I just crossed over to the dark side and bought a Howaby 300 Weatherby Magnumb. According to the Weatherby website it has a 24" barrel and a 1 in 10 twist.
I am looking for favorite loads in 165, 180 and 200 gr bullets. Any loads for the 180 TSX would be great.
I plan to start with H4831SC because that is what I have on hand. Will be trying other powders later on.

Thanks
ZM

Don't everybody speak up at once

ZM

H4831sc is a faster powder than I prefer for the .300 WBY, a cartridge that really shines with slower powders. However, your rifle may do well with it. I have come to prefer H1000 in my .300 Wby. IMR7828 and RL22 have given me good results as well. Though, I recently helped a friend develope a load using IMR7828sc and was not impressed. It seemed to be faster than any 7828 I have used in the past. Most of my shooting/loading has been with the 200 grain Nosler Partition, which out of my 26" barrel is initially sent on its way at around 3075 fps. For your 24" barrel I would expect a loss of 50-75 fps. I am reluctant to publish my max loads but I would start with 80 grs. of H1000 and develope a load from that baseline. My starting point for 7828 is 78 grs. and with RL22 74 grs. Do you have a chronograph? You really do need one if you are going to be working up loads from scratch to ensure your margin of safety. The Nosler number four and five manuals have excellent data as well.

I have a chronograph. I have a lot of H4831SC on hand.

I use H4831SC for most of my 270 loads. Makes sense to try it in 300 WBY since I have so much on hand.

I like the RL powders. I plan on trying RL-22. I'll add H1000 to the list. I have no plans to really push the envelope right away. No reason to right now.

And all this time I thought H4831 was a slow powder?

I am robbing a scope from the Tupperware Special to put on the Howaby. However, Monsoon Season just kicked off. It is either raining sideways at 40mph or snowing up at the gravel pits. Might be some time before I can wring the Magnumb out properly.

Thanks
ZM

Zeke,

I agree it seems odd to refer to 4831 as a fast powder as it along with the 4350's are probably the classic slow powders. I think that it will serve you well. I use it exclusively in my .416 Rigby and have used it in the .338 Win, .340 Wby, and .358 STA with good results in all. Instead of RL22 I would give RL25 a try. I've been meaning to try it but haven't gotten aroung to it yet.

My rifle, and every one I have tried, likes IMR-7828. I have not tried the short cut version of it. You will probably find the max load to be 82-85 gr of it with a 180 gr bullet. Be aware of the brass you are using - Remington tends to be thicker, I believe, and you cannot load as heavier a charge of powder in it!

Start at about 78-79 gr and work up slowly.

mine is

powder imr 7828.......79.5 grs

barns x 165 gr

fed primer
works great

Sierra 165 HPBT in front of 85.0 Gr. of IMR 7828 (the old stuff, not the newer version). 3125 FPS. Bring a bag to pick up the pieces.

Catmandu

I have had great success with IMR 7828 in my 300 WBY. I used 84.0 grains of it with the 180gr Barnes TSX. Of course though you will have to work up to the loadings for your own rifle. The barnes TSX's shot very well in my rifle, hopefully they will in yours.

quote:

Originally posted by safari:
I have had great success with IMR 7828 in my 300 WBY.

After a lot of testing that is the go to powder for my 300 as well. I'm shooting a 200 Gr. Sierra Gameking.

I use pulldown WC860 (out of military .50 BMG rounds) from Hi-Tech. Broadly similar to H870, mine seems to be slightly faster burning. The lot I have is volume limited in my rifle with 180 and 200 grain bullets. I can't get enough into my cases to produce pressure signs in my rifle, and the velocities are full load level (i.e., 2975 FPS w/ 200 grain Speer spitzer from 24" barrel) but not the highest possible. I use CCI 250 primers in Remington brass, neck sized with a Lee collet die and crimped tightly with a Lee Factory Crimp Die. Extreme velocity spreads typically run in the 10-20 FPS range, and it'll consistently shoot 100 yard groups in the .75" - 1.25" range at 100 yards. The Vanguard's magazine box will only work with bullets seated to the factory OAL, to the cannelure in most cases, and it's got around 3/8" of "freebore" before the bullet contacts the rifling. The crimp will aid consistent ignition in this situation.

I tried some AA-4064 67grs in a Rem case, with a Fed 215 primer and a 150gr Nosler BT, shot sub moa, and a mild recoiling load.

As for H4831SC, that's the first powder I tried. In my rifle, I hit high pressures rather suddenly a couple of grains below book maximum loads (which were loaded in Weatherby cases, I was using Remington.) Loosened primer pockets and ruined some cases.

None of my business, but I don't think a slower powder than 4831 will burn completely in a 24" barreled 300 Wby. I had a Win model 70 push feed 24" barrel and found H 4350 to be the best powder for up to 180gr. bullets. I now have a 28" Gaillard on an Enfield that likes the RL25 and WC867 types. My action and mag box have been modified to allow bullets to be seated out. Velocities are about 200-250 fps faster than the Win. I am not at home right now or I could look up some data for you. Mark

Well, there are slower burning powders that work well in the .300 Weatherby, whether they "completely burn" or not. My favorite is WC860, a .50 BMG surplus powder that's comparable to H870. It is inefficient in terms of charge weight for velocity, but it burns cleanly, gives excellent accuracy and consistency of velocity, and was very inexpensive.

'from a 24" barrel' I couldn't get any better vel. from a 24" barrelled Wby than a similar 300 win.This was my observation with 4-500 rd. fired.Your mileage may vary> Mark

I have been using 4064 for 8 yrs but I think just to see I am going to try 7828 ,I just bought a 7mm STW I could use this in both.

I have very good luck with H4831 in a 24" 300 WBY. 200 Noslers at 3100fps. Yes full power but case life was good and accuracy was great. 7828 works very well for speed as well.