I'm just beginning to work up some loads for a new Kimber in 300 wsm. I am planning on using 180 grain barnes triple shock bullets. Any suggested starting points or proven loads?

Thanks,

Bill

Is there anybody out there who has been working up loads for the 300 WSM?

Thanks,

Bill

I have been working up loads for the 300WSM with 180 Nosler Partions and Sierra 180 Pro Hunter. R-19 and MagPro. MagPro is giving me the best results so far. 76gr Magpro, 215 primers, 180gr Nosler Partions avg fps 2924 in Browning Bar/BOSS. Groups are about 1 inch, I will now try and tighten them up a little with BOSS addjustments. R-19 didn't do very well for velocity, and accuracy was a bit off.

My max loads for 180's in the 300WSM has been 69grs of RL-22 in a M-70 using Partitions, and 71.0grs in a HS Precision shooting 180 Barnes TSX's. Work up slowly especially to the 71.0grs, may be too hot in your Kimber. Good luck.....DJ

I have two very accurate loads I have put together for the .300WSM. 1.) 180 Swift AFrame-WW Case-64.5gr H414-CCI250. 2.) 180gr Nosler partition-WW Case 64.0gr H414-CCI250. Both shoot better than stout bullets should and right at 2900FPS. I have tried the new 180Barnes TSX with the same powder combination with just so-so accuracy, with slightly higher velocity. If you try to replicate the above loads please work up slowly. Another .5gr and I saw pressure signs....slight resistance to bolt opening on a fired case. Max listings for this powder in the Swift manual is 65gr, but I get excess pressure signs. A good deer load I have used to kill several white tails is 165gr Hornady SP-60.0gr IMR4320-WW Case CCI250 primers. This is a max load in the latest Nosler manual but shows no excess pressure signs at 3100FPS. I could not believe the accuracy and velocity I got with the IMR4320 powder, seems as though it would be too fast for a magnum cartridge, but I believe this shows the extreme flexibility of the .300WSM.

I have been useing the 180 gr TSX with 65.0 grains of IMR4350 and a fed 210 primer seated 40 thous off the lands and getting 2972 fps with very low deviations and 1/2 MOA groups. I took 2 whitetails and a springbok, blesbok, and kudu with this load so far. Maybe someday I will recover a bullet?? Rifle is a model 70 laminate that has been pillar bedded.

Llama, in the two 300 WSM's I've loaded for I found H4350 gave fantastic results. Unlike many powders it's "temperature stable" and gave excellent accuracy at 2,950 to 3,020 fps with various 180's... I tried RL19, H4831sc and RL22... H4350 is really all you need to know about the 300 WSM.

Thanks for the good advice, everyone. I'll start with IMR 4350 and go from there.

One last question. I notice some of you are using magnum primers and some are using standard primers. The only loading manual (Barnes) I have current enough to show data on the WSM series shows standard primers. Thoughts?

Bill

I only use standard primers. Magnum's boosted pressure (seemingly) with no real gain in velocity... go figure.

Why use IMR when Hogdon "Extereme" 4350 is available? Just a thought...

Arkie, the Ruger MKII chambered for the WSM is a fine rifle and would probably be the action I'd choose if building a custom WSM. Ruger wisely widened the magazine box to accomodate three down. I ran dummies through one and they fed better than any WSM I've owned or handled. The M70's magazine is definately crowded with three in the magazine compared to the Ruger. The Ruger magazine will accomodate overall cartridge length's out to 2.880"... that's better than the M700 but not quite as good as the M70. Still, reveiwing my load notes, I believe the M77 box length would work fine. As to barrel length, the first M70 I had I shortened the barrel to 22" after chronographing it at 24"... you should still be able to run 180's at around 2,900 fps and will lose around 30 to 50 fps per inch shorter than 24". If you believe 150 fps with a 180 is an improvement over the 06' by all means go for it!

Brad

Brad.. thanks for the info. I have been looking at the short mags a while now, don't really need one, just want one.if a fella could get anywhere from 3000 to 3100 fps from the shorter barrel with a 165gr. projectile that would just about cover any hunting situation he could find himself in.Did you chrony any loads from the 22 inch barrel other than 180's. I've read over on SHORTMAGS.ORG some very high velocities from the Ruger77's in 270wsm, but can't find anyone shooting the 300.I wish they would have put a 24 inch barrel on them to start with.

Arkie, yes I did chrono the 165's... you can expect to get right at 3,000 fps. Also, I'd never get a 270 WSM with a 22" bbl... forget it!