I picked up a 300 H&H a few months ago and I'm trying to figure out a load for it with 165 grain bullets. I loaded for the 300 H&H about 15 years ago but since that time I know my reloading manuals are out of date. Looking at the new Hornady Manual and it shows a max load of 64.3 grains of IMR 4350 at 3000 fps. The Sierra Manual list a max load of 69.3 grains of IMR 4350 for the same bullet at 3100 fps. That's a big difference in powder weight. I loaded some rounds with 64.3 grains of IMR 4350 and a 165 grain Sierra BTSP and they chronographed at 2775 fps. The rifle with this load recoiled like a .308 Winchester, not a 300 H&H. Does anyone have any idea what the load should be for this caliber now given the vast difference in powder weight between these two manuals?

Every rifle is different so one mans load is not going to produce the same results in another.

Having a baseline now with your mild load of 64.3grs giving 2775fps, I would load 2 rounds each working up a grain at a time to 69.0grs. Maybe jump to 66.0grs to start i.e. 66.0, 67.0, 68.0, 69.0.
Your chronograph will tell you where you are going.
Work up to the velocity you want monitoring pressure signs along the way and then tweak for the grouping you want.

Reloading manuals are notoriously inconsistant.

What powders do you have?
I've had great results with everything from 4350 to Reloader 22.

Perry

Thanks Eagle27 and perry,

I was going to try going up in small amounts and chronograph the loads to see if I can get to 300 fps without any noticeable pressure signs. I have several different powders I can try but I always had good results with IMR4350 in this caliber.

Got to the range this weekend with the 300 H&H and continued working up loads. With the 165 grain Sierra BTSP over 69 grains of IMR 4350 the rifle's velocity was exactly what it should be. The rifle averaged 3050 fps from the 24" barrel which is right on track with what my 1995 Sierra Manuel stated. There was no sign of high pressure. It amazes me why the Hornady Manuel lists a max load of 64.4 grains with that combination of bullet and powder.

quote:

Originally posted by Tpr.1919:
Got to the range this weekend with the 300 H&H and continued working up loads. With the 165 grain Sierra BTSP over 69 grains of IMR 4350 the rifle's velocity was exactly what it should be. The rifle averaged 3050 fps from the 24" barrel which is right on track with what my 1995 Sierra Manuel stated. There was no sign of high pressure. It amazes me why the Hornady Manuel lists a max load of 64.4 grains with that combination of bullet and powder.

If accurate, that load and bullet should be a great performer on game. I think the 165gr weight bullet in the 30cal is perfect for the magnums.

My nephews friend was using a 300 WinMag with 165gr Hornady SST bullets in his reloads on one of our tahr hunting trips high up in our Alps. Can't recall the MV for his load but was right up there for long range shooting using a rangefinder and dial up scope. The load certainly worked well at long range on bull tahr.

Trp
You can safely get into the 3,100's with that bullet if you are looking for more speed. I'm high 3,000's with 180gr bullets and no pressure. Using the 165 gr bullets I do not think I've done it with 4350 though. I believe 4831 and 4955.

Perry