Tuesday, July 24, 2018

Making the best of bad magazines: or: Re-purposing magazines.

A long while ago I got a large lot of HK-91 mags cheap all in various conditions. A few of the mags looked like they were dropped while fully loaded, the bottoms were blown out to the point the flanges that held the floor plate on were compromised. Seeing that the upper portion of the magazines were still in great condition I thought there was no good reason why the magazines couldn't be cut down into 3 and 5 round magazines for hunting and range use.  In one session and with the help of somebody who has worked sheet metal some before I cut up (down?) 6 otherwise ruined magazines and made them into stubby range/hunting mags. Shortening the spring and modifying some of the internals are required. I generally guessed at how long these mags should be and that got me a bunch of 6 and 7 round magazines. A quick weld job by a friend tacked on a piece of flat 1/8"x1/2" flat stock to the sort of "pelvic fin" of the magazine follower. Again I eyeballed the length knowing cutting off material would be easier than welding on more in the future if I guessed exact lengths wrong the first time.  Trial and error told me how much to cut off on the bandsaw and tuning them took little time. 

Followers for 2-5 round magazines and one 3 round.
It might seem a little over the top for some but I really wanted to pattern my modified magazines closely to the factory offerings as well as stay legal for any hunting I do in the future with my rifle. It seemed lazy to me to leave the magazines at 6-7 rounds especially when rifle restrictions in most states would have landed me in trouble with those capacity of magazines while hunting.

Range/field ready 5 and 3 round magazines!

AR-15 A2 adjustable gas block

The idea of being able to control the amount of gas operating your rifle has been a long toyed with problem in tuning certain platforms. The AR-15 pattern rifle has been the center of obsession with barbie gun builders and lego type gunsmiths. Bolt on, clamp on and drop in parts are the norm now for this ubiquitous platform that is America's favorite rifle to love and hate. Minor modifications can be done in the home workshop though that save money over the boutique parts companies offering the latest and greatest must have accessory. One such seemingly simple project is making an A2 front sight tower into an adjustable gas block, a friend of mine requested I take a look at this DIY project others had attempted and see if I could duplicate their efforts for him.  Having a bag of spare A2 gas blocks helped as I quickly learned that you really can not fit a 10-24 set screw in between the barrel rings and the pathway the tube occupies when installed. My first attempt using the 10-24 set screw would have resulted in having to further modify the gas tube prior to installing the set screw. 

The obvious conclusion that some had already come to and my weak google-fu later scared up was that 8-32 set screws were perfect for this job. A 6 series would also work though your restriction range may not be as great. The idea is drill the hole in the vertical path the gas takes, tap the hole and adjust the set screw so you get reliable function of the platform but not over gassing the system causing premature wear on parts and more recoil than is necessary.

My method for this project was 
1. locate along the vertical gas chamber where I wanted the set screw.
2. Using a center cutting end mill I milled a flat spot for the center and drill to work off of
3. Using a center drill locate exact place to drill hole
4. Using a #29 drill bit drill hole on right side of gas block (I chose the right side so that a right handed shooter could easily adjust/monitor the set screw) I went ever so slightly into the opposite side of the gas block with the bit so as to create a seat for the set screw if it was so desired to omit all gas from the system.
5. Tap for 8-32 screw.

If so desired locate and drill hold on the front for a long 4-40 set screw. Be sure to clear all chips out of the gas block....a good oiling and de-greasing with brake cleaner a few times will ensure all machining artifacts are cleared away.

As this is an experimental item for me it'll be interesting to see how this holds up over the long term. I know for the first couple of mags it would be smart to not have anybody standing to the right of the shooter lest the screw or taped threads decide to part company with the gas block.

Poor mans gun paint: or: Paint for those barrel melt down stages

One thing I'm always keeping an eye out for is a more affordable way to paint firearms in durable finishes. A friend recommended "Dupli-Color" Engine paint. It is an enamel with ceramic so I'm not sure about using it for internal parts but it seems plenty good for external parts. 

 The suspended ceramic did not seem to apply very evenly even though I tried my best to follow directions closely (shake a lot before use, and often during). It looks good however like most other off the big box store shelf paints only time will tell how it stands up to use and abuse, gun cleaners and other chemicals will be the real test. I've used Rustoleum camo specific paints in the past with really great results and those would be my go to recommended paints. For a raw barrel and other parts though I thought I would try something with a possibly higher durability. This paint would also serve as a good base for doing a rattle can camo job on top of as its textured well now....though unevenly.