.45Colt/.45ACP convertable

[pipehand]

A couple of months ago I purchased a 4-3/4" 45 convertable Blackhawk, and have been shooting it with both cylinders. The ACP cylinder with 200grain swc's prints dead on with the rear sight all the way down(as far as it will go using the screw). 285 grain group buy 45-283's print about 3 inches high at ten yards. The rear sight can be depressed almost 1/16th of an inch beforee it hits the frame, but the screw will not turn in further. I tried the screws from my Bisley 45, and the 357 50th anniversary, but nothing changed. I believe they just didn't tap the screw hole down far enough in the frame for the rear sight to bottom out. Does anyone here know what size tap is appropriate to recut the threads for the elevation screw though the backstrap?

[MT Gianni]

Make sure that it isn't the need of a shorter screw first.

[NHlever]

A couple of months ago I purchased a 4-3/4" 45 convertable Blackhawk, and have been shooting it with both cylinders. The ACP cylinder with 200grain swc's prints dead on with the rear sight all the way down(as far as it will go using the screw). 285 grain group buy 45-283's print about 3 inches high at ten yards. The rear sight can be depressed almost 1/16th of an inch beforee it hits the frame, but the screw will not turn in further. I tried the screws from my Bisley 45, and the 357 50th anniversary, but nothing changed. I believe they just didn't tap the screw hole down far enough in the frame for the rear sight to bottom out. Does anyone here know what size tap is appropriate to recut the threads for the elevation screw though the backstrap?

My new Blackhawk had the same problem unfortunately. The threads were not tapped all the way through, but I had a tap, and finished that job. ( I'm pretty sure it was a 6-48, but I can't be positive) Unfortunately, I found that wasn't the only problem. In my gun (also a convertable) the rear sight screw hole was also tapped quite a bit off center of the groove the sight rides in, and that caused the sight to bind, and there was a little "step" in the left side of the cast slot that the sight would stop on. I sent mine back to Ruger a few weeks ago (maybe 3), but don't have it back yet. Hopefully they will get it fixed up for me.

[Tazman1602]

Make sure that it isn't the need of a shorter screw first.

+1 on that one.

Art

[Tazman1602]

A couple of months ago I purchased a 4-3/4" 45 convertable Blackhawk, and have been shooting it with both cylinders. The ACP cylinder with 200grain swc's prints dead on with the rear sight all the way down(as far as it will go using the screw). 285 grain group buy 45-283's print about 3 inches high at ten yards. The rear sight can be depressed almost 1/16th of an inch beforee it hits the frame, but the screw will not turn in further. I tried the screws from my Bisley 45, and the 357 50th anniversary, but nothing changed. I believe they just didn't tap the screw hole down far enough in the frame for the rear sight to bottom out. Does anyone here know what size tap is appropriate to recut the threads for the elevation screw though the backstrap?

Dude just read this again, can you measure that screw and shoot me a PM? I have a good assortment of screws and if you can give me thread pitch/length I'll mail you a shorter one if I've got it.

Art

[MT Gianni]

Try a washer on top of it first.

[jh45gun]

Ruger has a better idea

[Dale53]

I guess I and my shooting buddy have been lucky with our SS Bisley .45 Colt/.ACP Convertible 5½". Both cylinders shoot VERY well. I have shot mine with .45 ACP target loads and it is well within the range of sight adjustment. I have also shot the .45 Colt with both target loads (5.6 grs of Bullseye with an NOE 454424 250 gr Keith) and a field load of 8.5 grs of Unique behind the same bullet with EXCELLENT results. You DO have to adjust the sights with the different loads but well within the sights range. My friends gun is doing just as well.

I haven't yet shot mine at 100 yards (not had it long enough) but expect it to do decently based on the closer range results. However, that will have to wait until spring.

Right now, it's light loads indoors at fifty feet.

Really nice outfit, tho'.

Dale53

[pipehand]

The shorter screw fix isn't going to work-- that was my first thought too. I shortened it a bit on a coarse sharpening stone when it dawned on me to check the screws from my other two blackhawks. I figured I could order and receive a tap from Brownells much faster than the turnaround to Ruger.

[pipehand]

NHlever's recollection of the tap size as 6-48 was confirmed by Starmetal in a pm last night. I'll be ordering a tap to finish the job Ruger started.

[pipehand]

Turns out I didn't have to buy a tap-- I had one all along amidst a chest of miscellaneous gunsmithing tools I traded for a couple of years ago. I wasn't looking for a tap, just kinda refreshing my memory of what was in the chest. Of course, Had I actually been looking for a tap, I wouldn't have found it!
It only took a minute to finish tapping the hole, and afterwards, the rear sight would fully depress. I just got done testing it- happy happy joy joy- poa=poi!
I'm gonna be carrying this one a whole lot- it is very accurate, portable, and powerful with the 285 grainers and 18.5 grains of 2400. Now it can be accurate in the right place.
Hope ya'll had a Merry Christmas. Gotta go back outside to continue smelting a couple of buckets of wheelweights.

[NHlever]

I'm sure happy that tapping that hole worked out for you! Mine is still at Ruger being tinkered on, but I'm sure it will be fine when it comes back. Mine seems quite accurate too, what little I shot it before sending it back.