Coldsteel 80% receiver and 53M kit

[bolex]

The semi bolt came in and all I am waiting on now is the new semi recoil spring.

This is what the coldsteel receiver and a yugo kit looks like.




This is the bolt:

[bolex]

I took several photos of the blast cabinet and the black oxide tank, just to give you an idea of how I did the receiver finishing.




Note that I put a hand valve on the bottom of the tank to drain it. As stated in a previous post the black oxide is a cold temperature operation so PVC works well.

[Bil]

Very nice! It also shows you don't need a lot of expensive tools to do these projects ,just some ingenuity.That really looks good,and thanks for all of the info! ---bil

[Rahatlakhoom]

suspense...torture...torment...madness.
attempting to maintain composure.

[Bil]

Bolex-what type of semi mods did you use? ---bil

[bolex]

Bolex-what type of semi mods did you use? ---bil

Bil,
1) I welded a hardened pin to prevent the FA bolt from fitting and machined the receiver grip slot for a Wise aluminum grip (AR fcg).
2) Thompson did the bolt conversion (nice job).
3) The inside of the receiver was ground to fit the buffer diameter at the cam diameter and the outer glide diameter. I also ground the buffer notch slightly for a better clearance around the charge handle bump in the receiver. Afterwards I noted that a clearance notch is cut in the receiver for this purpose.
4) I am planning on using the new semi recoil spring that are being made. If that doesn't work out then I will machine the buffer to permit a full size spring to fit (Instructions are in one of the stickies).
5) Machined the recuperator (sp?) to clear the grip tab, fa blocking pin and the bolt charge handle tab.
6) I plan on placing a stop for a modified charge handle to catch on to hold the bolt open. This is still in the design/thought stage.
7) Need to copy the safety I saw for the Wise hand grip and AR fcg. Looks easy and a very straight forward design.

The last two items will be after I get the recoil spring and verify that the firearm will function.

[Bil]

Very nice! I am also waiting for those new springs-I have looked into the full length spring conversion,a lot of work but do-able.Real nice job on yours-I am impressed! ---bil

[gdmoore28]

3) The inside of the receiver was ground to fit the buffer diameter at the cam diameter and the outer glide diameter. I also ground the buffer notch slightly for a better clearance around the charge handle bump in the receiver. Afterwards I noted that a clearance notch is cut in the receiver for this purpose.

Bolex,
Your SA conversion looks fantastic. I'm keeping your build bookmarked for later reference. I had a little trouble, though, following your description of the receiver/buffer modifications. Could you explain the mods a little further? Maybe pics, too?
GeeDeeEmm

[bolex]

This shows where I ground clearance for the buffer. This photo is before the cam pieces are riveted in.



I hope this helps. And remember this is the first MG42/M53 I have built so there can be better methods to do this. Dremel tool was my tool of choice for this type one cut. I used a cutoff wheel and ground the spots with it.

[gdmoore28]

Excellent. Thanks for the followup and pics. Seeing it makes all the difference.

GeeDeeEmm

[Mace]

Hi,
I was wondering if you used/or needed to use the "ratchet" plate that they have on weponeer?
Thanks
Mace

[bolex]

I used a "ratchet" plate of the "new" design from I believe RTG or BRP. The coldsteel reciever needs this part.

[Mace]

Just curious if you know if the one Weponeer is selling in a group buy is the "new" design. I would like to order one if it is.
Thanks for the help! All your pics have been great.
Have you got yours running yet?
Mace

[bolex]

I looked at the weaponeer ratchet and it appears to have the half bumps and the one I got has whole bumps along the top edge and the tab isn't bent. Mine also looks thicker than the other in the photos. Now as far as if it is the "new" design or the old design I am not sure, I thought I ordered the "new" design but it really doesn't make much difference to me because I have it installed and it works.

I am still waiting on the new short recoil "spring", the last piece of the puzzle (I hope!). The belts are loaded and installation should be a breeze.

[bolex]

Well, I couldn't wait for the spring any longer. When working on the bolt hold open device I needed a spring so I cut one down. Measured the buffer spring cavity depth, wire diameter, and cut the length so that the spring wouldn't go solid when hitting the buffer. Since it looks like a while before we get the new design spring I figured I try the short one. The 1978 Yugo ammo wouldn't work (hard primers..duh) with the standard AR15 hammer spring so I installed the higher load one (Wolf extra power #30093), and guess what..no problems. Only went through 30 rounds, no jams and fed the belt without problems. Moly coated (MoS2) the belt, I prefer the dry film lubricant over the oil. Ran out of time, so have to shoot it later. The belt was a new 308 belt.

So, the only problem I had with my build was with the hammer spring and I bought a stronger one over a month ago and was too lazy to replace it at that time. I'm happy.

Now I need that 8mm hopper kit for the 308 reloader..hint, hint Pirate

[bolex]

A short video showing the Coldsteel/Yugo kit firing.
http://s76.photobucket.com/albums/j25/b ... fire-1.flv

[Bil]

Very nice! Watch where you set your bi-pod legs! Did you drill your buffer bolt so the firing pin doesn't hit? It wasn't in the previous pic,I am using the same mods and drilled mine,I wonder if I needed to.Where did you get the stronger spring? I have also been told to use non-rotating pins and can't find a source for them.You have done a real nice job,and should be very proud.This is not an easy project. ---bil

[bolex]

My PSL doesn't kick as much as the MG42 so my pallet shooting bench hasn't been a problem till now.
I drilled the screw in the buffer to clear the firing pin using a carbide bit and my small lathe. I got the stronger spring from Midway for $1.19, description DPMS hammer spring AR-15 Midway P/N 217321, I bought 8mm headspace gauges at the same time. It was one of those things that I read about and decided that it was the only thing that i didn't have confidence that it would work on the gun.

"I have also been told to use non-rotating pins and can't find a source for them."
I used an old fcg that was replaced in my heavy barrel AR with a match grade drop-in so the pins were something I had around. I am not familiar with non-rotating pins. My match grade fcg for the AR used tiny e-clips. Thank you for the compliments.

[Bil]

Thanks for the info-I am getting real close with my project,your gun is an inspiration.The compliments were earned. ---bil

[rocco1911]

Well after 6 months the cold steel receiver arrived not as nice as the first one the first one had the cuts scribed on the receiver the last one did not the condition of the inside of the receiver was poor @ best lots of weld spatter get a better welder guys. The welds at the seams were thin will have to re-weld some of them can see light through them lots of voids in the metal also as a whole its getting worse on the quality of the receivers they offer & the wait was totally unacceptable but they already had my money so I was stuck if your lookin for a receiver buy from "Capt Kirk" my buddy Little Rhodey just got one from him I have it in hand & for the extra money its worth it the Cold Steel units are sub par In My opinion and for what thats worth but I have seen the difference and dont wast your money. mine may be up for sale soon but @ a reduced price dont want to screw anybody just need to save up for a Capt. Kirk Original. just bought a Vickers kit & Tripod thats where my money is going now. between the wait time & quality of this receiver I'm losing intrest in this will build when I get one from the Capt. Out.