Space-age rifle stocks have taken over the tactical world. It seems everyone today is offering modular aluminum stocks. Their prices range from under a grand to well over two. With adjustments galore, they accommodate pounds of accessories most shooters will never need. Often, a good old composite stock with simple adjustments for cheek height and length of pull is all you need.

Several companies still make composite stocks, but McMillan has been an industry leader for decades. The last duty rifle I deployed with was an FN SPR with a McMillan A5 stock. It’s one of the most rugged and reliable rifles I’ve ever used, and it’s still a tack-driving machine. Some of my older Remington 700-based custom rifles also wore McMillan stocks. The company’s composite stocks are lightweight, strong, easy to fit and come in variety of shapes, sizes and colors. Properly installed, these stocks allow for precision, rugged reliability and simple operation—exactly what today’s police countersnipers need.

I was recently looking for a stock for my 300 Blackout Remington 700 bolt-action rifle, and McMillan’s Adjustable A3-5 stock seemed ideal for my personal requirements.

Adjustable A3-5

Over the years, two McMillan stocks have popped up a lot during precision rifle training courses: the A3 and the A5. The A5 remains popular with its wider and flatter forend, butt hook and deep-seated action, but the A3 is still the most widely used. It’s lighter and offers a thinner, tapered forend. Designed to work well on sandbags, tripods or other supports, it is available with or without an adjustable comb. Both the A3 and A5 are adjustable for length of pull.

Well, McMillan took the best of both and made the Adjustable A3-5. This composite stock is a variation of the A3 stock but with the addition of an A5-type butt hook. The flat on the bottom of the hook is about 0.75 inches wide. This stock is only available with an adjustable cheekpiece that offers both vertical and horizontal adjustments and is available with either the standard or thumbwheel elevator system. The front sling stud is reinforced for bipod mounting, and flush quick-detach (QD) sling cups are molded into the left side at the front and rear as well as on the bottom.

The Adjustable A3-5 can be ordered without inletting or a basic or full inlet. My test stock came inletted for a Remington Model 700 short action using factory BDL bottom metal and included pillars. Several colors are available, and my stock came with an attractive olive, tan and black marble finish.

All Together

My Remington 700 SPS Tactical in 300 Blackout is a carryover from a gun review; it worked so well during testing that I bought it. Loaded with 125-grain supersonic ammunition, the rifle offers significant penetration in a small package. It’s accurate without producing much recoil. It also works well with subsonic ammunition and serves as a great practice rifle at 200 yards and closer. Some of its upgrades include Seekins Precision’s AICS bottom metal, which features an ambidextrous magazine release, a Timney flat trigger and safety, and a SureFire WARCOMP 762 flash suppressor, which helps reduce muzzle rise and accepts SureFire SOCOM sound suppressors. Ernie Bray at Red Creek Tactical helped me install and bed the barreled action in the McMillan stock.

For optics, I installed a Trijicon 1-6x24mm AccuPoint scope that uses a mil-dot crosshair reticle on the 20-MOA rail. A dial on top of the scope helps adjust the illuminated reticle, which is mounted in the second focal plane. This is a rugged optic offering plenty of adjustments and crystal-clear glass.

At the range, the Remington 700’s accuracy was noticeably improved with the McMillan stock installed. My five-shot groups measured right around an inch with 125-grain match ammunition from Gorilla Ammunition and PNW Arms. Barnes’ 90-grain range ammunition grouped in the 1.5-inch range. I also used some 120-grain Barnes TAC-TX and Gemtech 125-grain Nosler rounds, which proved perfect for short-range deployments due to their accuracy. The consistency also improved. The rifle was very solid in this stock, and the results were impressive, especially considering that it’s a factory action.

The rifle also ran reliably. Magazines ejected smoothly and bolt manipulations were fast. Brass ejected with authority. In short, the rifle was fast, accurate and flat-out fun.

Pinpoint Precision

Using the McMillan Adjustable A3-5 stock reminded me of why I loved the A5 in the first place. These stocks allow you to get very low to the ground, and the butt hook locks you into the gun. The A3-5 is lightweight while still being rock solid and well balanced. Once adjusted, the cheekpiece never moved. The forend worked well on barricades and against obstacles, remaining flat and stable. Shooting from prone with a rear bag was a cinch, and it was easy to adjust the length of pull by adding spacers as needed. This adjustment system is simple and reliable—there’s less to go wrong.

My original intent was to re-barrel this rifle after completing this test, but now I’m not going to touch it. Mating the Seekins Precision AICS to the McMillan stock resulted in a fantastic little rifle, and it is going to stay intact. It will make a perfect practice rifle and test bed for many projects to come.

McMillan has done a great job with this stock. Over the years, many shooters have clamored for a hybrid of the A3 and the A5, and the company has come through with flying colors. Whether it’s for your next custom build or duty rifle, make sure you give the Adjustable A3-5 stock a very close look.

For more information, visit or call 877-365-6148.

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