Thread: Comparative sequence of Nobel 78

Loaded 85gr 0.312 diameter commercial swaged lead wad cutters into 7.62x51(308) PSD cases with enlarged primer vents (to stop shoulder setback) and Murom green label LRP. Used two other common shotgun powders to make a comparative sequence with Nobel 78. The results may be of use to other reloaders who have stocks of Nobel 78. Data collected using a Labradar.

Green Dot
gr. ft/sec
3.0: 859
3.5: 896
4.0: 984
4.5: 1062
5.0: 1188
5.5: 1257
6.0: 1305
6.5: 1387
7.0: 1485
7.5: 1506
8.0: 1658

Nobel 78
3.0: 708
3.5: 773
4.0: 882
4.5: 1023
5.0: 1057
5.5: 1185
6.0: 1226
6.5: 1340
7.0: 1370
7.5: 1455
8.0: 1572

700X
3.0: 919
3.5: 944
4.0: 1033
4.5: 1129
5.0: 1206
5.5: 1328
6.0: 1397
6.5: 1446
7.0: 1545
7.5: 1632
8.0: 1717

Drilling out the flash hoie has nothing to do with shoulder set back, It is to stop the pressure from the primer charge pushing the primer out of the
primer pocket and locking up the bolt, I know this from experience nearly 50 years ago,
Thanks for the Data I have been looking for Green Dot to run . the same test

Extremely interesting test,it would be good to know where accuracy nodes where if you loaded more than one case for each load.I load light bullets in the 308 and find I need to get above subsonic loads to get good groups.

I loaded only one case for each increment, so no groups to indicate accuracy possibilities.

I've done incremental testing with N78 in 303B and 308. Some 6 years ago I worked on 303B but can't put my hands on my old notes at the mo. From memory went as high as 13.5gn in 303B which gave me in vicinity of 1850fps and occasional heavy bolt lift. After I had to use a mallet to release bolt I backed that down real quick and pulled the rest of those loads. Using Walkers 204gn lead cast HP with GC. Around 11.5-12gn N78 was sweet spot with around 1400-1600fps. Bolt lift fine, no primer issues, best accuracy.

In 308 12gn behind Walkers 151gn Cast gave 1587fps average over 5 shots and a tight group, around 2.5in at 50m. . No bolt lift issues but again, once over 1600fps groups spread quickly. Rifle was an Interarms Mark X with 22in barrel suppressed.

In figuring out loads for N78 I got info from an old shotgunner that N78 was a tad faster than AS30N of same era. ADI give AS30N as equivalent to Red Dot. I did load dev in several Pistol cartridges using Red Dot data from 1970s era and found no discernable diff in performance to Red Dot published data. Following "The Load" of 13gn Red Dot for 30cal rifles with heavier cast bullets is where I began my load dev. I started at 10gn and went down to 7.5. 13.5 was as high as I went and I don't recommend it.

My mileage was accuracy wasn't great down below 9.5gn, improved above 10gn, became optimal at 11.5-12.5gn (12gn best load in 308 @ 1587fps), got crappy above 12.5gn as velocity moved above 1600fps. This is all with lead cast bullets.

I have a good stock of N78 and for my purposes, Pistol calibres and cast boolit in 30 cal Rifle, its excellent.

I appreciate OP's data on 700x especially as that's where I'm headed when the N78 runs out.