338rum vs.338 Lapua

B

Bighorn

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I currently shoot a 308 win. 338rum and 300 rum. All of these are Remington left hand 700 series. I am about to re barrel my 338rum. I am very impressed with the velocities out of the rums. My 338 rum with 225 grain accubonds are getting 3070fps with 92gr. of IMR.7828. Groups from this gun are descent, I have recently found faster loads with RL25 apparently 3200FPS is achievable. My pet peve with my 338rum is the brass. In my opinion its terrible. I recently started shooting lapua brass through my 308 win, and I am amazed at the difference. Weighed them and measured them for length and found them to be very uniform. The loads I found for the lapua 338 are slower than the rum. I don't mind paying the extra money for brass but I dont want to lose 150-200 fps. does anybody have any pet loads to help close the gap. I would like opinions on both 338 rum and lapua. What are the advantages and disadvantages.
Thanks .
Trevor.
 
There are several versions of the improved 338LM.

The one I'm having built as we speak has a 40 degree shoulder and removes most of the body taper. I believe that Speedy has one that retains the original shoulder angle, but removes most of the body taper.

Case capacity for my verion should increase from the standard 108 grain of H2O to about 120-125 grains of H2O. My smith assures me that 2,925-2,950 fps with the 300 grain Sierra MK is easily inside the performance envelope of my 338 LM Improved (with a 32" barrel).

Jeffvn
 
338 Lapua.....

According to this website (http://en.wikipedia.org/wiki/.338_Lapua_Magnum) the Lapua has a slightly higher velocity than the RUM (http://en.wikipedia.org/wiki/.338_Lapua_Magnum). I don't know how accurate these numbers are, but I also have a .338 RUM and I shoot 210 gr. Barnes XBT at 3211 avg. over my chronograph with 87 gr. of IMR 4831. I have since started to moly my bullets and have not had a chance to chony them, so the powder charge will go up to maintain velocity. It also shoots decent, but nothing to get excited about. It definitely puts the elk down though. Sorry, I don't have any load data for the 338 Lapua.

Hope this helps,
JKM
 
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Another choice

You might check the .338 Edge. It's a .300 RUM neck up to .338
 
With my research some time back I too wanted to know how they ranked side by side for the exact same reasons... "the brass"

What I found out is just what you stated except in the reverse order. Meaning that the Lapua had 150-200 fps on the 338RUM plus the brass was almost a buck each for the Lapua brass at the time!!

Now I am sure that the Lapua brass is probably over 2 bucks each now?

I ended up chosing the RUM.

And if you want something different than get a 338Edge ofcourse you will be in the same brass category. Or possibly a 338AM?

Good luck
Kapac
 
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