Chambering short barrels in the headstock

[LVLAaron]

I used protruding fasteners and then engraved "knuckle buster" on the side.

 

[xr650rRider]

You could have just easily engraved "widow maker". Big reason for the thickness, is to have set screws at/below flush.

 

[LVLAaron]

I'm not married so knuckle buster is more appropriate.

I do like the idea of the flush set screws. I am sure I will make a set... I just dont want to make a set.

 

[Ken226]

Got the machining all done. I ended up putting some extra hole sets in while it was all set up in the mill. Easier now than trying to set it up again later if I needed additional positions.

Now I need to make some brass tip

Beautiful work!

 

[Jake P]

Beautiful work!

Thanks Ken

 

[Earl]

I have one of Bob Pastor's Viper barrel jigs mounted to a d1-5 backplate. It does work fine. I only use it when I have to for a barrel but it is the best choice for bolt work. The issue with all of these types of fixtures is the fact that the adjustment screws are only about 6 inches apart. Getting the first couple of inches of the chamber end to run true is always a challenge. I use a 50 millionths indicator to take a direct reading of the barrel bore (not the lands) so a little movement in the adjustment screws goes a long way on the indicator. I really don't like "secondary" measurements like the "grizzly rod" popularized by Gordy Gritters. (the bushing on the rod rides on the lands) In the "short range" benchrest game absolutely everything matters so there is no room for error.

 

[LVLAaron]

Gordy teaches that direct reading on the bore is the preferred method. He uses the grizzly rod to start the process and "get close" - then directly indicates. They're nice to have to at least test pilots

 

[Earl]

It depends upon which book you read or which video you watch. Quite some time back, he made a video for Shiraz Balolia (f class shooter and then owner of Grizzly) In that video he touted the use of a rod with a bushing on it. He held it in a drill chuck and used a .0001 indicator. PT&G started making them and called it a "grizzly rod". In that video he never mentioned nor measured directly reading off the bore. Times change and so do procedures. Whatever method that works for you is the correct one. My grizzly rod has sat in the drawer for a long time and I have never thought about testing bushings. I dont know why I would. When I get ready to chamber, I pull out my little bushing rack arranged by ascending size and try them one at a time until I find one that wont go in. I go back to the previous one and use it on the reamer. That process takes about 30 to 40 seconds.

 

[LVLAaron]

Haven't seen the DVD, but I was in Gordy's classes last year.


Anyway, I have a project for the new fixture/chuck! - I have a 300 blackout barrel that can't host a suppressor because the threads and or shoulder aren't aligned with the bore. I'll have to loosen up the threads a little bit and recut the shoulder. I'll post some photos of the process if it's successful

 

[LVLAaron]

Picture of tonights project.

Re-shouldered, and chased the threads.

The Jig works... but dialing is a real pain in the ass. Not being able to see the breech end of the barrel to get it roughed in by hand makes things a challenge, but it worked out in the end.

Top picture is self explanatory.

Bottom picture for the non gun guys - is an alignment rod through the bore and suppressor. Before rework the rod was touching the end cap, and would have been catastrophic if fired.