I liked the idea of using the stock to contain an extra spring, but I didn't like the length of the stock. Way too long in my opinion. I also didn't want to chop up the 'armed' plunger to allow for total compression of a shorter spring against the middle brace on the stock, though technically that last inch or so is vestigial. One Man Clan's original posting of the Recon showed the middle stock brace with a hole in it, supposedly for the 'armed' arm to fit in. So, idea. Though I have no version with an AR-15 spring to compare too, I suspect I'll still get a nice little bump on range using a smaller one at full compression. That and I like the shorter, more tactical stock.
Here's an initial picture of the materials. Already chopped up the later portion of the stock and left a bit hanging out the back of the middle brace so that I can have an attachment point for the shoulder stock. There's also a length of 3/4 inch PVC that I had to Dremel out a little so that it fit loosely over the extended plunger tube. Didn't take much. Make sure it doesn't stick anywhere, or obviously this doesn't work. The shorter length will go inside the mid-brace along with the smaller diameter piece which will go inside of that as an anti-kink guide for the compressing spring. Not certain if it really has any measurable effect, but I like to err on the side of caution.
Used epoxy putty to create a little nest for the tubes, make sure they're as centered as possible. The central one extends far enough out to keep the spring from rocking around too much in case it bounces out of the mid-brace after firing, but not far enough to touch the extended plunger tube. This is also a good indicator on whether or not a fully compressed spring will fit when the gun is cocked. The extra NF spring I had available fits just fine, and when I get a chance to replace it with a sturdier Handyman spring I'll see if i have to shave a little off the plunger tube or not. Making a sturdy base with the epoxy at the back screw keeps the spring compressing correctly.
Here's a shot of the mid-brace together and the spring inserted.
Now you can connect the chopped stock to the blaster and cock the gun so that the plunger acts as a guide to connect the large PVC; and if you Dremeled correctly, lining up perfectly with it. Here's a shot with some added epoxy supports. It slips on and off just fine and with the spring inserted makes a really nice 'thrum' when fired.
And a final shot with the shoulder stock reattached with some more epoxy ( god I love that stuff .) Just needs some cosmetic sanding and a coat of paint, and I have my new primary.
Within the next couple of days I'll be completing and posting the shotgun mod I've got worked out for the Recon too.
Hope this passes muster, more to come soon.
Edited by OberonFox, 16 February 2008 - 10:03 PM.