CM10 308 AR10 Magazine – 20-Round Magpul PMAG LR/SR

Chattahoochee Munitions offers the 308 AR10 Magazine, a 20-round Magpul PMAG 20 LR/SR GEN M3 magazine for its CM10 308 Winchester AR10 rifles.

308 Winchester 20-Round Magazine for the CM10

The CM10 308 Winchester AR10 uses the dual-feed LR/SR magazine pattern. This 20-round Magpul PMAG 20 LR/SR GEN M3 fits every CM10 308, from the 12.5-inch SBR and pistol to the 16 and 18-inch rifles and the CM10-SD subsonic AR10.

Magazine pattern matters. The CM10 takes LR/SR-pattern magazines; the CM7S bolt action takes AICS-pattern magazines. For a different capacity, see the 308 10 round magazine.

Magazine Specifications

• Capacity: 20 rounds
• Pattern: Dual-feed LR/SR (AR10)
• Model: Magpul PMAG 20 LR/SR GEN M3
• Follower: Self-lubricating anti-tilt
• Spring: Stainless steel
• Floorplate: Removable for cleaning
• Cartridge: 308 Winchester and 7.62×51 NATO

Compatible Chattahoochee Munitions Firearms

• CM10 12.5-inch: 308 AR10 SBR, 308 compact AR10, 308 AR10 pistol
• CM10 16-inch: 308 AR10 rifle, 308 battle rifle, 308 semi auto rifle
• CM10 18-inch: 308 DMR rifle, 308 long range AR10, 308 hunting AR10
• CM10-SD: 308 subsonic AR10

308 Winchester Ammunition and Magazines

Magazine fit and feeding depend on cartridge length. Factory 308 Winchester is loaded to a maximum overall length of 2.810 inches under the ANSI/SAAMI centerfire rifle standard. Chattahoochee Munitions 308 firearms can use 308 Winchester and appropriate 7.62×51 NATO ammunition; see 308 Winchester vs 7.62 NATO. The magazine does not change what ammunition a firearm is designed for: CM’s 300 gr subsonic load requires a 1:5 twist barrel (see 308 Winchester subsonic).

Suppressors and the CM10

Chattahoochee Munitions recommends a flow-through suppressor on a supersonic CM10 and an enclosed suppressor on the CM10-SD, which needs the extra back pressure to cycle subsonic ammunition. See the 308 suppressor guide.

308 Winchester Guides

• What Is 308 Winchester?
• 308 bolt action vs semi auto
• 308 suppressor guide
• Every 308 configuration in District 308

308 AR10 Magazine FAQ

Does this magazine fit the CM7S bolt action?

No. The CM7S uses short-action AICS-pattern magazines such as the 308 bolt action magazine.

Will it work in other AR10 rifles?

It fits rifles that use the LR/SR magazine well. Some AR10-type rifles use different patterns; check your rifle maker’s guidance.

Is a magazine included with a CM10?

Every complete Chattahoochee Munitions firearm ships with one magazine where permitted. This listing adds spares.

Why choose a 20-round magazine?

More capacity between reloads for range and training use, where local law permits.

Does this magazine require an FFL transfer?

No. It is not a firearm. Check your state and local capacity rules before ordering.

Which Chattahoochee Munitions firearms use the 308 AR10 Magazine?

Every CM10 308 Winchester AR10, which uses the LR/SR pattern, including the 12.5, 16 and 18-inch CM10 and the CM10-SD subsonic AR10, all manufactured by Chattahoochee Munitions.