Wednesday, October 2, 2013

Longshot shotgun grip: The Final Chapter!

Sup guys and girlfriend,

I can't believe I'm saying this, but it's finally time to wrap up the Longshot once and for all. It has been a tale of heartbreak, sacrifice, and persistence. At last it is time to move on to bigger and better things. After this mod, I can rest knowing that I've made this Longshot everything it could ever be. Join me in the final chapter in the Saga of the Yellow Monster.

Where we left off...

Required Materials:
  • 2 1/4'' PETG tubing (1/8'' wall)
  • 1/4'' polycarbonate sheet
  • 3/8'' 6-32 set screw x8
  • 3/16'' brass rod
  • 1/4'' #10 nylon spacer x2
  • 8-32 nylon lock nut x2
Required Tools:
The holy trinity: drill press, scroll saw, belt sander

Write-up:
Keep in mind that if you want to look like a dork with your bipod legs then this mod is not for you. Strip them off and prepare for major surgery:

Make it look nice:

Prepare the grip by cutting a 4 3/4'' section of PETG:

This is where the belt sander becomes indispensable--chop down the PETG near the middle lengthwise with a vise and hacksaw, then sand away until the half-pipe is 1 1/4'' tall:

Now to mark the pipe for drilling. The rear marks (left side) are for the polycarb "arms" that connect the grip to the bolt sled. The front marks to the right are for the pieces that keep the grip in the Longshot's natural "track" at the front of the blaster. They begin 2 1/8'' from the rear of the grip.

Drilled with the 7/64'' bit and ready to go! To get the holes perfectly perpendicular, prop the grip sideways against something standing straight up in the vise.

Now to cut out all the pieces that attach to the grip. The arms are 1'' x 10 3/4'', and the little guys are 3/4'' x 5/8''. The "smile" is a piece that will be solvent welded to the back of the grip and help with leverage for the K26 prime:

 Chopped and mopped:


Now you can hold the scrolled pieces up to the holes you drilled in the grip and make another set of marks. Drill them and assemble everything. Put the grip into place and push it all the way forwards. Make a mark on both arms where the hole is in the bolt sled.

Drill out the holes for the connecting rod with the 11/64'' drill bit and make any final corrections to the arms:


Just for shits and giggles I decided to make another catch. My 1/8'' catch was wiggling around and it made me very uncomfortable. I scrolled one out of my scrap 5/32'' polycarb.

By far the best I've made so far:

 Solvent weld the smile to the back of the grip. Not the most ergonomic, but gets the job done.

Here are some pics of the assembled grip:


 To get the grip on the blaster, you will need to attach one of the little pieces last:

Don't forget the connecting rod that joins the two arms and passes through the bolt sled! Use a #8 die to thread the ends of the 3/16'' brass rod. Don't just stick it in the vise like I did--use blocks of wood!

To fix my seal problems that have arisen as of late, I decided to glue a piece of 5/8'' brass into the mouth of the plunger tube. It seems to be working great, especially after applying some oil.

Everything in its right place:

Velocity with 1 1/4'' #6 slugs:
I'm definitely pleased with the performance, and I'm getting 20-30 fps faster velocities than before (with the bad breech/plunger tube seal). Not quite as powerful as the original creation, probably due to excess friction between the new neoprene plunger head and plunger tube. Well that wraps up another mod for this guy! I'm pleased to have finally finished this, as I can finally move on to 100% homemades. Hope you guys enjoyed this write-up :)

Cheers,
~T

11 comments:

  1. Wow, amazing job.
    If you make a rainbowpump I know that it is going to destroy mine in terms of quality. You are amazing at making everything look extremely clean.

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  2. Thanks fellas! It's a combination of left brain, right brain, and corpus callosum.

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  3. Very nice! Will be following your blog from now on.

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  4. Replies
    1. Ah yes I nearly forgot! I'll get that up ASAP.

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  5. How did you fit a 3/8" Catch in? I though that something like 1/4" was still too thick. Nice job on the foregrip!

    ReplyDelete