338 Norma mag

[whiter02]

I have a barrel that is getting ready to be chambered in the 338 Norma mag. I have read a good bit about barrel lengths and the majority says 26 inch is optimal. I have a 30 in barrel 9.5 twist. I was wondering if I should keep it at 30 or shorten it. I plan on using RL-33 and 300 grain bergers. I have read a little bit about RL-33 in this cartridge but not a lot. Any real world experience with a barrel longer than 26 inches and with RL-33 would be great.

 

[dkhunt14]

30 inch should be good. I wouldn't go no shorter for a big case and long range shooting. Don't know about the 338 Norma but my buddy shoots a 338 Ultra IMP with R33 and 300 grain Bergers.. he gets 3000. You will lose velocity with each inch shorter and 100 feet per second at long range makes a difference in wind drift. Matt

 

[whiter02]

Thanks for the reply. I have read that in this case you get full burn in a pretty short barrel. In barrels longer than 26 you don't see much velocity gains and in some cases past 28 inches they will lose velocity. This was in older posts with different powders such as RL-22 and RSM. I don't know if different powders change that or not but RL-33 is what I'm going to try first, if that doesn't pan out then H-1000.

 

[dkhunt14]

I am not sure I belive this because most big cases gain velocity up to 46 inches. It starts to slow down around 36 but is still gaining after that, even the little Dasher gains from 26 inches to 30. The R33 is designed to burn out through the barrel and not give a pressure spike at ignition. That is why it gets 100 to 150 more FPS over most other powders. It also does well with the bigger heavier bullets. It seems to like to be close to or in the lands. Matt

 

[Drop Port]

The gains are not as much as some of the larger cartridges, this may change a little with R-33. Most find H-1000 a little on the fast side to reach top FPS BUT it is usually extremely accurate. H-1000 was the most accurate in both of mine, R-33 is showing promise in my current. I am running 10 grains more 33 than 1000 and speeds are up but so far it wont match the accuracy of H-1000.

I have found the 338 Norma to be extremely easy to tune and just a great cartridge. If you are looking for more speed its not worth trying to stand on it they often come in around 2750-2800. R-33 will run faster if it likes it, if you are looking for more I would just go Lapua improved.

 

[whiter02]

Thanks for the information. That is pretty much spot on with what I have read about H-1000 and RL-33. I am not looking to load it on the edge of pressure but I do want to take full advantage of the barrel length and get good velocity out of it. I was hoping for 2800. If RL-33 doesn't give me the accuracy that most are seeing in this cartridge then I will be switching to H-1000. Accuracy it more important to me than speed, but it wouldn't hurt my feelings any if I could get it it to shoot at 2800 lol. One of the big reasons I went with the Norma mag is reading about how easy it is to tune and the accuracy.

 

[whiter02]

My rifle should be done any day now. I will be starting load development with the berger 300's and RL33. I was just curious what everyone else load looks like running this combo.

 

[Kurz]

Here is the reply directly from Berger: