Re: SPS 308 load development
Personally, I have my own routine on load development, as everyone probably does... a quick version of mine goes as such:
1- load 3 rounds of test round starting load, 3 rounds +.5gr., 3 rounds +.5gr., etc, until I reach maximum published charge... if I have already settled on a charge weight, and am testing for a certain bullet's accuracy in relation to freebore, I load 3 rounds at normal C.O.L., 3 rounds at +.05", etc. until I reach the length that gently kisses the lands.
2- Set up your chronograph (a VITAL tool for accurate load development), and fire the first set. Check the velocity and examine cases for overpressure signs (leaking or blown primers, split cases, expanded caseheads; a good quick way to check for casehead expansion is to bring your shellholder along... if the fired case is hard to get in the shellholder, it has expanded and is too hot). Do this for all test groups and record all data (velocity, group size, personal notes such as recoil, muzzle blast, wind, etc.)
3- Take the data for the best grouping loads that exceed the velocity you need, and load 10 - 20 more rounds of those. Final test on those rounds to decide on one using 10 shot groups minimum, giving plenty of time for the barrel to cool in between groups, a at least 20 seconds between shots.
I do this same process whether I am testing for the best charge on a particular powder, or testing to see what C.O.L. shoots best for a certain bullet, testing cases, primers, pretty much anything. Just remember, if you are testing for powder, make sure to keep ALL other components the same (case, primer, etc), and the same goes for testing for bullets, keep all other components identical, so the only variable is the item being tested.
I have a Remington 700 SPS Varmint in .308 w/ 26" heavy barrel, with a Jewell trigger (2 lbs), Bell&Carlson A5 stock (best stock for the money out there), with a Bushnell Elite 4200 4-16x50 SF mounted on it. The loads I found out that worked best for my rifle were:
For Target shooting:
168gr. Sierra Matchking
F-C. cases, CCI BR2 primers
C.O.L. - 2.83" (to fit magazine, well off the lands), no crimp,
I am getting .4 MOA @ 2630 FPS, ES@8
165gr. Nosler Ballistic Tip (deer>250 yds) or 165gr. Hornady SST (deer<250 yds)
F-C cases, CCI BR2 primers
C.O.L. - 2.80", light crimp on SST's, no crimp on Nosler BTs,
Getting .7 MOA @ 2700 FPS, ES@11
These loads a little hot, and were worked up in my rifle. Always start low and work up.
The .308 is among the easiest rounds to load for. Theres a ton of great powders available: RL-15, Varget, N140, N540, IMR 4064, 3031, H-4895, Win 748, H-BL-C(2), and H-4320 just to name a few.
Hope this helps! Good Luck!
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Last edited by Damascus; 12-05-2012 at 12:26 PM.