I am loading some 300 Wthrby's. for an uncle and will be using a 180gr. Speer Grand Slam. I was looking through my load books last night and this powder kept getting my attention as one of the top powders for this cal. What has been your experience with this combo of powder and caliber?
My other choices of powder are IMR-4831 or RL-22.
Thanks,
Elk Country

Although 7828 seems to get you the highest velocity, accuracy in my rifle was not up to par. Best results were with RL22. I did play with RL25 as well but it seems to be too slow for good results. IMO Rl22 is the best option.

You'll only know when you try it.

I load for the 300 win mag and 300 H&H and use IMR-4831

There's no reason the 7828 wouldn't do as well.

quote:

Originally posted by fritz454:

Although 7828 seems to get you the highest velocity, accuracy in my rifle was not up to par. Best results were with RL22.

I agree with this. With IMR 7828 I get 3200+f.p.s. from 180 gr. bullets and 3000+ f.p.s. with 200 gr. bullets from my Rem. 700 in 300 Weatherby, with its 24 inch barrel. RL 22, however, gives me better accuracy, at a sacrifice of 50 to 100 f.p.s. in top velocity.

I got my best accuracy ever from this rifle with RL 22 and the 200 gr. Nosler Accubond bullet.

7828 is THE powder I use for the 300 Wby. 85 grains behind a 180 Nosler partition gives me 3220 fps. and 3/4 inch groups. Animals die quickly.

IMR 7828 is my go to powder in 300 Weatherby. But I'm using a 200 grain bullet. It has been my fastest and most accurate.

I also use the 7828. With 200gr bullets I am getting 3000 fps with a 24" model 700. I am not happy with the accuracy (1.5") but I am not blaming that on the powder just yet. I am trying some 180 accubonds with 7828 just to see. I tried RL25 with the 200gr and got erratic velocities. I think I will pick up some RL22 at the next gunshow and give it a try.

IMR 7828 - Best velocity and most accurate out of 2 Winchester 70's in 300 Wby. that I've owned - one blue, one stainless. 180 gr. X-bullets at something over 3200 fps and I've gotten a couple groups around 1/2" @ 100 yards. Under 1" is the norm for my particular rifles. Works great with 200 gr. Partitions and 200 gr. Speer PSP also.

My 300wby likes RL22 with 180gr bullets, I get my best accuracy with 200gr bullets using 7828. I am only getting 3170 using 81.0 gr of RL22 with a 180gr TSX, but I have a short throat. You'll just have to try each and see.