Anyone have experience/luck reloading for ar10/15 accuracy by adjusting bullet jump?

[Morndorff95]

We're you able to try seating them deeper? If so how did it work?

I did not mess with seating depth at all, at least not with the 223 as I was able to achieve sub Moa with them and that was my goal. Might try it with the 308 in the future.

 

[bamban]

We shoot service rifle legal AR15s prone slow fire at 200, 300, 500, 600 and across the Palma course. By rules loading has to be single shot only. Back in the day 90 grains were popular, these days with 7T barrels I've shot 80s to 88 grains projectiles. Barrels usually have .218/.224. I've played with .219/.224 as well. I still have a good gain twist Bartlein that ends at 6.5 that I shoot the 90s at 1000 yard matches.

Seating depth testing is paramount depending on barrel, chamber, and freebore. I have reamers with the ubiquitous Wylde, and derivatives of aforementioned reamer with 0.0619 through 0.170 freebore length, and different freebore diameters.

Here is group my buddy sent to me today shot at a 500 yard prone slow fire match. He used one of the barrels I chambered with 0.140 freebore using Berger 85.5. We tuned his load at 200 yards. The final timing was varying seating depth. By the way he holds the 1000 yards service with optics (4.5X by rules) at Bayou Rifles in Houston with this same upper.

 

[Earnhardt]

Great post bamban!

 

[bamban]

Great post bamban!

Thank you

 

[jbs2014]

We shoot service rifle legal AR15s prone slow fire at 200, 300, 500, 600 and across the Palma course. By rules loading has to be single shot only. Back in the day 90 grains were popular, these days with 7T barrels I've shot 80s to 88 grains projectiles. Barrels usually have .218/.224. I've played with .219/.224 as well. I still have a good gain twist Bartlein that ends at 6.5 that I shoot the 90s at 1000 yard matches.

Seating depth testing is paramount depending on barrel, chamber, and freebore. I have reamers with the ubiquitous Wylde, and derivatives of aforementioned reamer with 0.0619 through 0.170 freebore length, and different freebore diameters.

Here is group my buddy sent to me today shot at a 500 yard prone slow fire match. He used one of the barrels I chambered with 0.140 freebore using Berger 85.5. We tuned his load at 200 yards. The final timing was varying seating depth. By the way he holds the 1000 yards service with optics (4.5X by rules) at Bayou Rifles in Houston with this same upper.

View attachment 358794

When you tuned your friend's rifle how far off the lands did you go?

 

[bamban]

When you tuned your friend's rifle how far off the lands did you go?

We started with jam, equal mark on the bullet and started seating them back into the case at 0.003 increment. With this barrel 85.5s we end up with 0.015 jump.