JP High Pressure Bolt Question

[One1Bravo]

I ordered what I thought was the complete kit for the JP high pressure bolt but I ordered the wrong thing and it only came with the assembled bolt and firing pin. I tried to put in in my BCG and noticed that the cam pin will only barely slide in before it binds up. Just wanted to ask if anyone knew if I had to use the specific JP cam pin or if maybe something else was up before I spend the money. Thanks.

 

[The King]

Is the bolt oriented in the correct direction? Extractor and ejector in the right places?

 

[One1Bravo]

Is the bolt oriented in the correct direction? Extractor and ejector in the right places?

Yup. Also tried it with the bolt out of the BCG.

 

[The King]

if you have the ability to precision measure the cam pin diameter you may find it out of spec.

Or the bolt may have gone into the swaging machine backwards lol. It happens, if the factory fixture doesn’t have a locator pin for the ejector.

My understanding was that bolt parts are DPMS spec on JP

 

[One1Bravo]

 

[One1Bravo]

Anyone? Still haven't heard back from JP yet.

 

[The King]

Sorry i was going to measure mine and realized it was in my other safe that is behind 200 bags of concrete right now.

 

[One1Bravo]

Sorry i was going to measure mine and realized it was in my other safe that is behind 200 bags of concrete right now.

No worries! Lots of knowledgable folks here, figured someone may know.

 

[The King]

I would suspect that .375 is the exact spec.

designers either pick a dimension based on sound engineering practice or a healthy dose of “whatever”.

“How big does it absolutely need to be? Add 20% and call it....or just make it some round number.”

Many times it’s easy availability of cutting tools for the hole it goes in that drives the target size.

 

[One1Bravo]

Sounds about right to me. I've got emails in to JP and DPMS waiting on responses. Best I could measure on the cam pin hole on the bolt itself was .373.

 

[MotoFlier]

I've got .376/.377 on the bore and .366/.367 on the pin. This is out of my AR10 I can check the Ar15 as well.

 

[One1Bravo]

I've got .376/.377 on the bore and .366/.367 on the pin. This is out of my AR10 I can check the Ar15 as well.

Thanks for the data to compare @MotoFlier!

 

[MotoFlier]

Just because I had the stuff out and It might help someone searching in the future the AR15 measures .313 on the bore and .310 on the pin.

 

[awpk03s]

For what it’s worth, at one time I tried to put a JP HP bolt into my Larue carrier (AR10). The Larue cam pin would not fit at all, similar to what you describe.

 

[One1Bravo]

For what it’s worth, at one time I tried to put a JP HP bolt into my Larue carrier (AR10). The Larue cam pin would not fit at all, similar to what you describe.

Thanks for the info. I'll probably end up trying the Toolcraft bolt carrier anyway. Hopefully the pin will make it in. The pin hole on my bolt is measuring a bit smaller than Moto's.

 

[One1Bravo]

Just to finish this thread off- I ordered a Toolcraft nickel boron carrier and key and a nickel boron cam pin. Cam pin fit perfectly and everything went together without a hitch.