Checking gas rings

[Radioactive]

Can the ar 15 method of extending the bolt and seeing if tension holds the bolt carrier when standing on bolt face be used with the 308 bcg? Is the 308 bcg too heavy for this check? I’m asking because my new JP bolt won’t hold my carrier and I’m still seeking potential probs (leaks?)as to why not cycling like it should. Have not installed my new buffer spring yet - just chasing random thoughts.

[jtallen83]

26 minutes ago, Radioactive said:

I’m still seeking potential probs (leaks?)

There are several manufacturers touting this loose fit as a solution for overgassing. 

[Radioactive]

I see how this could solve the overgas issue but isn’t it creating another problem to deal with 1 that already exists? Cheaper and less time consuming than tuning at the gas port I guess. 

I’m not sure if the fit I have is loose or the fact the carrier weight is more and it’s not a viable test in the large framed guns.

[unforgiven]

Toolcraft Nitrate .308, Aero NiBor .308, PSA 5.56 Nitrate. All pass stand test.

[Radioactive]

7 hours ago, unforgiven said:

Toolcraft Nitrate .308, Aero NiBor .308, PSA 5.56 Nitrate. All pass stand test.

Hmmmm maybe part of my issue with cycling

[unforgiven]

I have a 5.56 phosphate PSA BCG with over 5k rds. also still stands.

[98Z5V]

10 hours ago, jtallen83 said:

There are several manufacturers touting this loose fit as a solution for overgassing. 

Which is probably not overgassing, at all, in reality.  How many of those guys that are saying this, because they're using 3.8oz H1 buffer weights and weak springs? They're not even close to being overgassed - but they ARE under-recoiled, in a big way...  Not a question for you, Jim - you already know it, man.

Just food for thought, at the amount of compromises that are made in this platform, because companies want to do their own thing, and think that "their own thing" is the way to go...  They're so far off-base it's not even funny.

JP Rifles makes Race Guns, too - that's what they're know for.  Race Guns are for the Gamer Crowd - how many rounds can you keep on target in a few seconds on target, keep your score up, have heavy projectiles going "xx" speed (Power Factor calculation) - and beat the other competitors...  Race Guns are not hunting or fighting rifles, they're not truck guns, and you don't beat the shiit out of them...   Race Gun parts have their place, but it's not everyplace...  

Just like you woudn't take an F-Class competition rifle to a Combat Zone.  It wouldn't last out there, in the combat zone...  Might be accurate as fuk - until you have to strap it to a rucksack and kick it out the door or tail  of a helicopter, on a questionable landing zone, in the middle of the night, in snow, at 8,000 ft valley base elevation...  

Edited December 9, 2019 by 98Z5V

[carverelli]

i just finished a 6 cm build on a aero precision set of receivers. A seven V carrier and a jp high pressure bolt. Very little resistence (if any) between the carrier and gas rings. havent shot it yet

[Radioactive]

Must be the JP bolt

I did not try it with the orig dpms bolt and haven’t pursued it much since I opened up the port a little and it seems to be working

havent put many rounds through it yet

[carverelli]

I'm just really curious if it'll be ok to shoot it like this. I swapped bolts with my previous build, a 6.5 CM, and there seemed to be at least some resistance as i pushed the bolt into the carrier. Are there available fatter gas rings to take up a little more space, or is it even a big deal. What's the worse that can happen ? 

[98Z5V]

8 minutes ago, carverelli said:

 Are there available fatter gas rings

 

What's the worse that can happen ? 

Fatter gas rings?  No.

Worst that will happen?  If might short-stroke.

Race-Gun parts belong in Race Guns.  Not in working guns.  You bought some JP Rifles Race Gun Parts, and it doesn't look like you're building a Race Gun here. 

[Radioactive]

I wasn’t intentionally buying race gun parts for my 260 build. JP was just about the only option I could find for the small firing pin /hole. Only other option I could find was sending original out to be welded up and redrilled - didn’t want to wait 4 months

that may have been a contributor to my short stroking but it’s currently working and I shouldn’t have the primer flow problem from higher press and large firing pin hole that is commonly discussed -whether it’s true or not I’m not sure

hind sight I should have used orig and worried about it if problem cropped up - live and learn... sometimes the hard way

[carverelli]

13 hours ago, 98Z5V said:

Fatter gas rings?  No.

Worst that will happen?  If might short-stroke.

Race-Gun parts belong in Race Guns.  Not in working guns.  You bought some JP Rifles Race Gun Parts, and it doesn't look like you're building a Race Gun here. 

just got a call back from a tech at V Seven. He mentioned JP has been using a one piece gas ring on their  bolts..Macfarland ring i think he said. Said he hasnt seen or didnt see any issues with it. We'll see.

  There isnt any slop side to side, just very resistance going into the carrier itself

[Ravenworks]

JP makes both styles,you can obtain new ones from Primary arms for a couple of bucks.

I keep a couple sets in my parts box amongst other small consumables.

[carverelli]

21 hours ago, Ravenworks said:

JP makes both styles,you can obtain new ones from Primary arms for a couple of bucks.

I keep a couple sets in my parts box amongst other small consumables.

good to know..thanks

[unforgiven]

On 12/21/2019 at 8:53 PM, carverelli said:

i just finished a 6 cm build on a aero precision set of receivers. A seven V carrier and a jp high pressure bolt. Very little resistence (if any) between the carrier and gas rings. havent shot it yet

Can the BCG pass the stand test ?

[sagebrush]

On 12/23/2019 at 5:25 AM, Radioactive said:

I wasn’t intentionally buying race gun parts for my 260 build. JP was just about the only option I could find for the small firing pin /hole. Only other option I could find was sending original out to be welded up and redrilled - didn’t want to wait 4 months

that may have been a contributor to my short stroking but it’s currently working and I shouldn’t have the primer flow problem from higher press and large fi't ring pin hole that is commonly discussed -whether it’s true or not I’m not sure

hind sight I should have used orig and worried about it if problem cropped up - live and learn... sometimes the hard way

i to used a jp high pressure bolt in my 243 win build( didn't know about checking ring resistance) for the same reason. i had no trouble with mine working correctly, ran appx. 250 rounds through it shooting at prairie dogs 

[carverelli]

9 hours ago, unforgiven said:

Can the BCG pass the stand test ?

no....not even close

[carverelli]

9 hours ago, sagebrush said:

i to used a jp high pressure bolt in my 243 win build( didn't know about checking ring resistance) for the same reason. i had no trouble with mine working correctly, ran appx. 250 rounds through it shooting at prairie dogs 

does it pass the stand up test with the bcg standing upright on the bolt without bcg falling into the pin notch in the bcg?

[carverelli]

did a google search for jp gas rings and got this site. www.nokick.com

they're selling the new and improved one piece jp gas ring. looks like a key chain ring. they say it reduces friction yet improves the gas seal.

  Apparently...its the future🙄

[Ravenworks]

8 hours ago, carverelli said:

did a google search for jp gas rings and got this site. www.nokick.com

they're selling the new and improved one piece jp gas ring. looks like a key chain ring. they say it reduces friction yet improves the gas seal.

  Apparently...its the future🙄

Their prices are high, you can almost by 2 of those at Primary arms

 

[unforgiven]

There was a guy that welded up the gas ring area on the bolt then machine that....  for no gas rings. He hasn't been around for a while.

[unforgiven]

At that point the saying is "don't complicate $hit with complicated $hit"..   words to live by.. 

[sagebrush]

22 hours ago, carverelli said:

does it pass the stand up test with the bcg standing upright on the bolt without bcg falling into the pin notch in the bcg?

the bolt does pass the bcg stand up test with the carrier its installed in, but the carrier is a lightweight carrier also(8oz. lighter than std) so may not be good test. will pull another carrier (brownells std weight) and try jp bolt in it tomorrow after work.

[sagebrush]

@carverelli, i pulled the jp bcg out of .243 win. it consists of a high press bolt and lightweight carrier. the bolt has the seal you described(looks like key ring). i pulled the brownells bcg out of 260 rem.(hasn't been fired). i installed the jp bolt in the brownells carrier and it does pass the stand up test.