[VThillman]

I installed a new front sight (Marbles "gold" bead) on my Taylor & Sons/Chiappa 1892 (.357 Magnum) Wednesday, and took the gun to the range today. The sight picture through the Skinner rear sight is much improved.

Mounted 8" targets at 25 and 50 yards. Shot a couple rounds at 25 yards; holes in target 2-3 inches high, about the same amount left. Drifted both sights for windage, lowered the Skinner peep ½ turn. Fired 3 rounds - good windage, still 2 inches high. Turned the peep down another ½ turn, shifted to the 50 yard target, fired 2 rounds. 2 inches high, 2 inches left. Drifted the front sight a little more, turned the peep down another ½ turn, fired 2 rounds. About an inch high, maybe an inch left. Decided to shot 3 more rounds to get a meaningful group. Nothing on the paper, though the holds seemed decent. Noticed that the barrel had become on the hot side of warm.

Hah!

Next time I bring it, I will shoot 3 rounds cold - make adjustments as necessary - and set the gun aside until the barrel is cold again.

That seems like a pretty dramatic shift of POI; is it?

 

[phideaux]

I have seen drift on my rifles from cold barrel to hot barrel.

But, I cant say that I have seen it drift that much.

I am referencing 100 yrd, and seen as much as 1 1/2 inch left /right /vertical drift .

I usually ,(if Im accuracy shooting) let the rifle sit and cool after a couple 6 round groups. It does affect accuracy .

Bull barrel are more stable and forgiving.



Jim

 

[VThillman]

This gun doesn't have a barrel band, but the front of the fore-end is attached to the barrel. Also, it is a take-down gun with relatively poor contact between the barrel and the action/breech - which means there is poor heat transfer between them. Also, I could have done something stupid, that happens regularly. I do know that the sights didn't move. Next time out with it, all will be revealed.

 

[VThillman]

I shot the 77/357 at the 100 yard range today. 15 rounds in a shorter time than with the Chiappa - and no discernible drift. Actually, the barrel was barely warm when I finished. I'm really wondering if the reduced heat diffusion because of the take-down makes the Chiappa barrel get hotter. Used the new Tasco spotting scope; it worked good.

Used factory (Federal) loads, so I have some cases for comparison with my reloads.