I am loading for a Rem. 700AWR in .300 Win. Powder is RL22, Fed. nickel cases, Nosler 180P's, Fed 215's, bullets 0.02 short of the lands - Basic load data from the latest Nosler book. Max listed load for this combination is 75.5 grains of RL22 for 3118 fps.
I need 2 more grains of powder than the manual suggests to match their max velocity. I show no signs of excess pressure (sticky extraction, burnished case heads..)but do not have the tools to measure case head expansion. Everything below is the average of 3 shots chronographed with a Pact I.
As I go from 73.5 grains (2915 fps)to 75.5 grains (2995 fps), velocity increases at ~42 fps per grain of powder (the book tells me to expect ~47 fps per grain of powder in this range.
When I go from 75.5 to 76.0 grains, velocity increases at only 12 fps per grain of powder.
When I go from 76.0 (3005 fps) to 77.5 grains (3130 fps), the velocity gain per grain of powder is linear, but jumps to 84 fps per grain.
Accuracy is best at 2915 fps, but is consistent all the way up through the series.
QUESTION - Am I about to blow mysef up?

I doubt you'll blow yourself up but you're on the ragged edge. Question? If your best accuracy is at 2900 why mess with a couple of hundred fps? Check your energy at terminal range. There's not that much difference. If you hit it where you want to, what ever it is is going to drop.

I would say 75.5gr load is your max and stay at or below it a bit depending on the temperature you worked the load up at and the expected temperature you plan on hunting in. e.g. Load worked up in 80 degress and you will hunt in 40 degress then 75.5 is fine, but if ther load was worked up in 70 degress and you will be hunting in 90 then I would back off. 200fps is not worth the chance of sticking a bolt or a case in you chamber while hunting.

In my experiance if you have been gaining 50fps/grain and all of a sudden vary from that a lot (either up or down) you have reached the MAX for the cartridge in question.

BTW - I agree with Bob338, of the loads you listed if the 2915fps is the most accurate I would use that. The confidence you have in the accurate load will far out way the 200fps gain.

Good Shooting
Jeff in ND

Thanks Bob338 and Jeff. Loads were shot at ~70F and I'll surely never hunt at temperatures above that up here. Why did I do it? I considered that my chamber may be been on the large size and responsible for velocities substantially less than the book (the gun averages 80 fps under book for 9 factory loads and 140 fps under book for 7 handloads). I was also looking for another sweet spot for accuracy at a higher velocity within the generally reported velocity range for a .300 Win./180; I had hoped to hit it again by ~3050 fps, but it didn't happen. When I got home and plotted velocity gain vs. grains added I vaguely remembered hearing something about the relationship becoming non-linear when approaching no-no land, but couldn't put my hands on the article. Another symptom of something becoming fishy that I did not mention earlier was a 50% jump in SD coincident with the velocity gain becoming non-linear. 2915 in 0.4" @ 100 yd will do nicely.

Compare the casecapacity of your cases to the cases from the book, it can vary a lot in 300WM.
Hugh.

Froze Buba,
your fine, most of todays manuals are two grs. or more under max because of litagation fear...99% of my loads are over book max. and safe in my guns...

However, one thing to keep in mind when loading for max velocity is that at some point you reach a point of deminishing returns and start getting about 20 or 30 FPS increases per grain of powder, THAT'S the time to cut back a little as your just pissin in the wind with thoes kinds of gain, and it's not worth the wear on brass..Find your accuracy, a 100 FPS gain is not important in the game fields.

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Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com