Hey all I'm looking for so load data for a 338 lapua ai. 250 and 300 grain pills, like to here what everybody is running. A like info on my gun, defiance rebel action, benchmark 8.5 twist finished at 30" mcmillan a5 stock, timney Calvin trigger seekins bottom metal, stock bedded with devcon. NF 5.5-22x50 np r2 scope
338 lapua improved data
- Thread starter Shawn_338
- Start date
Lapua Scenar 300gr seated 0.020" from the lands. 100.0gr Hodgdon Retumbo gets me velocity of just over 2900fps. That's measured with a Magnetospeed V2.
The best accuracy I've found with my 338 Lapua Improved 40 is with 98.5gr or 100.0gr of Retumbo. That's with a Broughton 1 in 9.3 5C barrel, finished to 28.5".
My brass is 4x fired and in perfect condition.
How do you plan to fireform?
The best accuracy I've found with my 338 Lapua Improved 40 is with 98.5gr or 100.0gr of Retumbo. That's with a Broughton 1 in 9.3 5C barrel, finished to 28.5".
My brass is 4x fired and in perfect condition.
How do you plan to fireform?
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My last bunch I went with the COW method. Worked good but I think I'll go with what you did next round.
Schecter 81
Regular
- Location
- Edmonton Area
I had stevesummits old 338 Improved. We both ran the 300 Bergers at 20 thou of the lands and 107-108 grains of US869. I chrony'd it at 2925fps with a 28". He was breaking 3000 with the 30" before he set it back.
I have a new one in with the smith who built the first one. Full custom. My action just showed up. Defiance Rebel single shot, extended tenon, Krieger 1:9.3 twist, APA Fat Bastard break.
My McMillian A5 is still on order. Its like having a baby with McMillian. Last one took 9mths. Im expecting this one in spring or summer.
For the new build, I am stocked up on Retumbo and Bergers. I also have some Lapuas to give a try.
I have a new one in with the smith who built the first one. Full custom. My action just showed up. Defiance Rebel single shot, extended tenon, Krieger 1:9.3 twist, APA Fat Bastard break.
My McMillian A5 is still on order. Its like having a baby with McMillian. Last one took 9mths. Im expecting this one in spring or summer.
For the new build, I am stocked up on Retumbo and Bergers. I also have some Lapuas to give a try.
I could just get over the 3000fps with Retumbo. I would like the brass to last so I backed off a bit. You'll like the APA brake.
Alliant RL33 is producing better velocities yet than Retumbo or NH570. I plan on burning up some RL33 at the end of the week.
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Schecter 81
Regular
- Location
- Edmonton Area
Where did you find RL33? That seems like it would be ideal, but I have never heard of it in Canada. Most people seem to use either Retumbo or H1000 for the Lapua or the Edge. I just made the leap and went with Retumbo. That and I could find it.
I think that is why Steve started with US869. It is easy to find. I never found it that consistent and with a new build figured I would just start fresh.
I think that is why Steve started with US869. It is easy to find. I never found it that consistent and with a new build figured I would just start fresh.
I've had a new A5 on order for awhile now....still waiting but a buddy of mine just bought the almost twin to my gun so we traded my aics ax for his A5 with a seekins bottom metal and two clips. I had to do a little inleting to the barrel channel and re bed it but no big deal. Turned out good and will do till my new stock shows up 
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Schecter 81
Regular
- Location
- Edmonton Area
Are you running the Seekins bottom metal or single feed? I ended up just going single feed because my OAL is over 3.9 anyways. At least with the Seekins you can get to 3.9. Should be fine with the Lapuas or the SMKs. The Bergers are really long. I think my OAL was 3.975 and I was still .020 of the lands. AI 40degree
I am running a custom ATRS action with a 30" Lilja barrel, Mcmillan A5 stock, ATRS brake, Nightforce ATACR am shooting 300 gr Berger hybrids in front of 111.4 grains of US869 I am getting just over 3000fps with this combo I also have had good results with 98.3gr of H1000 running bullets 20thou of lans
- Location
- Prince Albert, Sk
Mine isn't improved 
I feel so inadequate reading this thread.
I feel so inadequate reading this thread.
I've had my 338AI since July but haven't had much time to tinker. I started with 300gr SMK's and US869. 111.5 gr of 869 seated 0.010'' off the lands was good for around 2950fps and 1/3moa @ 300 m. I found it to be quite temp sensitive though ( 3050+ fps summer(+30), low 2900's in Dec (0 deg) . I'm starting again with 250gr berger otm's and H-1000.
Well it's taken me months to get here but I've got some 250 gr Berger Hybrid info to share.
First off the rifle is an ATRS custom. 30'' kreiger w/ 1-9.3'' twist, maverick action, A5 stock.
I loaded 3 shot groups with H1000, fed 215m primers, lapua brass and bullets seated just off the lands. I started at 99gr and went up in 1/2 gr increments. All groups were shot at 200m. I found my best node between 101 and 102gr. I started to see slight ejector marks at 103.5. The group at 101 was ruined by me (two in the same hole, 1 an inch right). 101.5 produced a 3 shot group of 0.170''. Both of those 3 shot groups had little to no vertical. I'll be headed out today with a bunch of rounds loaded at 101.2gr. I'll shoot a few groups and try to verify velocity shooting out to 500m (chrony gave up on me a couple range trips ago).
First off the rifle is an ATRS custom. 30'' kreiger w/ 1-9.3'' twist, maverick action, A5 stock.
I loaded 3 shot groups with H1000, fed 215m primers, lapua brass and bullets seated just off the lands. I started at 99gr and went up in 1/2 gr increments. All groups were shot at 200m. I found my best node between 101 and 102gr. I started to see slight ejector marks at 103.5. The group at 101 was ruined by me (two in the same hole, 1 an inch right). 101.5 produced a 3 shot group of 0.170''. Both of those 3 shot groups had little to no vertical. I'll be headed out today with a bunch of rounds loaded at 101.2gr. I'll shoot a few groups and try to verify velocity shooting out to 500m (chrony gave up on me a couple range trips ago).
