HELLO THE CAP FIRE!

I have been using IMR 4350 to load .300 WBY, but my groups are blown all over the place. Is there a prefered powder for this ctg. The rifle groups well with Weatherby brand 180 grain store bought amunition. I am not new to the reloading game but just started loading for this rifle. I have used IMR 4350 in 30-06 sucessfully for many years. I am using CCI large rifle primers, and once fired Weatherby Brass. I hae also found the IMR 4350 in .270 with sucess adn 7mm mag with not so much sucess.

Judge Sharpe, a poor widows son

Try Rl-22, H-1000, RL-25, or Retumbo. Or check whichever Relaoding manual you have(or several) and see what they recommend. If you have a 26" barrel one of the above choices should give good results, they are all very slow burning powders, with RL-22 being the fastest of the four.

You might also try IMR-7828, it's a damn good powder for the 300 Wea.

Ditto Neverflinch, My favorite powder for normal mags is RL-22. My favorite powder for the overbore mags is becomming Retumbo. I would have suspected that Retumbo will end up getting the best accuracy/velocity but my pet 300 Weatherby shoots so well with RL-25 and 180gr Failsafes I haven't even tried Retumbo in in yet. IMR-7828 is the traditional choice but I've always seemed to get better accuracy with the others.........DJ

I always used MRP which is what Weatherby uses, but now that it is no longer available, H-4831 woks well, but RL-22 has produced the most consistency for me (81gr)with 180 Barnes Triple shocks. MV around 3150 which is a bit shy of factory specs but accuracy is right at 3/8". DJ, care to share your RL-25 formula? jorge

Try fed 215 caps and RL 25 or IMR 7828.

Every .300 Wthby I have loaded for has liked 81-85 gr of IMR-7828 with a 180 gr Interlock or Partition over a FED 215M primer. Start low and work up. My rifle cannot take over 82 gr, while my buddy's rifle loves 85 gr.

I agree with Calif Hunter again. I like IMR7828 in my .300 Southgate Weatherby. I use 84.5 gr. but that may be hot in some rifles...start lower and work up. Other slow burning powders (R22, R25,etc) will be suitable,
but you need a slow powder to to the "overbore"
i.e. case large for bore...faster powders like IMR 4350 are too fast. (I'm speaking of 180 bullet weights here). Best Regards, Tom

IMR 7828 has consistently produced the best results for me in my Sako 75 .300 Weatherby. If I want a 180 grain bullet (any kind) to shoot accurately I just put about 84 grains of 7828 behind it in Norma brass and ignite it with a Fed 215M primer. Of course, I always work up to this load when starting with any new component.

I've also had good luck with RL22, H1000 and H4831. I haven't tried RL25 or Retumbo, but I might this year. It's kind of hard to justify trying something else though considering the excellent accuracy and velocity I'm already getting with 7828 and RL22. H1000 doesn't give me the velocities the others do, but it gives great accuracy.

Here's what I'm currently hunting with:

168 gr. Barnes Triple Shock
84 grs. of RL22 or IMR 7828
Norma brass
Fed 215 M primer

Good luck with it.

IMR-7828 is the 300 Wby powder. My old German Mark V thrives on 89.5 grains of it with a Fed 215 Primer in real Weatherby brass only. Groups in the .2's with 180 grain Partitions.

Jorge, My RL-25 load is probably on the mild side. I get about 3150fps which I think will be just fine with Failsafes. The following group is about typical 200 yard accuracy with my Sako, the group isn't just a 1-off.....



Alliant list 88.5 grains with a 180 Sierra at 60K psi, so I think the 87.0 grs may be a little below max, but with a hard bullet like the Failsafe why push it for 50-75fps. I wanted a good hot weather load to maybe someday use in Africa........DJ

Hellow the Campfire!
Thanks for all of the information.
I went to the IMR site to see what losd they recomend. With a 180 gr bullet they saydo not exceed 75.0 gr 4350. my starting losd form three load books( Hornaday, A-Square and Nosler) all start) and go up to 78 gr. I have no pressure signs at all. I have a M70 with 24 inch barrel that shot sub 1" with Weatherby factory shells. Recoil from all of my loading seem about the same as the factory stuff so I can not tell if I am a lot hotter than they are. I am going to try RL-25 next, I think.

Judge Sharpe, a poor widows son

IMR-7828

IMR-7828 with 180 grain Partition. .261" group
Totally stock German 300 Weatherby Mark V Deluxe.

I, too, use IMR 7828 in my Weatherby with 180 interlock. Never had to look any further. It also worked well in my 270 wsm.

Abbottsford,Wis??? Abbottsford,BC,home of the Airshow of the same name is just up the road from me!
Another vote for 7828. derf

I got the best velocity -- 3200+ with 180 gr. bullets, and 3000+ with 200 gr. ones -- with IMR 7828 powder. RL22 gave me slightly lower top velocities -- maybe 50 to 80 f.p.s. lower -- but the best accuracy in my 300 Weatherby, a Remington 700 with a 24 inch barrel.

I haven't tried RL25 or Retumbo. IMR and H 4350 gave lower velocities and no accuracy advantage. IMR and H 4831 did seem to give a bit better accuracy than IMR 7828, but with a velocity sacrifice.

The best accuracy I've gotten from this rifle was with 200 gr. Nosler Accubond bullets, moly coated (I did it myself), 80 gr. of RL 22 (a very hot load -- don't start there), in Remington brass with a Federal 215 primer, loaded to 3.67" overall length and crimped with a Lee Factory Crimp Die. Some 3-shot groups with this load were under 3/4 of an inch at 200 yards.

I am still shooting the same pre-war M-70 Winchester which Roy Weatherby rechambered from .300 H&H to .300 Wby in 1948.

For hunting purposes I started out using 83 grains of 4831 behind 180 gr. Hornady Secant Ogive bullets. Of course, this was/is Hodgdon 4831, NOT IMR-4831. In those days IMR-7828 or RL-22 hadn't even been imagined yet.

(This 83-gr load is OVER MAX in most rifles...do NOT use it without working up to it, if at all. When I first started using this load it WAS "book max", A couple of years later, "max" had dropped to 82 grs. in some books. Over the years I have seen "max" listed by various books even lower...clear down to 79 grains in one publication.)

Later, when Nosler "partition" bullets came on the market, I switched to them, also in 180 grain weight, with the same powder charge.

This particular load will group very well, often as low as 3/4" at 200 yards and, from my rifle, averages 3,187 FPS 12 feet from the muzzle.

Lesser amounts of H-4831 behind the Nosler 200 gr. partition became my standard load after about 1980.

I admit, it kills so well and shoots so ccurately I have never felt the need to try anything newer.

If the 7828 and Re-22 powders recommended in earler posts don't "fit your pistol", try the old standby H-4831. It WILL work well enough to get the job done in style.

Alberta Canuck

I think you should try some CCI Magnum primers or Fed 215 primers instead of the CCI Large Rifle.

I use 84.5 gr. IMR 7828 in my .300 Wby Accumark for 180 gr Scirocco and 84 gr IMR 7828 for 180gr Matchkings.

I do not get the groups that djpaintles, HiredGun or others so I think I will try some of the Alliant products.

Good post.