My do-it-all rifle build


#1

I just got back from a long-range shooting clinic at a ranch in central TX (I’ll update in here with a link to the TFB writeup when it goes live on the 6th), and it has inspired me to return to my main battle rifle build and finish it off and seriously try to start pushing it out further.

I’m not a person who buys a lot of guns; rather, I mainly just focus on one “project gun” at a time for a couple years. My first was a Ruger Mark III with all the Volquartsen mods back in the day, and this is my latest one since ~2013. Of course I do have other guns, but they fit specific needs (i.e. home defense shotgun, carry gun, plinking rifle, etc.) and were not bought to scratch a collector itch – the collector itch is scratched by the project gun builds. So I’d way rather spend $400 on a small upgrade or two to an existing project gun than on a new range toy.

Anyway, the theme of this build is “all the cool operator things, spare no expense.” It’s supposed to be a CQB out to ~600 yard gun.

The foundation of the build is a .308 “AR-10”-pattern rifle: the LMT LM8 MWS:

This is not a rifle that you really want to do a lot to, apart from accessorizing, but I couldn’t resist two tweaks:

  • Giessle DMR High-Speed Trigger
  • JP Silent Captured Spring

I’ve added a pair of KAC flip-up sights, and topped it with a Leupold Mark 8 CQBSS 1.1-8x optic on a LaRue mount. (However, I recently got a mount from ZRODELTA in and it’s better than the LaRue. It’s only 30mm though, and the Leupold has a 34mm tube. I may get the 34mm ZRODELTA though.)

Just last week I added an Atlas Bipod BT10 LW17, which has been really nice. I wanted the KAC bipod but didn’t have time to get it in before I had to leave for the clinic (I also needed a bipod for the bolt action I used there), so I settled for the Atlas for now. At some point, though, the Atlas will live the on the bolt gun and the KAC will live on this gun.

I also run a VTAC sling, and a Surefire M600V on QD mount from LaRue.

Because I’m getting into long-range shooting (with a bolt action, the Sabatti STR in 6.5 Creedmoor), I’m thinking of picking up a 6.5CM barrel for it. But first, I need to address the stock’s lack of a cheek riser. Some googling turned up this guy, which looks pretty sweet:

https://battlelineindustries.com/bli-new/?q=sapr/sapr-sopmod-gen-ii

It turns the SOPMOD stock into a lightweight, compact DMR stock with a cheek riser and finer grained adjustment of pull length.

The other thing I’ll need is a better barrel in .308. I’ve got the standard 16" chrome-lined barrel on there, but LMT doesn’t guarantee 1MOA with anything but their 5R stainless barrel, which you have to buy separately. They have a new lightweight stainless barrel that shaves some ounces off the gun, and it’s available in a 5R 11.25" twist 16" version, so I think that’s next.

https://lmtdefense.com/parts/lm308b116s

Anyway, I have a home gunsmithing project with it for this week going on. The JP Silent Captured Spring I put in is only an H2 weight, but the gun ships with an H3 buffer. So I ordered the tungsten ring to convert the JPSCS to H3, but that’s kind of an involved project.

The other thing that I did was get a replacement spring kit for the Geissle DMR trigger. That trigger install was the first one I ever did, and I didn’t realize I had to remove the ambi safety first before I could fit it in there, so I ended up fighting it and bending one of the wire springs that holds the trigger in place. This hasn’t seemed to really affect things, but I don’t like it because I know that spring is bent out of spec and I figure it’s going to bite me someday. I need to replace those springs.

Anyway, I’ll take some pictures and post them in here as I tinker on it.


#2

Nice writeup. I have also struggled with trigger installs before realizing the safety needed to come out…

Can you explain a bit about the smithing you plan on doing to get the JPSCS to an H3 buffer? Description on MidwayUSA’s site reads:

“Full correspondence between SCS masses and H1, H2 and H3 buffers”


#3

There is a long instruction page that comes with that buffer. You have to compress the spring and hold the buffer down, heat up one end and loosen the threadlocker, do some other steps that I’m not clear on, then finally use solvent to clean the threads and screw before re-applying thread locker, all just to replace one of the weights.