The HS3 is Modular Driven Technologies (MDT) newest chassis for Remington 700 short action rifles. The foundation of the system is an aluminum frame that adds a detachable box magazine and accepts AR-15/M16 M4 stocks and pistol grips. The HS3 is MDT’s first offering with polymer skins on the sides of the chassis.
If you read Modular Driven Technologies (MDT) HS3 Chassis Review: Initial Thoughts, you’ll know my first impressions of the HS3 were positive. I was lucky enough to find the time (and weather) to shoot this afternoon between snow storms. Yesterday was the tail end of Nor’Easter, tomorrow we have a “historical” blizzard coming. Around here, you go to the range when you can this time of year, it isn’t always easy.
For testing and evaluation of the MDT HS3, I mounted the Remington 700 barreled action that was used in 308 Winchester / 7.62x51mm NATO: Barrel Length versus Velocity (28″ to 16.5″). The barrel is a Shilen unturned blank I cut to 16.25″ in length and tapered to a DRAPA XM3 profile. This is a custom barreled action, however, any factory Remington 700 short action would drop right in.
The test rifle was built with the following parts from Brownells; Remington 700 short action receiver, Shilen .308 1:10 match grade stainless steel unturned barrel blank, Badger Maximized scope rail, Spuhr ISMS scope mount, Nightforce NXS 5.5-22X56mm Mil/Mil Scope, MAGPUL PRS stock, and TangoDown BG17 grip.
An important note on this barreled action, the barrel was abused for the first 500 rounds of its life in the barrel length experiment. The action has not been trued and the factory trigger is 6 pounds, 11 ounces! This is anything but a ringer.
Weather conditions were fair, the temperature was 37F. 10-15 mph intermittent full value crosswinds, and the late afternoon winter sun at 12 o’clock to the firing line made conditions less than ideal (note sunlight coming through bullets holes in first two groups below).
For ammunition, I used Federal 168 grain Gold Medal as well as my non rifle specific, generic 175 grain Sierra MatchKing hand loads on once fired Federal brass.
All groups were fired at a distance of 100 yards, from the prone position with a Harris S-BR bipod equipped with a KMW Pod-Loc, and a rear bag. Groups sizes are measured center-to-center in inches. I used a 5 round, AI, AICS magazine. Targets were 1″ self adhesive orange dots on paper.
The first three rounds, with my generic 308 Winchester hand load, including the cold bore shot, formed a group .239″ (.228 MOA). Way better than I had anticipated with the trigger and range conditions.
My best 5-shot group with the Federal Gold Medal was .544″ (.519 MOA).
The best 5-shot 175 SMK hand load group, .671″ (.641 MOA).
The chassis was accurate, proving it could hold sub MOA accuracy despite a heavy trigger. With proper load development and a trigger swap, I’m confident this rifle would stay sub 1/2 MOA or better.
Shooting the 16.5″ 308 Remington 700 with an HS3 was a pleasure. The gun tracked well and was quickly placed back on target. While this rifle isn’t light, it isn’t particularly heavy either; the rifle, with optic, magazine, and bipod weigh in at 13.75 pounds. I found it more controllable then a similar setup I have in a McMillian A3 with the same Surefire brake.
I fired one group off a bench and the ergonomics were fine. From my experience, this isn’t the case with some chassis- occasionally I find designs that work well in the prone position, and that is about it (I fear having to shoot my AICS AX off a bench). Moving to alternate field positions, the rifle handled well, like a heavy AR-15, for sitting, kneeling, and off hand shooting.
The magazine system fed well and I didn’t experience any feeding problems. The factory AICS magazines I have been using were very tight when inserted into the magazine well. I did speak to MDT and they told me the production model (mine is a preproduction prototype) will fit the steel OEM AICS magazines better. The upside of the tight fit, was the magazines didn’t rattle as much as they do in other systems I have used. Note the magazine release in front of the trigger guard (above).
This barreled action was the same one I used to review the MDT LSS. I took a picture of both chassis next to one and other (HS3 (top), LSS (bottom)). Note the increased length of the HS3. For a $100 premium, the HS3 gives you quite a bit more than the LSS. I liked both, but preferred the HS3.
I showed the HS3 chassis to a group of experienced shooters whose opinions I value and they were all impressed with it.
I plan on swapping out my 6 pound 11 ounce trigger (yikes) before I shoot it again.
I’ll post another review once I have more time in the field with it. I’m hoping to get a regular production unit to examine as well.