I saw where you have been loading the 300 WSM and was wondering if you would be willing to share the results of your loading with the rest of us. Might save a us a lot of time and experimentation on this new round.

I'm particular interested in your powder and primer choices. I've heard that primer makes more difference in this round than in longer magnums.

Thanks.

GA:

Sure thing. I worked up my loads in a Winchester M70 Featherweight .300 WSM. I hand weigh each charge.

I tried the listed loads using W760 which are found the the Winchester ammunition website and was very disappointed. Some of the loads were too damn much for my gun. For example, they list 66.9 grains with the 180 grain Power Point flatbase bullet for 2960 fps. I could not get past 65.0 grains with a Hornady 180 grain boattail bullet (which has less bearing surface than the Power Point) without sticky bolt lift.

W760 apparantly also has some extreme temperature sensitivity in this cartridge. Using 65.0 grains and the 180 grain bullet, on a 70F. day the chrono registered 2935 fps. On an 85F. day it was 2995 fps, with some rounds close to 3050 fps, and bolt lift got sticky. All shooting was in the shade if you are wondering.

The Winchester factory ammo is very accurate. But it showed the same wild velocity swings with the temperature variable.

All of which is not really a good state of affairs if you are handloading in the summer for a fall hunt at 25F.: your trajectory and zero goes to hell. Nor for loading in Ann Arbor for your safari in Cameroon at 95F.: the gun blows up (note, JUST KIDDING, -- but an over-pressure round can stick the bolt or cause some other problem).

The results were similar with other bullet weights. W760 was accurate but I didn't care for the velocity and pressure spread.

I figured IMR4350 was close in burning rate so I gave that a try. But velocities were disappointing before pressures went up, and accuracy lousy.

Alliant powder data hadn't been made available at the time I was developing, but it is now on their website. I wouldn't use it anyway as the results are inconsistent temperature-wise in every cartdige I've used them in. In that regard, I've found RL-15 ok, but RL-19 not too good and RL-22 plain awful.

I don't use Accurate Arms powders so I wasn't about to start experimenting with an unknown quantity, but they were the first to publish data.

On a lark I tried H4340 and was immediately pleased. The velocity readings are excellent, the 180 grain Hornady hitting 3040 fps with no excess pressure signs, although I load it to 3000 fps. Accuracy is 3/4 MOA.

Now for a word about primers. I use WLR primers, not WLRM or any magnum primers. WLR primers are the hottest non-magnum large rifle primer, according to comparative tests I've seen in several published sources. It's my opinion that the shorter powder column in the WSM does not require a magnum primer, and the WLR is enough hotter than other standard primers to ignite the whole charge without going overboard pressure-wise and wrecking accuracy.

Hodgdon subsequently published data. However, the Hodgdon (and later Hornady) data was developed using WLRM primers (magnum). By using standard WLR primers in my rifle, charges with H4350 are somewhat higher than Hodgdon or Hornady has listed, and there are no pressure signs, and the primers pockets are tight. This has resulted in a higher velocity for some loads. In the WSM case, I believe all a magnum primer does is raise pressure without any increase in velocity, and is detrimental to accuracy.

So I'm not going to publish what my charge weights are, but they are completely safe in MY rifle with WLR standard, not magnum, primers. The only powder I use now is H4350. The velocity averages are within 15 fps at all temperatures from 50F. to 90F.

As for bullets, the Hornady 150 grain SST shot incredible sub-1/2 MOA groups with all the powders. It also shot well in a Browning A-Bolt I tested. I load that bullet for medium game at 3275 fps with no problem. Funny, that bullet shoots like crap out of my .308 Win.

The 180 grain Hornady is accurate (3/4 MOA average) and I think it would be fine for any game under 800 pounds. Having used Hornady's before in this velocity range, their shocking power is excellent. However, if you hit a shoulder on thick game you won't get complete penetration if that is your thing. The vitals will still be wrecked, though.

At safe charges, the Nosler Partition and the Speer Grand Slam get about 50 fps less than the Hornady in the 180 grain weights.

I took a load using the Sierra 200 grain SBT at 2870 fps to Africa. Accuracy is 3/4 MOA, and the terminal effect is excellent, on everything from little Impala to big Blue Wildebeest. I like this load when hunting a variety of game of different sizes. I was considering hunting Eland which are on the order of size of a large Moose, so thought the 180 grain bullet might be a little too light. The extreme B.C. of this bullet retains good velocity and energy at long (300+ yards) range.

If you are maniacal, you can get 2650 - 2700 fps with 220 grain Hornady bullet, and blast down brush on the way to your chosen game animal.

I full length resize all brass. I didn't intend to, but the RCBS dies will not allow anything else. When I tried to set up for partial resizing as I usually do, the cases would not rechamber easily. Perhaps this is an RCBS thing as I have encountered it before with their dies. A Hornady or Redding or other die might allow partial resizing.

Case stretch is very minimal. I trim after the first firing, and neck anneal after five. The cases haven't needed trimming again until the 10th firing. At the 10th, resize, trim, and then anneal.

Hope this helps.

[This message has been edited by KuduKing (edited 12-06-2001).]

[This message has been edited by KuduKing (edited 12-06-2001).]

KuduKing,

Thank you very, very much. Your info is a sure to be a great help.

H 4350, huh. This is the first time I have heard this load mentioned. I was under the impression that Reloader 19 or 22 was to be the powder of choice. It's a shame it's not since I have scads of both.

I can live with the 50 fps reduction in the Grand Slam load since I am so attached to this bullet. I love the terminal performance on the Grand Slam, having taken several elk, mule deer and whitetails with the same load. Like you said, better expansion than other premium bullets with still enough penetration to take large game. Also, even if trajectory is more accute with the Grand Slam, it is very consistant. I'm become pretty good at adjusting for distance in my other rifles, taking a mule deer three weeks ago at 400 yards with a Grand Slam loaded in a 300 Win Mag.

I am now getting ready for a moose/caribou hunt in Newfoundland next fall and will try other bullets in my new WSM. But I suspect that I will have matriculated back to the old Speer stand-by when the final rounds are packed for the trip.

I like how the Grand Slam performs too. The expansion and penetration is excellent and the weight retention is about 80%.

I have lots of RL19 and RL22 myself, but H4350 is very consistent and so I won't compromise just because I have lots of the other stuff. I sometimes trade it with other shooters.

For moose and caribou, why not try the 200 grain Grand Slam at 2800 fps?

200 grain bullet would be great for moose, but woodland caribou rarely exceed 400 pounds and shots can be upwards of 300 yards. The 180 is better suited for the duel role of taking both.

By the way, Kudu, what is the maximum case length and the trim to length of the 300 WSM?

Also, Hodgdon shows the maximum load for the 300 WSM as 64 grains of H4350 with a 180-grain Swift Scirocco, which is the only 180 grain load they show. WHY WOULD ANYBODY USE THIS BULLET IN A 300 WSM? Every gun writer in America has been recommending bullets with lower ballistic coefficients in the short mags because of the reduced case volume. Are you exceeding this load? You must be if you are getting over 3000 fps.

My gun won't be finished for another month (I'm having a custom rifle built in this caliber). I've already got components, but I'm afraid to start loading until I get the rifle and can measure the freebore.

The case OAL is 2.100" and the trim length is 2.090".

My H4350 charges, in MY rifle, exceed the Hodgdon published loads. However, they are using the very hot WLRM primer, and I'm using a standard WLR primer which reduces the pressure for the same powder charge.

Don't ya hate having to wait to load ammo? But it's better than pulling bullets......

I had excellent luck this weekend with 66 grains of RL22, CCI 250 primer and a 180 grain Swift A-Frame. .75" grouping for 5 shots at 100 yards from a synthetic SS Win 70 .300WSM.
Overall cartridge length was 2.810. Factory Winchester cases full length sized. This bullet has a cannelure and I adjusted the seating die to apply a slight crimp.

No chrony was available so I don't have velocity info .

So far I've tried IMR4350 with 180 grain Failsafes and 200 grain Barnes X. No luck yet with either bullets or powder.

Jeff

JHC10,

From what I've been reading, stick with the shorter bullets, like the A-Frame, in the WSM. I know Winchester offers their factory load in the Fail Safe, but that is with a faster powder than what you and I will be using. I haven't heard of anyone having success hand loading it.

Sounds like that Reloader 22/A-frame combination is a winner. Too bad you couldn't chrono it.

JHC110:

That sounds like a great load for heavy game (elk, moose, etc). I am going to guess that the velocity will only be 2850 fps though. RL-22 has a bad, and well-deserved, reputation for temperature inconsistency, with swings of 100-150 fps over a 50 degree range not uncommon. I don't have experience with it in the WSM case, so maybe it will prove better in that regard.

How do you like the stainless rifle? The accuracy is certainly there.

I don't shoot or load for the .300 WSM. But I do find the comments here about H4350 to be very interesting. I've found that this powder is significantly different from IMR 4350 -- it's slower burning and much more consistent. In loads that I made for the .375 H&H using H4350, for example, my shot-to-shot velocity variation is very small, and sometimes two shots will have exactly the same velocity. So, if you've tried IMR 4350 and gotten disappointing results in an application where, from loading table, it would seem to be a good choice, don't assume that results with H4350 will necessarily be similar.

It's unfortunate that these two powders have the same number, as this leads to much confusion about them.

KuduKing, this is my second Winchester Mod 70. I own a Featherweight SS in .270 that shoots Federal 140g Trophy Bonded Bear Claws into .580" groups all day long. It also shoots 130 grains almost to the same point of aim and just slightly larger groups. This rifle has spoiled me.

My expectations were high when I bought the .300 WSM. Buyer's remorse has me wishing I'd bought the Featherweight instead.

I don't like the stock & will replace it before going to Africa with a McMillan Hunter stock. I can't get the trigger to less than 4lbs. without an accidental release with a blow to the butt. So it's off to the gunsmith to see what kind of miracles he can perform. Stainless actions are not as smooth as chrome moly in my opinion.

With all that said, however, I had a smile a yard wide with the group I got from the Swifts.

This rifle is to be my main firearm for a plains game hunt this September in RSA. I would like to have some 200 grain loads working for the trip as well.

Jeff