Anybody got any pet loads for a 300 wsm with 150gr Interbonds? I can get some good groups with 150 SSTs and IMR4350 and WLR primers, but 150 accubonds and 150 interbonds don't seem to want to shoot as well.

Another question, do you guys use magnum primers in your 300wsm? My best groups have been with mild loads and large rifle primers, but looking to try something different to get the bonded bullets to shoot better.

I know you've asked about 150's, but I feel compelled to offer my experience otherwise.

I have a Browning A-Bolt Medalian in .300 WSM that I was about to use as a boat oar until I was convinced to accurize it. Well, I did (Glass/Pillar Bedding, trigger honing & locking lug truing) and now I've developed two loads that fill every need I can think of;

165gr Interbond @ 2800fps for med game (62.5gr IMR 4350 & Fed 215 primers) and everyting else (Barnes 168gr TSX w/ 66.6gr RL19 and CCI 250 primers at 3000 fps) Both loads are under 1 MOA sanbagged, of course. Up to me off hand, well, they look like a scatter gun group )

All loads are for MY rifle only and should be worked up to safely following published loading guidelines.

Good Luck,
EMC2

My 300WSM likes WLRM primers.

I had a really hard time finding a good 150 grain load. 165, 168, 180, and 200 grainers were no big deal...but I struggled with 150's a lot. Eventually I had to settle with (1-2 grains below book max) fast powders in the 4895 and Varget range. Velocity was well below potential (around 3000fps IIRC) than with slower powders like 4350 or 4831, but accuracy finally hit MOA...using matchkings and ballistic tips.

With 165-200 grainers, this Win M70 (stainless synthetic, bedded) is a .6-.75" rifle from the bench...so the MOA with 150 grainers was less than optimal.

My 300WSM experience is somewhat limited.
I got really excellent results with 150 SMK bullets over IMR4350 and Fed. Match Mag primers ( 210's ). Powder charge was at the lower end of the data just above the start charge.
My testing was done at a measly 100 YDS , and made ragged holes , some as small as .250 ( center to center ) with an out of the box Savage heavy BBL short action.
YMMV , I am in awe of this rifle , maybe I just got the luck of the draw.


Travis F.

Looks like most people are using mag primers. I'll change to some Federal 215's and see if the groups tighten up with the higher charges. I haven't really thought about trying varget, but I've got a couple of pounds on hand. I may give them a try with the 150's and see what happens.

OOPS !
215's not 210's...


Travis F.

The accuracy crowd is using BR-2's and Fed 210M's.
Mag primers don't seem to give a consistant burn with the 300WSM.
I'm currently working up a load for the 210 Bergers. The first test looks like this.

What are the Federal 210M primers? I thought 210's were plain large rifle primers, what does the "M" designate?

I loaded some 150 ABs up one day for some foulers and they shot pretty well. 150 ABs ontop of 70 grn H4831. Win brass and WLR primers.

Good Luck

Reloader

The M stands for Match.

Swamp Fox,

Those are some pretty impressive groups as a work up. If you're willing to share, I'd appreciate the load and rifle used to make them.

Many thanks,
EMC2

jb177,

The "M" means "match". They are a bit more consistant than the regular primers.

EMC2,

The number beside each group is the grains of IMR-7828ssc used.

Shot from a reciently customized Savage model 12 in 300WSM.

Norma brass
CCI BR-2 primers
Berger 210VLD bullets

Velocities

1) 2662.0 6) 2720.0
2) 2637.0 7) 2727.0
3) 2674.0 8) 2746.0
4) 2674.0 9) 2774.0
5) 2695.0 10) 2790.0

I got to the range late so there is one velocity reading (the first shot) from each group due to failing light. These were shot round robin with a 10 min cooldown between every 5 shots.

Thank you Swamp Fox,

Curious, any cleaning between groups?

No cleaning between groups. Shot 5 rounds to foul the barrel.
The barrel was fairly hot at the end, even with the 10 min cool off between 5 shots.

I'm amazed on how accurate my Win. Mod 70 Featherweight 300 WSM has turned out to be. The only thing done to it is to smooth up the trigger. With 150 Accubonds and 72 gr. IMR 4831(warm),F215, I get 3 shot 3/4" or less groups and 3350-3380 fps. I've talked to other Featherweight owners and they have had much the same experience with this rifle/cartridge combo.
Just my .02.