Type 81 build/conversion in 223/5.56 NATO

Below is a video of Brandon Herrera speaking about a 5.56 AK. Perhaps it's magazine could be useful for the project, pinned to Canadian legality.
Brandon Herrera on YouTube said:
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I’ve got some magazines to send up dang I forgot and seeing this bumped reminded me.

Can’t Polytechnic just make us one in 5.56…they did the Type 97 I mean, is this too much to ask?
 
Hi Everyone, my apologies for the lack of updates and thanks for your patience! I have been framing my house since December and my workshop still doesn't have power. I can't wait for when I finish roof and run a 2-phase wire to the shop to resume the project.
Had to park a few other projects due to my construction, all of course within the N/R parameters:
T97 in 300blk
T81 in 6mm ARC
Lee Enfield No4 in 223
Lee Enfield No4 in 45-70

So far almost completed Lee Enfield No4 in 9mm Luger and it is a joy to shoot, just need to do some machining to put the sight protector back
My buddy having fun with it: https://youtu.be/nQoZE2rHs3A
View attachment 568697

Thank you and God Bless!
 
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Coffice, thank you again for your kind contribution and sorry for dragging this for so long!

The contractor should soon remove piles of dirt in my yard so I can re-run power to the shop and to resume the project. Can't wait to get it finished myself.
As for the next step in the project that your mags helped to identify - trunnion needs to be modded, as the 223 mags are a bit longer than the 7.62. It however looks pretty doable - grinding off an old front catch and spot welding of a new one, for the 223 mag

Kind regards
 
That’s good news on the home front! Hope it’s going well. We are all just along for the ride hoping you have success.
 
Hi Everyone,
Sorry about the long break - was framing a house so one year of my life went to a sawdust bin :) And I wish perspectives of owning semis in Canada were better at this point. However, the darkest hour is before the dawn and we probably are not there yet, but I am sure this political theatre is toothless, and we get to keep our investments. Canada will be a country of free and proud people once again.

Had to dust off the parts and continue where I left off:

Reaming holes for the retaining pins in the barrel, to pin gas block and sight base in place
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Burring the surfaces inside the bolt where the steel ring will be soldered. It is important to remove whatever coating is on there, to help better adhesion of solder. Degreased as well.
AK bolt is a piece of art - full of nuances and subtle things and surfaces, each of them is designed to enhance reliability. That groove going around the face perimeter is a "ditch" for debris that potentially can get between case head and bolt face and prevent bolt from closing. I wish I could keep it - may need to modify the reamer to cut it later on
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Gunsmithing solder and flux - had to order through friends in the US. With conversion rate and shipping, this is $200 CAD in the picture :)
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Soldering is done, things look ugly with soot from the torch. Regular blue bottle, who would have thought? Metal is good though, not overheated, just brought to the melting point of the solder. Heating was done from outside the bolt head so contact surfaces were kept clean. It later came to me that soot is not from the torch - it is from the residue of the break cleaner that I used to degrease
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Started removing excess metal in the lathe, all the soot and gunk is gone, need to modify my reamer to do the fine cutting. Cartridge rim diameter is 9.6mm, so 10mm reamer should do the trick
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God Bless Everyone!

To be continued...
 
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Headspacing:

Barrel is pressed into the trunnion. The goal is to provide the minimal head spacing, yet allowing it to cycle on all brands of ammo. Advantage of the AK/T81 breech design is its accessibility. the locking lugs are perfectly visible and you can really see and feel the effort required to close the bolt. Headspacing is performed with the extractor and firing pin removed.

Bolt open
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Bolt closed
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Headspacing test on live ammo (extractor and firing pin removed)

Chambering, Extraction and Ejection test on live assorted ammo. Extractor installed, firing pin - not. Ejection pattern is good and consistent, bolt does not close on the 0.010" aluminum foil. Good.
 
DaveMachine said:
Can you go in depth on how you pressed the barrel and front sight block in/out?
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Just a basic vertical shop press from Princess Auto. I don't have special jigs for the job, just using various blocks of scrap steel to support the work. Couple of important items (as it seems to me):
- When pressing barrel in, gun should be supported by the trunnion by the two transfer bars, going through the magazine opening.
- If pushing against breech, I put a scrap wide-head bolt loosely into the chamber first, so its head acts as a transfer plate, to protect the breech end.

I like gas block and sight base pressed on, before the whole barrel gets into the trunnion

B-Wingpilot, my "Guru", made his own jig for barrel removal:
 
This is coming along very well - I can’t wait to see how the front trunnion is modified to accept 5.56 AK magazines. If all goes well I might have to see if I can have this done by a provider on CGN.

It’s good to see someone take the steps and put the process out there ensuring others can follow the path, like a good trail breaker!
 
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