PDA

View Full Version : REM 700 Bolt knob


mountainman
March 16, 2016, 18:10
http://i65.tinypic.com/2mcdf60.jpg

http://i67.tinypic.com/2a8qj52.jpg

http://i67.tinypic.com/15wgint.jpg

anybody interested? I also do sako extractors. Could try AR type extractor.

ftierson
March 16, 2016, 19:19
Do you also drill, tap and bolt the bolt handle to the bolt body when you do this?

If not, you'll probably be losing some bolt handles along the way...

Forrest

ftierson
March 16, 2016, 19:23
By the way, my point is mostly that people want this done to add one of the 'tactical' big knobs. The problem, of course, is that the bolt handles don't always stay on that well with the original knob...

In addition, if you turn the head down and thread with a lathe, the bolt handle will often come undone...

Forrest

gunplumber
March 16, 2016, 19:33
Very nice. Did you come to the same conclusion as I did with PTG lathe fixture? I thought it allowed for too much lateral torque and after having to re-solder two handles, decided that was enough. But then I was cutting from the side. Maybe boring from the front would cause less "slapping"

I've also run into a problem with too long an oversize handle. When driving the bolt forward, the further from centerline, the more lateral force applied to the bolt body - to the point where I could get it to bind. Taking the same (Badger/Brownells type) oversize knob, and threading it on further, kept the force more in line with the bolt body.

So while your stop/shoulder is aesthetically pleasing, it will possibly require a shorter knob. Maybe a round ball like on the AI.

mountainman
March 17, 2016, 07:39
Look at the time stamps on those photos Mark. I don't know how long the PTG fixture takes to do the job, but this process was a little over 1.5 hrs. Now, on the other hand the benefit is that there is barely any force applied to the metal while cutting. Roughing was .02" metal off at a time ( 3/8 E mill) and finishing was maybe .002" off at a time using a coordinate chart I got from interpolating in CAD with a 3/16" end mill. That is how I got away with such a lousy fixturing of the part.
How far below that shoulder would you have gone?

gunplumber
March 17, 2016, 07:42
If you thread any higher, you lose the shoulder/stop. And then the transition looks funky. I don't really care on my rifle because I rattle-can finished it. But the transition with the teardrop shaped knob always looks kindof weak to me.

Depending on the length of the knob, I may cut the original ball off and start threading there.

I am curious about using a round ball knob. I'm also curious what a round ball knob that spun would feel like.

JR in the NW
April 01, 2016, 02:15
http://i65.tinypic.com/35btdnm.jpg

Round knob I did yesterday.

JR in the NW
April 01, 2016, 02:18
http://i66.tinypic.com/2rnaq2x.jpg
Tear drop style as well. I do these on the PTG fixture using a cnc lathe. Go slow and dress up the transition using grinding stone and craytex wheels on a dremel. Takes around 30 minutes or so to completion.

Parga
April 11, 2016, 02:43
The latest from PTG has various inserts and is self centering. Very quick accurate