Ruger Blackhawk Thread Choke

[Catpop]

I was reading a current thread by Analogkid about which 45 Colt SSA to buy/not buy and someone brought up " the well known problem of the Ruger SA thread choke". I have one with that exact problem.

Is it in fact that well known? I thought it was just my 1973 .357 Blackhawk. But it seems, like diseases, it now has its own disease name.

If it is that big a problem, shouldn't the manufacturer correct it or, at least state the gun is not suitable for use with lead boolits?

And what about current production, do they also still suffer from this disease?

I'm tiring to firelap out with limited success. AND currently working with Ruger to resolve the issue- which isn't productive yet.

Any comments appreciated?

 

[Varminterror]

Been a known problem for a long time. Generations. I first learned about it over 20yrs ago, and it wasn't new news then.

Fire lapping won't really do anything productive, and is more destructive than helpful. Sure, a range rod will run down the bore after, but that doesn't mean you actually did yourself a favor. Hand lapping is the way to go, if you service it yourself.

Best method is to send it back to Ruger. If the owner had not interfered with it, Ruger is good about replacing the barrel at their cost. The most I have ever paid in doing a couple dozen of these with Ruger has been the outbound shipping cost, only because I've occasionally forgotten to call them for an RMA. Never has cost me a dime for the new barrels, and they've always taken care of me.

Mind you, that's a couple dozen revolvers with issues out of a couple hundred revolvers.

It's not unique to Ruger either, they just happen to sell twice as many as any other revolver makers (combined).

 

[Catpop]

Varminterror,
Since you brought it up. I called Ruger and they asked me to send it in. I bought a fedx label from them for $30. Heck, that was $36 dollars cheaper than the $66 when I shipped a Tarus back for service AND they didn't even fix the problem! Another story.
I explained all the leading issues I had with it and what i had tried to do to solve the issue. I was up front and honest! But they said because it had been modified they could not repair it (trigger job, cylinder throats opened up .001 for lead, recrown muzzle- all done by me over last 30 years. I was a gunsmith from 1973 to 2000). They did offer to replace it for $342 and scrap my pistol. That for a 45 year old pistol! I was impressed with tjat offer. Would have to come back through ffl dealer.
I told them to ship it back unfixed and I'll just deal with the leading issue. Gun shoots great and is very accurate, just leads very badly just after forcing cone.
Just bought a new super blackhawk, sure hope it doesn't have same problem!!!!!
Thanks for advice

 

[200Apples]

Gun shoots great and is very accurate, just leads very badly just after forcing cone.

Have you slugged the barrel only to the restriction (frame), and then slugged it again all the way through? in an attempt to measure the bore restriction? Only curious, having not yet slugged any of my bores (but I have the lead to do so. Only need to get the proper dia hardwood dowelling)...

 

[murf]

firelapping takes care of that problem, or you could have the gun taylor throated. either method reduces leading and improves accuracy.

murf

 

[Catpop]

Murf, please explain "Taylor Throated" to me.

 

[DT Guy]

I found this on Grant Cunningham's site.

HTH

 

[murf]

here is more info: http://www.sixgun-forums.com/sixguns/node/132

i haven't found the ross seyfried article, but you can probably do a search.

i have firelapped a few of my blackhawks to get rid of the barrel restriction. i have not had any guns taylor throated.

murf

 

[Catpop]

Murf,
I did a short search and learned Taylor throating is basically increasing freebore. Some indicated it worked well with jacketed, but not with lead. Think of Roy and his Mark V magnums.
On a different note:
It seems it would be easy enough to increase land diameter, but that doesn't do anything for groove depth and this seems to be where the leading collects.
Fire lapping gets both. How did your firelapping efforts work out?
By the way, my pistol has 200k plus down the barrel, so it ought to be broken in by now

 

[Varminterror]

Murf, please explain "Taylor Throated" to me.

It's a terrible gimmick which has somehow gotten a foothold among unwitting few.

 

[Catpop]

Varminterror,
I can see the lead stripping problem using lead in a Taylor throat.
Think I'll stick with firelapping.
Thanks

 

[murf]

i purchased the lapping kit at beartoothbullets.com

if you are serious about this, check out the firelapping article at http://www.gunblast.com/FerminGarza-Firelapping.htm

i've done three of my blackhawks and all have less leading and a bit better accuracy.

luck,

murf

 

[Catpop]

Murf,
sounds like I need a few pin gages and more firelapping! That was a great article, even though I think I read it before I broke my leg. You may have even recommended it to me then. But that time I may have not heeded the need for pin gages. The rest is pretty much what I've been doing.
Thanks again friend!

 

[98Redline]

I used that article as a guide several years ago to firelap my SBH Bisley Hunter. Prior to the lapping, it leaded badly with any lead bullet (regardless of size or hardness). The gun had a definite constriction at the threads and a smaller one under the barrel rollmark. It took 100 firelapping rounds with the Beartooth kit to get the restriction out. What was left was a mirror smooth bore.

Using the same hard cast loads that leaded before firelapping now ran completely clean and produced 2.5" groups at 100 yards (supported off the bench).

 

[murf]

if you don't have pin gauges, you can use the lead sinkers. you will feel when there is no more restriction at the barrel threads as the sinker will push through the same all the way down the barrel.

the only thing i change in the firelapping procedure is to clean the barrel after every shot, when starting out. my reasoning is i don't want to firelap the lead in the barrel left from the firelap bullet. after so many firelapping rounds, the leading will diminish enough to go the five, or ten rounds between cleanings.

luck,

murf

 

[Catpop]

Murf,
I got a set of pin gages on the way from MSC for both my 357 and my 44.
Slugging with a pure lead rod is how I found out I had a thread choke. Once started, it slid smooth until it hit the thread area. Then it slammed on the brakes!
Thanks for advice!

 

[Catpop]

Update:
44 mag 2017 super blackhawk
Pin gages came in but I should have included .427 and .428 also as .429 would not start in the barrel, so no barrel/choke measurements there yet.
Cylinder throats did measure .431 which I think is good. MissourI boolits easily slip through.

357 mag 1973 blackhawk:
Again I should have ordered .355 and
.356 as .357 would not start in barrel.
Cylinder throats measured almost .359. Missouri bullets are a finger slip through fit.

Will give barrel results when other pin gages come in.

Todays 44 range session with 30 rounds of 10@ 8.0, 8.5, 9.0 Universal under missouri 240 kieth yielded plenty of leading in first 1.5" of barrel.

Today's 357 range session with 50 rounds of 4.0 win 231 under 158 missourI 12 bn lswc also yielded plenty of lead in the first 3/4" of barrel.

More later

 

[Salmoneye]

The SAAMI spec for land diameter of .44mag pistol/revolver is .417"...Groove is .429"

Saami spec for .357 Mag is .346" and .355" Groove

You need pins that will fit the lands, not the grooves...

 

[Catpop]

Well choreboy my lead out and clean my barrel, I sure misfigured that one!
I'm confused; no wait maybe I'm not! (seriously, I am embarrassed!)
Thanks Salmoneye!

 

[98Redline]

Catpop, your cylinder throats mimic what I have seen on all of my Ruger 44s.
I consider .431 as a minimum size for cast with .432 being the preference.

The .429 and .430's will lead even my firelapped barrels. They are easier to clean out, but will still lead somewhat with the undersized bullets.

 

[Catpop]

98Redline,
Thanks for advice. I ordered a box of Montano 255gr kieth .431 to try. I've got 25 loaded up with 9.5 unique and will try them tomorrow. Let you know how it goes.

 

[Catpop]

Range test so-so.
Montana 255 kieth .431, 15 bhn, 9.5 unique, 1.700 from rest at 25 yards
Average of 4 five shot groups and 1 three shot group was 2.875.
Leading with .431 seemed reduced and cleaned up much fast than with .430 boolits. But these are true flat based bullets and the .430 MBC are heavily beveled. So that may be a factor also.
I first ran a #9 saturated patch through barrel hoping for no lead! Wasnt my lucky day! As the leading was there.
Then 10 brush strokes with #9 followed by a clean patch. That got about 60% of it.
Then repeated and that got another 20% of it.
I finished up with Chore boy for a 99% clean barrel.
Not the results I was hoping for. I may order some .432 next time.
All for now.