Ok, now that I have your attention with that title, I often get asked how to fit the various furniture parts of an AK to a given rifle – the gas tube cover / upper hand guard cover, the lower handguard and the buttstock. Most of the work can be done with a secret tool – a slightly modified single cut file and patience.
Most of the time with new furniture, you need to remove material and a single cut file works great for that. With the pictured PSA Redwood furniture set, I needed to think the half circle ends of the gas tube cover and I also had to fit the lower hand guard just a tad.
Now here’s the trick to really make this tool work for fitting furniture – grind one thin side smooth – literally get rid of the file’s teeth. This will allow you to quickly and easy run the file right against a raised edge, such as the lips of the gas tube cover, and remove material that you want while leaving the raised edge untouched.
I find an 8″ file just the right size. 8″ is the measurement from the front edge, or “point” of the file, to the base of the heel – the bottom of the main body before the tang starts.
Any brand of file ought to work. Some come with a “safe” edge meaning no teeth. Just test it first to see if any of the teeth from the perpendicular surfaces protrude enough to cut – if they do then knock them down so the smooth surface can ride on the material you are working on with zero cutting happening from that side.
Just be patient – look at where the furniture is binding, remove a small amount and test the fit. In general, you want AK furniture to fit snug vs. rattling around. Patience is the key though – don’t rush things. Just keep inspecting, filing off a bit and testing over and over.
A single cut file with one thin edge ground is the secret tool but you need to be patient when using it. I can’t even begin to guess how many lower and upper handguards I have adjusted with this file over the years plus I have learned a bit more patience as well.
I hope this helps you out.