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338 Win Mag 1000 yard build questions

I don't shoot my 338 Win mag at 1000 yds but I just got done chronographing some 275 gr Speer hunting bullets with RL26 and reached a velocity of 2674 fps, from a standard 24" barreled hunting rifle. So the 285 Hornady MATCH should get 2600 fps + if single loaded, cause its probably too long Of a bullet for mag length and still get enough powder in the case.
 
Well I discovered that the load is excessive. Primers on some cases were loose. Great accuracy, short case life. A 338 version of mk248. Will reduce loads for the next round.
 
Well I discovered that the load is excessive. Primers on some cases were loose. Great accuracy, short case life. A 338 version of mk248. Will reduce loads for the ne
to be clear mk248 mod 0(190) and mod1(220smk) are both safe in the proper chambers...and reloadable.
i worked up a mod 0 load for my mk13 rifle with no issues, then switched to rl26 and 230 bergers. more velocity better accuracy and useful case life. still waiting for 5/10 shot groups at 1k
 
Talk about temperature sensitivity.... I found my problem. I developed my load using an old bottle of 4350, when I ran out I got a new bottle. New lot#... between developing the load in the spring and then shooting it in the middle of summer with a new lot# the pressure really climbed!
 
I am a HUGE fan of 338 Win Mag for hunting!!! For ringing gongs or punching paper at 1000yards + it can do it but is the wrong cartridge for the job today.

I am also a HUGE fan of 300 Win Mag for hunting and for long range target work. Given the ELD/VLD heavies in 30Cal the 338 WM just does not have the powder capacity to push the best bullets for long range shooting and you are far better off with the 300WM in standard length action.

All of the above said I say if you want to play that game with this cartridge go for it and have fun. I have a Mauser 48 built with machine gun barrels and blue printed action just to shoot the 8mm Mauser as accurately as possible at 1000 yards with all mil surplus parts! LOL...Why? Because I could!

Since you are shooting at known distances with I would presume prone bipod or bench with bags just make sure the action is blue printed and the barrel is as good as you can afford fitted by a gunsmith into precision!

RL19, H1000, IMR4350 given the case capacity and bullet weights it is not going to matter you can not stuff enough in to matter.

Not tried F-Class with 338WM. Like someone else mentioned you will likely want some more throat over SAMMI. You will likely want 28-31 inch barrel to give all the powder a chance to burn. Max loads and +P loads on 300WM in a 26" barrel often produce a fireball of unburnt powder.

I have always wanted to try 338RUM or 338Edge. I have always thought a 8mm Magnum would be fantastic for 1000 yard+!
 
“RL19, H1000, IMR4350 given the case capacity and bullet weights it is not going to matter you can not stuff enough in to matter.”

Seems true so far for me, rl19 loads from alliant seemed high but i shot some with speer 225 btsp and seemed to match. 74 grain start load and i shot 75. 75 gave 2850 fps in my rem 700. Thats basically powder to neck shoulder junction and 78 is listed as max, idk how it fits. Def compressed
 
It is a long bbl@28". It is a long throat@.200". It is a tight chamber@ custom Manson reamer. It is a great bbl@ pacnor. I reduced the charge 3 full grs yesterday and still got nearly 2900fps in Tenn heat! Now that orig load was 3.0 gr higher still & developed with the old bottle and was chronoed at 2850. I didn't think to Chrono with the new bottle and I don't plan on trying it again!!! The primer pockets did go loose with that new bottle.... So to counter your statement. Yes, yes you can stuff enough IMR 4350 into a 338 win mag case with a 250 grain bullet and get yourself into trouble. When loaded properly, there is room to spare in the case even at this level and it will fall out without having to be picked apart because it is not crushed........ Shot like a laser though ;-)
 
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Okay, finally made it back to the range. 1250 yd 5 shots with one of them a flyer. Opened the group to 23",the rest are in an 8"x9" group
 

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