have GP-100 and S&W. Give it time! Oh and as far as I've experienced and also read, reaming the throats has never hurt accuracy. May stay the same ... or get better... never worse.

I can vouch for what Rclark says about single actions being harder to shoot. I am a pretty decent shot with a S&W Model 66 or GP100, but a 357 Blackhawk took some getting used to.

As for the base pin issue, my first Single 7 had a burr inside the base pin latch hole on the frame. Might check that. If it is a burr, the extra power spring is just a band aid that may not work forever.

BASE PIN 'JUMPS' UNDER RECOIL:

In every case that I've diagnosed, the base pin is not properly locking due to poor fitting or the latch isn't completely tightened down.
To trouble shoot and diagnose the problem:

When released, the latch should return all the way out to the left with or w/o the pin installed. If it doesn't return as far to the left with the pin installed, that's the dead giveaway that the notch on the cyl pin is not deep enough, or the Super Blackhawk groove (the circular cannelure) is not deep enough, to fully engage the latch. The pin will shoot loose. Some cases take awhile and some shooting before the pin slips.

File the notch deeper or chuck the SBH pins with the groove all the way around, in a power drill and deepen the groove with a small rat tail file.

I don't waste the time or money on a stronger base pin spring or more money and modify the gun with a locking pin, although it's your gun and you should do what you prefer. One can get a mighty sore finger operating the latch with stronger spring, but that's a personal thing.

The cyl pin latch can also be miss-shaped.

A stronger latch spring has solved my problem. It is not difficult to use.
Ruger did send a replacement latch and spring assembly, but it did not help.