Cutting grooves in barrel for fsb and hand guard retainer pins.

[riggs1117 0]

What do you guys use to cut the grooves when swapping the FSB and lower hand guard retainer? Was thinking of ordering some jewelers blades offline anyone got a specific tool/file they use so I can avoid trial and error?

[ChileRelleno 7,070]

Retainer notch can be filed with any appropriately sized round metal file, very simple to do.

The FSB pins should, IMO, be done precisely with a drill press, you don't want to fuck these up, cant the FSB and have to redo them.

[poolingmyignorance 2,191]

I use a clamp and a hand drill, it took a few reworks and weld over/blending to get right the first few times... proceed with caution

[riggs1117 0]

What size file did you use? was thinking maybe a good chainsaw file.

[mancat 2,366]

Buy a jewler's file set. Most basic sets are cheap and you will find a file in them appropriately sized for making the handguard retainer locking pin channel. It's good if you have another AK to compare to - take the round files and place them in the channel of your other AK until you find one that most closely fits.

 

As far as doing pin channels through the GB/FSB, I don't have a drill press, so I've used a cheap drill guide rigged up to a square of plywood. You can set up a pretty solid drilling rig this way.

 

Get the appropriate sized drill bit for your pins - I reused factory 3mm pins, so I purchased several 3mm bits from Fastenal - they are about 2.9mm so they give a tight fit. Rig up and secure the receiver, drill half way through on one side, flip it over, and drill half way through on the other.

 

[riggs1117 0]

good idea, I'll order a jewlers file set and just test fit it on the original groves on the bottom of the barrel (mine was pinned already, just not in the right spot).

[mancat 2,366]

I'm not sure if we're on the same page

 

the file is only meant for creating the channel for the handguard retainer locking lever.

 

don't expect to get good results if you're trying to file in the pin channels. you need to drill them.

Edited November 6, 2013 by mancat

[jamesavery22 54]

drill and ream... 7/64 drill bit then a 3mm reamer. That's if you have a virgin FSB. If your FSB already has pin holes drilled then it's a 7/64 end mill then a reamer.

 

Need a mill for that work.

 

Else the press fit is really all that's keeping the FSB from twisting.

[Inebriated 31]

I did mine today.

 

Drilled using a 1/8" bit, then made pins out of 1/8" drill stock. Cut to length, crudely heat treat, and tap them in. Took me all of 10 minutes, most of which was simply setting up the rifle to sit securely under the press. I used a drill press, but I feel as if I could have gotten by without one, as long as the rifle was in a vice and secure.

[riggs1117 0]

I just tackled this last night, as well as threading the barrel. the only bitch was trying to find the right spot to file for the lower handguard retainer.  If I were to do it over again I would buy an extra lower handguard retainer and drill the lever out of it then use it as a guide to file the notch in the barrel.  I ended up filing to far toward the receiver at first but got it to work, It ain't pretty but works

[riggs1117 0]

Almost done. Still need to paint the receiver before I attach the trigger guard

[NM0 586]

Almost done. Still need to paint the receiver before I attach the trigger guard

Your rifle looks good.  Dig that grey laminate.  Congrats.

 

When I filed the grove for front hand guard retainer on my 5.45's I started a little too far back and gradually kept going forward till it locked up tight.

[Inebriated 31]

Looks good! Pro Tip: Rustoleum's High Temp Ultra (semi-gloss)is a perfect match for the Saiga finish. I didn't do anything but mask-off the places that needed finishing. Can't even tell.

[riggs1117 0]

Thanks for the compliments. I picked up some duplicolor engine enamel but maybe I'll try the rustoleam. i also started filling to far back before I learned that I could place the lower handguard on followed by the handguard retainer. I then snugged the retainer toward the receiver and whacked the lever on the receiver with a hammer. This left a mark on the barrel showing me where I needed to file.

That's black tapco timbersmith furniture. I wanted red but it's sold out everywhere. I think they are discontinuing the tapco wood. I probably would still buy the red tapco if I could find it.

[Sim_Player 1,939]

I found the flat black rustoleum high temp rubbed off too easy.

 

Repainted right over the rustoleum with Duplicolor 1634, let it dry for a few hours and then baked in the oven on warm for 4 hours to speed the curing.

[Cobra 76 two 2,677]

drill and ream... 7/64 drill bit then a 3mm reamer. That's if you have a virgin FSB. If your FSB already has pin holes drilled then it's a 7/64 end mill then a reamer.

 

Need a mill for that work.

 

Else the press fit is really all that's keeping the FSB from twisting.

+1 on the end mill vs a drill bit. Drills can tend to walk or try and curve while cutting. Especially if you try and drill the pin holes and barrel groove with FSB installed. An end mill rather, cuts with a sharp square shaped end instead of a v or bowl type shape, so it will remain straight.

[Sim_Player 1,939]

You can fabricate an end-mill from a drillbit by reshaping the end with a dremel. You want a very slight taper (but almost flat at the end). Maybe 15-20 degrees (guessing).

 

Make sure the two end cutting surfaces have a slight "back-taper" so that the sharp ends will "bite".

 

This saved me time and money on my kit build. You can quickly resharpen it too by repeating the process.

 

Cut through my virgin barrel like butter. Keep it oiled and clear the chips as you go.

 

Did mine very carefully with a handdrill. Start one side then switch to the other until both sides meet.

 

Have you drilled and pinned the FSB already?

 

Rifle looks nice!

Edited December 2, 2013 by Sim_Player

[riggs1117 0]

I already used a cordless drill and didn't run into any problems, everything is pinned on including the handguard retainer.  I used a file for the handguard retainer and drill bits for everything else. One problem i did run into was that the plunger pin does not go all the way into the fsb enough so that I can remove the slant brake.  Im going to have to remove the fsb again to get the slant off then file the U cutout in the plunger a little bit so that it goes in further.  That or find a crush washer.

Edited December 2, 2013 by riggs1117