Rock Solid Industries

Rock Solid Industries builds custom rifles and manufactures precision gunsmithing parts, with a reputation earned through detailed Mosin-Nagant and Swiss K-31 work. They don't just install components—they design and machine their own parts in-house, which is why their scope mounts show up in Gun Digest's "Top Mosin-Nagant Scope Mount" lists.

Scope Mounts & Rails - Mosin-Nagant scope mounts with Picatinny-style rails (standard and +20 MOA versions) - Swiss K-31 scope mount system - Scout mount systems for modern tactical builds

Rifle Components - Swiss K-31 replacement firing pins (hardened steel, USA-made) - Custom Swiss K-31 firing pin springs - Mosin-Nagant bolt handles (threaded designs) - K-31 and K-11 10-round magazines

Shotgun Conversions - Remington 870 conversion kits - Mossberg 500 series conversion kits

Reloading Tools - Swiss K-31 Berdan military crimp cutter (works with 7.5×55 GP-11 brass, 7.62 NATO, and other calibers)

Rock Solid has partnered with MBT Gunsmiths in Arkansas to handle bolt handle and scope mount installations. This keeps turnaround times tight while maintaining quality control.

Gun Digest recognized Rock Solid's Mosin-Nagant scope mount as one of the top options for 2021, noting that it "more than lives up to the company's name."

They maintain a full online store with product documentation, installation guides, and reloading information. If you're doing a Mosin or K-31 build, their site has detailed resources on ammunition compatibility, firing pin upgrades, and scope mounting techniques.