Ilya, you might be surprised what you can get out of 308 with N150. I always thought that while the powder gives excellent results and good consistency with 155s, MVs were low. My short-distance 155/N150 loads would give around 2,900 fps from a 30-inch moderately long-throated FTR rifle, although that wasn't maximum by any means.
However, an old friend and former colleague on the GB FTR team (who unlike me still shoots internationally) surprised me a while back by getting >3,150 fps from his wife's FTR rifle with the powder and 155.5gn Berger in Palma brass. I won't say exactly how much above that figure, but it was right up with his seriously hot usual H4895/VarGet figures. If I hadn't been shooting on the next bench and seen the Magnetospeed readings with my own eyes (and saw him load the test cartridges at the back of the firing point), I'd not have believed it possible. Not that he or I would normally recommend this, but for some reason his wife's rifle will not perform with the usual Hodgdon pair. Let's say that even with a VERY long drop tube on the powder funnel, there was a lot of charge compression.
Yes, I have shot 200gn Hybrids in a suitably throated barrel and tried various powders under them. While a lot of our people have shot the older Berger 210gn BTs for many, many years in rifles built around them, and many now use the 200 Hybrid or not so commonly the 215 version, it didn't work for me and I've shot consistently better with the 155.5 BT and 168gn Hybrid Bergers. For the early 185gn BT Juggernaut and 210 BT shooters (and a few who've stuck with the latter bullet) Viht N550 was initially the norm, but we later found we could get almost as high MVs with N150 in Palma brass and with less throat erosion. With 25-deg C a very hot day here, temperature stability is much less of an issue for us and that allows a lot more latitude in powder choice.
As to the general point about slower powders being chosen these days, I felt a lot of kinship with Idahosharpshooter and his longstanding load in post #29. That was the sort of load most of us put together when I started handloading 30 odd years ago - lowish charges of faster burning powders, lighter bullets, modest MVs and 308 Win barrels that lasted forever. We mostly shot short distance by today's standards on larger target centres with much less fierce competition than now and with a very large eye to cost and barrel life. Anyway, nobody had access to chronographs, so nobody knew what their MVs were and manufacturers' loads data were usually 'optimistic' on the promised velocities, just like the quoted MVs of most factory cartridges in those days. Things have moved on and FTR has really pushed the envelope, which some decry as a 'bad thing', but I welcome as we know a great deal more today than we did back then and everything equipment wise and ammunition component wise has progressed immensely. One of the results is that 308 MVs are way up on where they were 10 years ago, never mind 30, although as always not everybody actually needs the performance standards of the 1,000 yards FTR competitor, nor the component and barrel wear costs that go with them, so there is a fair bit of over-specification going on.
It isn't just MVs though - it's also ES and SD values. Back in 'the old days', not only did we have little idea of our real MVs, but we knew even less of what sort of spreads they had. A good 100 yard test load maybe did, maybe didn't perform well at longer distances and it was a case of 'suck it and see' and if you had a couple of poor mid-range results, it was back to the drawing board and try again. However, if most of your shooting was at 200/300 yards, spreads didn't matter much anyway as long as the load grouped. Today, people get upset if they can't get single figure spreads and SDs of 5 or less. I mentioned Ken Waters' light loads in 308 of powders like H322 for the predominately short-range match shooting of that generation. Sometimes, these combinations can give very good spreads despite case fill-ratios in the 80%s; sometimes not at all small values!
The other local factor that has had a major influence over here is that our Hodgdon powder supply was for some years even worse than for you people in the US. There was period of around 18 continuous months without any H4895 or VarGet being available anywhere in the country with many serious FTR shooters going spare over it. Many people went back to European propellants, especially Vihtavuori, plus the newly available Nitrochemie manufactured Reload Swiss grades most of which don't find their way across the Atlantic. I went to IMR-8208 XBR for my 155.5 loads which although an excellent combination hasn't caught on here, so XBR was available in large enough quantities for a season or two's shooting for me at a time when the other ADI grades had simply disappeared. For the 168gn Hybrid, Reload Swiss RS52 (Europe only powder) matches H4895 or VarGet in groups and MV spreads and betters either in MVs without undue pressures. This is a slightly slower burning powder than VarGet, very much akin to Re15 in this respect.
