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**Unclenick** · May 19, 2012, 10:27 AM

Splatman,

I agree with you on the die. You want to get that sorted out. The alternatives already discussed would serve you better.

In the Precision Shooting Reloading guide, one of the authors tells how, in loading for his 220 Swift one day he accidentally turned the micrometer adjustment on his seating die the wrong way when changing bullets and wound up seating them 0.050" off the lands instead of 0.020" off, as he normally used. He considered pulling the bullets, but decided to fire them as practice rounds instead. To his amazement, the gun, which had never before been able to put 5 shots into less than 3/8", gave him two 1/4" groups and two bugholes in the ones (0.100"-0.199") with those 20 "practice" rounds.

The lesson is that seating depth off the lands is a tuning factor and there is no magic "right" number. You have to find it for your bullet choice in your chamber. Indeed, Berger has found for it's VLD's, that as much as 0.150" off the lands can be best. Read the first post, here.

If you haven't read it yet, look at Dan Newberry's site for a systematic approach to load development.

Edit:

I just tried the stability calculator at the JBM Ballistics site and found most of the .338 bullets sold by Lapua, Sierra, and Hornady in your weight range and a little higher are running stability factors of up around 2.5 in your 9" twist bore. That's a bit fast. It's not that it can't shoot (a lot of service rifles are shooting in that range), but it's not best for Benchrest accuracy. 1.4 to 1.7 are usually recommended for peak accuracy. Also, I think a bullet that diameter at maximum velocities could experience core stripping in a 9" twist barrel, which could limit accuracy. I would try the Berger 300 grain hybrid tactical bullet or maybe even the Barnes Lapua Tipped Triple-Shock™ X Boattail which is a 265 grain bullet. Both are long and run a stability factor of nearer to 2. The heavier Berger should fly enough slower to reduce the chance of core stripping and the Barnes is a solid, so it has no core to strip.

May 19, 2012, 10:27 AM	#33
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	Splatman, I agree with you on the die. You want to get that sorted out. The alternatives already discussed would serve you better. In the Precision Shooting Reloading guide, one of the authors tells how, in loading for his 220 Swift one day he accidentally turned the micrometer adjustment on his seating die the wrong way when changing bullets and wound up seating them 0.050" off the lands instead of 0.020" off, as he normally used. He considered pulling the bullets, but decided to fire them as practice rounds instead. To his amazement, the gun, which had never before been able to put 5 shots into less than 3/8", gave him two 1/4" groups and two bugholes in the ones (0.100"-0.199") with those 20 "practice" rounds. The lesson is that seating depth off the lands is a tuning factor and there is no magic "right" number. You have to find it for your bullet choice in your chamber. Indeed, Berger has found for it's VLD's, that as much as 0.150" off the lands can be best. Read the first post, here. If you haven't read it yet, look at Dan Newberry's site for a systematic approach to load development. Edit: I just tried the stability calculator at the JBM Ballistics site and found most of the .338 bullets sold by Lapua, Sierra, and Hornady in your weight range and a little higher are running stability factors of up around 2.5 in your 9" twist bore. That's a bit fast. It's not that it can't shoot (a lot of service rifles are shooting in that range), but it's not best for Benchrest accuracy. 1.4 to 1.7 are usually recommended for peak accuracy. Also, I think a bullet that diameter at maximum velocities could experience core stripping in a 9" twist barrel, which could limit accuracy. I would try the Berger 300 grain hybrid tactical bullet or maybe even the Barnes Lapua Tipped Triple-Shock™ X Boattail which is a 265 grain bullet. Both are long and run a stability factor of nearer to 2. The heavier Berger should fly enough slower to reduce the chance of core stripping and the Barnes is a solid, so it has no core to strip. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; May 19, 2012 at 11:01 AM.