.338 LM Load Help

[Arbogb06]

Gentleman,

Brief history: I bought a Savage 110 FCP in .338 Lapua a few weeks back. Now after compiling some reloading equipment I shot a very nice (in my eyes) group at 200 yards (my zero).

Load:
92.0 gr Retumbo
300 gr Berger OTM
3.750" COL
Lapua Brass

Now having said this I shot just under 0.5 MOA (by my calcs, ignore the 0.27 MOA on picture used wrong calculation) with this load and was going to tinker with it a little more but ran out of powder (only bought 1 lb of Retumbo in case it liked the H-1000 better). So I just received another 1 lb bottle of Retumbo and loaded some rounds with 92.0 grains, same bullets, same COL and they shot terrible. It seems this new powder is somewhat hotter as I am getting primer flattening and a sticky bolt which did not happen with the original bottle. I have narrowed it down to the powder solely because nothing else has changed. The only other variable was that the first time I shot the cases were brand new Lapua brass and this time with the new powder they are once fired (trimmed to spec.) brass.

Any advice? Buy 8lb bottle and start load development over, so once load is figured out I should have plenty of powder left? I'm afraid I will get this bottle of Retumbo shooting good once I figure out the load then will be out of powder. This is the first time I have reloaded and I have made sure the process, consistency, tolerances, etc. is the same. I am very frustrated because it took a while to get the load right and if this happens everytime I need more powder it will take a few weekends to get the gun shooting good again.


Please feel free to give any advice.

 

[alaska]

Try 92.0 of H1000 with the 300gr

26" Barrel upper 2800's in my Rem 700 338 Lupua

Sometimes different powder lots produce different burn rates......and vel.


gun)

 

[Broz]

Yes, it is a very high possibility the new lot of powder is hotter. This is why it is always best to work up the the old charge when changing powder lots. I prefer H-1000 for the 338 LM with 300 Bergers, but if you back off 2 or 3 gr you can probably find your original load again. My last order of H-1000 was 48 lbs all the same lot number. That way I am good for a while.

Jeff

 

[alaska]

I have been using 300 gr SMK but just ordered the new berger elite hunting 300gr to try

 

[Arbogb06]

Thanks for all the replies. I guess I will try backing the Retumbo down 2-3 grains and try 89.0, 89.5, 90.0, 90.5, 91.0 and see if I can find the sweet spot again.

This is my first long range gun and first time really shooting beyond 100 yds.

When originally developing my loads, I had 1 lb of H-1000 and could not produce a group better than the picture above but I will try working that load up again, if others are having better luck.

Also, Broz I noticed you said you bought 48lbs of the same lot. This may be a dumb question but how? Is there a specific retailer or store where you can ask for all the same lot? I bought the powder I am using from Powder Valley. Would they be able to do this and give me several bottles of the same lot?

Thanks,

Brandon

 

[4xforfun]

First, you can not judge a load by shooting one three shot group. Second, yes, powder lots can change. The solution is to get a good chronograph and find the speed of the best loads in the gun. If you change lots of powder, or changer type of powder, and the speed changes, you will know what to do.

 

[Terry Scott]

While the powders you are using are not very temp sensitive were there any large temp differences in your range conditions?
Just another thing to check... everything still snug with your optics?
In the end you will probably just find out you have a slightly hotter lot of powder, something easily adjusted.
Good luck shooting. Have you run these over a chronograph?

 

[Arbogb06]

Thanks for the added insight. I have a chrono ordered that will be here before the weekend. I will try this method as to it should directly point to if the powder is hotter or not. Never really thought about this method but it makes the most sense and will clearly show if the powder is hotter or not.


I have not checked the optics but had my gunsmith mount them and he also used some type of blue loctite or something on the rail, rings, etc.

Thank again guys I really do appreciate the replies.

Brandon

 

[snowpro440]

Brandon , You might want to check the rail , as I have the same gun and have had the same problem , I loaded some test rounds then went to the range a found 2 loads that shot good . I loaded 50 rounds of the better load then went back to the range only to find that my load shot worse and my rail has come loose. Went back again after locktite aplied to find that load is way worse than all the rest that I shot before. I had to start all over again.If you dont lock it down on those big guns it will come loose. Fingernail polish works great too for the things you need to take apart at a later date because locktite seems to be permanent on small screws, even the removable kind. I bought the 8lb jugs of H1000 so that things wouldnt change once I found the right combination because those magnums sure can eat some powder.I have tried the berger 300 OTM with no success . I ended up with the 300SMK's @91.8 of h-1000 215M and 2 thou. into the lands. Good luck and let us know how it shoots then when you get it up an running.

 

[Broz]

Broz I noticed you said you bought 48lbs of the same lot. This may be a dumb question but how? Is there a specific retailer or store where you can ask for all the same lot? I bought the powder I am using from Powder Valley. Would they be able to do this and give me several bottles of the same lot?

Thanks,

Brandon

Powder Valley is where I usually buy my powder. That order was six eight pound jugs. They will charge a hasmat fee but I think it will cover up to 50 lbs. Just ask them how much they have of the same lot and they will fix you up.

Jeff

 

[Arbogb06]

Powder Valley is where I usually buy my powder. That order was six eight pound jugs. They will charge a hasmat fee but I think it will cover up to 50 lbs. Just ask them how much they have of the same lot and they will fix you up.

Jeff

Jeff,

Sounds good. I will definitely be doing this next time. Any idea on shelf life of H-1000 or Retumbo? (Stored properly; no moisture, room temperature)

Thanks,

Brandon

 

[Broz]

Jeff,

Sounds good. I will definitely be doing this next time. Any idea on shelf life of H-1000 or Retumbo? (Stored properly; no moisture, room temperature)

Thanks,

Brandon

Keep it cool and dry, out of the sun and it will store for years. Especially containers with the seal not broken. If a large open container is going to last you over a year, you can take the lid to an auto parts store and get an "O" ring that just fits in the lid. Then you will have a sealed container again. Mine does not last that long..

Jeff

 

[Arbogb06]

Gentleman,

Just an update. Everything was snug on the gun. Once I checked out my bullets I noticed they were in an orange Berger box and not the yellow box. For some reason I was sent the 300 grain Hunting bullets and not the 300 grain otm hybrid bullets (not sure if this was my fault or retailers fault). Although both have the same BC they DO NOT shoot them same at all. I just got in the 300 grain OTM's friday and shot the gun yesterday and the gun is back to 0.50 MOA using 91.5 grains of Retumbo (powder seems a little hotter than prior batch). I tried the H-1000 again with no luck. I guess for some reason the gun likes the retumbo better.

Aslo, prior to shooting the gun this weekend I used some JB Bore Paste on the barrel and go all copper fouling and residue out since a few suggested this could be a problem as well.

I did just accompany the gun with a Ross Schuler muzzle brake and the gun now has minimal recoil for a .338. This brake was leaps and bounds better in terms of recoil over the stock brake. Someone on here suggested this and I feel as though this was the best $60.00 I ever spent for this gun.

Thanks again for all the help,

Brandon