POI Jump - costing points

[Erik Cortina]

You said it jumped up two clicks at 500 on the first shot? Do you mean it shot high because your DOPE was off maybe? If you shot 600 with 2 clicks down just like you did 500, it sounds like there is nothing wrong with it. If it jumps up and down in the middle if a string then there is a problem, but if it stays there then I don't see a problem.

 

[6BRinNZ]

Yeah I had wondered about that - but I am using the berger ballistics app with the G7 BCs. When I was shooting the relays last week both at 500 yards the first string was ok the second string jumped two clicks and stayed there.

this week unfortunately the yardages where all different...300 was bang on...moved to 500 get a certain round count and bang it jumps. The first shot that jumped took me two rings out, it was huge...the spotter (the good national shooter) went ...."WOW"....I said "yep thats the problem". The next couple of shots went a little low and two clicks high and then it stayed two clicks out. Almost like it reached some critical point took a couple of shots to bed down and then found a new POI of happiness. I belive it cost me 3 points in that relay.

So I am confident that there is some sort of weird issue. Maybe I will have to live with it, but I guess I am coming from the point - I paid good money for this rig, and I believe that I am a competent enough shooter and loader to not be causing this issue....but where could the issue be?

Thanks

 

[jo191145]

By switching yardages you'll have a hard time identifying the problem, if any, or what it might be.
I would suggest you take 20-25rds or more to the range with a clean bore. Set up 4-5 small bulls at 200yds and comence a slow but steady rate of fire.
If your POI jumps up finish that group and stop. Let the gun cool 20 minutes or so and recommence firing. POI remains high you can at least rule out heat. As long as the conditions aren't all twitchy.

Would'nt hurt to clean your barrel as you normally do at this point and start again.
If it drops back down to the original POI you have your answer.

No sighters? All down and dirty? Sounds like a tough game your playing
I have a hard enough time at point blank when they let me fiddle with my scope to get on paper. ;D

 

[6BRinNZ]

By switching yardages you'll have a hard time identifying the problem, if any, or what it might be.
I would suggest you take 20-25rds or more to the range with a clean bore. Set up 4-5 small bulls at 200yds and comence a slow but steady rate of fire.
If your POI jumps up finish that group and stop. Let the gun cool 20 minutes or so and recommence firing. POI remains high you can at least rule out heat. As long as the conditions aren't all twitchy.

Would'nt hurt to clean your barrel as you normally do at this point and start again.
If it drops back down to the original POI you have your answer.

No sighters? All down and dirty? Sounds like a tough game your playing
I have a hard enough time at point blank when they let me fiddle with my scope to get on paper. ;D

Tough Game - yeah but we're up for it ...nah kidding...first two in each relay are sighters or counted in..since i wanted round count I discarded and went for score on the remaining.

It will be a little while before the 500-600 yrds come up again. I have a two hundred yard range I can go to....I can setup the chrony as well...so I will head up there and try what you have suggested.

I had the bore checked out today and there is no significant powder or copper fouling...but he did say there was significant tooling marks some of which were across the lands....not what I would have expected....maybe I just need a gas axe to rectify