Impact point with different 243 bullets

jab22 · #1 10-01-2005, 04:50 AM

Set up my T3 243 for 2 inches high at 100 yards with 100 gr GKs. When I shoot 70 gr MKs or BKs with max loads of Varget, they impact lower and to the right with the same shooting technique (i.e., hunting position with sling in tention and hand on a rest). Why? Is this expected and I'll just have to adjust my scope before I go after chucks?

Look forward to your responses [img]/ubbthreads/images/graemlins/cool.gif[/img]

Mikecr · #2 10-01-2005, 09:17 AM

If you reload. You need to work up the most accurate load for each bullet. Otherwise it's all left to the abstract. If you don't reload, resight.

Taos · #3 10-01-2005, 11:37 AM

My 6-.284 does the same thing with most bullets. What Mike said makes a lot of sense and that is how I make it work.

sewwhat89 · #4 10-01-2005, 11:39 AM

Sometimes you get lucky and different loads/bullet weights shoot to the same point. Sometimes you dont. My 22-250 puts every load I shoot to the same 220 yd zero. My 300 SAUM Sendero puts 175/178 gr bullets in one spot and the 155 gr in another and the 168 bullets split the difference. I can't explain why, but I could show you.

BTW, since you handload, try H414. I am shooting 85 gr NP at 3420 fps with 44.5 gr H414. I have not used Varget in my 243 yet. My dad's old loads were 42 gr IMR 4320 with 75 gr HP and 42 gr IMR 4350 with the 95 gr NP. The 75 gr print 1 inch higher than the 95s in his rifle. It makes for nice 200 and 300 yds zeros for MOC accuracy (minute of coyote)!

jab22 · #5 10-01-2005, 08:04 PM

The smaller bullets group well, just a different impact point. If i'm working up the loads with bench rest shooting technique these would be my most accuate loads. And why would they impact lower than the heavier, slower round? I think the right drift might be related to some complicated gyroscopic effect on the lighter bullets with high rpm. Twist rate is 10. I think I will try the Sierra 80gr. Blitz next.

jab22 · #6 10-01-2005, 08:14 PM

Sowhat, ment to ask what brand of bullet you were using for those 75 gr.HP coyote loads. Also how did you folks make out with Rita? Hope alls well. Thanks!

sewwhat89 · #7 10-01-2005, 09:03 PM

75 gr Speer HP

Rita was only strong enough in my neck of Houston to blow out the dead branches left in the trees from the last tropical storm. Not bad; however, my friends in Jasper, Polk, Nacogdoches and Angelina counties did not fair so well. My friend's parents still cannot even get to their house. They own about 15 acres, and only one tree is left standing on it. Trees are on their barn, boat, tractor, carport, house and several on their long driveway. Thanks for asking.