New m53 build

[roadrunner]

I agree, BRP provides an invalable service for hobbyist builders. Without recources like his we would have to fab a whole lot more stuff or just be left scratching our heads. Actually I was just looking at his bolt mod. parts and I checked his print page. Lo and behold,Tasty new graphic diagrams with buffer machining measurements.
Thanks Brian

[roadrunner]

Got back in the shop today, Straightened and milled charging handle, Milled rear of barrel shroud square, milled receiver shells to length and turned split bushing for front of shroud. "havent split yet." Hopefully tomorrow I will fab my copper backer jig and work on buffer clearance. Should be ghttp://www.mg42.us/download/file.php?id=12648&mode=viewoing tig crazy soon.

[roadrunner]

Haven't freed up much time lately for my project but I managed to finish up my weld jig for the bolt carrier today. Nothing new other than I decided to slug the feed roller pin holes to prevent distortion. Also included a pilot into the ejector button bore. Figured I would get everything ready for welding before I get into any of it.
BTW, picked up a new miller synchrowave 200 for home use. Really sweet control for a home unit. RR.

[roadrunner]

Heres my expanding copper backer jig . It will ensure a smooth seamless interior of the butt welds. After welding remove jacking bolt, drive center pieces in and forward, then sides in and forward. I've used this method on other jobs and had good results. Nothing fancy but effective especially on the radius corners. BTW, I will be using a 75% chamfer leaving a .025" edge to maintain length.

[jcmg42]

Wow!

[engr]

Wow!

Definite Wow!

Well thought out plan.

[roadrunner]

Got to work on my front end a bit today. Cut back shroud to halfway on the barrel bushing flat. Clamped it all up and checked barrel fit and travel. Just waiting for some .040" filler rod. With a .035" average gap I hate to throw the heat at it that 1/16" rod will require. Later guys.

[roadrunner]

Had the day off work today and welded up my front bushing shroud area.I really shouldnt drink 4 cups of coffee and weld. Anyway it came out fine but not pretty. Now to dress everything down and fill in any low spots. Going to practice with this new machine more before I weld receiver.

[crash520]

RR,
that is awesome!!!! I wish you lived somewhat close to me, I would pay for lessons and pay and pay and pay, your work is clinical.

GT

[roadrunner]

Thanks for the props crash but I think credit is due to the guys that came up with these ideas. Anjongni-bushing window, Thompson machine-bolt carrier jig, and Iron worker-split shroud bushing. That guy deserves the mg ingenuity award for his home built receiver. I'm just lucky to have stumbled onto this site while looking for parts. This site has a first class bunch of quality people with like interests. p.s. if you need any of my jigs in the future I will gladly share them with you and any other members.

[www.Prussia.us]

Bravo "Roadrunner"

Not only are you showing excellent pictures for the legions of builders that want to undertake this project, but like the other guys working through the BRP stampings, the advice you can give going forward will help sustain this site's ability to have members that can dispatch technical advice through experience w/ these BRP builds.

Good work

[roadrunner]

File dressed the welds down. After bead blasting they should be unnoticeable. That pretty much wraps up the front end. Barrel travel is perfect and bearing slides freely. Next on to the rear. Tough finding time for this project lately with work and child. Bare with me. Thanks RR.

[roadrunner]

Finally preparing to join my back halves. Milled some 2.00" internal spacers so I can clamp tightly. Copper backer alignment jig fits very snug. Rear of shroud width is exactly 2.2" so I will maintain this on the rear. This will result in .070" clearance for the bolt within the rails. This seems excessive. Might consider spacers behind rails since the BRP shells have no dimples and my forward rail hole does. Anyway, after welding halves I will slide rear off and chuck up in 20" lathe to bore buffer clearances. Then off to better things like making this one piece. RR

[robertmcw]

I have a kit but I do not have that copper jig. Have thought selling one? I could sure like to have one.
Robert

[Gulfstream4]

You are quite the artist with a welder. Thanks for the play by play with your build.

[roadrunner]

Hey Robert. Like I said I will gladly share any jigs i've made with members. Just pm me and after I am done welding I will send it to you. I just milled it from an old 1/4" bus bar. Matched the radius corners to my shroud and then had to do a little file blending work on my BRP halves in the corners to match. take care. RR
p.s. thanks Gulfstream, I dont have any friends locally that share my interests in building so this is the next best thing.

[robertmcw]

That would be awesome.

Robert

[roadrunner]

Welded up my back half today. Didn't want to go overboard on the cutout sections. Got full penetration on the buffer section and cleaned up the inside with a die grinder and stone. started dressing the outside. When I punched the rear spacer out I was afraid it would shrink more but got away with a .004" reduction in width. I think I can live with that.

[robertmcw]

I just sent you a PM.

Robert

[roadrunner]

Got my bolt and receiver semi mods prepped last week. Almost ready to join front to rear. Been along time coming. RR