I just took my newly finished .375 Wby. out to check her out. I was primarily intending just to take a few shots to familiarize myself with the trigger, the hold, the cheek weld, etc. I had some 250 gr. X-bullets over 86 gr. of AA-4350. Barnes claims a shade over 2900 fps with 87 gr. of H-4350 with a 24" barrel. I got dead-nuts 2700 fps. out of a 26" barrel. What the heck??? Is there that much difference between the 4350's?? I had heard that AA-4350 generally put out more velocity than either Hodgdon's or IMR. Anybody have any experience or words of encouragement??

AA4350 was a slow load in 375 HH and 250 Sierra. RE15 or IMR4320 faster, also 4064. Swift manual quotes H380 as being a fast powder with 250 AFRAME, in HH.

Did you get pressure signs?? Sometimes you need more AA 4350 than either IMR Or H 4350.

You should have used:
IMR-4320 From 74.0 grains to 79.0 grains
Federal 215 Primer

And there is a difference between the 4350 powders:

Faster
*176 IMR-4350
*177 H-4350
178 S-365
179 TU-7000
180 N-550
181 H-205
*182 AA-4350
Slower

quote:

Originally posted by bowhuntrrl:
Did you get pressure signs?? Sometimes you need more AA 4350 than either IMR Or H 4350.

No visual pressure signs. Very rounded primer edges, buttery-smooth bolt lift........ I did not do a PRI measurement. But, considering the load density at 86.0 gr. I don't think I'll be able to fit enough powder in the case to achieve the Barnes velocity number.

Ricciardelli..........

I assumed there would be some slight differences in burn rate amongst the different 4350's. I did not count on the difference in "oomph" being so large. Funny you should mention 4320. It's on my grocery list for a trip to the gunshop this week........along with some H-414. Am also going to try using IMR-4350 just to see.....

My experience with current powder lots on hand is that H4350 is getting more velocity for me than I4350 (equal charges) and AA 4350 is so slow it's almost more like I4831. Now the "golden question" is do you keep adding AA4350 till you get near the same speed as the other 4350's.......or is it possible it's slow BUT it still makes near the same pressure.
I think I'm all done trying AA powders....it's not worth the buck or two savings and then wondering what the burn rate really is.

Not sure what the answer is. If the velocity number was just a bit off, I'd be tempted to start adding grains. But it's waaaay off. I don't think the case has enough capacity to reach the claimed Barnes number. I love the AA pistol powders....this is my first go with their rifle powder and I ain't impressed.