The first run of factory 7mm SAW brass is in final QC this week and getting ready to ship! With delivery inbound, we thought this would be a good time to post some of our test data on this brass. This data was compiled using the final pre-production case batch, and based on the data gathered we gave the green light to Alpha Munitions to go forward with full production. From the very beginning of this project through the final product the team at Alpha Munitions has provided invaluable insight, professional service, and unbeatable quality. On personal level, this has been extremely fulfilling to watch this concept go from a thought to a mainstream cartridge!
This test was performed using my personal competition rifle built on a Bighorn Arms TL-3 LBRP action, and running a 26″ Bartlein 1-8.5″ twist 5R rifled MTU contour barrel. This barrel has the 7mm SAW II chamber, and runs from AI A/w magazines. This gun also runs our own WTO Mk2 muzzle brake.
Case weight: 171.1 grains, Standard Deviation 0.2 grains. Sample size was 20 cases, all randomly selected from a box of 100 pieces as received. Neck wall thickness measured .0146″.
Load 1: 162gr Hornady ELD-M, 41.8gr Hodgdon Varget, CCI BR-4 Primer, 2.250″ base to ogive length. 2809FPS average, 8.7FPS SD over 12 shot test
Load 2: 150gr Hornady ELD-X, 42.5gr Hodgdon Varget, CCI BR-4 Primer, 2.230″ base to ogive length. 2939FPS average, 18.1FPS SD over 4 shot test
Load 3: 162gr Hornady ELD-M, 42.5gr Hodgdon Varget, CCI BR-4 primer, 2.250″ base to ogive length, 2854FPS average, 8.1FPS SD over 5 shot test
Load 4: 185gr Nosler RDF, 44.5gr Alliant Reloder 16, CCI BR-4 Primer, 2.250″ base to ogive length, 2674FPS average, 27FPS extreme spread. 3 shots only in test
Load 5: 185gr Nosler RDF, 45.0gr Alliant Reloder 16, CCI BR-4 Primer, 2.250″ base to ogive length, 2683FPS average, 5.3FPS SD over 6 shot test
Load 6: 162gr Hornady ELD-M, 46.2gr Alliant Reloder 16, CCI BR-4 primer, 2.245″ base to ogive length, 2878FPS average, 9.0FPS SD over 6 shot test
Load 7: 160gr Sierra TMK, 41.8gr Hodgdon Varget, CCI BR-4 primer, 2.281″ base to ogive length, 2813FPS average, 24FPS extreme spread over 4 shot test
In this initial testing, all of the loads listed above produced 100 yard accuracy of .5MOA or better. All of these loads also showed no evidence of excessive pressure in the test rifle, although the heavier charge weights are approaching maximum for this barrel. After further waterline testing at 200 and 600 yards, I selected Load 7 with the 160gr Sierra Tipped MatchKing as my competition load for this barrel. The muzzle velocity average has increased slightly to 2820FPS as this barrel has settled in, and has stayed extremely consistent. This load was used to take my first Top Ten finish in a national level match last month at the Rifles Only Brawl, and will continue to be my go-to load on this rifle for everything but ELR matches.
WARNING: ALTHOUGH THESE LOADS WERE VERIFIED SAFE IN THE TEST RIFLE, ALWAYS START LOW AND WORK UP IN YOUR OWN RIFLE! THERE ARE MANY VARIATIONS IN BORE/GROOVE SIZE, POWDER LOTS, BARREL LENGTH, AND OTHER FACTORS THAT CAN EFFECT CHAMBER PRESSURES.