.338 Lapua load query

[Gluv]

Hi All

I have been developing a load for my AIAW . It has recently been fitted out with a new 32” 9.3 twist barrel. I am working up a load for 300 gr Berger OTM with Viht 570 and cci magnum primers . I have started low 2700 fps and found a decent node at 2850 fps. However I have carried on testing as I have not found any signs of pressure No heavy bolt lift, ejector marks and no visible signs on the primer . In fact I can’t see any difference between my starting loads and where I am now. However my speed is now upto a very nice node at 2960 fps using 95.2 gr of viht 570
Real world data for 570 seems limited out of 32 “ barrels . Does anybody have any experience or advice?
I am aware it is a hot load but as I said I can see no pressure warning signs

Gluv

 

[143lrsd]

Following

 

[Dave62677]

Work your load again at summer time for safety measures. I got load shoot fine at winter time but stiff bolt lift at summer time. I use to load my 338lm at 2900ish with n570, but I found my load at 2700 have consistent hits at 24”x24” plate at 1800 yards. Do you need 2900 ish at 1 miles? No. If u shooting beyond 2000 yards then Yes

 

[Gluv]

Work your load again at summer time for safety measures. I got load shoot fine at winter time but stiff bolt lift at summer time. I use to load my 338lm at 2900ish with n570, but I found my load at 2700 have consistent hits at 24”x24” plate at 1800 yards. Do you need 2900 ish at 1 miles? No. If u shooting beyond 2000 yards then Yes

Thanks for the reply
The plan is to shoot out beyond 2000 . I guess if I’m honest I wasn’t expecting such high velocities with no signs of pressure. Most reloading data seems to be for 27” barrels which isn’t much help .
Gluv

 

[diverdon]

Hi All

I have been developing a load for my AIAW . It has recently been fitted out with a new 32” 9.3 twist barrel. I am working up a load for 300 gr Berger OTM with Viht 570 and cci magnum primers . I have started low 2700 fps and found a decent node at 2850 fps. However I have carried on testing as I have not found any signs of pressure No heavy bolt lift, ejector marks and no visible signs on the primer . In fact I can’t see any difference between my starting loads and where I am now. However my speed is now upto a very nice node at 2960 fps using 95.2 gr of viht 570
Real world data for 570 seems limited out of 32 “ barrels . Does anybody have any experience or advice?
I am aware it is a hot load but as I said I can see no pressure warning signs

Gluv

When you find real world data you'll see that the .338 LM lacks the ass to push the 300 gr fast enough to benefit from the bullets ballistic awesomeness. Then you'll have to decide if you need to find a hotter .338 cartridge or just use the 250 gr bullets.

 

[Gluv]

When you find real world data you'll see that the .338 LM lacks the ass to push the 300 gr fast enough to benefit from the bullets ballistic awesomeness. Then you'll have to decide if you need to find a hotter .338 cartridge or just use the 250 gr bullets.

Out of interest what speed does The 300 gr require ? …..Not that I’m going any faster!

 

[wade2big]

Out of interest what speed does The 300 gr require ? …..Not that I’m going any faster!

I would think 2960 is enough. I think the man didn’t read your whole post. He must have stopped at 300gr .

 

[Dogtown]

Real world data for 570 seems limited out of 32 “ barrels . Does anybody have any experience or advice?

I shot 26" 1:10 .338LM barrels for many years and preferred the 250s @ 2900fps but I really struggled to be competitive past 1600m with that combo. The guys with the long 32" barrels with the 1:9 twist were able to push the 300s to about 2900fps and really squeeze every ounce of performance out of that cartridge. The best load I had for vanilla .338LM with 300s was 92.7gr N570 (2500fps out of 18" barrel and @2915fps out of 32" barrel). Basically it gave me at least 100fps advantage over guys shooting more standard 24-28" barrels.

So for real world experience with a 32" barrel shooting 300s, you're pretty much at the limit. Going any longer with the barrel is diminishing returns unless you use an Improved chamber. N570 is almost perfect for that combo, though from my experience it wears throats out of vanilla .338LM faster than say RL33 or LRT, but those are slower powders and you won't be getting the velocity advantage of a long barrel with them. Also N170 works well and doesn't generate as much heat to wear the throat, but again, you won't get anywhere near the velocities you get with N570 and that's the whole point of shooting a long barrel in the first place.

To take the .338LM much further I got a 36" .338LM Improved 40 1:9 made and this is pretty much where I stopped. I've now had three different barrels made in this configuration and it's my go-to .338 setup shooting 300s at 3050fps (RL33) and 285gr solids at 3100fps (N570). The only vanilla .338LM I still shoot is that 18" barrel because it's fun but stays well inside of a mile while the Improved has made hits out to 2654 yards.

 

[Gluv]

I shot 26" 1:10 .338LM barrels for many years and preferred the 250s @ 2900fps but I really struggled to be competitive past 1600m with that combo. The guys with the long 32" barrels with the 1:9 twist were able to push the 300s to about 2900fps and really squeeze every ounce of performance out of that cartridge. The best load I had for vanilla .338LM with 300s was 92.7gr N570 (2500fps out of 18" barrel and @2915fps out of 32" barrel). Basically it gave me at least 100fps advantage over guys shooting more standard 24-28" barrels.

So for real world experience with a 32" barrel shooting 300s, you're pretty much at the limit. Going any longer with the barrel is diminishing returns unless you use an Improved chamber. N570 is almost perfect for that combo, though from my experience it wears throats out of vanilla .338LM faster than say RL33 or LRT, but those are slower powders and you won't be getting the velocity advantage of a long barrel with them. Also N170 works well and doesn't generate as much heat to wear the throat, but again, you won't get anywhere near the velocities you get with N570 and that's the whole point of shooting a long barrel in the first place.

To take the .338LM much further I got a 36" .338LM Improved 40 1:9 made and this is pretty much where I stopped. I've now had three different barrels made in this configuration and it's my go-to .338 setup shooting 300s at 3050fps (RL33) and 285gr solids at 3100fps (N570). The only vanilla .338LM I still shoot is that 18" barrel because it's fun but stays well inside of a mile while the Improved has made hits out to 2654 yards.

Thats good info , thanks. I found my previous barrel dropped off at just under a mile firing 250gr at about 2850fps 27” 1-11 Viht165

Gluv