The 300 norma imp. Really has my attention running 230gr pills. I've been researching it and there seems to be some controversy over going to the 40 degree shoulder, some are saying only go to 35 max. Any experience with this gentlemen, looking for solid data as to whether or not there are any issues. How much more oomph does the imp have on the standard. My build will be sporting a 28-30in barrel.
you could try pm Tom post 4 I think, he just built 2 cant remember for sure 3200 vel. think he hade 35 degree on shoulder, he has a 338 LAI also and is a very experianced 1000 bench shooter.
I have just got my fireform gun done in what we are calling 300 FOG. It is an improved 300 norma, and I have made 80 pieces of brass so far. I use 338 norma since this way my false shoulder is all ready there to headspace from. Ever since Shawn showed me a 338 norma case, I wanted a 30 for the big bergers.
So far the fireforming load has shot a .115 and a .225, this is with 220 scenars @ 2943. I couldn't help myself, so I made up a ladder with 5 brass. 230 hybrid targets ahead of 96,97,98,99, and 100 grs of 33... I hit pressure at 100 by feel AND measurement of the head. My workable velocity will be about 3,160 and down, the top load (too much) went through the ohler at 3,205. Looks like my 338 LIMP might just be a shelf piece!
Going next weekend to get the real ones, sister rifles for my buddy and I.
Tom i think kirby is getting 3160 with the 338 ax-LIMP WITH THE 300 GR BERGER .818 BC with r-33. Joe
My rifle has been ordered a 300 norma improved 40d shoulder, stilled tac 338, manners adj. stock. Hopefully it all works out with the brass. I know there have been some issues with decking down to .284 but and having the sticky brass, but I don't expect that to be an issue. I will post more after I get the rifle.
He very well might be, maybe he will chime in. In the limited time I had with the same combo in my LIMP, I decided on a 2985 node. I got to 3040, and saw precision deteriorate so went back. I didn't find over pressure however, so maybe the next window was achievable.
Rigmover, the only thing you could run into is the thickening of necks and having that be tight in your chosen chamber dimension. I chose .338 neck, so I was going to be turning them regardless. I believe firmly that is one of the things we do that actually does show up on paper. If it is a problem, they do make headstamped 300 norma brass for you to use on your build.
I just recently finished my LR build. I was seriously considering a .338 of some kind. Most likely would have been the edge. But then I started looking at long range ballistics between a fast 300 using 230 Bergers compared to a slower .338 pushing 300 grain Sierras and OTM's. I was able to design and have a rifle built (full custom 300 RUM CMT) that easily pushes the 230 Berger Target at 3250fps with no pressure. It prints well inside .5 MOA. When compared to a .338 cal 300 grain Sierra at 2850fps, I walk all over it even past 1500 yards. Several hundred fps more speed and a couple hundred more ft/lbs energy past 1500 yards. Now with the .338 300 grain OTM (2850fps) I'm neck and neck on energy but surpass it by about 150fps on speed again all the way to 1500 yards. I was really looking hard at impact velocity and getting the bullet to open better at really long distance. Now if you step up to a faster .338 then that's a whole new ball game.
Now thats fast for a 230 out of a 300 RUM whats the load
I have a .30-338 Norma Imp with a 35 degree shoulder and .341 Neck. I don't have to neck size using 300 Norma brass. I have enough spring back to give plenty of tension on the bullet. I have some test loads with 230's but haven't shot them yet. I've been shooting 208's up to this point.