vertical stringing

[lil toad]

I have a friend who has a Colt Defender that he says strings shots vertically after the barrel is warm. I told him I have no idea why it would do that? Anyone have some insight?

[stumbler]

Watch his hands as he fires. If he moves his gripping hand, this could cause his point of impact (POI) to change. Watch his eyes and see if he blinks as the trigger is pulled. Have you fired his firearm and had the same problem?

[lil toad]

Watch his hands as he fires. If he moves his gripping hand, this could cause his point of impact (POI) to change. Watch his eyes and see if he blinks as the trigger is pulled. Have you fired his firearm and had the same problem?

No. I am simply asking on his behalf because I have never had or seen this problem before.

[stans]

In rifles this is a symptom of a bedding problem, but in handguns it is usually the shooter's grip that is changing.

[lil toad]

Thanks for the reply.