7 Rem Mag reloading downloaded
You asked about the downloading of the 7 Mag. It came along when the Browning Auto started using the 7Mag and the lawyers got involved. I use a original Rem 26" Sendero. I've been reloading the 7 Mag since 1975 and understand this round very well. I reload by neck sizing, forget the shoulder, trim to 2.490 max, use Noslers, both BT and Accubonds, 140 Accubonds at 3.365 COL, 140 BT at 3.378, 150 BT at 3.324, 160 Accubonds at 3.362, 160 Sierra Game Kings at 3.252, 120 BT at 3.378. I'm running 5 thousands off the lands which allows for better burn and a lot more speed and accuracy. I generally have a five shot spread never exceeding 5 fps where-the best factory loads can have up to 50 fps in spread depending on the gun and average 100 fps slower than my mild 63 grains 4350 in the 140's are running at 3143~3148 fps. I easily get over 3300 fps running with 65.5 grains of RL19 and a bit faster with 67.5 grains of RL22. They all provide sub half minute MOA's at 100 yards with pressure beginning to get my attention but not anywhere close to loads I use to get years ago before all the newer powders of today. The IMR 7828 SC is something you need to get familiar with too. Senderos are, especially the first run, essentially custom-guns that came from the custom gun room at Remington. They were cut to the closest minimum acceptable tolerances. My bolts are snug and shooting factory loads that are shorter COL do not give me the accuracy I want. I use a Jewel trigger at 1# both hunting and at the range shooting with a 5 minute cool off to save my barrel. Should easily get over 3000 rounds at this pace before any fall off in accuracy. I know this since my previous 1972 Rem 24" ADL went 3000 rounds using these cooling techniques before falling off. Went longer on the reloads and the accuracy came right back. Always weigh each shot to get your consistency in both velocity and accuracy. You may email me if you need more info. I've tried everything for over 35 years with the Big "7" to stay with and outrun 30's consistently and it's all coming together.