sick. looks awesome!
Steve has built 3 with a cap screw, I have built 2 with a bearing. My bullpup is going to have a cap screw. Simpler like Steve says.
Last edited by SHARPSSHOOTER5090; 09-12-2008 at 02:32 PM.
For the bolt carrier guides, there is a .650 height measurement. Could I use some .625 outside dimension DOM tubing cut down for the rails. Will there be any problem with losing the .025, going from .650 to .625? It would allow me to use off the shelf tubing and not the shelf brackets.
The only thing it should effect is that there will be a bit more side play of the bolt carrier and I am not sure if the extra side play will give you enough the side to side movement of the feed cam. You could use .75 outside dimension DOM tubing cut down to .65. With .625 DOM tubing you will lose a little with the corner radius also. .75 outside DOM tubing is a standard size also.
What procedure did you use to anneal the rear of the bolt carrier in order to drill it? Could it be done with a MAPP torch?
Also, when you revised the bolt carrier extension length shorter, do I also need to make the firing pin extension that much shorter as well? It seems too long at its current length made as per the print.
To anneal the end of the BC I used a MAPP torch and heated the rear 1" portion only to a dull red and let air cool. Clamp the BC in a vice around the bolt cam section so the vice acts as a heat sink so you don't anneal the cam section as well.
The firing pin extension sould be shortend also to the point that when the hammer strikes it the bolt is fully rotated into the locked position.
I will have to correct that on the drawings. Thanks for catching that.
I need to get my rail material in and I'll have all the pieces finished. Pics to come soon.
I made the 4 1/2" 1/4-28 cap screws by silver soldering a nut the some threaded rod then grinding the head down to round and cutting a screw driver slot in the head. The other option is McMaster-Carr has 1/4-28 hex head bolts up to 8" long. You would have to grind the heads down to round and cut a screw driver slot in them also. I you have line up issues with the BC and BC extension the take a round file and open up the hole in the BC extension in what ever direction you need to get the correct lineup. I had to do that on the last BC extension I made. You may have to square up the rear face of the BC to get the BC extension to clamp parallel with the center line of the BC as the rear of some BC are not necessarily perpendicular with the BC center line. If you have to open up the hole much you can use that "ug" dredded JB WELD to fill in the space then tighten the bolts once you clamp the BC extension where it's should be and let the "ug" JB WELD set up.
hey just curious if you made any adjustments to the tutorial or blue prints
I am getting ready to install the barrel trunnion. I am using a regular Hungarian non-bulged trunnion. The front of the trunnion obviously needs to be flush with the front of the receiver.
My question is this, at what vertical height should it be placed? A measurement from the barrel centerline to the top of the receiver, or a measurement from the top surface where the bolt carrier stops (on the right side because the trunnion is reversed) at the trunnion to the top of the receiver on the right side would be of great help.
I hope I made that understandable.