.300 HAM'R Ammo
The .300 HAM’R (Wilson Combat’s proprietary designation) is a .30-caliber cartridge designed to deliver .30-30 Winchester–class performance from a standard AR-15 magazine and bolt face. Based on a lengthened .223 Remington case necked up to .30 caliber, the .300 HAM’R pushes a 130-grain bullet at 2,500+ fps from a 16-inch barrel — significantly more energy than .300 Blackout at supersonic velocities, making it a genuinely capable deer and hog cartridge from the AR-15 platform out to 200+ yards.
Read our full .300 HAM’R Buying Guide ↓
.300 HAM’R vs. .300 Blackout: The Key Differences
.300 Blackout was designed for suppressed subsonic use and short-barrel optimization — it excels at close range with subsonic loads through a suppressor, but its supersonic loads top out around 2,200 fps with 110–125 grain bullets. The .300 HAM’R was designed for maximum supersonic performance from a 16-inch barrel — it pushes 130-grain bullets 300+ fps faster than .300 Blackout, delivering 40–50% more energy at 200 yards. If you want suppressed subsonic performance, .300 Blackout is the better choice. If you want maximum terminal performance on deer and hogs from an AR-15, .300 HAM’R is the step up.
Wilson Combat Rifles in .300 HAM’R
Wilson Combat is the developer and primary manufacturer of .300 HAM’R rifles. Their AR-15 platform rifles in .300 HAM’R use a standard AR-15 lower receiver with a .300 HAM’R-specific upper — the barrel, chamber, and gas system are caliber-specific, but the lower, magazine, and bolt face are shared with .223/5.56. This means .300 HAM’R uppers can be swapped onto your existing AR-15 lower for a caliber conversion.
.300 HAM’R Ammunition
Wilson Combat produces factory .300 HAM’R ammunition in hunting (130-grain Barnes TTSX, 150-grain Nosler Ballistic Tip) and training (125-grain Sierra) configurations. Because .300 HAM’R is a proprietary Wilson Combat cartridge, ammunition availability is more limited than mainstream calibers — Wilson Combat is the primary factory source, though handloading with published .300 HAM’R load data is straightforward using .223 Remington parent brass.
Hunting with .300 HAM’R
The .300 HAM’R’s sweet spot is deer and hog hunting from an AR-15 at ranges where .300 Blackout supersonic loads run out of energy. A 130-grain Barnes TTSX at 2,500 fps carries roughly 1,400 ft-lbs of energy at the muzzle and retains over 1,000 ft-lbs past 150 yards — adequate for whitetail and hogs at typical hunting distances. The cartridge also meets straight-wall requirements in some states that have adopted expanded rifle-cartridge rules (verify your state’s specific regulations).
Magazine and Bolt Compatibility
.300 HAM’R uses standard AR-15/M4 magazines and a standard .223/5.56 bolt face. This means your existing AR-15 magazines (PMAGs, USGI, Lancer) work with .300 HAM’R. The barrel and chamber are the only caliber-specific components.
Frequently Asked Questions
Who makes .300 HAM’R?
Wilson Combat developed the cartridge and is the primary manufacturer of both rifles and ammunition.
Can I convert my existing AR-15 to .300 HAM’R?
Yes — a .300 HAM’R upper on your existing AR-15 lower is a caliber conversion. Same bolt, same magazines, different barrel and chamber.
.300 HAM’R vs. .300 Blackout?
HAM’R for maximum supersonic hunting performance at 100–200+ yards. Blackout for suppressed subsonic use and short-barrel optimization.
Is .300 HAM’R ammo expensive?
More than mainstream calibers due to limited production sources. Handloading significantly reduces per-round cost using .223 parent brass.
See Also: .300 Blackout Ammo • Wilson Combat • AR-15 Rifles • Hunting Rifles • Reloading