With one of the first nice days of the winter.....in the upper thirties and a lack of howling winds, I was able to get out and fire a few shots over the pro-chrono . FWIW to anyone.......
The gun is a M-70 classic stainless 300 wsm, once fired W-W cases and regular strength WW primers . 180 gr. Nosler ballistics seated to 2.9 inch OAL . None of the shots showed primer flattening or heavy bolt lift .
62.5 gr. 2890 fps
64.0 gr. 3003 fps
65.0 gr . 3062 fps
Well, obviously we've all started to hear a bit of the RL17 BUZZ, and I've been curious about it for some time.
Since I've known SD on this and another forum for a good long time, and I know he's an honest reporter and a guy that doesn't red-line, his RL17 post sparked something in me to try and locate some of the stuff... as luck would have it, one stop at Yellowstone Gateways Sports and I had a pound (they got their first shipment yesterday!).
I'm totally under the weather with a cold, but since I found out my 300 WSM has a potential liking for the 200 gr Partition, and since it was a drop-dead beautiful, warm, and windless day, I decided to ignore my cold and work up some loads based on SD's post and the Alliant website.
I took the Kimber MT and went up to our property in the Shields Valley this evening (the nearly full moon was just rising over the Crazy Mountains). I set up the chrono and bench and hunkered down for some shooting.
200 gr. Nosler Partition / WW Bras / Fed 210 Primers / Seated .030" off lands:
62.0 = 2,858
62.5 = 2,861
By comparison, 61.5 gr's of H4350 gives 2,801 fps in this rifle.
180 gr. Nosler Partition / WW Bras / Fed 210 primers / Seated .030" off lands:
64.5 = 3,037 fps
65.0 = 3,067 fps
By comparison, 63.5 gr's of H4350 gives 2,954 fps in this rifle.
All loads gave similar (easy) bolt lift as my H4350 loads (which are .5 gr's below Hodgdon's MAX loads).
With the 200's I'd go with the 62.0 gr load... it gives exactly the same .9" accuracy that H4350 has given and obviously going .5 gr higher yielded very little velocity gain which leads me to believe the 62.0 gr load is MAX in my rifle.
With the 180's I'd be comfortable with either 64.5 or 65.0 gr's... since I'm conservative by nature, I'd go with the 64.5 gr load just to keep everything nice and easy.
This particular Kimber dotes on 168 TSX's and now (apparently) 200 partitions, but absolutely doesn't like any 180 grain bullet I've tried in it (go figure!). The 64.5 gr/RL 17 load turned in a 1.25" group (which is totally acceptable) but this rifle shoots much better and more consistently with heavier and lighter bullets.
So, at first blush I'd absolutely give Alliant credit that, at least with the 300 WSM cartridge, the hype appears to be true. Obviously more testing is warranted but, so far, I'd cautiously say RL17 is a real winner, giving identical accuracy as H4350, but a fair bit more velocity.
BTW, a word of caution, Alliant's site lists 66.0 gr's with a 180 Speer (300 WSM)... that would be over MAX in my rifle.