Anyone know why??

[Peacemaker]

Went to the range yesterday. Took my old model Blackhawk convertible, .357/9mm. Fired 6 rounds, all re-loads, 3 .357 and 3 .38 spec. The three rounds directly below the red bull are the .357's. The three to the left of the red bull are the 3 .38s. Exact same sight picture, dead on hold, exact same gun, all rounds fired within 60 seconds of each other. If the groups weren't so consistent I might say I pulled three shots, but hey, a little coincidental for that, huh? Explanation????

 

[Jimbo357mag]

There will be a difference in POI between two different loads usually. It also looks like you have some horizontal stringing going on there. You hold vertical well but the gun goes a little side to side when you are sighting. :shock:

 

[WIL TERRY]

NEVER EVER EXPECT TWO DIFFERENT LOADS to shoot to the same POI. not to even mention two different cartridges. As noted also you have a severe windage [back'n'forth ] problem which can be caused by numerous things. Solve this and the other may disappear. AND then again maybe not; never know without impirical testing. I surely do love those wonderful sixguns that put everything together in nice round groups.

 

[Iron Mike Golf]

Concur with what Wil said.

To add: grip/position will also drastically affect POI. Rested, two hand, one hand, etc.

 

[Chuckbuster]

Looks to me like you changed your grip, especially "how much" finger you had on the trigger. I think the "rule of thumb" (no pun intended) is pushing the group left for a right hand shooter indicates too much finger extended on the trigger, actually pulling trigger with first joint of finger rather than the tip.

Just trying to remember what I learned some where....

 

[Jim Puke]

As noted also you have a severe windage [back'n'forth ] problem which can be caused by numerous things.

I do not see a severe windage problem, especially given that the group was fired from 2 different calibers using the same sight picture.

 

[Peacemaker]

As noted also you have a severe windage [back'n'forth ] problem which can be caused by numerous things.

I do not see a severe windage problem, especially given that the group was fired from 2 different calibers using the same sight picture.

Exactly my point, thanks. I fired the six rounds within minutes of each other keeping the same sight picture and had two distinct groups. It seems unlikely that I would keep a perfect hold on the first three and pull all three of the last rounds to the left. So what made the last 3 hit to the left? Could it be the bullet jump with the 38's fired out of a magnum, or possibly have something to do with barrel lag?

 

[Jim Puke]

As noted also you have a severe windage [back'n'forth ] problem which can be caused by numerous things.

I do not see a severe windage problem, especially given that the group was fired from 2 different calibers using the same sight picture.

Exactly my point, thanks. I fired the six rounds within minutes of each other keeping the same sight picture and had two distinct groups. It seems unlikely that I would keep a perfect hold on the first three and pull all three of the last rounds to the left. So what made the last 3 hit to the left? Could it be the bullet jump with the 38's fired out of a magnum, or possibly have something to do with barrel lag?

Which caliber is the gun sighted to?

Most calibers will require different settings for precise shot placement. Also, it could be you...not the gun, caliber or load.

 

[Peacemaker]

Sighted dead on hold for the .357's. .38's shooting a little left with same hold.