Alexander Arms RTA65SG 6.5mm Grendel 16in 10+1
Pros & cons
What works
- 6.0 lb weight — 2.3 lb lighter than comparable .308 AR platforms
- 16-inch threaded barrel with 1:8 twist stabilizes 120-130 gr projectiles optimally
- M-LOK handguard provides 13.5 inches of accessory mounting real estate
- Maintains standard AR-15 lower dimensions for trigger/grip/stock compatibility
Trade-offs
- No iron sights included — adds $100-200 for backup sights or optic
- 6.5 Grendel ammunition costs $1.25/round versus $0.45 for .223
- Proprietary magazines required at $45 each versus $15 for standard AR mags
- Mil-Spec trigger has 7.5 lb pull weight — needs $80-150 upgrade for precision work
Video review
Expert review
Specs at a glance
About this product
The Alexander Arms RTA65SG 6.5mm Grendel 16in 10+1 is a semi-automatic AR-platform rifle designed for precision shooting with modern mounting capabilities. Built on Alexander Arms' proprietary 6.5 Grendel platform, this 16-inch barreled rifle balances ballistics with practical handling dimensions. It represents one of the few factory-built 6.5 Grendel options that maintains standard AR-15 receiver dimensions while optimizing for the cartridge's ballistic advantages.
What is the Alexander Arms RTA65SG used for?
The RTA65SG is primarily a medium-range precision platform suitable for target shooting, hunting, and tactical training applications. With its 1:8 twist rate barrel, it stabilizes heavier 6.5mm projectiles effectively out to 600 yards, making it superior to .223/5.56 platforms for medium game hunting and mid-range competition. The threaded muzzle and M-LOK handguard allow straightforward suppressor mounting and accessory configuration without gunsmithing.
How does the Alexander Arms RTA65SG compare to the Stevens 334 .308 Win?
The RTA65SG offers faster follow-up shots and lower recoil than bolt-action alternatives like the Stevens 334 in .308 Win, though the Stevens provides better long-range precision with match ammunition. Where the Stevens 334 delivers sub-MOA accuracy with premium .308 loads, the RTA65SG achieves 1.5 MOA with factory ammunition while maintaining semi-automatic functionality—making it better for rapid engagement scenarios where the Stevens' bolt-action design would be limiting.
What does it weigh and what are the dimensions?
Unloaded weight is exactly 6.0 pounds with an overall length of 37 inches and 16-inch barrel. The receiver measures 8.75 inches long with a 13.5-inch M-LOK handguard providing ample rail space for lights, lasers, or forward grips. Compared to heavier .308 AR platforms weighing 8+ pounds, the RTA65SG's 6-pound weight makes it noticeably handier for extended carry sessions without sacrificing ballistic performance.
Who is this NOT for?
This rifle isn't suitable for beginners seeking a low-cost plinker or those wanting maximum long-range precision without customization. The 6.5 Grendel ammunition costs approximately $1.25 per round versus $0.45 for .223 Remington, making practice significantly more expensive than standard AR-15 platforms. Additionally, shooters needing sub-MOA accuracy for competitive benchrest shooting would be better served with a dedicated precision bolt-action like the Stevens 334 in .243 Win with its heavier barrel and crisper trigger.
What's in the box?
The rifle ships with one 10-round magazine, owner's manual, and cable lock—no optic, sling, or cleaning kit included. Alexander Arms packages the RTA65SG minimally to maintain the $1669.99 price point, requiring buyers to budget approximately $200-400 additional for a magnified optic, mount, and bipod to utilize the platform's capabilities fully. The absence of iron sights means immediate additional expense for functional use.
Is the Alexander Arms RTA65SG worth it at $1669.99?
At $1669.99, the RTA65SG justifies its price through specialized chambering and quality components that would cost more to assemble separately. A comparable custom-built 6.5 Grendel AR with similar features (B5 stock, threaded barrel, M-LOK handguard) typically runs $1800-2200 when sourcing parts individually and paying for assembly. For shooters specifically wanting 6.5 Grendel performance in a reliable factory-built platform, the RTA65SG delivers tangible value over piecemeal builds.
Key attributes
| upc | 819511021851 |
| manufacturer | Alexander Arms |
| manufacturer part number | RTA65SG |
| action | Semi-Auto |
| barrel length | 16" |
| caliber/gauge | 6.5mm Grendel |
| capacity | 10 + 1 |
| safety | Thumb |
Frequently asked questions
- Is it compatible with standard AR-15 parts?
- The lower receiver and fire control group use standard AR-15 dimensions, but the bolt carrier group and magazine are 6.5 Grendel specific. You can use any Mil-Spec trigger, grip, or stock, but must use Alexander Arms or compatible 6.5 Grendel bolts and magazines—which cost approximately $45 each versus $15 for standard AR mags.
- Does it work with .223/5.56 magazines?
- No, the RTA65SG requires dedicated 6.5 Grendel magazines due to different cartridge dimensions. Attempting to use .223/5.56 magazines will cause feeding failures and potential damage to the feed lips. Alexander Arms recommends their proprietary magazines or ASC 6.5 Grendel magazines for reliable function.
- How long does shipping take to FFL dealers?
- Standard shipping to licensed FFL dealers takes 3-5 business days after order processing, which requires 1-2 business days for background verification. All firearms ship via FedEx with adult signature required and tracking provided within 24 hours of shipment. International orders require additional compliance documentation.
- Can I return it if there are malfunctions?
- Alexander Arms provides a limited lifetime warranty that covers manufacturer defects but requires inspection at their facility. Return shipping must be arranged through an FFL holder and typically takes 2-3 weeks for evaluation. Non-defective returns are not accepted due to federal firearms regulations prohibiting direct consumer returns.