November 17, 2008, 02:37 PM
After a lot of searching in reloading manuals, on this board and on the internet in general I haven't found much information on using VihtaVuori N120 with a 405 grain SP bullet (from Remington). The VV reloading guide lists a few loads using N130 and one N120 CAS load for a 510 grain bullet. There's a lot of IMR 4198 and IMR 3031 data out there and I'm wondering if the VV data in Lee's manual (2nd Ed.) is reliable ... it looks like it was added as an afterthought and the numbers just don't make any sense. Referring to VV's powder burn rate chart, IMR 4198 and N120 have very similar burn rates. Referring to VV's load data where they have N120 and N130 loads for the same bullet, it seems that the N120 loads are 0.8 x N130 loads. A "popular" load for IMR 4198 and a 405 grain JSP has a range from 34.0 to 38.0 grains (< 28,000 CUP). Lyman's 48th Edition lists an N130 load for the 405 grain JSP with a range of 43.5 to 48.5 grains. Multiplying by 0.8 (estimated for N120) gives 34.8 to 38.8 grains which is the same as the IMR 4198 load listed for the same bullet. Anyway, before I blow myself up experimenting with N120, if anyone has some "proven" load data for the 405 grain SP with N120 I'd really appreciate it.