RMR 69gr BTHP in BCM Service Rifle

[Robert Nichols]

Team,

The following is the load I worked up in my BCM AR15 with 20in Barrel 1:7 Twist. I sorted Lake City 14 brass into 0.5gr buckets. I used batch (92.0-92.5gr). I then did ladder testing in 0.3gr increments from 23.6grs (2573fps) to 26.3grs (2958fps) with Win 748 w/CCI450. The sweet spot/node was 25.7grs ES 18, STD 7.7, 2888fps avg. At 1000ft elevation, they will stay supersonic out past 800yds. Measured on CED Chrono.

I normally use a Wilson Headspace Micrometer with a Wilson Headspace gauge. I typically size them to be -.003 less then chamber and they function flawlessly. FYI. I remove gas tube to determine chamber specs on fired cartridge (if ya care).

[cbrodin]

Thankyou Robert. It confirms my choice of win748 with this bullet.

[Kyle Kennedy]

My BCM has the 20\” 5.56 NM 1:8
Best accuracy from this bullet so far has been 25.1 CFE223 @2800 fps
Trying 748 next

[Wei Song]

I didn\’t do any ladder test. Just want a quick load for practice. Will update later if I get a chrono.

White Oak service upper 20\” 1:7 no muzzle thread.

LC brass unsorted, once fired. Case length under 1.76
Sellier and Bellot SRP. (Never can find that anymore)
Ramshot X-TERMINATOR powder 24gr
OAL 2.26

bench sitting, 5X5 at 100yd, Avg0.878MOA, with Athlon Helos BTR 1-4.5×24 ATSR3 FFP

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