Delayed Roller Blowback - Understanding Actions, Gap and Ammo

[Smokehouse69]

+3 on this post, great info that should be a reference for all of us!

[NSR500]

Tremendously good information in this thread!

[rustypirate]

I added this thread to the Stickies in this forum.

Very thorough work BW!

[jarhead1775]

Great info Blade! My build would not be possible if it weren't for the experience and info from this forum. Keep the good stuff coming!

[oldpaint0]

Very well done bw, people like you,sdk,holescreek,smokehouse,etc. etc. make this a very interesting sight. Very helpful folks here indeed. Thanks to all that contribute their knowledge.

[3bikebill]

Bladeworks, Thanks for the info. I just received my very first gun kit. Wouldn't you know it, I picked what seems like a complicated kit to start out.
Would pressing the barrel into the trunnion correctly, at the prescribed .005 -.030 be a main thing? I have read many forums, and one said that you can check the bolt gap before you install the barrel/trunnion into the receiver. Does that make sense? Also, where can I buy a US made fire control group so I can aquire some 922r item counts? Thanks in advance. Bill

[bladeworks123]

3BikeBill, Welcome aboard first of all, and congratulations on your recent addiction. Yes you can set your gap outside the receiver, there are some posts on the site that detail that fairly well, here in the CETME and Hk stickies and inside the "FAQ" thread. Learn to use the search feature and it will become your best friend. If you have trouble finding them just yell, one of us can get them for you, or start another one. ( We like that part) As far as gap is concerned, yes, that is probably the primary concern in getting your build correct. You need to be between .004" and .020" with .016" to .018" being optimum. Take some time to read all the great stuff here, like build tutorials etc., until it all makes sense and then delve in. Look through the 922r compliance threads and get a clear picture of what you need for a US parts count. Take your time, ask any questions of the guys here and somebody will no doubt jump in to help out. As far as a place to get a "US" made FCG, there isn't truly such a beast. You will find some that have US components, i.e. hammers, triggers etc. Or you can modify one yourself, there are instructions here about that too, and member Turbothis makes some pretty nice US compliance parts for your FCG. I would recommend looking at RTG for ready to drop in semi auto FCG's and any other parts you might need as well. Hope that helps....

[3bikebill]

Thanks for the welcome Bladeworks. I formerly was addicted to Harleys. I restored three of them and I still ride a newish one. Then, I was addicted to old gas pump restorations. I completed two. I still have three in my garage to restore but, shoulder surgery side-lined me. Now, that is getting side-lined for Gun Kits. I love Guns and I didn't know there was even such a thing as Gun Kits. Sitting on the couch with the computer for 2 1/2 months, I discovered alot of things. I am really excited. I ordered two flats from ORD.
I hope I didn't order too late. Anyway, I'm glade I found you guys.

[sawed12]

well done!!

[bladeworks123]

BTT ....Today I added a little more about headspacing at the end of the original post....