n 150 among a few others but the one i dont see mentioned is 4350.i am just currious why??its very close to n 150.is there anyone using 4350 in competition like ftr or palma?
This is why simply comparing published burning rates is potentially misleading. The two may look similar on that basis, but aren't when you try them in actual applications. The powder manufacturers used to advise readers of their burning rate charts that positions are only approximate and that relative positions may even change in different applications.
I've heard of the occasional person trying the 4350s in 308W with heavy bullets, 185gn and up and getting good groups but modest velocities. I don't know of anybody this side of the Atlantic who uses them in long-range F/TR loads, but that's not too surprising with high-energy Viht N550 available here in the UK cheaper than the US powders and with a reputation for giving very high velocities with mid and heavy weight bullets in the cartridge. I've not heard of anybody trying the 4350s with 155gn bracket bullets for long-range loads at all, while N150 works very well in this application at the cost of being maybe 50-75 fps short on potential MV compared to those in the VarGet, N140, Re15 class. (That's not to say there isn't a handful of 4350 enthusiasts out there who use one powder in every cartridge they load - working fairly well and proving optimal are two different things.)
Just out of interest, I ran a bunch of powders using my own set up (roomy Norma brass, 32-inch barrel, longish freebore, 168gn Berger VLD - I actually use that weight Hybrid but not in the database) through QuicKLOAD.
On that basis, we should all run Alliant Re17 and Ramshot Big Game, both breaking 3,000 fps with slightly compressed charges and 100% charge burns. Re15 is a fairly close 3rd at 2,976 and right on 100% fill-ratio and with 99.9% of the charge consumed. N550 isn't quite so well matched needing a little compression, not quite giving a 100% burn and another 30-odd fps down. Note, these are all double-base powders. If I ran H414 / W760 too, I know it'd be right up with them as well, on paper at any rate.
Varget is unsurprisingly shown amongst the best of the single-base powders at 2,928 fps and everything else looking good - right on what I do get from my long-range load with the 168 Hybrid and this powder. By the time you get to N150 and the 4350s, velocities are suffering and loads are getting heavily compressed in order to get these velocities. N150 is calculated to give a desirable 100% charge burn, but the 4350s all drop, H4350 running at an estimated 95.9%.
This is all just computer modelling of course, but it gives some indications. Nevertheless what works best in real life on the range can vary from such predictions. I tried Re17, and several others I know did so too, and it only seems to work out in this cartridge with heavier bullets (200 and up) and at full-on pressures. That N140/540, N150/550, Re15 and Varget are all known to work really well in practice and are so widely used speaks for itself.
Incidentally, QuickLOAD points to one other potential 'star' performer, one that I believe often is but doesn't seem to get the recognition it might - H4895. 2,950 fps MV, 97% fill-ratio and 100% charge burn in my example looks very good indeed and I've often had excellent results with warm loads in 308 with this powder in real loads.
