for 223 and 4895 just say no. Its never done fast speeds and accuracy. Though at 2450 80s were shot into knots. Not that I'd know what to do with 2450...
Any time we got speed we got too much pressure.
Rounds other than 223 yes.
I keep H4895 handy for rainy days. But it will never see a 223
Put a hat on, Texas Sun getting to you… 🤪 I tried all the powders everyone talks about for high power. Varget, RL15, 8208, H4895, and everything else in between. I never achieved any ground breaking velocities everyone talks about 2800-2900 fps. Only powder that gets me anywhere near 2750 range is AR-comp (18 inch barrel). I have messed with your all time favorite N540, like I mentioned to you yesterday I bought 4 more lbs of it. I will say again my H4895 load I use is for reduced yardage xtc matches. My 2495 load with 75gr ELD-M is close to 2800 i think 2785 if I remember right. But as of now if I had a choice it be A2495 or AR-Comp. N540 I need to mess with more.
There was a note about pressures. I've had mine run for pressure with N540. I don't recall the exact results but lets just say the 52 load and the 80 and 90 loads were done, and they were somewhere around 60 IIRC. Which doesn't bother me in the least.
That said to play with N540 your re going to have to get it hot. It doesn't like mild or medium loads.
Lets talk about pressure vs speed. Just so its out there. The only barrels I worried about a certain speed on were 20 inch tubes. And there was never a factory tube in that bunch. All custom like shilen, Krieger, Rock, Pac Nor, a couple of junk Douglas that never got to speed, and one blackstar.
Shot with state team shooters. And quite a few others that could verify the N540 stuff. One of the La Berge family of long range shooters too. In fact he is the one that told me to open the powder measure a bit more.
To the end I ran odd groove Pac Nor 6.5 twist tubes but ran LOTS of 7.7 and 7 twist Krieger etc...
Moly all bullets.
Only LC cases.
Ran only 77 SMK. 75 H bthp couldn't deal with the base pressure. 75 amax were fine but not fast. Some of the mag length 70ish bullets have a long bearing surface. IE they can't get to the speeds an 80 with less bearing surface could.
So some bullets simply won't run fast.
Can or did powders change. Sure its all possible.
We ran an Oehler 35P chrono at about 15 feet.
I don t' know if I can find an7 80 moly data and if I did it would all be JLK. 80 SMK never did all that great for us. 80 Bergers were ok but a bit slower than JLK with lower BC
I did pull some 90 loads apart to verify powder, that data is in Delta but was either 25.7 or 25.9. With a 90 JLK seated out long single load.
4895 produced fine accuracy mostly way back when. But it was sure slower than we wanted.
For general non match work that wouldn't bother me a bit.
Varget was ok for speeds, 2850 with 69s maybe close to 2900. RL15 never did much for me.
The above is simply for your info.
Dont' discount primers either, though we finally were down to more or less R7.5/CCI M41/450 and CCI BR4 and those did all we needed, but primers can double a group size or cut it in half and they can affect velocity also.
And recall all my data is 2005 or earlier data... I've no clue what happened since and thats almost 20 years... but according to the tiny knot I shot with a 90 ilk load in October the load still works.