MDT ACC Chassis Stock: The Ultimate Long Range Build

Shown in the photo is the MDT ACC Chassis, MDT Vertical Grip, MDT Weights, Seekins Precision Havak Action and barrel, Triggertech Diamond 4-32 ounce trigger, SilencerCo Suppressor, and Leupold Mark 5 5-25 optic.

MDT has recently introduced a very modular chassis for long-range precision target shooting. It’s not a budget chassis or the cheapest stock you can buy but I think it may be one of the best and most adjustable chassis on the market.

This MDT ACC Chassis stock has so much going on that I kind of “nerded” out and went a little crazy on this review (it’s long). For those of you that don’t want all the details, here’s a one-paragraph summary of the stock.

It’s a precision CNC machined stock that is built out of aluminum and steel. Almost everything on it is adjustable and it has options for just about any position you could imagine shooting the rifle from. It accepts detachable magazines and has very unique options for adding weight to control balance and recoil.

Buttstock

The buttstock is made from steel and aluminum. It’s fully adjustable for cant, length of pull, the height of buttpad, and has a fully adjustable cheekpiece that adjusts up and down as well as left and right. It accepts an optional weight for balance and has the option of a bag rider that attaches via M-LOK on the bottom of the stock if desired

Bag rider and weight aren’t attached but are shown. The small set screws on the left allow you to lock down the stock so that it’s not adjustable.

Not only are there roller adjustment wheels for adjusting the length of pull and cheekpiece height but there are thumbwheels that lockdown so there is absolutely no movement or wiggle of any kind. The adjustments have markings so that settings are repeatable.

The empty holes you see in the MDT ACC buttstock are QD sling mount holes.
The threaded holes are for small set screws that allow you to “lock-in” your settings.
As you can see in the photo, the cheekpiece is adjustable left and right so that you can get perfect alignment behind the gun regardless of the shape of your face.
Also, note that the buttpad is adjustable up and down.
Here you can see the buttstock adjusted for the author and you can see the weight installed.
Here’s a shot of the buttpad and the buttstock.

Receiver

The receiver section of the ACC chassis is made from 6061 aluminum and is available for most precision type actions on the market. MDT has a complete list of actions on its website. For this build, I’m using a Seekins Precision Havak action and barrel and it uses the Rem 700 footprint.

NOTE – The Seekins Havak Action uses a larger bolt diameter than a Remington 700 and I had to remove the magazine release and mill off .064 from the top of the magazine release so that magazines would lock-in. This is not an issue with the stock as it’s the action that is out of Rem 700 spec and I’d have had the same issue with any stock with a detachable magazine.

I was impressed with the quality of the machining and everything fit perfectly. The buttstock attached with a fairly large bolt and there is zero play or slop.

The receiver section is specific to your rifle action.

The receiver section has an integrated oversized trigger guard, accepts AICS style magazines, has a flared magazine well for easy and fast mag changes, a barricade stop on the front, and thumb ledges or rests along the sides for your thumbs to rest in a neutral position. The MDT vertical handgrip is what I’m using and is what you are seeing in the photos but the ACC will use any AR-15 style pistol grip that doesn’t have a beavertail.

Your thumb lays naturally on the thumb rest.

Grip

The MDT vertical pistol grip is shown above. 1) is what attaches to the ACC Chassis and 2) is the actual grip that screws to 1. Notice how the holes in 2 are oblong. That allows the grip to be moved closer or farther away from the trigger for perfect placement of the finger on the trigger.

The MDT Vertical pistol grip does not come with the ACC stock. It’s a $49 add on and I think it’s well worth it. I love the vertical grip and think it makes it easier to pull the trigger straight back. The grip adjustments allow the user to get perfect finger placement on the trigger.

Forend

The Forend

The forend is 17 inches long and has M-LOK slots along both sides and the bottom allowing you to attach anything that attaches using M-LOK. Of course, you can add Picattiny rail and attach the myriad of accessories that attach to Picatinny. Also, along the bottom of the forend is a full-length ARCA rail that allows accessories, bipods, or tripods to slide and lock up and down the full length of the forend.

Here you can see the full-length ARCA rail complete with stop so that attachments don’t slide off the end.
The ARCA rail is shown here attached to both a tripod and a bipod. Either can be instantly slid up and down the full length of the forend.
Here’s an example of why it’s important to have an ARCA rail and be able to adjust where your bipod sits instantly.

Weights

The MDT ACC without weights or action/barrel but with the MDT Vertical handgrip weighs in at 5.23lbs. So if you were trying to keep the weight down, that’s not actually that heavy. Most of us shooting precision long-range like our rifles a little heavier and that’s where the MDT steel weights come in. You can place them in the buttstock and up and down the barrel channel for perfect balance and to help mitigate recoil. You can use some, none, or all.

Neither the MDT M-LOK weights nor ACC Interior Forend weights come with the stock but are an optional accessory.

The first set of steel weights can be installed below the barrel in a channel in the forend.

Weights installed in forend.
Even with the forend weights installed you can still use M-LOKs on the bottom.
You can add up to 2.4 lbs in the barrel channel and you don’t need to remove the action to install them.
These are the MDT weights that attach using M-Lok along the outside of the handguard (they’ll work with any gun that has M-LOK). Four pairs are pictured but the ACC Chassis can handle five pairs just on the sides if desired.
That’s a Seekins SP10 in 6.5 Creedmoor that I attached the MDT M-LOK weights to for added recoil control for a match.
Here’s what one of the MDT M-LOK weights weighs.
The steel MDT Buttstock weight.
All the weights together weigh just over 6lbs (You can fit more weights on the rifle. That’s all I have).
My Seekins barreled action with scope base and TriggerTech Trigger weigh 6.6 lbs.

Essentially the Chassis weighs 5.2 lbs, all the weights weigh 6.1 lbs, and my barreled action weighs 6.6 lbs which is a total of 17.9 lbs. Add in a 2 lb scope, rings, and bipod and you’d easily be over 22 lbs if you wanted to be.

How does it shoot?

The stock is comfortable. It’s easily adjustable and it’s ergonomic. It has every feature you could possibly hope for in a stock. It tracks well when you shoot it. The Seekins Havak barreled action I dropped in is chambered in 6.5 Creedmoor and it hardly moves when you shoot it. Easy, in one word.

As far as accuracy goes, I’ve now shot the gun all the way out to over 1200 meters with first-round hits on every target starting at 300 meters.

It rained a little during initial sight in.
1st five-shot group and first shots ever out of the Seekins barrel. 100 yards.
2nd five-shot group. Things are starting to tighten up.
3rd five-shot group.

The barrel took about 10 shots to settle down. The 3rd group is really pretty impressive considering this is factory ammunition and was shot in the rain. The ammo is Hornady American Gunner 140 gr BTHP Match in the bulk 200 round ammo cans.

Final Thoughts

If you’re interested in building the ultimate long-range rifle the MDT ACC Chassis stock should be on the shortlist of stocks. It is well designed, well thought out, and well-executed. It looks amazing, is available for most actions, has a number of color options available and while not inexpensive, isn’t ridiculously priced. The ability to make infinite adjustments and balance weight is pretty incredible.

If the MDT ACC Chassis isn’t what you’re looking for, then MDT might have one that is, as they make five other chassis systems that are completely different than the ACC.

MSRP Starts at $999

Visit MDT to learn more about the ACC Chassis by clicking HERE.

Learn more about the Seekins Precision Havak action and barrel by clicking HERE

Learn more about the Leupold Mark 5 scope by clicking HERE.

Learn more about the TriggerTech Diamond Trigger Here

About the author: True Pearce is the Managing Editor at GunsAmerica. He’s a competitive shooter, hunter, instructor & attorney. You can see and follow his adventures on Instagram. @true1911 https://www.instagram.com/true1911/

{ 2 comments… add one }
  • Zupglick August 26, 2019, 10:27 am

    I would like to see something similar for .50BMG.

  • Steve August 26, 2019, 7:06 am

    Wow! A beautiful rifle, I had to get a towel to catch the drool out of my mouth.
    Price is reasonable.
    I would love to have one. 😁

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