Born Again wrote:Thanks for the pointers. I'm glad to see N140 mentioned as that's what I'm currently using (42.9gn, 168SMK, 71mm OAL, Fed210M). I also have a tub of RL15 unopened.
I dont suppose this will help, and no doubt some wag will say its not worth a fig but...
I cannot see how you could get a node calculator given that even 2 identical rifles may behave differently, sadly practical testing is the only real way forward. You could shoot a ladder test that (if shot accurately) will give you an idea for the nodes, where you could start doing a load test proper. Barrel length and stiffness is a huge factor, as is anyhing stuck on the end and how it is bedded/rested. MY dolphin was up about the 3150-3200 mark (over HME as were the majority of FTR rifles then) using palma brass, RS52 and a 30" lilja barrel. The latter only had 3 grooves and shot fast. These speeds were clocked by several indipendant chronos but my point is that it was a specialist application that took some thinking about and lots of testing...which I hate and is a PITA

and why I take "accuracy" loads with a pinch of salt because they may have been right for the test rifle, but meaningless in another.
I dont get that you NEED to push a bullet past 2800 FPS for an accurate load as again, it depends on your application. Long range FTR then I get it but otherwise. My 16" barrelled AR is accurate enough with a relatively low load of 42.5 or 43 grains of RS52 but it wont get used past 600 yards. There are many accurate .303 rifles shooting about 2440 ONO.
You may do well to try some of the RS powders such as RS52. They are a more modern powder that give better velocity for less powder and less spikey pressures.
The 168 thing goes back to the SMK 168 HPBT that was designed as a 300m bullet, so would not have to be "Booted" hard to stay supersonic at 1000. As a result it has quite a steep and short boat tail compared with a lot of the 155 Palma bullets. By default it used to usually get upset at long ranges and as was the custom back then, if something was good, it got copied, so a lot of 168 HPBT bullets were direct copies of the 168 SMK.
Bottom line, test. Dont get hung up over chronos etc, just test as you would be shooting. The data you will get back is realtime and worth its weight in gold
