Got hold of some VV N340 that was recommended by VihtaVuori as a 2400 replacement (see https://forum.castbulletassoc.org/thread/current-powder-prices/). I tried it in my Remington 1903-A3 (4-groove) and my Finn M39 in 7.62x54R. The Finn has a 6x scope for Modified Scope class, the 'A3 is as-issued. I'm no great shakes as an iron sight shooter, so maybe the groups don't mean a whole lot, but here's the results (one 10-shot group for each load).
1903-A3 (314299 cast of WW+Sn)
A-2400 17.0 grs. 314299 210 grs. 1515 fps (appx) 5.43"
VV N340 14.0 grs. 314299 210 grs. 1433 fps 2.63"
VV N340 15.0 grs. 314299 210 grs. 1493 fps 3.38"
I hadn't shot the rifle since April and so the first 2 shots with 2400 (no fouler) were the group size. It settled down a bit after that and put nine in 3.84". The smallest 10-shot group I've managed with this rifle is 2.28".
I also tried the Hoch 310-185 bullet cast of linotype:
A-2400 17.0 grs. 1619 fps. 2.53"
VV N340 14.0 grs. 1540 fps. 3.31"
For the M-39 Finn I also used the 314299 but cast of linotype and sized .312", weight 196 grs. I had shot this rifle for the Military match the Thursday before the CBA National Tournament and had some ammo left over from that.
VV N110 17.0 grs. 1574 fps. 2.02"
A-2400 16.0 grs. 1550 fps. 2.65" (9 in 1.91")
VV N340 14.0 grs. 1523 fps. 2.22"
Standard deviation for all loads ran from 5 to 11 fps, so all the loads burned well. I typically use large pistol primers in my "modern" rifles and large rifle primers in my military rifles, but out of habit grabbed the WLP's for all these loads, so rifle primers might make a difference. Cartridges were carefully chambered with the powder to the rear of the case for uniformity.
Glenn