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+--- Thread: JP bolt wont headspace (/showthread.php?tid=18743)
JP bolt wont headspace - Eodbrownguy - 04-11-2019
Anyone ever have a JP bolt not headspace? I bought a liberty 12.5 and it came with a bolt. I ordered a Jp enhanced bolt and Manson headspace gauges. The liberty bolt headspaced but the JP did not, closes on the no-go. Just curious if anyone else had the same thing happen to them.
JP bolt wont headspace - hill37 - 04-12-2019
The liberty barrels use a.125 bolt. The Jp has a .136 bolt face recess I believe. http://www.65grendel.com/forum/showthread.php?13760-65G-Bolt-face-Depth-Infographic
JP bolt wont headspace - Eodbrownguy - 04-12-2019
That would make sense, thanks!
JP bolt wont headspace - Eodbrownguy - 04-12-2019
So is there a list of who supplies .125 bolts?
JP bolt wont headspace - hill37 - 04-12-2019
Google Columbia river arms.
JP bolt wont headspace - hill37 - 04-12-2019
Looks like I misled you on Columbian river. I thought they still sold bolts but they say they use any good 7.62x39 bolt.
JP bolt wont headspace - Eodbrownguy - 04-12-2019
Will the JP enhanced extractor work on a .125 bolt?
JP bolt wont headspace - LRRPF52 - 04-12-2019
hill37 Wrote:The liberty barrels use a.125 bolt. The Jp has a .136 bolt face recess I believe. http://www.65grendel.com/forum/showthread.php?13760-65G-Bolt-face-Depth-Infographic
Since when did Liberty start using .125" bolt face depth?
Every Liberty barrel I've seen or installed used a .136" face depth.
JP bolt wont headspace - centerfire - 04-12-2019
Their site says Grendel 2. Why change the bolt in the first place?
JP bolt wont headspace - Texas - 04-12-2019
I have 3 linerty barrels and they are all .136 bolts. When we were mass producing M16s, occasionally we would have a combinaton that would not headspace. We would try up to three different bcgs to obtain proper headspace before the upper would be set asside.
The only way I can explain it is thar barrels, bolts and barrel extensions all have +/- tolerances, and the headspace problem arose from the various parts being close or at max tolerance variations.
JP bolt wont headspace - hill37 - 04-12-2019
MY mistake I thought Liberty barrels were the Satern barrels with the .125 bolt face. That's what a 70 year old memory does to you. Sorry about that I'll double check from now on.
JP bolt wont headspace - Eodbrownguy - 04-13-2019
The bolt I have looks like a maxim arms and the liberty site says .136, with this being said, would it lead one to believe the bolt is out of spec?
JP bolt wont headspace - LRRPF52 - 04-15-2019
hill37 Wrote:MY mistake I thought Liberty barrels were the Satern barrels with the .125 bolt face. That's what a 70 year old memory does to you. Sorry about that I'll double check from now on.
Satern has been using .136" bolt face depth from the start.
.125" face depths were used by Model 1 Sales and BHW for a while (they break extractors and the Model 1 Sales bolts in their 6.5 Sporter were often worthless).
Everybody in the industry with a good reputation is using .136" face depth bolts, with maybe the exception of one company who changed names, don't even know their status anymore.
JP bolt wont headspace - LRRPF52 - 04-15-2019
Eodbrownguy Wrote:The bolt I have looks like a maxim arms and the liberty site says .136, with this being said, would it lead one to believe the bolt is out of spec?
What's the face depth and lug lengths on the JP bolt? Doubtful the JP bolt is out of spec.
What's the variance on the Manson gauges between GO and NO-GO?
JP bolt wont headspace - NugginFutz - 04-15-2019
centerfire Wrote:Their site says Grendel 2. Why change the bolt in the first place?
Grendel II, with respect to Satern / Liberty, is referring to their chamber modification - NOT the bolt.
TYPE II is BHW's unfortunate contribution to the Grendel world of regrettable terms, which is something they introduced to distinguish between their barrels headspaced for the .125" bolts (AKA Type I) and the barrels headspaced for the .136" bolts, which are used by Alexander Arms, Les Baer, etc. etc. (AKA Type II).
In short:
Type I and Type II are BHW names for Bolt depth.
Grendel II is Steve Satern's name to identify his barrel which is chambered WITHOUT the SAAMI compound throat.
JP bolt wont headspace - Eodbrownguy - 04-16-2019
LRRPF52 Wrote:What's the face depth and lug lengths on the JP bolt? Doubtful the JP bolt is out of spec.Now I have to buy batteries for my calipers, lol
What's the variance on the Manson gauges between GO and NO-GO?
JP bolt wont headspace - centerfire - 04-17-2019
Why do you want to change the bolt in the first place?
JP bolt wont headspace - Eodbrownguy - 04-17-2019
Im not a fan of the finish, the extractor seems fairly weak in it. Im also weary about the thickness of the material supporting the rim. I dont know what bolt Liberty supplies with their barrels but it looks like the maxim. I know JPs quality and what materials they use. So I want to go from an unknown to a known, If that makes any sense
JP bolt wont headspace - A5BLASTER - 04-18-2019
Eodbrownguy Wrote:Im not a fan of the finish, the extractor seems fairly weak in it. Im also weary about the thickness of the material supporting the rim. I dont know what bolt Liberty supplies with their barrels but it looks like the maxim. I know JPs quality and what materials they use. So I want to go from an unknown to a known, If that makes any sense
Take a few pics of the bolt, I have 2 maxim bolts in my safe, I will compare them and see if I find anything that matches.
But to behonest, I would just keep the JP bolt and return the Liberty setup for refund and spend my money on a sammi chambered barrel and use that JP bolt with it.
Edit to add.
All 6.5 grendel bolts with have the same sidewall thickness where it supports the case rim.