.338 load data questions

[7.62_Reaper]

my load so far seems to have low velocity around 2590 fps is my anverage

300 gr lapua sencers

89.2 gr of H1000

CCI Mag Primers

lapua brass

26" barrel 1:9.5 twist

does this seem too low of a velocity to you, is there any other powders i might want to try. The groupings that i have been getting are not up to par, any suggestions?

 

[17874]

Crap, I run 300 gr SMK, Lapua brass, Fed GMM mag primers, and 87.5 grains of H-1000 .030 off the lands. I am getting right at 2,700 fps out of my GAP with a 27" 1:10 barrel.

 

[Loud&Proud]

I have been loading with 300 grain Berger OTM using 92 grains of h1000 and I'm getting 2815 average out of a DTA 26" barrel and have had real good luck with it

 

[7.62_Reaper]

ya i'm going to continue to tweak it and see if i can figure out what im doing wrong, im also going to try and use some RL-22 and see what changes i get

 

[ChrisGarrett]

ya i'm going to continue to tweak it and see if i can figure out what im doing wrong, im also going to try and use some RL-22 and see what changes i get

Don't use RL-22 with a 300gr bullet out of the 338LM. Way too fast, IMO.

RL-25, RL-33, Retumbo, US 869, VV-170 and VV-N570 are all powders that are appropriate for your needs.

You're basically at 2600 fps, which is low even for the 300s, shot out of a 26" tube. Some barrels are fast, some are a bit slow, but 2750-2800 fps should be doable without trashing your primer pockets on the first go-round.

Chris

 

[hooksz86]

I shoot the 300SMK with 91.5gr retumbo, CCI mag primer and lapua brass, 2756FPS is my average. Groups under or at MOA easy out to 1400yrds. One main thing to look at for grouping is your bullet run out witch comes from neck to case body concentricety. your neck to body should be under .002 for your bullet run out to be under .005. Then you will have good bore alignment, witch will also give you a more consistant FPS.

 

[Grizzdude]

That sounds a little low, I use 90gr h1000 and push the 300 bergers at 2740 fps. Maybe the sun is hitting your chrono at a weird angle.

 

[jkonzal]

I have great luck with RL-25.
Lapua Brass
Fed 215M
300gr SMK
91gr RL-25
2885fps with 30" Krieger 1:10

 

[7.62_Reaper]

ok i think i may have fixed it......BTW when testing loads for your .338 LM what distance do you typically shot at? today i test loads starting at 84gr of H1000 up to 89gr, increasing the load by 1gr for each set, each set contained three shots. i fired at a distance of 200 yards and i have found that the load with 89gr of H1000 did the best by a huge margin. this group by far is the best three round group i have ever fired out of any of my rifles. the group measured only .38 edge to edge. im going to take it out again with the same load to make sure that is wasn't just luck.

am i shooting too close for testing a .338 Lapua Mag?

i'll try to get a picture up of the group if i can get it to work.

 

[Loud&Proud]

I test all my reloads at 100 yards from 223 to 50 bmg what kind of velocity are u getting at 89 grains

 

[7.62_Reaper]

not sure yet i'll be using a chrony soon after i make sure that group wasn't a fluke

 

[7.62_Reaper]

there is a pic of the three round group, the target was 200 yards away