Rising shot string.

[Swamp Hunter 38]

I have one more question tonight. When I test some of my close to max loads, I shoot 3 or 4 times in a row and my shot string climbs from touching bullets to 1-2 inches high. Is 3 or 4 in a row too many. Is the heat causing this? I know better than running a half a box at a time but it just seems that 3 consecutive shots shouldn't cause that much of an increase in velocity.

 

[FOTIS]

Try cooling the barrel between shots.

 

[Guy Miner]

It's not necessarily an increase in velocity that is causing the shots to string like that. Merely the barrel heating up can do it. Metal moves.

This is one reason why target rifles usually have heavier barrel contours. They're more stable over a long string of fire.

 

[JD338]

Also check to see if the barrel is free floated or pressure points.

JD338