1a. BULLET: .277 dia. 135gr Sierra Match King OTM item or .277 dia 140gr Classic Hybrid Hunter Berger Bullet. End user will accept projectiles not listed if precision dispersion is better than specific projectiles/bullets listed. If an optional projectile is proposed the optional projectile cannot weigh more than 150gr.
1b. Brass: Hybrid steel/brass 6.8x51mm, hardness must meet mil specs.
1c. PRIMER: prefer factory best available primer option Mil spec or match quality.
1d. POWDER: vendor best option any propellant that meets safe reliable function of ammunition. Powder should be temp stabilized for lowest possible velocity spread between 0-125F. Example of acceptable stabilized propellant velocity spread: 70F Avg MV= 2600fps 30rds, 125F Avg MV= 2640fps 30rds. (30rds straight or 3 separate 10rd tests at each temp range is acceptable).
1e. CARTRIDGE LENGTH: Max 2.82 OAL intent is Magazine length for SIG 6.8x51 semi auto rifles.
1f. MUZZLE VELOCITY: ammunition must produce a velocity sufficient to provide Sub MOA accuracy from 16" Bolt Action barrels & 1.15 MOA or less from semi auto barrels and maintain low SD of MV. Standard deviation of MV should be 13 fps +or- 1 fps (or less) for avg of 30 rds tested at 70F. Actual muzzle velocity shall be a mild velocity ammunition not to exceed 64 KSI from PSI test barrels at Hot temp ranges. 70F degree test barrel & ammunition should produce an avg of 58-59 KSI. End user not specifying specific muzzle velocity.
1g. Ammunition lot size shall be no less than 20,000 rds, no more than 40,0000 rds from the same production run.
1h. A lot consists of the same lot of bullets, primers, brass, and propellant.
1i. PSI at 70F should not exceed 60,000 PSI casemouth or Conformal- manufacturer option.
1j. PSI at 130F should not exceed 64,000 PSI casemouth or Conformal- manufacturer option.
1k. ACCURACY STANDARDS- Rifle 16” barrel: Ammunition must average less than 2.6” inches ES Threshold, 2.25 ES or less Objective at 300 yards when fired from 1 ea USAMU Bolt Action Test Barrel. 5 each 5 rd groups. ( conditions will be 2mph or less winds if outdoors )
The AMU posted an RFQ to SAM.gov for 6.8mm match grade ammo, so we get a peak at what they need out of that round. When the solicitation was posted yesterday, word was that they already had a vendor secured. That's how contracting works, sometimes.
This ammunition purchase follows a previous solicitation from the AMU for a dozen MCX-SPEAR rifles in May.
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