Anyone tried IMR 8133 in a .338 Norma Magnum?

codyadams

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Almost have this build finished, and I am starting to think about loads to try out. I have Ramshot Magnum, Retumbo, and H-1000 that would be suitable, but if IMR 8133 could get the velocity of Reloder 33 with the claimed temp stability and cleaner burning, that would be fantastic. I have considered N570, but simply cannot find it, and the high price is a bit of a turn off as well. Plan on running 300 Bergers in it, and it has a 28", 9 twist carbon six barrel.

So, does anyone have any experience with IMR 8133 in a .338 Norma Magnum?
 
That case size with heavies, 8133 is a good choice, it sits between Retumbo and N570. RL26 works for guys in 338 rum. Norma 217 may be another option. Judging results in the 300 norma with 230s, 8133 has slower velocity than RL33 & N570, but only 50-60fps or so.
 
Never a 338 NM, but I have used 8133 in my 300 RUM with 212s. I picked up 50 fps over Retumbo with the same cartridge and bullet combination. I'd put it right at about the same burn rate as N570 with comparable velocity.
 
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Sounds promising. Anyone else out there tried it yet???

Hey Cody. I'm pretty new to the forum stuff. I came across this post as I also was looking for a place to start on a load for my 338 Norma with 300 grain OTM's and IMR8133. I know this post is kind of old and you may already have the info you were looking for but if not, I just did some load development with it today.

Since I couldn't find data anywhere, I started with some load data I got from Berger a few years ago that had n570 and retumbo loads. Since imr8133 is right in between the two, I started towards the low end of what those two powders were charged at.

My 338 has a 26" benchmark, 9.3 twist with about 250 rounds through it.
I'm using Norma brass, fed 215 primers and 300 grain OTM's. None of the loads showed any pressure at all. All of the shots were fired with a magnetospeed attached to the barrel. All the groups were 3 shots at 100 yards.

89.5gr grouped awesome. I think in my gun 89.5grains is it for sure with this powder. I am pretty happy with the results. My velocity with 8133 is about the same as I got with H1000 with slight ejector marks. 8133 works great in my 28 nosler as well with the 180 grain ELD-M.

Attached is a picture with all my results today. Charge, average velocity, es, s-d, and environment.
 
I've shot 8133 and N565 in my Norma Improved with 215 Berger's. I hit harder pressure at 3150 with 8133 than I did with 565 at 3240. However, the nodes look good with 8133 and everything landed within an inch at 100. More testing to come.
 
I have tried 8133, but in my 28N, I was not overly impressed, the velocity is about the same, maybe slightly more than Retumbo, but what I found in my gun, it was dirty, a lot of carbon on my patches after 30+ rounds. I started to see groups open a little, that is why I cleaned and couldn't believe how fouled it had become after 30 rounds. Maybe others have better luck with that part, maybe my lot was different.
 
No. I do agree with the dirty part, but after 20 rounds or so I usually clean anyway so I guess I haven't given it time to be an issue with accuracy. I find that it will take me 5-6 patches that are pretty black before it gets better and with retumbo it's usually just a couple before its pretty clean. In the 28N, I only switched to 8133 from retumbo because, well, I have no reason. Just to try. Lol. Both powders have worked great for me. In the 28N with 180gr eldm's, retumbo put a bull down at 1104 yards and 8133 put one down the next year at 1245. I like em both. I have just been wanting to try it out in the 338 Norma. But again, i agree, it does seem dirty.

I loaded some more rounds with imr8133 today in the 338 Norma, 300 grain OTM's. This time it was 91gr and 91.3gr.

I had fed 215 primers on the top dots, 5 shots each dot, 91gr left and 91.3gr on right and cci 250 primers on the bottom dots, 3 shots each, 91gr left and 91.3gr on bottom right. I don't know velocity yet, but I was really surprised how much difference my groups were with only primer change. I had very slight ejector marks with 91.3gr with both primers. Very slight. No stiff bolt. Just a slightly sore shoulder. Lol. Just kidding.

I'll have velocity on 91.3gr and cci 250's tomorrow.
 

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My velocity of the above load was an average 2731 over 6 shots. ES of 19 and s-d of 7. Very very slight ejector marks. 7 shot group attached that was shot before shooting another 6 over magneto. Only 100 yards.
 

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I am going to try some 8133 in my 338 Norma. I shoot almost exclusively 250 grain berger elite hunters in it..I prefer a bit of extra velocity. Looks very promising with you guys loading.
 
8133 was disappointing in my 338 Lapua improved. When compared to RE33 and N570, It showed pressure signs way early and the velocity was a lot slower.
 
I'm glad to finally have gotten the chance to get to do some testing. I have been using H1000 previously and was hoping to get a little more velocity out of 8133. And I did, with less pressure sign. With H1000 I had a lot stronger ejector marks at 2704fps and slightly stiff bolt. Not real bad. It shot great. With 8133 the ejector marks a very faint and no stiff bolt at all at 2731fps. I think you'll like it. I'm pretty happy with the results I got.

I had never tried CCI250's in this gun until now. Even with the same given charge of 8133, my groups were significantly tighter with cci over the FED 215's. I had never tested different primers with same given load in any gun. It made a big difference on this one. Good luck man.
 
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