IMR 4350 for .338 LM...

[Spectre1]

Hello everyone.

Need some help with load data for IMR 4350 for the .338 LM.

Will be loading 300 gr Nosler AB and Berger 300 gr elite hunter.

I would really perfer to use Retumbo, but it is unobtainium currently.

I have IMR 4350 and WLRM primers on hand.

Any info would be appreceiated!

 

[ChrisGarrett]

Hello everyone.

Need some help with load data for IMR-4350 for the .338 LM.

Will be loading 300 gr Nosler AB and Berger 300 gr elite hunter.

I would really perfer to use Retumbo, but it is unobtainium currently.

I have IMR 4350 and WLRM primers on hand.

Any info would be appreceiated!

I was going to post that IMR-4350 probably isn't the best choice for the 300s because it's perhaps a bit too fast.

I went and looked in my Sierra V manual and IMR-4350 is actually listed as their 'accuracy' load (78.2grs.)

300gr SMK and IMR-4350:

Start: 72.9grs @ 2500 fps

Max: 78.2grs @ 2650 fps

It is a bit fast and so velocity is a bit less than the slower powders, but there you go.

The AccuBond shouldn't be all that much different, but always start low and work up.

Chris

 

[Spectre1]

Thanks, Chris!

 

[P7id10t]

That's interesting - give it a try and see what you get. If Sierra published a load, then they've tried it.
RL19 is considered a fast powder for 338LM. RL17 is considered as approximately same burn rate as 4350, and I don't see any recipes for it (more correctly, haven't looked).
Have you seen relative burn rate comparison charts?

 

[Spectre1]

That's interesting - give it a try and see what you get. If Sierra published a load, then they've tried it.
RL19 is considered a fast powder for 338LM. RL17 is considered as approximately same burn rate as 4350, and I don't see any recipes for it (more correctly, haven't looked).
Have you seen relative burn rate comparison charts?

I have not seen any burn charts, but I have different loads listed in manuals for IMR 4350 for the .338 LM, but only up to 200 or 225 gr weight projos. I figured it could be safely used for the bigger bullets, too, just not sure that the accuracy or velocity will be where I want them to be. Chris' post indicating that the IMR 4350 loads were the most accurate tested is encouraging. I use this powder for all my rifle loads for stuff bigger than the .308, so I'm not shocked by those results. This is just a stop gap as my rifle should arrive this week and I currently dont have any ammo for it. I gotta at least put a couple fouling shots down the tube to function fire it, right? ;-)

I realize that these will not be ideal loads for this round, but until I can source some Retumbo,they will have to do...

 

[Spectre1]

Very happy with todays results. Sierra Game King 215 gr over 81.0 gr 4350 with WLRM primer. After the first five rounds to get a rough zero, I was able to put the next 5 into one hole. Not ideal for long range, nor did I bother to chrono the loads, but these would certainly put a hurtin on an elk...

 

[Spectre1]

Forgot to mention that I called Nosler today and they didn't have any data for IMR 4350 with the 300 gr AB's. Still looking for Retumbo, and any other data I can get for the 4350 I have...