[Odessa]

I was doing some range work today and ran into a problem with my .41 Mag NM Blackhawk. Twice, upon cocking the hammer back the cylinder did not advance, and twice the cylinder advanced to a position half way between two chambers. In fact the first problem was a "half-advance" and I pulled the trigger (not realizing the problem) resulting in the firing pin hitting the rim of the case. I was able to half advance the cylinder once by noting that upon full cock there is still about 1/8" of travel in the hammer until it stops, the half advance occurred during that last 1/8".

The total number of "misalignments" was four (as described above). The ammo was a accuarcy/pressure test series of 210 Hornady XTP bullets over Hercules 2400 (10 rounds each of 17.0, 17.5, 18.0, 18.5, and 19.0 grains) Rem 2 1/2 primers and new W-W brass. (Chrony'ed from 1154 avg fps for the 17.0 grain load to 1253 avg fps for the 19.0 grain load). I am well with-in two different load manuals (Lyman 47 and Hornady 5) all cases extracted easily and primers stayed rounded. No high pressure signs evident, recoil was stout for the last load, but certainly less than a full-throttle 45 Colt in a Blackhawk - I do not believe too high a load was the problem. However, I could not duplicate the problem using some 1000 fps W-W factory loads. Incidently the problems occurred in the 17.5 and 18.0 grain loads.

What do you Ruger revolver fans think? I am going to Ft. Irwin CA for the weekend (leaving Thursday night, back on Sunday night). I will check on what you think on Sunday evening.

Thanks,
Odessa

 

[MikeG]

Did the base pin jump forward? It has to be all the way back or the transfer bar can hang up.

Take the cylinder out and make sure that the hand is not broken. That will also tell you if the base pin is gummed up and causing the problem.

 

[Old Jim]

My .44 SRH did the same but didn't allow me to fire on a short advance. I took it apart and cleaned the trigger assembly (has all the esential parts for cylinder advance enclosed) and cured the problem. I blamed the gunk on a heavy diet of Unique. 2400 is not the cleanest burning powder so you may have a similar problem.
My 2¢

 

[Tio]

My guess is that you have a revolver with hand/ timing problems, that only show up under certain conditions. It may only show up when the gun is dirty. And, if you counld not duplicate the problem with another load, maybe your problem load had high primers, bent or thick rims, or something else that made the cartridges drag against the recoil shield while going into battery. If you still have some of the problem cartridges unfired, examine them. If the fired ones had high primers, they won't after being seated by the firing pin.

Hope it helps

Darrel

 

[Odessa]

Thanks for the idea's. The cylinder pin stayed in place the entire time, never shot loose. I am taking the Blackhawk by the gunsmiths today and will carry a copy of this thread with me to show him. Thanks again, Odessa