Author Topic: Ruger Blackhawk shoots high with cast bullets (Read 1285 times)

Phil Tolson · « **on:** April 29, 2005, 12:55:49 PM »

I have an old model Blackhawk in .30 Carbine and made a few cast bullets that weigh 130gr. I am using small rifle primers and 11.7 gr of 2400. My groups aren't great but I don't think it is too bad, it is shooting one inch at 25yds. The only problem is that the point of impact is about 5in high and the rear sight is turned down all the way. What do I do to fix this? Is there a higher rear sight that I can have put on? Taller ramp?

Lloyd Smale · « **Reply #1 on:** April 29, 2005, 02:15:38 PM »

you have to either shoot a lighter bullet or speed up the heavy one if its not allready to max

frank405 · « **Reply #2 on:** May 03, 2005, 04:08:14 AM »

My 30 carbine new model Blackhawk also shoots high with 120 grain bullets and even 95 grain ones. Of course they cast of wheel weights and loaded in front of 12.5 grains of WC 820 for about 1475. No leading, how do the experts for hard bullets explain that? I need to make anew front site and free spin this little zapper, shot a jackrabbit (bull) lst week with a 311359 HP, pretty good exit hole and a loud noise when it hit at 75 yards. It surely isn't a 45 with a 310 Keith but it is a fun. Can't wait to call in coyote and dump him with the hollow point.

Blackhawk44 · « **Reply #3 on:** May 03, 2005, 03:02:08 PM »

Most problems with high shooting handguns can be traced to the bullet weight, not whether cast or jacketed. The factories regulate the sights for the common weight range of the round chambered, ie; 30 Carbine common factory loads are 90-110gr. Most heavier bullets would be beyond the adjustment range of the sight. A cheap way to make up for this with Ruger sights (since the blade protrudes above the sight body) is to take the rear sight blade out of the sight body and with fine files cut the notch deeper. The range would be a good place to finish this project. Now, with the blade reinserted and the sight at its lowest setting, begin to file off the top of the blade. After a few good strokes, try it on target. You may want to remove the blade again as it nears the sight body. Alternate filing and testing until you get the results needed then touch up with cold blue. The reason I suggest this is that replacement blades are cheap and easy to get in case of screw ups and this operation gives the effect of a taller front sight without the heavy gunsmith bill. Not a cure all, but worth a try.

frank405 · « **Reply #4 on:** May 04, 2005, 04:14:10 AM »

I replaced the factory rear blade with one .030 shorter. yes it helped but still isn't enough. I am waiting for Dustin Linebaugh to get home so we can make a new front sight and free spin this little blaster. I never did like those ramp front sights anyway, the raked post works much better.

frank405 · « **Reply #5 on:** May 06, 2005, 06:26:33 AM »

Got it gone last evening. The front sight measures from the bottom of the barrel to the top of the sight 1.140. Barell diameter is .635 so the front sight is now .505 high. I came up three clicks from the bottom and sighted it in last night at 20 yards. Shot some rocks at 100 to 200 yards, this little cartridge is fun but it sure is noisy!!!

willbird · « **Reply #6 on:** May 17, 2005, 06:59:51 AM »

I have noticed shooting my 30 carbine ruger, and amt 30 carbine, and 7.62x25 cz-52 that the bullets getting there so fast takes some getting used to......with most normal handguns it is pow..........thump

with the fast and flat ones it is pow-thump

Bill

Doctor Sam · « **Reply #7 on:** May 29, 2005, 06:35:39 PM »

This problem is not limited to the .30 caliber carbine in the RBH. My .45 Colt does the same thing, shoots high, even with the 250-255g cast bullets. With the 300g they are nearly off the paper at 25 yards. The RBH doesn't lend itself to changing the front sight. Ruger factory folks are no help either. I have not tried filing down the rear sight but will do so.
Time in the barrell is one of the key factors in this situation. Heavy bullets take longer to leave and therefore shoot higher. I suppose if I wanted to run a 250g at 800 fps everything would be OK. Shouldn't bother the cowboys with their spitwad loads...........
Dr. Sam

Duffy · « **Reply #8 on:** June 05, 2005, 05:36:21 PM »

Hmm, the part # I show for a front sight blade for a .30 is .442" tall.
I know they make shorter rear blades also, it's just tough figuring out which part # to order as they don't give heights for them.

Leftoverdj · « **Reply #9 on:** June 05, 2005, 07:19:56 PM »

Haven't done it to a Blackhawk, but I have made a few sights shoot lower by making them into sourdough sights. Filed a flat on the top and laid a bead of braze on top. Filed it square, and adjusted height as needed. Worked great.

You might try Lee C309-113-F first. It's a bit lighter and you can push it a good bit faster. Be glad to send you a handful as cast for you to GC and lube.

cbrick · « **Reply #10 on:** June 06, 2005, 03:16:01 PM »

The good Doctor is correct. Heavier bullets (or lower velocity of lighter ones) leave the bullet in the bore for a longer time. This is the time that the muzzle is recoiling up. The longer before the bullet leaves the barrel the higher the muzzle when it does exit and the higher the point of impact. Revolvers exaggerate this and single actions are the worse. Must be the reason they call em "plow handles".

cabezaverde · « **Reply #11 on:** June 07, 2005, 04:04:47 AM »

My 45 colt Blackhawk was doing the same. My fix was inadvertent. I put Pachmayer grips on, and that made the difference.

All I can figure out is that the way I hold the gun, it delayed the swiveling action that style grip frame is famous for.

Needless to say, after stumbling onto this, I was a happy man.