Super Blackhawk Issue

[Bigscot]

I bought a 5.5" Super Blackhawk new a couple of years ago and broke it in with 50 rounds of jacketed bullets. I have since only shot cast in it. I have never been able to get good group with it. I get 2-3 inches at 25 meters with some flyers.

I slugged the bore and found the the bore was tight at the front site, loose in the middle and tight at the rear. A friend of mine measured the cylinder and found two chambers @ .4315, two @ .432 and two @ .432+.

I sent the gun back to Ruger and they replaced the cylinder latch. I did not even know there was a problem with it. Since getting it back I have shot many different loads, styles and sizes in cast and still cannot get tight groups. They are a little tighter though. The other day I happened to look at the target Ruger tested the gun with and it was a ragged hole about an inch + or so at 15 yds. They were shooting Federal American Eagle 240gr. bullets. I have not tried jacketed in it yet but got to thinking that maybe I need to ream the forcing cone to 11 degrees. Has anyone had this problem? Any thoughts or recommendations?

Bigscot

[runfiverun]

i'd remeasure the throats on the cylinder.
big,little, medium, big, little.
that can't be good.
432 ish throats, and then lapping the bbl. maybe getting things closer to 430
is what i would be looking at.
then you could shoot 432 boolits.
just getting things more evened out would make a huge difference.

[Maven]

Big Scot, In keeping with runfiverun's suggestion, you may want to contact this guy: http://www.cylindersmith.com/ Also, check the screw holding the front sight to the bbl. as it may be loose. That happened to my BH and Mark II Gov't. Model. Needless to say, accuracy went south until I discovered and remedied the problem.

[CJR]

Bigscot,

You didn't mention the cast bullet design used or the powder load used or the velocity of the load. Some cast bullet designs are more accurate than others . Likewise, some powders are more accurate than others. Likewise, if the velocity is too low for the cast bullet, the cast bullet may not be stabilized enough for consistent accuracy.

I would recommend you pick an accurate cast bullet design and a accuracy load out of a handloading manual and see what you get before you do any "tweaking" on the gun.

Best regards,

CJR

[seagiant]

Hi,
I will have to say just having gone thru this with my Ruger Blackhawk in .41 mag that everyone has given you very good advice. In my case as my reloads were fine,the biggest thing I did to help accuracy was to open the chamber throats so my boolits were not swaged down on the way to the barrel.

If you really want to learn about cast boolits and improving a pistols performance,I think Veral Smith's book "Jacketed Performance with Cast Boolits" is at the top of the list and he explains in layman's terms WHY this or that works!

[Bigscot]

Thanks for all the suggestions. I have tried the 210 Lee RNFP, 250gn RCBS K, 265 gn Ranch Dog and a few others. I tried sizes from .430 to .432 using powder like 2400, Unique, Bullseye and WC820. The only thing I have not tried since getting the gun back from Ruger is jacketed. If jacketed shoots well, should I ream the throat? I have thought about reaming the cylinder too.

Bigscot

[Old Caster]

Pull one of your lead bullets after loading and see what size they are to make sure they aren't getting swaged down from the brass. If you would somehow have a set of dies that are a bit tight or if your expander is not large enough your bullets might be less than you think before they leave the chamber.-- Bill --

[CJR]

Bigscot,

Load velocities? A suggestion before you start cutting on your piece. Since you have a Keith clone (i.e. RCBS), try some IMR4227. I use 25 gr. IMR4227 behind a 0.430"D Lyman 429421 (~250 gr.) for a chron'ed 1350 fps. Years ago, this was a Lyman accuracy load and then they reduced it some to I believe 23-24 gr. Also for your other powders, find accuracy loads and try them in your piece. If the standard accuracy loads don't perform, then it's time to start thinking about corrections to the piece.

Best regards,

CJR

[pdawg_shooter]

You buy a Ruger you get a learning experience at no extra charge!

[Rattlesnake Charlie]

Might try fire lapping. It will help with the tight cylinder throats as well as the constricted bore where it screws into the frame (common problem with Rugers).

[knifemaker]

Your cylinder throats may not be the real culprit as they are slightly oversize. If they had been undersized, that would cause accuracy problems and possible leading of the barrel. You stated there was a barrel constriction at the breech end, where barrel screws into frame and at the muzzle end under the front sight.
This is common and I would look at lapping the barrel to relieve the constriction and make the groove dia. consistant the intire lengh of the barrel. I would not worry about the cone unless you have severe leading there and that may be a timing problem. Read up on fire lapping and if done right can open those two constricted areas and possibly increase accuracy with cast lead. Since you are using cast lead for reloading, making your own fire lapping boolits is very easy.

[44man]

Hi,
I will have to say just having gone thru this with my Ruger Blackhawk in .41 mag that everyone has given you very good advice. In my case as my reloads were fine,the biggest thing I did to help accuracy was to open the chamber throats so my boolits were not swaged down on the way to the barrel.

If you really want to learn about cast boolits and improving a pistols performance,I think Veral Smith's book "Jacketed Performance with Cast Boolits" is at the top of the list and he explains in layman's terms WHY this or that works!
This is the best idea.
I would lap the two tight throats so a .432" boolit will push through and leave the rest alone. Very easy to do and it is explained in Veral's book.
Very slight tight spots in the barrel will go away but fire lapping is also easy and can relieve the thread area. It sure will not hurt anything. Fire lapping can all be done from the two tight throats only, it will also loosen them.
I don't know the alloy being shot but Ruger seems to like a harder boolit and it must be hard enough to resist sizing in the brass.
What dies are used? Some can never make the .44 accurate, throwing case tension all over the place. I pitched the RCBS dies years ago and will not even consider Lee dies. Going to Hornady makes me loads as good as my BR dies. Yes, I have collar dies for the .44!
Brand new brass will have case tension variations all over the map.
Magnum primers will open groups, not needed with any powder. I use nothing but a Fed 150. CCI 300 is OK.
95% of accuracy problems occur at the loading bench.
The factory hammer spring might have taken a set, they stink. I use Wolff over power 26# springs.
If you shoot enough to warm the gun, stay away from 4227's. Use 296 in the Ruger. Light boolits and light loads thrive with 231 and Unique. Lots of good powders for light loads.
Then comes the question of operator error. Are you letting the gun "roll?" Is torque or recoil in control? Do you let the gun fly all around? Do you use a "high" grip? A revolver is 100% controlled by barrel position at boolit exit. Get tough with the gun and don't let it do what it wants.
I can go on but you get the idea.

[Bigscot]

Looking at the LBT web site, I am leaning toward fire lapping.

Any suggestions or tips?

Bigscot

[44man]

Looking at the LBT web site, I am leaning toward fire lapping.

Any suggestions or tips?

Bigscot
Just follow his instructions. It is real easy. Just a bit messy.

[lbaize3]

http://www.castbullet.com/misc/accrsa.htm

It gives some insight to what others have experienced....