8mm Remington Magnum

Too Tall Rosenwald

Well-Known Member
Sep 27, 2009
Thompson Falls Montana
I was wondering if anybody has ever necked the 8mm Remington Magnum to a .338? I was wondering if it would be worth it, for the higher BC bullets available. I think the action is long enough for the Ultra length stuff. So the magazine must be longer too, right?
338 Gaillard

This may help.


8mm Rem Mag case necked to 338 that has been fire formed. This gives you a 10 thousandths case taper & a 38 degree shoulder
215M Primer
250gr HPBT Sierra
89.5gr RL25
3050-3070 FPS





The top left target was some 416 Rem Mag brass I was fireforming with 225 Hornady Interlocks. 85gr IMR 7828 & CCI 250 primers. 2967 FPS (Low), 2995 FPS (High). I also notice that that target should have been rotated 90 degrees CCW as that is how it was at the range.

The top right target was the last 3 rounds left from my 1st 338 Gaillard that I had. They were loaded with 250 Sierra HPBT, 340 Fire Formed Norma cases 89.5gr RL25 and CCI 250 primers.
2887FPS (Low), 2959FPS (High).

The lower left target is a 5 shot group of Barnes 225gr XXX. These were Fire Formed 8mm Rem Mag cases with 86gr IMR 7828 and CCI 250 primers. 3054 (Low), 3077 (High).

The lower right target was an experiment. 200gr Nosler Ballistic tips with Fire Formed 8mm Rem Mag cases with 88gr RL22 and CCI 250 primers. Nosler does not make a ballistic tip in 200gr anymore, only the Accubond. I figured I'd try these before I used my Accubonds. I must say I was impressed!
3249FPS (Low), 3271FPS (High).
I have used 8 mm in my 340 , sized and trimmed to length. Buddy had a 8mm rem mag. Still does but shots a 338 win. That gun is too purdy to go where I go, sweet whitey also, super tall.
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Plus it looks like it kick the crap out of ya. I'd put a modern synthetic stock with modern recoil pad and load up and GOOOOOOOO
Plus it looks like it kick the crap out of ya. I'd put a modern synthetic stock with modern recoil pad and load up and GOOOOOOOO

That stock is just for looks, here it is when it's out working.


Yup, you got to hang on to it too :D I had to put the updated bolt guide stop kit in it this year :( The new kit has 2 pins instead of 1. First time a Sako has failed me in the field.
several years ago, I built a 338x416, this has been a great gun, built on a 700 sendearo. It was difficult to neck down the 416 brass, also had to fire form it or it was ugly. I now use 8mm brass with no changes, the std 338 expander in the die set works fine. I have taken this gun to Africa twice, both times needed brass with correct 416 head stamp. This gun has # 5 shilen bbl./ with shilen triger. You can't go wrong with this combo, but mark bbl 8mm x 338

Been done quite a bit since the 70's. It is a 340 wby with cheap remington brass. It is an excellent chambering and easily capable of 1000 yard hunting. In 28-30 inch barrels you can drive a high BC 250 grain bullet to 3050 fps or so which is plenty for 1000 yard elk. I have driven the 300 SMK to 2700 fps with my 340 wby with a 28" Hart barrel 1-10 twist. I have an accuracy load with it at just under 2700 fps and you see what others on here are doing at 2700 fps with the ultramag and lapua cases. You can get an excellent barrel from pac-nor chambered in it.
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