Questions for ELD-X and a 243 AI

[Jpete]

I have a 243 AI, it is a 24 inch Brux barrel 1-8 twist, 700 trued action and Mcmillan stock. Accuracy seems to be alluding me at this time and am looking for suggestions. I have tried Berger 105 hunters, H1000, H4350, RL22 powders, BR2 primers and am using Lapua cases.

49.5 gr of H1000 has produced the lowest SD(7) and ES(14), but accuracy is 1.5 moa and the bore gets very dirty, I switched to magnum primers but still the same results.

I have changed the seating depth from .005 into the lands, .020,.050,.060, .070 and .090 away from the lands. I looked at the bore and throat with a borescope and all looks well.

I decided on trying H4831SC and ELD-X bullets, my question is on the seating depth for ELD-X bullets. Are they best pushed up in the lands or away?

 

[Bc'z]

I shoot the 143's @ .060 off

 

[JEFFPPC]

I like 4831SC. Pick a charge closer to the heavy side than the lighter side. Seat bullets to get a square mark, shoot 2 shots. If they cut shoot a third see if it stays or shoot a second 2 shots to see if it repeats. Now start seating the bullet deeper into the case .005 at a time, you will know when you hit a sweet spot. Now if you want, at the sweet spot go .003 either side of it see if it gets better. Once you have that good spot now you can try going up or down a tenth at a time in powder if you want to try to make it tighter or if your looking for a higher velocity. If your not showing pressure you may go out of a node going up but then back in to an even better node.I have had better luck with 4831sc with Magnum primers. Once you find your sweet spot you might find you willget get lower ES with another primer IF it retains the accuracy, which trumps all.

 

[Jpete]

I like 4831SC. Pick a charge closer to the heavy side than the lighter side. Seat bullets to get a square mark, shoot 2 shots. If they cut shoot a third see if it stays or shoot a second 2 shots to see if it repeats. Now start seating the bullet deeper into the case .005 at a time, you will know when you hit a sweet spot. Now if you want, at the sweet spot go .003 either side of it see if it gets better. Once you have that good spot now you can try going up or down a tenth at a time in powder if you want to try to make it tighter or if your looking for a higher velocity. If your not showing pressure you may go out of a node going up but then back in to an even better node.I have had better luck with 4831sc with Magnum primers. Once you find your sweet spot you might find you willget get lower ES with another primer IF it retains the accuracy, which trumps all.

Thank you for the information, I will most certainly try this.