Did I get bad headspace gauges?

[Boostd]

Im just finishing up my first long range hunting rifle build and I was curious if it is pretty common to get these go/no go gauges out of spec?

I have a TL3 action with a proof 6.5 PRC prefit. Barrel torqued to about 75ft lbs. The go gauge isn’t chambering and not only that it gets jammed up when trying to chamber. I’ve been very gentle with it but the bolt gets stuck too. I can chamber a live round with no issues nice and smooth!? Thoughts? I don’t have the right tool to measure them at the moment, maybe it’s time I order something. All I can say is these seem way off when trying to chamber.

Thanks for any help, had a hard time finding any info on this. Forgot to add they are Clymer gauges.

 

[Supersubes]

What do you mean by the gauge and bolt getting stuck?

 

[spife7980]

Are you sliding it under the extractor first?
Whats your go gauge comparator measurement thats problematic vs the factory rounds that arent? (I know you dont have the tools but see how helpful they could be?)

 

[Steel head]

Does the brass you intend to use chamber?

Check brass against the no go gauge.

 

[John Glidewell]

I assume you took out the bayonet firing pin? If so, the bolt head retaining pin can fall out and get the bolt stuck.

 

[Supersubes]

You need to slip the gauge up into the bolt face/under he extractor before you chamber it. The t-slot style extractors dont snap over gauges very well, and usually the gauges are quite sharp on the back end, which exacerbates the issue.


Ive installed a half dozen proof PRC barrels on tl3’s and Origins. Every one of them was on the minimum side of headspace. Some were touching on the go gauge.

 

[spife7980]

I assume you took out the bayonet firing pin? If so, the bolt head retaining pin can fall out and get the bolt stuck.

Another good point, push the cross pin back up from inside the magwell

 

[Boostd]

You need to slip the gauge up into the bolt face/under he extractor before you chamber it. The t-slot style extractors dont snap over gauges very well, and usually the gauges are quite sharp on the back end, which exacerbates the issue.


Ive installed a half dozen proof PRC barrels on tl3’s and Origins. Every one of them was on the minimum side of headspace. Some were touching on the go gauge.

I’ve done it this way and it gets jammed up and locks up the bolt (best way I can describe it.) I have to pull the bolt back pretty hard to get the go gauge out. I still wonder am I overlooking something simple I am new to this and I did change the bolt from .308 to the magnum bolt, these are all left handed components too if that matters?

It’s almost like I received 2 no go gauges and one is marked incorrectly. What’s an affordable tool I can use to measure them accurately and compare? Why would the live round chamber and the go gauge wont?

 

[Boostd]

I have not removed the firing pin or ejector, is that the problem? I have read about people removing the ejector, I didn’t have to on my .308 so I didn’t here..

 

[John Glidewell]

The TL3 is a mechanical ejector, so no need to remove it. Maybe some pics or video would help us.

 

[AllenOne1]

Are you not having any issues with the No Go Gauge. Hard to believe you received a bad gauge, recheck the marking on it to be sure it is what you think it is though.

I have a Savage and I did take the firing pin out, not sure you would have to but I think it will give you a truer feel on the bolt at the least.

 

[John Glidewell]

Honestly I would pull the barrel off and try the go / nogo gauges by hand and see if they are sticking. It is easier to do off the gun.

On your other question, yes removing the firing pin releases the spring tension on the bolt so you can feel the gauge. There should be no resistance on the go, or you might barely feel it touch at the very bottom of close. The nogo should be a hard stop at the top and should not close at all or barely drop a smidge.

Cheapest head space comparator is prob a Hornady set.

 

[alfmoonspace]

I bet he is putting the headspace gauge in the chamber then trying to close the bolt. The extractor is pushing against the gauge and not closing.

I would check the extractor too just to see if you didn’t damage it.

 

[spife7980]

I have not removed the firing pin or ejector, is that the problem? I have read about people removing the ejector, I didn’t have to on my .308 so I didn’t here..

You have mechanical ejection baking a tl3. A push feed has constant spring pressure from the ejector which you want to remove.
You need to slide the gauge under the extractor.

 

[Boostd]

I bet he is putting the headspace gauge in the chamber then trying to close the bolt. The extractor is pushing against the gauge and not closing.

I would check the extractor too just to see if you didn’t damage it.

Negative, I put the gauge under the extractor just like I mentioned above.

It jams up with light pressure pretty bad.

 

[Boostd]

Honestly I would pull the barrel off and try the go / nogo gauges by hand and see if they are sticking. It is easier to do off the gun.

On your other question, yes removing the firing pin releases the spring tension on the bolt so you can feel the gauge. There should be no resistance on the go, or you might barely feel it touch at the very bottom of close. The nogo should be a hard stop at the top and should not close at all or barely drop a smidge.

Cheapest head space comparator is prob a Hornady set.

I would say after double checking my savage 308 with its gauges, the prc go gauge definitely feels like a no go gauge with this thing but it’s also locking up with very light pressure.

But a normal hunting round chambers smooth as butter? So what’s the next step pull the barrel?

 

[alfmoonspace]

You could measure the go gauge with a comparator once you get it.

I would tear it down and re-torque the barrel to a bit lower torque (55-75 range). You might be one in a thousand but you could have a short chamber.

You could also have a bad gauge. Shoot up NSS, they have Forster or Manson gauges pretty much in stock. I might have a 6.5 PRC gauge lying around I can send to you just to compare.

 

[Milf Dots]

Have you tried the NO Go gauge in it? If so, was the result identical or even worse than with the GO gauge?

 

[Boostd]

You could measure the go gauge with a comparator once you get it.

I would tear it down and re-torque the barrel to a bit lower torque (55-75 range). You might be one in a thousand but you could have a short chamber.

You could also have a bad gauge. Shoot up NSS, they have Forster or Manson gauges pretty much in stock. I might have a 6.5 PRC gauge lying around I can send to you just to compare.

Thanks! I was looking on Forster I dont think they make one for the PRC unfortunatley! I did find one on Pacific Tool and Gauge. After chambering that no go gauge again im thinking I have a bad GO gauge it stops just shy of the bolt fully seating and binds up. The NO GO gauge is smooth and doesn't close but feels perfect.

Have you tried the NO Go gauge in it? If so, was the result identical or even worse than with the GO gauge?

Good call, I just did it again and it feels way better (doesn't bind) but doesn't close as it should.

 

[Lost_Phil]

If the NOGO gage lets you close the bolt only 3/4 of the way and a factory round fits just fine with no hard force or drag when closing the bolt all of the way, I would take it out and shoot it.

As for the GO gage that does not fit, I would compare it measurement wise to the NOGO gage and see what the diameters are. I bet the GO gage is wider by a few thousands. or its egged shaped. I would also send it back and ask to exchange it for another one that's correct.

 

[Criver600]

Minimum headspace is not a problem

 

[Wannashootit]

^^^
This.
As long as you can chamber your ammo, minimum (or less than minimum) isn't an issue.

Non-match grade factory ammo in particular is very inconsistent from manufacturer to manufacturer.
Sometimes rifles chambered go +.001 won't chamber all factory ammo, which is why I usually add an additional thou or two for those that shoot factory only and do not handload to help insure that any ammo will chamber.

 

[Steel head]

Minimum headspace is not a problem

Well sometimes it can bring issues resizing but I still try to run it pretty tight.
My new ADG 7 saum brass is .002 shorter than my go gauge and I cut/set my headspace so I can just feel the bolt tighten up a bit at the last part of closing with go gauge.

 

[porridgebird]

Thanks! I was looking on Forster I dont think they make one for the PRC unfortunatley! I did find one on Pacific Tool and Gauge. After chambering that no go gauge again im thinking I have a bad GO gauge it stops just shy of the bolt fully seating and binds up. The NO GO gauge is smooth and doesn't close but feels perfect.

Good call, I just did it again and it feels way better (doesn't bind) but doesn't close as it should.

What brand is the suspect go gauge?

 

[smoothy8500]

What brand is the suspect go gauge?

Flip your phone sideways and you'll be able to read the name in the picture.

 

[porridgebird]

Sorry I went back and saw they are Clymer. I ordered some from Pacific Tool and Gauge for 300PRC.

 

[Boostd]

Sorry I went back and saw they are Clymer. I ordered some from Pacific Tool and Gauge for 300PRC.

I was looking at those, a member has offered to help me out! I will be getting measurements soon. At least this thread may help someone in the future because I couldn’t find much on the subject. Being new to long range builds didn’t help, still concerned its something I did too.