Originally Posted by Shawn Carlock
No, it is not simply freebore like Roy did years ago, we are running the bullet .005" off the lands. The reduction in pressure allows the use of other powders other than h1000. But when using H1000 we run an extra 6-8 grains over the standard 90 gr load gaining about 125-150 fps. The use of other powders gains about another 75-100 fps. Longer barrels do not get 35 fps per inch, they run about 18-20 fps per inch. So if you use a 34" tube , VV N570, and the +P chambering you should be in the 3100 fps or more range. In the video clip we were running almost 3100 fps (3070 fps ) with a 32" Kreiger (because Hart only builds a 30"). The standard LRKM package in 338 Edge +P, N570, 30" barrel etc, runs really well in the 3000-3050 range.
Thanks Shawn for your response and clarification,
My guess is a modification to the throat angle would seem to be the answer here.
Would it be fair to ask if these new speeds might possibly be achieved at somewhat higher pressures than previously achieved.
If so this would have required stronger actions such as a Defiance/Raptor action as the standard Rem700 would be deemed possibly unsafe.
Am I right in this.
Also I note that you mentioned using Vihtavuori N570 in this development and it was mentioned that conditions are very cool and tests were performed at higher than normal altitudes. Interesting.
Vihtavuori N570 powder is a double based powder that has a reputation for erratic behaviour when temperatures are on the rise.
Have you now moved away from the stability of powders like H-1000 was well known for.
In my own personal experience I achieved/noticed a significant increase in speeds of around 60+fps in velocity with my 30-378 when I loaded with RE25, which is a double based powder.
In this experiment I left the round chambered for 30 seconds in a fairly warm chamber and experienced two speeds of 3311 and 3314 over my usual speed of around 3250 fps.
Just wondering if your loads with N570 in these cool conditions wouldn't be an issue in a hot desert environment.
Before I conclude I was just wondering if you have performed any further experimental work with those "two cases" Bruce Bertram recently sent you.
Seems like there could be even more impressive developments with the Edge coming up on the horizon.
I can see some interesting days ahead.
I like the impressive performance of the LRKM.