Set out today to work up a new load in 338 LM. Originally was pushing a 285 gr Hornady with 86.5 grains of H1000. Was getting 2715 fps out of a 30" tube measured with a Magnetospeed V3. New load testing was done with the same 285 gr Hornady but using Retumbo behind it. Started at 91 grains then 91.5, 92, 92.5 and lastly 93 grains.
Most other load development that I have done with other rounds normally has had some separation of noticeable distances in groupings with increase or decrease of powder amounts. That is what made today somewhat strange to me. All grouping are pretty tight. All though there is some separation in some of the groups, I attribute that primarily to the person behind the trigger.
All groups are three rounds rather than five, All are suppressed and at 100 yds. Guess I need to go back with the exact same loads and get data on them. None of the loads showed any signs of over pressurization.
Along with the 338 loads, I got some good numbers on my Grendel load that I have been using.
123 gr Scenars, Lapua brass, Wolf Magnum primers and 27.5 grains of 8208 seated to mag length was getting me 2560 fps out of a 24" tube. No pressure signs to show of. Think I could push it a little harder but the groupings are tight and all is working well. If it aint broke, don't fix it.
Below are pics of the 338 build and test groups. Enjoy.
Most other load development that I have done with other rounds normally has had some separation of noticeable distances in groupings with increase or decrease of powder amounts. That is what made today somewhat strange to me. All grouping are pretty tight. All though there is some separation in some of the groups, I attribute that primarily to the person behind the trigger.
All groups are three rounds rather than five, All are suppressed and at 100 yds. Guess I need to go back with the exact same loads and get data on them. None of the loads showed any signs of over pressurization.
Along with the 338 loads, I got some good numbers on my Grendel load that I have been using.
123 gr Scenars, Lapua brass, Wolf Magnum primers and 27.5 grains of 8208 seated to mag length was getting me 2560 fps out of a 24" tube. No pressure signs to show of. Think I could push it a little harder but the groupings are tight and all is working well. If it aint broke, don't fix it.
Below are pics of the 338 build and test groups. Enjoy.
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