Magpul PRS GEN3: Modern Longstock

First introduced at SHOT Show in 2016, the third generation of the Precision Rifle/Sniper (PRS) stock is the latest evolution of its hallmark rifle stock that has been part of the Magpul lineup since 2013. Today the PRS remains one of the choice stocks for long range shooters and professionals.

Featuring “tool-less” adjustment in length of pull and cheek height, via two aluminum detent knobs with locking click detents, the PRS GEN3 gives a stable platform for most AR styled rifles. The GEN3 is now also compatible to not only rifle-length receivers without the A2 spacer, but also mil-spec carbine and A5-length buffer tubes with standard Castle Nuts and End Plates.

The GEN3 also has an adjustable cant/height rubber butt-pad with rotation-limiting Quick Disconnect sling swivel cups. There is also a 1.25” aluminum sling loop that is reversible, while the buttpad itself is rubberized to prevent slippage.

Lastly, the GEN3 has M-LOK slots on the bottom of the stock for a MIL-STD-1913 Picatinny rail (length depending). This enables for additional accessories like a stock monopod.



  • Enhanced strength butt-plate that withstands severe impact and recoil (up to .50 BMG)
  • Steel adjustment shafts finished with Melonite® for wear and corrosion resistance
  • All aluminum components finished with MIL-A-8625F, Type III, Class 2 hard anodizing
  • Weight, w/rifle receiver extension: 31.2 oz.
  • Weight, w/carbine receiver extension:  31.7 oz.
  • Length, Max: 11.5-12.9 in.
  • Length of Pull, Adjustment Range: 1.4 in.
  • Length of Pull, M16 Collapsed: ~14.3 in.
  • Length of Pull, M16 Extended: ~15.7 in.
  • Cheek Height Adjustment Range: 0.8 in.

The PRS GEN3 comes in Black (featured), Flat Dark Earth, Urban Gray, and OD Green.

Product Evaluation Scores:

  • CostAverage (3/5): At $254.95 the GEN3 is a bit on the high-end for stocks, even for Magpul. But the cost is likely directly attributed to the sheer mass of materials involved. The GEN3 is a singular, solid piece (excluding the adjustable cheek riser and buttpad). Add into that the hardware has undergone extensive hardening, then the price makes a little more sense. Still though, other market alternatives are Seekins ProComp10x ($195), the Luth-AR MBA ($139), or Lewis Machine & Tool DMR308 ($249) all are styled after the same concept but come in under the GEN3 price.
  • Comfort Fair (2/5): The comfort of the GEN3 was split, due to deviations from the previous GEN2 design and factors that previously made the PRS so appealable. The
Screen Shot 2019-08-02 at 8.03.27 PM
Difference between GEN2 (top)/GEN3 (bottom)

weight of the GEN3 (as in previous generations) directly assisted in the stock mitigating some of the recoil while firing. However, because of changes in the Length of Pull (LOP) from the cheek riser in relation to the shooter (the GEN3 is approx. ¼” longer than the GEN2), the riser is now slightly smaller and starts further back. On the GEN2, where the shooter’s cheekbone was toward the front (as was most common), it now rode uncomfortably on the front edge. Also, the GEN3 really only benefited optics with a longer tube, not combat/compact optics like an ACOG TH11H or those with a shorter tube. Optics used during the evaluation on the GEN3 had to be mounted to the extreme rear to accommodate for the extended eye relief. The result was still not getting a full view of the objective lens.

  • Durability – Excellent (5/5): The polymer material of the GEN3 gave credence to the high durability of all Magpul products. Add into it the hardening of the aluminum, and Melonite finish to the steel adjustment shafts, and the GEN3 pretty much exudes durability and strength.
  • Functionality – Good (4/5): The function of the GEN3 was fairly straight forward, as it mounted easily and directly to the available mil-spec carbine buffer tube. Unfortunately, some modification was necessary to the angled ramp of the LaRue OBR’s carbine buffer tube (the part that enables for length adjustment) used for this eval to get the QD plug and mount to clear. Despite that, the GEN3 still did not mount flush due to the OBR’s overall buffer tube length, though was still able to mount securely. Magpul does state on their website “Due to the wide variety of designs and dimensions of carbine receiver extensions as well as the associated mounting hardware, proper fit cannot be guaranteed.  Mounting to a rifle-length receiver extension is recommended to ensure optimal fit and function”. Otherwise the instructions for mounting the GEN3 to rifle-length buffer tubes appeared to be just as easy. The locking detents to the adjustment knobs were verysolid and enabled a secure lock to take the riser and buttpad to its maximum extent and back. The adjustment shafts to the buttpad provided smooth travel, and the cant/height adjustment aspect was also easily performed. One aspect that could have improved the GEN3’s score in functionality would have been to address the issued raise that impacted comfort (i.e. the added length and smaller riser).
  • Weight – Good (4/5): Weighing 27.8 ounces, the GEN3 is one of the heavier precision stocks for precision carbines. But that weight played to its advantage and intended purpose in absorbing the recoil and mitigating impact. Add in the added reinforcement in hardware and steel adjustment shafts, then its weight is more understandable.

Overall Rating – Above Average (18/25)

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I am reviewing this product as a courtesy to the manufacturer and via STL Shooting Enthusiasts, so that I can evaluate it and provide my honest feedback. I am not bound by any written, verbal, or implied contract to give positive reviews. All views are my own, and based off my personal experience with the product.

The views and opinions expressed on this website are solely those of the author. The views and opinions do not necessarily represent those of the administrative staff, and/or any/all contributors to this site.