I recently had the chance to visit the Seekins Precision factory for an open house and VIP shoot. While I was there I had an opportunity to shoot one of the company’s short-barreled rifles (SBRs) chambered in 300 AAC Blackout, or 300 BLK. The company’s Pro Series SPROV3 has an 8-inch barrel. Designed for use with a sound suppressor, Gemtech was also on hand for the shoot, and it provided one of its titanium Sandstorm suppressors. This lightweight suppressor is designed for precision rifles, but it works on AR-platform weapons in 300 BLK as well. Gemtech also provided some of its 187-grain, polymer-tipped Silencer Subsonic ammunition. To my surprise, this rifle never malfunctioned during a long day at the range after firing hundreds of rounds. Intrigued, I later had a SPROV3 rifle sent to me for a complete test and evaluation.

The SPROV3 has several custom-grade features. The upper features a Melonite-coated, 8-inch, radial-fluted barrel; a 12-inch, free-floating handguard; M4 feed ramps; an adjustable gas block; and a BCM Gunfighter Mod 3 charging handle. The lower features an Ergo Deluxe grip, an ACT trigger and a Magpul STR stock.

I already have the Gemtech Sandstorm in house, and Gemtech was also kind enough to send several boxes of the same 187-grain subsonic ammunition. It was time to see if this setup worked in a bit less controlled circumstances. You see, I’ve tested several 300 BLK rifles over the years, and none have worked with both subsonic and supersonic ammunition without adjusting the gas block or swapping out springs and/or a buffer.

I tested the SPROV3 with various types of ammunition right out of the box. Too my surprise it ran with supersonic and subsonic ammunition interchangeably! Not only did it work, but it also was accurate, light and very comfortable to shoot.