LRRPF52 Wrote:What is GRT estimating for those different charge weights under the 120gr Scenar-L, specifically up to the 31.5gr LEVERevolution load?
GRT flags 31.5 gns as overpressure @63,578 PSI and 2718 FPS. Using the propellant mass calculation function of GRT it came up with 30.29 gns to produce 2600 FPS and flagged it as a dangerous load @ 54817 PSI. GRT flags anything at Pmax absolute - 15% as dangerous. This was using velocity data from my rifle and current load workup to calibrate program and powder values. The reason I mention this is I use my chronograph as a indicator of over pressure, I find it much more reliable than primers and case head marks because of the different hardness of the brass used in different manufactures cases, firing pin hole sizes etc.
Hodgdon's fastest FPS for 120 gn bullets is listed is with H335 @ 2508 with a 24 inch test barrel
Sierra goes a bit farther @ 2600 FPS using power Pro Varmint
Berger has maximums for several powders up to the 2570's
Hornady stops @ 2500 FPS with CFE 223
When developing a load and I reach what I think is max FPS for that bullet and cartridge I stop regardless of the charge. Since I took up long range shooting I have seen two people destroy custom rifles trying to get that last few FPS. Luckily both walked away with their hands and face and no bystanders were injured in either incident. Although I am sure both had to trash their underpants afterwards. One gave up shooting entirely and sold all his gear and took up golf, no kidding. He was a a damn good LR shooter too, always in the top 2 or 3 at matches