HM Defense 12.5" 5.56 Monobloc M-LOK Midlength Complete Upper - 12-5MBUP-556
$795.00
Only 1 left in stock
The MonoBloc Upper features a HM barrel with an integral machined patented gas block, and a carbine gas system. It is also 4150 Chromoly, match grade, tripled honed, and button rifled. Its handguard is free-floating and uses a Picatinny rial, Magpul M-LOK, and machined from 6061-T6 aluminum. Upper and Lower receiver are made of 7075-T6 aluminum with a hard coat anodized finish. The MonoBloc Upper also includes a patented HMB bolt, Mil-Spec components, charging handle, and a dust cover with an American Flag.
- Patented HM MONOBLOC Barrel with integrally machined Gas Block
- Free-float rail with Picatinny and M-Lok
- Patented HMB Bolt which replaces cam pin hole with cam pin socket and tapered cam pin
| Weight | 48 oz |
|---|---|
| Dimensions | 24.5 × 5 × 5 in |
| Barrel Finish | |
| Barrel Profile | |
| Gas System Length | Midlength |
| Barrel Length (inches) | 12.5 |
| Barrel Chamber | |
| Twist Rate | |
| BCG / Charging Handle | Included |
| MPN | 12-5MBUP-556 |
| UPC | 854164007203 |
Compliance
NFA (National Firearms Act) compliance is crucial for legal ownership and transfer of regulated firearms and accessories like short-barreled rifles, suppressors, and certain types of ammunition, ensuring adherence to federal regulations to avoid legal penalties and ensure responsible firearm ownership.
Customer Reviews
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HD Defense for the win
I already purchased the 9.5 inch HM Defense upper from AR15 Discounts, and now the 12.5 inch. The HM Defense lineup is excellent for the money. Great quality product, shoots very accurate, and looks great. I don’t mind the built in gas block, just not sure if it would work if you want to go suppressed (contact HM Defense), and need an adjustable gas block. It has the mid-length gas block, no issues there. I’m using a standard buffer spring, and Carbine Buffer in both of mine. You should probably start light during the break-in period, and work up if you feel the need for a heavier buffer. They do need a few mags run through them (break-in period), and then everything seems to cycle well after that.
