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Old July 19, 2019, 04:33 PM   #51
Metal god
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Quote:
Originally Posted by Gary at PSA
We use PTG gauges to head space all of our bolts and barrels. Yes, our techs did check headspace before installation.
I just received the PTG NoGo gauge from Midway USA 2 day air . The upper FAILED the gauge .

Needless to say , Its going back for refund .
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Old July 19, 2019, 04:50 PM   #52
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This is going to be interesting to see their response.
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Old July 19, 2019, 08:06 PM   #53
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Quote:
This is going to be interesting to see their response.
Maybe not , There was a second email I received from them answering my question of can I still return the upper for a refund which is in post #48 ( not the response just the question ) . They said yes because it was still with in the 30 period . Either way I sent an email asking for the refund and shipping label but that was this afternoon ( end of there day ) so I likely wont get a response until Monday at best .

My guess is they only test a Field gauge and call it good . Which I'm not comfortable with . I considered keeping it so I had everything I needed ( gas block , rail , upper carrier ) if I wanted to buy a new barrel but just decided to be done with it .
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Old July 19, 2019, 08:35 PM   #54
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I just noticed from your picture that you left the ejector and extractor on your bolt when you tested with the shim--you do know that you should remove them when using the gauges?
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Old July 19, 2019, 08:49 PM   #55
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I just noticed from your picture that you left the ejector and extractor on your bolt when you tested with the shim--you do know that you should remove them when using the gauges?
Yep and I did address that in the other thread . In a nut shell I did not want to disassemble the bolt in case it had to be returned for repair . I do not have the proper tools to do so and would surely have marked up the bolt . I didn't want anything I may have done to allow them to void my warranty . Not to different then only firing factory ammo . Regardless having the extractor and ejector installed in the bolt does nothing to hinder the results of the bolt closing fully on a NoGo gauge . The reason you want them removed it because they may cause the bolt NOT to close on the gauge resulting in a false reading . In this case the bolt closed completely on both brand NoGo gauges and it should never close on those . There is nothing that having the extractor or ejector still in the bolt would cause the bolt to close on both brand NoGo gauges that they other wise would not have . I'm OK with how I did it and the results I believe it shows .
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Old July 20, 2019, 09:49 AM   #56
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What is the actual length of your no-go gauge? Have you actually charged the carrier and let it fly on the gauge?
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Old July 20, 2019, 12:43 PM   #57
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Quote:
Have you actually charged the carrier and let it fly on the gauge?
Why would he? That's not the way to use a headspace gauge. In fact, this is the first time I have ever heard anyone suggest doing that.

Letting the bolt "fly" forward under spring pressure risks damaging the rifle, and the gauge, AND giving a false reading.

Metal god, IF your gauge and their gauge are the same, and they get a pass and you get a fail on the same barrel, logic says someone isn't doing something right.

You sound like you are doing things right, we expect and assume a manufacturer does its tests right, but with opposite results, you can't both be right.

Just for personal satisfaction, I would have a competent 3rd party do the check as well. With their gauges, and with yours, if possible.

If I'm doing it wrong, and somebody shows me I'm doing it wrong. I say, "dang! I did not know that..." and learn to do it right. But if I'm a company, selling products to the public, and I believe my people are doing it right, and someone isn't, I need to know that, so I can fix it.

Simplest would be just sending it back and getting something else or your money back and be done with it.

Best would be finding out who is in error and fixing it.

Good Luck
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Old July 20, 2019, 12:50 PM   #58
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Quote:
Have you actually charged the carrier and let it fly on the gauge?
Quote:
Why would he ?
The question was asked likely for the same reason given . If I were doing that I would likely be damaging the bolt and do it enough I would likely start getting false readings .

I don’t let the BCG fly home on any of the gauges . I remove the upper from the lower , place the gauge in the chamber and slowly push the carrier foward until it stops then from the butt of the carrier I try the force it closed with the palm of my hand .

I once used a light rubber malet to tap it closed but it turns out that’s not needed . The bolt is closing on the NoGo gauges with firm pressure with my palm on butt of the carrier .

I have not measured the gauges but they operate correctly with fully assembled bolts on 3 other 308 rifles and the fact it fails two different brand gauges would seem reasonable to me the gauges are not the issue .

Quote:
Metal god, IF your gauge and their gauge are the same, and they get a pass and you get a fail on the same barrel, logic says someone isn't doing something right.
I agree however Gary has not said that it passed any specific gauge . Meaning he has not said "we use PTG gauges and it passed our NoGo gauge" He only states they use PTG gauges and it passed . I know one can think that's the same thing but it's not . I still contend and this is just my opinion . It only passes there field gauge and not there NoGo or maybe they don't even test a NoGo knowing a field gauge pass is all that is really needed .
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Old July 20, 2019, 01:54 PM   #59
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Quote:
Why would he? That's not the way to use a headspace gauge. In fact, this is the first time I have ever heard anyone suggest doing that.
I didn't suggest he do that--I asked the question specifically because he was using the gauge with the extractor and ejector--as well as a shim--still attached to the bolt face. The gauges will not work properly, nor were they ever intended to--with the extractor and ejector still integral to the bolt. Because of the inherent resistance to the extractor people sometimes (incorrectly) force the bolt--including dropping the charged carrier.

This thread has crossed into the absurd zone--I'm out.
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Old July 20, 2019, 02:15 PM   #60
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Quote:
This thread has crossed into the absurd zone--I'm out.
Not sure where you get absurd but maybe you don't have many conversations with people . If we were all face to face this "conversation would be over in about 20 min but because it's on line through the written word where people can talk on the own time . It's seems to drag on and be incomplete at times .

All I've been doing is having a conversation with" friends " in between responses from the manufacture . That's how I view these forums . You clearly view them differently .

However I understand how I'm doing it wrong , can you explain how a bolt will close on a NoGo gauge the way I'm doing it and not close on that same chamber when done "correctly" ? I mean does the chamber grow or the gauge get smaller the way I'm doing it ? The gauges eject freely with no binding of the bolt lugs just as if I were ejecting a case . If I had to mortar the gauges out then maybe my way is giving me false readings and If I did have to mortar them out I'd likely be ok with the headspace .

I've already explained why the bolt needs to be stripped the way I understand it . Maybe you can explain how you believe a bolt can close and freely eject on a NoGo gauge that is properly spec'd regardless of how you test it ? .
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Old July 20, 2019, 03:42 PM   #61
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https://www.youtube.com/watch?v=VvI97DVQS70

https://www.youtube.com/watch?v=-LgBEIzBQTY

https://www.youtube.com/watch?v=_jIqlIdUCco

https://www.forsterproducts.com/pdf/...structions.pdf

It would not appear that a no-go gage relates to max sammi chamber dimension. It would also appear that forcing a gage into place may wear the gage surface/bolt/chamber contact surface. Am not a gunsmith, but the included links are from manufacturers, including PSA.
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Old July 20, 2019, 03:46 PM   #62
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You all have convinced me , I’m taking it to a gunsmith today .
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Old July 20, 2019, 06:39 PM   #63
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I always thought if the bolt closes on the NOGO gauge, it doesn't necessarily mean the rifle is unsafe. But does indicates you need to check with the Field gauge to determine is the firearm is safe to shoot. The Field gauge is the absolute maximum headspace. If a bolt closes fully on the Field gauge then the firearm is not safe to shoot. If the bolt closes with slight resistance with the NOGO gauge, then it's still within spec.
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Old July 20, 2019, 09:51 PM   #64
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FWIW... The PTG Go, NoGo gauges are used in both the .308 and longer 7.62x51 milspec chamber.

".308 Winchester


22 - 243 Win, 243 Win, 260 Rem, 270 - 08, 270 – 308 Win, 338 Federal, 338 Federal CIP, 338 - 08, 338 - 358 Win, 358 Win, 6.5mm Panther, 6.5mm - 08, 7mm - 08 Rem, 7mm – 308 Win, 7.62mm NATO, 7.62mm x51

And PTG also says to remove the ejector and extractor.

And..

The .308 Winchester chamber headspace is between 1.630 and 1.6340 inches (SAAMI Info). The 7.62x51mm NATO is between 1.6355 and 1.6405 inches.
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Old July 20, 2019, 10:48 PM   #65
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Sounds to me like you're doing it correctly. It's been a long time and I'm just going from memory and my experience with GI M16s in the 70s, but that's how we were trained to do it.

Upper off the lower (or hinged open), gauge in the chamber, push the bolt carrier by hand until it stops. Firm push but no hammering, tapping or hard shove. If I remember correctly the gauges we had had relief cuts in the base to clear the extractor and ejector, so we didn't have to remove them from the bolt for an accurate reading.

If the bolt carrier stuck out past the end of the upper, on the go gauge, it was bad. If it DIDN'T stick out on the No-Go and field gauge, it was bad (the other way).

I would expect the same to be true with the AR 10 series, but I'm not an expert on them. Am interested to hear what the gunsmith says. Do let us know, and yes, to me its just a friendly conversation, also, and I agree, if I could see what you were doing, we'd save a lot of typing!
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Old Yesterday, 08:07 PM   #66
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Im at the range now and brought the PA-10 with me .

Federal 150gr power shok measures
1.616 before firing and 1.626 after . That is 10 shots but 2 of the 10 only grew .009

In contrast , same ammo in my Ruger precision rifle measured
1.616 before and 1.618 after .

The PA-10 fails the gauge and the Ruger passes it . That can clearly be seen in there respective fire formed cases .

I’ve only fired those 10 shots in the PA-10 and not going to shoot any more today . I will say the cases are coming out way better looking with no tool marks compared to the last barrel . This one has a much smoother chamber . I also do not see any bloating at the web at this time .

EDIT

Got home and checked a few things . The fire formed cases measure .003 longer then the PTG brand gauge PSA uses to check there headspace .

Oh and anther interesting tid bit . I buy all my once fired LC brass from the range I shot at today . The military uses are ranges and the primers are still crimped in . Want to guess what those measure ? 1.626 to 1.627

After all the measuring and comparing I've done . I have no doubt that PSA has there barrels/chambers cut to 7.62x51 NATO specs and are stamping them 308 Winchester .
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Old Today, 05:50 AM   #67
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Given PSA's previously reported problems with too tight of chambers, the chamber appears to be cut for reliability. Another item is that measuring the datum on semi autos may not be accurately reflective of of the chambers datum as semi's can "stretch" brass on extraction. Likely the camber is cut longer, just not to the extent you are measuring from the brass.


If memory serves, Federal commercial brass has the shortest shoulder datum have measured yet.
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Old Today, 08:02 AM   #68
Bart B.
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Quote:
The .308 Winchester chamber headspace is between 1.630 and 1.6340 inches (SAAMI Info). The 7.62x51mm NATO is between 1.6355 and 1.6405 inches.
Compare those chamber dimensions to that of the ammunition:

http://forums.thecmp.org/showthread.php?t=146769

Compare case to chamber differences to see how case head clearance to bolt face when round fires will sometimes be a crush fit if the bolt closes full into battery. And several thousandths clearance with maximum chambers and minimum ammo.

Last edited by Bart B.; Today at 08:29 AM.
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Old Today, 10:02 AM   #69
Metal god
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Quote:
Another item is that measuring the datum on semi autos may not be accurately reflective of of the chambers datum as semi's can "stretch" brass on extraction.
I agree but all 10 cases pretty much came out the same . When that happens I consider those measurements representative of the head space and bump my shoulders .003 for semi auto's and have never had an issue with my sized cases chambering . I had some light loads , think they were PMC . That gave me very erratic head to datum measurements . I how ever have had relatively consistent measurements when measuring higher pressure full power loads regardless if fired in a bolt gun or semi auto .

Quote:
Originally Posted by Me
After all the measuring and comparing I've done . I have no doubt that PSA has there barrels/chambers cut to 7.62x51 NATO specs and are stamping them 308 Winchester .
Quote:
Originally Posted by in link from BartB
SAAMI .308 Winchester:
GO: 1.630 in.
NO-GO: 1.634 in.
FIELD: 1.638 in.

FN FAL:
GO: 1.6325 in. (FN & Brit/commonwealth. Canadian is 1.6315 in.)
NO-GO: 1.638 in.
FIELD: 1.640 in.

7.62 NATO (M14 US MILSPEC):
GO: 1.6355 in.
NO-GO: 1.638 in.
FIELD: 1.6445 in.
Quote:
Originally Posted by a poster in the link
Ok you missed it again, both 308 WIN and 7.62 NATO are the same period. The headspace specifications for the cartridges are SAMMI 1.627- 1.634, NATO 1.628-1.634. The only reason NATO went to the larger chamber was for battlefield reliability,
Ok just so I understand , is the NATO chamber cut larger ? You have guys posting specs that say yes and others that say NO PERIOD then add they went to a larger chamber ???? It's like saying , They are the same but not really . So is she pregnant or not ?
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