Going crazy with an Open Division M&P

A new potential customer contacted us a few months ago with a request for an Open Division pistol built on an M&P 9L. Neither Randy nor myself had really considered building an M&P up that way but we decided to go for it anyway.

Our customer chose the 9L because the slide is the lightest of the long slide M&P’s and the extras you get with the 9Pro were going to be removed anyway (Perfocmance Center Sear and Sights).

He chose a Speed Shooter Specialties Magwell for this project, which we agree is the best option for this application. The SSS Magwell is well made, easily fitted to the frame and just plain sexy to look at.

Since Bar-Sto doesn’t make a barrel for the M&P yet, we used a Storm Lake extended threaded barrel and fitted a slightly modified Jager Products Compensator to it. We also added a few ports to he barrel and milled a slot down the center line of the slide to reduce some weight.

A Leupold Delta was chosen as the optic for this project. The Delta comes wth a Dovetail instert that fits the slide and an adapter to make it a seamless fit. I have to say I’m impressed with Leupold on this one, the Delta comes with enough dovetail inserts and adapters to mount to just about any modern slide available. Good Job Leupold.

Taylor Freelance makes some really cool mag extensions that add 10 rounds to the M&P’s 17rd mag, so that one was a no brainer for this gun.

We set this project up with our Comp Action Enhancement Kit, Reset Assist Mechanism and of coarse our Failure Resistante Extractor. The trigger pull ended up being right at 2.5lbs with a clean break and nice snappy reset.

In setting up the recoil spring weight, we wanted to get a better picture of how the fun was cycling, so our customer sent us a High Speed Camera that shoots 1000 FPS to get footage of the gun running. We got some great shots of the M&P cycling with all different types of ammunition. We were able to see the gas blowing out of the port holes in the barrel and comp just before the slide opened up as well as a good view of the brass ejecting.
Open M&P at 240 fps

When all was said and done we ended up with an open gun that has very little muzzle flip, light recoil and is fast to drive around the range. I did a side by side comparrison with a friend’s Open Glock. His gun weighs nearly double what the Open M&P weighs and we’re talking about a stainless steel optic mount and a tungsten weight in the grip, but when I shot the Glock with the same ammo I run in the M&P, the recoil was greater. So we have a gun that’s lighter and has less muzzle flip than the heavy weight Open Glock I tried.

I really hope the owner likes what we came up with for him, this project was certainlty an adventure for Randy and I.

Scott Folk

scott / January 12, 2011 / Random Apex


  1. Doug - January 12, 2011 @ 1:08 pm

    Very cool.

    Can you give an explanation for why the 9L has a lighter slide than the Pro version? Im sure im just not thinking of something but I always figured they were the same (minus the sights and trigger). Thanks


  2. scott - January 12, 2011 @ 1:31 pm

    The scallops on the sides of the 9L slide are deeper, which reduces weight. The 9mm Pro slide assembled with Warren Tactical Sights is 13.5oz and the 9L slide with the same sights is 13.2 oz. Not much of a difference, but when you’re dealing with an Open gun, it makes a difference.


  3. Just finished an Open Division M&P - Weapons Cache Forums
  4. Todd - January 12, 2011 @ 6:03 pm

    I noticed the up-down motion in the slo-mo movie. I had a Burris Fastfire on my M&P FS9 and found I had a lot of motion muzzle up/down to acquire the red dot. Seeing similar problems? Wold be a LOT better if mounted further down the slide, like my Colt Scout C-More on my Colt AR 9mm.

  5. Doug - January 12, 2011 @ 9:20 pm

    Thanks, I never would have thought about that. But if I can ask, why not shave the rail? But I mainly ask that because I want to see a derailed M&P, and am not sure I want to sacrifice mine just yet. Thanks again

  6. scott - January 13, 2011 @ 10:35 am

    @Todd – The up and down movement you’re seeing is more from the shooter’s (Randy’s) hands. We didn’t have a good set of bags or rests to rest the gun on, so Randy held the gun down on the table and fired it, essentially losing his normal means of controlling muzzle flip to allow the camera to see it better.

    @Doug – The customer doesn’t want the rail removed, so we didn’t remove it.

  7. George - January 14, 2011 @ 6:47 am

    I fired the gun yesterday and it runs flat. It doesn’t have the motion you see in the video.

  8. Allan B - January 15, 2011 @ 8:00 pm

    Randy and Scott,

    Do you think it would be possible to put a side winder racker on the slide? Sometimes there would be stages in USPSA where you have to start with the pistol on the table or something. If you have a racker on the pistol it would work as a kick stand that way you can get you thumb under the pistol easier. Thank you for your time….


  9. Tom - January 15, 2011 @ 9:58 pm

    Just curious…
    Does this gun shoots 9mm major or minor?

  10. George - February 15, 2011 @ 3:46 pm

    The gun is shooting 9 Major.

    MG124 JHP, WSP, 6.6 – 6.7 AutoComp, OAL 1.165

    Chrono: Avg – 1380; ES – 30; SD – 9; PF -171

  11. Compensator for m&p?
  12. Rob - May 24, 2015 @ 2:00 pm

    Scott, I just installed your competition enhancement kit, wow what a difference! I’m purchasing a Storm Lake threaded Barrel and a SSS compensator and I was wondering, will I have to get a lower poundage recoil spring, and if so what would you reccomend starting at?

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