Printable View
Hey guys im not sure why but IM shoting Tikka T3 7mm rem mag and hornady precision hunter 162gr ELD X my groups at 100Y are clover leafing but buy the time i get to 450 yards they are starting to open up dramatically. any ideas why this would be happening surely its not becoming unstable ? its not my shooting as i can shoot 4 inch groups at 700 yards with my 270 win .
Thanks Michael
What were the conditions like? Are you shooting with flags? Is it open country from the shooting position to the target?
Obviously I’m thinking variable downrange wind. I shot a very similar outcome last week in hilly and partially wooded country, at 100m perfect, and 500m hopeless. When I walked the line of the shot, the wind was all over the place, nothing at the shooting position but lightish variable to gusty winds downrange and more than enough to screw things up.
If it's consistently bad at 450 and your consistently good with other rifles out past that distance and it's mint at 100 it has to be the ammo
Sent from my iPhone using Tapatalk
Have you run them over the chrony? As the more spread in velocity you have the worse it gets the further out you go
Cherrs guys no I have not run them over a chonoy.
I'm taliking groups of about a meter at 550 yards in still conditions and they clover leaf at 100 yards .
Did you shoot at 100 again after the wayward longer shots to make sure still performing? Sounds like something has gone wrong somewhere, something come loose etc, otherwise would suggest chrony as above, its a pretty drastic change though, got me thinking something must have gone astray in the setup
I'm not the most expert in this but:
If you personally shoot good 500m groups with the 270 and with the 7mm shoot good groups at 100m,
(ie it goes from 100m cloverleaf to 500m metre group and back to cloverleaf in the same session. If you shoot 2cm at 100m its reasonable to expect 15-20cm elevation at 500m using the same setup but could easily get 50cm spread for windage.)
then its likely this factory ammo is very high quality for the factors affecting 100m accuracy (concentricit and bullet quality) but somehow doesn't fit your rifle for the longer range requirements (cartridge headspace and case base to ogive). I think its unlikely they've got a problem with neck tension but it could be their outside neck diameter doesn't match your chamber. Probably the ammo will perform well in a range of other rifles. Its unlikely your tikka is suffering from overheating during strings. Their guarantee is only for 3 shots but they dont wander or walk when shot hot.
Parallax can give problems at longer range if not adjustable on the scope. Some are set to 100m, which will cause variable impact at longer range if you don't have good cheeeck support.
Not many people rely on factory ammo at 500m.
Try a few different brands of factory ammo and see if there is a difference. It seems pretty odd for it to do this though.
Iv had trouble in the past with 7mm rm , mostly screws on the rings or stock coming loose , I Loctite everything now and no probs