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View Full Version : Another PTG Bolt Head Thread



OLEJOE
01-14-2018, 10:22 PM
I know. I know. But the machined surfaces on the PTG Bolt Head look so good. The firing pin fit perfectly as far as diameter but had to adjust the protrusion. Set it at .038. Then had to adjust the depth of the cocking piece. Then if that wasn't enough, bolt head hit the back of the barrel before the headspace got set. So I turned about .010 off the breech face and now it works. Case doesn't project out to the extractor groove on the case so it should be good? Still have a little more than an eighth of a turn of the action before the bolt head hits after the go gauge bottoms out. Everything works and fits well. Is that enough gap between bolt and breech face?. I also ordered a new extractor and ejector, springs and pin. What say ye?

Hotolds442
01-14-2018, 11:24 PM
A properly sized cartridge, or a go gauge, should protrude approximately .125” from the chamber. Any less than that and you run the risk of breechface/bolt head contact as you’ve already seen.

OLEJOE
01-14-2018, 11:36 PM
The rifle came headspace .002 more than my Go gauge. I've got 8 to 10 thousandths between the bolt and barrel now. With the deeper bolt head, I don't know if I could have taken as much off of it as I did the barrel. Haven't shot it yet but it chambers fine.
Bolt face depth is .130.

Robinhood
01-15-2018, 01:03 AM
Lets see, case protrusion .125. Bolt face depth .130? Hmmmm

Blackthorn
01-15-2018, 09:47 AM
I had the same issue recently with a PTG bolt head I bought from Bullets.com. I would have returned it but needed to get this build off my bench. I did the same as the OP. Took some metal off and I was good to go. The three I have ordered previously fit with no issues. I was very surprised that this problem existed. PTG bolt heads have been top notch...I wouldn’t hesitate to buy another. Actually been thininking about ordering one without the ejector..

OLEJOE
01-15-2018, 07:51 PM
I got mine from Grizzly at a good price and it is a work of art. Very precisely machined but the dimensions were wrong. I was really glad the firing pin diameter was correct. I'm still waiting on the ejector, spring, and pin. Anyone noticed how slow Midway has gotten on getting their orders shipped ? This is the third one that has taken nearly a week to be shipped. All in stock.

OLEJOE
01-16-2018, 02:36 PM
Well I fired it today. Just checking primer strike. works fine. Also got the ejector installed. GTG