Jumping crosshairs

[kevin c]

I have a 6" Performance Center 629 with the original, unmodified action, mounting a 2X Leupold. Carefully dryfiring in single action, I see the crosshairs jump off my 25 yd aiming point as (after?) the hammer falls. The gun will shoot 0.8" six shot groups, though, even in my unskilled hands.

Is what I am seeing normal for this degree of magnification? Is it my poor technique that makes the gun move (the groups don't show any consistent tracking/stringing though)?. Or would an action job with new internals or new springs get me some more accuracy?

TIA from a novice scoped revolver shooter.

[Bubber]

Kevin,

I have waited a while to reply to your post. Mostly because I rarely shoot single action. I tried dryfiring single action and while I don't have magnification I could not see any jumping of sights. I use a Red dot scope. Does your sight lift, drop or move right or left. And does this only happen when dry firing? It may be caused by pulling beyond the point that the hammer releases from the sear and this pressure on the frame causes the revo to move in your hand. And if you can hold a .8 inch group at 25 yards that is temendous. Even if it be sandgagged rest. Scopes and dots just let you see better. And any movement is more noticeable with a scope/dot. Try putting a trigger stop and see if there is any difference. You can make a cheap one with the eracer from a pencil glued to the back of the trigger. Hope this is helpful. rdd

[kevin c]

Thanks for your comments, Bubber.

The X-hairs jump to the right pretty consistently. I can't see what happens to the X-hairs in live fire (there's a bit too much going on). I do have small hands, and not a whole lot of hand strength (double action is a bear for me). I will try a stop, as you suggested, perhaps an action job anyway, to get me a DA I can work with, and to put in a permanent stop if I find it helps.

Thanks again.

Kevin C.

Sorry, that should read, "jump to the left".

Kevin

Edited May 15, 2004 by kevin c

[slughammer]

OK, Now that Bubber has spoken I'll throw in my 2 cents.

I've seen hammer force move the whole gun. I was working up loads for my brother's 14" Contender in 223. The scope is a 2 ½ - 7x Simmons. I was shooting at 100yards and I did more fiddling with bag placment and dryfiring than actual shooting. Eventually I was able to refine bag placement enough to minimize this movement.

What is the scope for? Ammo testing, fun or hunting?

[shred]

Is the scope on tight? I've seen a small dot jump with single-sided mounts for red-dots.. I think it's the vibration from the hammer fall shaking the mount just a bit.

[kevin c]

"I've seen hammer force move the whole gun."

That's what I want to know: is seeing the mvt. normal or not for just a fixed 2X scope aimed at a 3/4" dot at 25 yards?

"What is the scope for? Ammo testing, fun or hunting?"

Just for fun. I won it in a match (lottery, not shooting skill, to be honest) and it came with a sub 3" bbl. When I had it rebarreled to make it shootable, I mounted the scope for kicks. Also I'd always heard that the 44 could be very accurate, and I wanted to see for myself. I figured it would be more saleable this way too (but I like it too much to sell it now, even though my hand complains to me after every few cylinders full).

A buddy of mine says I ought to go pig hunting with it.

[kevin c]

Is the scope on tight? I've seen a small dot jump with single-sided mounts for red-dots.. I think it's the vibration from the hammer fall shaking the mount just a bit.

Weigand rings on a Weigand mount. It seems pretty solid to me, but what do I know. How do you tell if the mount/scope is loose? Would the hits start walking? Or would the group just open up?

[Ray Chonlatid]

Hi Kevin,

0.8" six shot from 25 yd, with 3"bbl. Could you share your loading data ? Thank you.

[shred]

Is the scope on tight?  I've seen a small dot jump with single-sided mounts for red-dots.. I think it's the vibration from the hammer fall shaking the mount just a bit.

Weigand rings on a Weigand mount. It seems pretty solid to me, but what do I know. How do you tell if the mount/scope is loose? Would the hits start walking? Or would the group just open up?

To see if a scope is loose, push on it in most possible directions. You can push firmly and see if anything moves. Much trouble zeroing is another symptom.

I was thinking more of "not extremely beefily mounted" scope mounts where some vibration might shake the mounts a bit. You've got a hammer rotating and smacking into the frame with some poundage of spring driving it, so that alone may be moving it a bit.

[kevin c]

To see if a scope is loose, push on it in most possible directions.  You can push firmly and see if anything moves.

  You've got a hammer rotating and smacking into the frame with some poundage of spring driving it, so that alone may be moving it a bit.

Will I see this or feel it?

I don't think that I could see the movement of the scope off the point of aim unless the gun was clamped in a vise.

The zero holds pretty well. At least it did until I let the gun recoil too freely and let the scope whack me in the forehead. After my vision cleared, I rezeroed and it still held the zero well.

***

Would a lighter hammer spring (please forgive any ignorance of proper revolver terminology) make the vibration go away? Or does it matter if it mostly happens after the hammer falls and the round is most likely out of the barrel?.

[kevin c]

Hi Kevin,

0.8" six shot from 25 yd, with 3"bbl. Could you share your loading data ? Thank you.

Sorry, the groups were shot off a rest after the rebarreling to 6". Anyway, if it did shoot that well out a 3" bbl, wouldn't that still be more the gun than the load?

The load is the classic 23.4 gr H110, R-P brass, Federal Magnum Large Pistol primer, using the 240 gr. Sierra Sportsmaster jacketed hollow cavity, COL 1.600, with a generous crimp. The brass was multifired but segregated from the same lot, and the bullets were from a lot of 500 that were sorted to the nearest 0.1 grain.

[slughammer]

That's what I want to know: is seeing the mvt. normal or not for just a fixed 2X scope aimed at a 3/4" dot at 25 yards?

Just for fun.  Also I'd always heard that the 44 could be very accurate, and I wanted to see for myself.

The amount of movement you see will be dependent on how you have the gun supported and how much force there is in the hammer fall. You can move around the bags and practice dry firing till you reduce this. The bullet is not out of the barrel instantaneously and the hammer fall will affect the results. I'm not a believer in having the grip rest on the bench. For something the size of a 6" 629 I prefer to wrap my top sand bag with leather (the blast from the cylinder gap will tear cloth). I locate the top bag near the junction of the barrel and frame going forward from that point. Dry fire til your ready for ammo. (If I were supporting the barrel with a mechanical rest and the grip with the bench, I would expect to see movement to one side. I never liked the results, so I don't work like that no more.)

An action job would be an improvement, I recommend one that will fire any type of primers; 10-12lbs double action.

Yes, 44 mag can be very accurate. I take it the range you shoot at does not have 50 or 100 yard facilities? You are achieving very good results, no doubt you could strech that .8" out to 50 yards.

[kevin c]

An action job would be an improvement, I recommend one that will fire any type of primers; 10-12lbs double action.

Yes, 44 mag can be very accurate... no doubt you could strech that .8" out to 50 yards.

Thanks again to you all for all your comments.

Slughammer, I think that perhaps I will get an action job done.

As far as sub one inch groups at 50 yards, I can only look forward to gaining that level of skill. I'm sure, though, that I'll have fun trying.

[Ray Chonlatid]

Hi Kevin,

0.8" six shot from 25 yd, with 3"bbl.  Could you share your loading data ?  Thank you.

Sorry, the groups were shot off a rest after the rebarreling to 6". Anyway, if it did shoot that well out a 3" bbl, wouldn't that still be more the gun than the load?

The load is the classic 23.4 gr H110, R-P brass, Federal Magnum Large Pistol primer, using the 240 gr. Sierra Sportsmaster jacketed hollow cavity, COL 1.600, with a generous crimp. The brass was multifired but segregated from the same lot, and the bullets were from a lot of 500 that were sorted to the nearest 0.1 grain.

Thank you Kevin !

[kevin c]

You're welcome, Ray. Be advised, though, that the load, given to me by a friend, is considered hot. Use at your own risk, etc.

FWIW, out of this gun that load chrono's ~1300 fps, with an ES ~50, SD ~20, and AD ~17. It may not be a bear hunting load, but it shoots accurately for me, and keeps me honest.

Kevin C.