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Knoxx "Breachers" Gen III Recoil-Reduction Grip Mod for Shockwaves with Crimson Trace Saddle Laser

Ernst asked, so here are some photos.

Some folks on the interwebnets have said that a Shockwave with both a Knoxx "Breachers Grip" and a Crimson Trace saddle-style laser has no problems.

Others warned that recoil would cause the Knoxx to move forward, and shatter the plastic of the expensive laser. Uh oh...

So, a prudent man eliminates the problem in the worst case scenario, which was 15 minutes work, requiring only a steel rule, a stick of chalk, a coping saw, and a small fine-grit file.

First, remove the crossbolt and the big spring from the Knoxx, as we want a worst-case scenario where the spring has fully compressed and the Knoxx grip has moved as far forward as it can. This is shown below:

Knoxx_Mod_1 (Medium).jpg

The laser is removed above, note the hole where the trigger group pin goes, just below the 1.25" mark on the ruler. I have drawn a red line to show the furthest possible forward travel. Below we compare with the laser mounted:
Knoxx_Mod_2 (Medium).jpg

So, the red line shows that it IS possible that the Knoxx might travel forward far enough to ram into the laser, and maybe break it right where the side retaining bolt holds in onto the receiver. Not good, but we can fix this.

Knoxx_Mod_03 (Medium).jpg

Drawing a line to denote the rearward edge of the laser, we can see that we only need to remove the inner surface of the Knoxx on the right side of the receiver, above the slot upon which the Knoxx Grip slides on the part of the Knoxx grip that is bolted to the receiver.

Knoxx_Mod_04 (Medium).jpg

Transposing the ruler marks from the first photo, with all photos scaled and aligned as layers in Photoshop, we can see that removing a triangle 5/8th's of an inch on each side from the inside surface of the grip will do the job. I marked mine with chalk marks.

Knoxx_Mod_5 (Medium).jpg

Above is that triangle of plastic removed down to a level that is equal in depth to the channel in the grip on the right side of the receiver (only). I cut with a coping saw, and then smoothed with a fine-grit file, holding the grip in a vice.

Knoxx_Mod_6 (Medium).jpg

Hard to see here, but one ends up with about 1/6th of an inch clearance between the innermost surface of the Knoxx grip, and the outermost surface of the laser in that worst-case scenario, which is more than sufficient clearance, as there is zero side-to-side wiggle on the Knoxx grip.

knoxx_mod_7 (Medium).jpg

Finished and reassembled.

Now, a LOT would have to "go wrong" (like maybe a shattered spring) for the grip to go so far forward as to actually impact the laser, but why take chances when the fix is simple, and easy to implement?

...and yes, the Knoxx Grip makes the overall weapon length a little longer than the standard birds-head grip, so there should be no complaints from the painfully young, neatly dressed, excruciatingly polite, and heavily-armed agents of the BATF. Still "Not-A-Shotgun".

And yeah, the safety... awkward... hence my still-unanswered question about a Maverick 88 trigger group fitting in a Shockwave, to get a trigger-guard safety.
 
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