We ran the 300 grain SMK’s over 89.7 grains of Retumbo and got 2,760 FPS with no pressure signs. I’d start closer to 86 grains with the OTM’s and work up. YMMV
H1000 85gr / 300gr OTM.
I took this load for 1905yards w/ 20” plate. Very good result.
I took this load for 1905yards w/ 20” plate. Very good result.
What custom dies are people using for a 338 Norma AI? I have whidden FL and they suck. I have them for two other cartridges and dealing with the same problem. They barely resize the brass. The resizing die is almost two full turns from touching the shell holder. Any closer and the shoulder bump is way too much. After a few firings its hard to close the bolt on a resized brass even with the shoulder bumped back 3-4 thou. Whidden's FL dies are basically just neck sizing dies. Just curious what others are using. Looks like Redding and Hornady area accepting orders for custom dies now. I use lapua brass in all my cartridges. Just wondering what dies are working for people out there that are wildcating.
Greetings, I have 38 rounds down the barrel on my new barrel. It was a 338 Lapua. I have 300 Sierra’s and 300 Bergers. For powder I have Retumbo and H1000. What charge should I start at? It’s a 27 inch Shillen 1.250. Thanks.
I have found that with the SMK’s and A-Tips, Retumbo has been safe to start at 84 grains. For H1000 I would start at 82. I’ve run Retumbo up to the high 80’s and H1000, I won’t mention because it’s certainly far higher than I probably should have. Work up slow, looking for pressure signs. As with everything, YMMV, be safe.
Put my first rounds through a Barrett MRAD factory barrel, 26" .338 Norma Mag and thought I'd post/share my results since it seems like data on this combo is sparse.
Lapua virgin brass
Lapua 300g OTM Scenar, seated 3.68
N170 powder, F215M Primers
Shooting suppressed wit Barrett AML338/Mk22
64F dry day with a light variable breeze. Target is 100yards. First two shots where sighters and barrel warmers on a different target.
Results of an N170 ladder between 84.0 and 88.0 grains shown below
No pressure signs but I want to back off the seating depth a bit and see what happens, as well as play around a bit more in the 87+ gr zone as I like the looks of those groups. Then again, I like that group "B" was tight and a strait 1mil "Down" from my .300NM barrel zero. I'm mainly just fire forming the brass and burning up the Scenars and then I'll switch over to Bergers and probably N570, but didn't want to burn up the N570 just yet.
This is a new caliber to me (and pretty new to loading magnums in general), so any tips are welcome.
Lapua virgin brass
Lapua 300g OTM Scenar, seated 3.68
N170 powder, F215M Primers
Shooting suppressed wit Barrett AML338/Mk22
64F dry day with a light variable breeze. Target is 100yards. First two shots where sighters and barrel warmers on a different target.
Results of an N170 ladder between 84.0 and 88.0 grains shown below
No pressure signs but I want to back off the seating depth a bit and see what happens, as well as play around a bit more in the 87+ gr zone as I like the looks of those groups. Then again, I like that group "B" was tight and a strait 1mil "Down" from my .300NM barrel zero. I'm mainly just fire forming the brass and burning up the Scenars and then I'll switch over to Bergers and probably N570, but didn't want to burn up the N570 just yet.
This is a new caliber to me (and pretty new to loading magnums in general), so any tips are welcome.
Similar threads
