Sunday, January 29, 2012

Tacticool Trapdoor

I've been forming the idea that trying to chase small variations in group size wasn't going to be very effective if my overall group is still out at 6 or 7 inches.  A 1/2 or 1 inch improvement is good, especially if coupled with one or two other improvements, but I can't find them very well in the shotgun pattern of my shooting.  The solution, my thinking goes, is to mount a scope for my testing sessions.  This should pull out all the variation due to any visual problems.  So, off to the all knowing interwebs for ideas.  There are a couple of examples out there, but they mostly involve attempts to mount historically accurate long tube brass scopes.  These need a funky swing away mount to make room for the trap door to open, or else need to be rigidly mounted along side the barrel.  I'm not sure I agree with this line of thinking, as the trapdoor was pretty much a high volume cheap soldiers gun, not a real marksman's piece of kit.  Anyway, I'm not looking for a permanent or classy solution, just something for testing.  Here's my solution:



 I know, it looks hideous.  The scope is an NC Star (super cheapo) pistol scope using a modified mount for a Thompson Center Contender.  I used the pistol scope because I had to mount the eye piece so far away to make room for the trap door.  The Thompson Center mount needed one hole opened up to take a stock rear sight screw and another hole made from scratch.  A small notch had to be machined to allow the stock loop to pass through.  All in all, another fine simple adaptation that in no way modifies the original rifle. 

Here's a close up:



As you can see, there's only one set of body clamps that will mount up, but the system seems to be pretty secure anyway.

Shooting it was pleasant.  The scope is only 7 power, but it gives a substantially more refined visual picture.  The adjustments seem pretty accurate and repeatable.  I did notice some parallax error.  It is set for zero parallax at 50 yards.  The texts seemed to say parallax gets less important at longer ranges, but I could notice a good couple of inches motion as I moved my head from right to left in the scope.  There are adjustable scopes that will take this out, but they cost money.

So, did it work?  Unfortunately, no.  There was nothing wrong with it, it just didn't shrink my groups an appreciable amount.  Tacti-uncool.  I intend to keep using it for ammo testing, but it certainly makes me feel better about my current aperture setup.

I haven't posted my spending lately:

Current cost per shot = $2.43
Shipping is 9.14% of all costs.