Home Forums Reloading Big Game Rifles 300 Weatherby

Gonna try out some 180 SST's IMR 4350 and Siroccos H4831 tomorrow and see how it does. I only have Weatherby brass.

Had really good accuracy with 200 partitions and IMR 4831. Heard about false shoulders for fire forming. Didn't really thoroughly get all the info on it. Only have RCBS FL die set. So just partially neck size to chamber with a stiff load and it should be good ? Please, only people who done it, reply.

Lots of ideas out there, but I have been shooting a 300 WBY for quite a few years. First of all, I would recommend full length resizing. Weatherby has higher chamber pressures than most standard cartridges will be loaded to and that will cause the brass to expand quite a bit.

I load 180 grain Nosler Ballistic Tips and get great accuracy with those bullets and IMR 7828 SSC powder with velocity near 3200 fps. You will probably find IMR 7828 the best accuracy and velocity in the 300 WBY.

Bonded and partitions aren’t necessary either, I have killed a bunch of elk with that combination and you will find Nosler will substantiate that…

Agreed.
if it is a weatherby use 7828 first

Always try 7828 first. Shrap suggests a great bullet too. That's what I started out loading in my 300WBY's. 84 grains usually did the trick quite nicely. However lately, I've tried the 175 LRX with 7828 and they shoot damn well.


H4831 is also a great powder to consider.

As far as sizing die setting. It's just like any other cartridge. PFL sizing with your RCBS die will work just fine. The 300WBY is not that finicky.

Best accuracy in our .300 Bees has been with 150 or 168 gr TTSX. The 200 gr NP also gave decent accuracy in our guns. 7828, yes, all day. F215 dogma notwithstanding, have done just as well with WLRMs.

Be aware Remington and WBY/Norma case capacities differ substantially. Comparing various data manuals should be enough to understand this. But never stuff a max charge safe in WBY brass into a Rem case.

Need to do the false shoulder drill is binary. You either need it, or you don't. If factory loads fired in your rifle end up with incipient separations above the belt after a couple firings - whether you FL, PFL, or neck size - you ought to consider doing the false shoulder drill. It is far more reliable and productive than the other technique: sticking the bullet hard into the lands. Good luck sticking a bullet in the lands of a WBY, anyway.

The false shoulder drill is very simple to perform. Have done so for multiple rifles, not all of them belted cases. On a .300 I just run virgin case necks over a .338" button, then back down just enough so chambering requires effort. After firing, can neck size several times before a slight shoulder bump is needed.

Same method here. 338 mandrel and then size to fit. Pretty easy deal.

My sons 300 gets a steady load of 7828 and 200 grain Noslers.

7828 going once, going twice………….

How is it temp sensitivity wise ?

One other thing...20 years ago a guy told me get a Weatherby and forget it. At the time I was just getting into shooting and hunting, and my father in law shot a group he covered with his thumb, that his Rem 722 .222 rem made. So from there I struggled through trying to make my 200 dollar rifles shoot. Did I have to buy a 1500 dollar Mark 5 ? No. I bought, back in '14, a Vanguard, 300 Weatherby, synthetic stock, two lug bolt that was too easy to load for. My Winchester M70 shoots well, but I can't seem to fire form that easy.

Question.. According to SAMMI the case head to datum on the cases for the 300 is 2.3857 + .008 ? = 2.394 base to datum fireformed or minimum HS ?

Don’t let the internet get to you. Most of what you read is irrelevant. I have hunted my entire life with all sorts of guns, modern and antique and never checked datum. As a matter of fact, I never even heard of datum.

Full length resize your brass, watch for the incipient case separation that was mentioned earlier and load up your 300 with 7828 and your favorite bullet. It will work and the weather won’t affect it enough that you or the elk will ever notice.

Before you go hunting, run all the ammunition through the action that you are taking with you to make sure you don’t have any tight cases that may interfere with the cycling of your action when you are shooting. The 300 WBY can stretch the case enought to make it hard to close the bolt even with the gun you first fired it in…

I've only used Weatherby factory ammo, but my .300Wby Vanguard loves 180grn TTSX's. And they do a number on cow elk.

as another LOONY here 300 Weatherby mag. is a great cartridge and i feel the only 3 actions i would have a 300 Weatherby mag. in is a Weatherby mark 5 , Ruger #1 , or a Winchester model 70 with the claw, in all 3 manufactured rifles.

Good post. I often see and read about temp sensitivity. My best suggestion is to work up your load in the fall/winter months. Around the same temps you intend to hunt. Absolutely no issues or concerns doing it this way. Most of us are not going to be hunting elk in the summer time. The LRX load I worked up for my 300wby rifle was worked up in late October (right before elk season). Temps were in the 30's:


Then after double checking poi and accuracy after replacing the stock:

Temp was in the 40's, so little to no difference in accuracy.


I tend to work up all my elk hunting loads in cold weather. The matching pre 64 338wm to my 300wby that shot those groups above:

Same thing. Never worried about my loads worked up with so called temp sensitive powders. I run a lot of IMR4350 in my 30-06's without worry as well. The obsession about whether it's "temp stable" or "temp sensitive" should be left to the varmint hunting rigs, not elk hunting rigs. Generally speaking..

what's this pre-64 model 70 rechambered from a 300 H&H or custom barrel?

One load with 7828 wasn't good.. 86 grains barnes 150 TTSX 1-1/4 inches at 100
Best groups were RL 25 and H4831. 82 of 4831 w/ 168 TTSX 3/4's at 100, 82 of 25 w/ 200 PT..1/2 inch at 100, 72 of IMR 4350 w/180 SST 1 inch at 100. Got rid of 25 and 7828 and H1000, I know.. why !?? Got mag pro thinking it would be better.

I say this much the hot loads, max charges are the best, no matter what powder. I guy I used to hand with said his buddy ran his barrel hot getting mad because it wouldn't group, .338 Win Mag. The hotter the barrel got the better it shot.

Ok so I'm ok with just FL sizing. What bullet shines with any powder you guys loaded with any powder ?

A Ballistic Tip or similar Hornady or Sierra can be pretty easy. Usually if a rifle won't shoot any of those for beans, something is messed up.

Forgot about the Nosler BT. Funny story about the same guy who knows another guy who's 06 would not shoot any factory ammo at all. Loaded a BT problem solved.

IMR 4350 is one of those temp powders. I don't usually load in the summer months anyway. My 06 and 270 like 4350.

Don’t get too caught up on groups. A 1 1/4 inch 100 yard group is 6 inches at 500 yards. Remember you aren’t shooting bench rest here, you are shooting elk. 6 inches may sound like a lot, but the truth is, you are still only 3 inches from point of aim and that should keep you in the kill zone of an elk.

You don’t need a 1/2 inch group to kill elk…

I don't need tight groups but it keeps me busy between seasons. Just like to see what the rifle is capable of that's all. I only hunt deer, no elk for me. I could do a lottery in PA but I can't justify paying for years just to kill an elk. Although there are some really nice ones up where I go.

7828 is the tits in the 270 Westherby mag also..mb

very good advice and trying to get a super load for a tight group with the recoil can be painful too .