RL33 in 338 Lapua Magnum

[D.Stone]

Recently ended up with a 20 inch 338 Lapua Magnum. I am going to be getting a new barrel because the 20 inch barrel is just obnoxious and doesn't shoot well.

Does anyone have some go-to loads for the new RL33 powder that Alliant says is specifically optimized for the 338 calibers? Specifically with 300gr Berger Hybrids?

 

[Tempest]

Yes. My best load was 100g RL33 and 300g Berger in Norma brass at 2,800 FPS. Was a 26" barrel and worked pretty well to 2,000 yards.

 

[Carolina Hillbilly]

I've had the best luck with RL33 in longer (27"-30") barrels at higher pressures where you could burn it completely. I've had better luck with RL25 in shorter barrels with 250gr Scenars. H1000 & Retumbo may be considerations as well.

 

[D.Stone]

Just an update.

20 inch 338 Lapua is kind of miserable to shoot. I didn't find a good load with RL33 or Retumbo, and I sent the barrel back to Accuracy International due to a defect in the chamber.

 

[shortthroat]

I found 93 gr. behind 300 gr. Berger with Fed.215G primer worked very well in 28" Alexander Ulfberht, but I also found RL-33 to be a rather dirty powder. A 20" barrel is too short to burn the slower powders the .338LM needs. You will be burning a big portion outside the barrel.

 

[dsinfour]

With RL 33 I use 97.50 grains behind a 300 grain Sierra which was my load to shoot the 1 mile range in my 338 lapua mag. You know the drill start low and work your way up and remember to keep them all in the center of the target.. shoot on... later

 

[Kurz]

A 20" barrel is too short to burn the slower powders the .338LM needs. You will be burning a big portion outside the barrel.

Re-33 is not a great choice for a short barreled .338 Lapua. You can't get enough powder in the case at magazine length to make the combination work. But some of the slower powders work quite well in the 20" barrel length and this is by test.

Norma 217
Re-25
Re-26
Retumbo
Ramshot Magnum

Take a set of flat white sheets (2, not the fitted ones) and spread them out end to end in front of the barrel. Do NOT, repeat DO NOT use your wife's sheets for the bedding at home! Get some from the discount store and keep them just for shooting. This will catch any of the ejecta from your tests. Full loads of the above powders all burn inside the barrel and all you will collect is burnt if anything but fouling.

Smokeless powder does not burn outside of the barrel once it leaves the muzzle. If you are confusing this with muzzle flash, which is the plasma or super heated hot gas which the burning powder creates to push the bullet down the barrel, not extra powder igniting.

 

[Larryh128]

I had a decent load for 270 Eld's with RL-26 BUT seeing there isn't any, I'm going back to trying RL-33 with showed promise. If you find a good load please post it.

 

[Alaska Bush Man]

In a 20” barrel 338 Lapua
You really don’t have a Lapua and probably not even a 338 Win Mag in performance.
With powder charges approaching 100gr you need a longer barrel.

 

[284winner]

In a 20” barrel 338 Lapua
You really don’t have a Lapua and probably not even a 338 Win Mag in performance.
With powder charges approaching 100gr you need a longer barrel.

Well, you definitely exceed 338 win mag performance even in a 20" barrel. No doubt about that BUT your not getting the performance of what the 338 LM does have. I think a 25-26" barrel gets close to even a 30" barrel based on some tests I've seen. Having a 338 Lapua improved, the 28"+ barrels are needed for optimum performance.

 

[D.Stone]

I traded the 20 inch barrel for a spare bolt body for standard calibers. I have a whole thread on my results with my other barrel.

For short barrels, Retumbo was the ticket. It was more accurate and provided the same velocity. I think I was able to safely get around 2650 feet per second with the 300gr Berger when loaded to magazine length. Don't take that as gospel truth, I can't find my notes on it.

Ballistically, it should be able to do most things a hot 300WM or a 300PRC do, with more energy downrange, but at the cost of more drop. However it is only 8 mils of drop to 1000 yards.

The barrel was unpleasant to shoot though. It would probably be a reasonably good setup if I had a big suppressor to go on the end of it.

 

[lb-ft]

If you want to have some fun while waiting on your new barrel, RL 19 and 225 SST or 230 ELD are both great combinations. Ought to be far superior to slower powders in your 20” configuration.