Home Forums Hunting & Shooting AR and Tactical Rifles Didn't pass no go headspace check..now what?

Several years ago I bought a stripped AR 15 barrel and just recently dug it out thinking I would use it for a build.
After cleaning it up I checked the headspace and the "go" checked fine but it failed the "no go".
I know who I purchased the barrel from but no idea who it was manufactured by. It is chambered for 5.56.
I haven;t yet contacted the seller, but as it's been so long since I bought it I'm not sure what they'll say.
My question is what can be done with this barrel? Re-chamber? If so, to what? Or am I now the proud owner of a 16" paper weight.
Lesson learned....check it for proper headspace when you get it!
Any and all suggestions/recommendations appreciated.
rookie

Of course if it closes on a NoGo it's going to close on a Go.

If it closes on a NoGo, try a Field. NoGo isn't great, but at least you can size brass to fit it and it isn't a safety hazard to fire new brass in it. If it closes on a Field, other than setting the barrel back, it's trash. I only know of one guy who is willing to set AR barrels back and it costs more than most barrels are worth.

Is the headspace gauge .223 instead of 5.56 by any chance? I think they are slightly different.

I don't have a field gauge and forgot to post in original posting that I tried three different bolts and they all closed on the no go gauge.
Yeah, kinda figuring that doing anything with it might not be cost effective.
rookie

They are Clymer 5.56.
rookie

Mostly what Tyrone said about using it, but if you use it, keep the brass separate from other brass & use it again in that gun only with only setting the shoulder back about .002", but you need a tool for being able to measure that.

But I'd advise getting a better idea of where the HS really is first.

There's a fair amount of difference in HS of civilian chambers & what the military allows, so you can read the info in the chart in the link, but remember, the military isn't reloading any of their ammo.

So take it for what it's worth; if it were mine, my 1st option would be to attempt to return it.

MM

Randall's 5.56 HS Specs

Also consider the bolts contribution the headspace.
Did you try multiple bolts, preferable one's known to headspace properly in other barrels?

What's the barrel chambered in?
Is it 5.56 or .223 Wylde. Wylde throat is actually longer than 5.56, but narrower, so it's possible to fail on a 5.56 gauge but pass on a Wylde gauge.

Not exactly..................HS gauges do not extend into the throats, only to the neck datum point. The chambering, 223, 5.56 or Wylde all measure HS to the same point.

The differences comes in what maximum length dimension is acceptable, ie, how much a case is allowed to stretch, more or less per the chart I posted.

Keep in mind that all new brass is (supposed to be) at zero or below minimum SAAMI dimension. Most is .002-004" below minimum so as to chamber in all chambers, but it's common to see some at zero or even +.001" given the range of world wide manufacturers of ammo.

MM

Your right.
I was thinking of these, chamber function gauges, not head space:

Get something you know the thickness of, add a thousandth or 2 to the back
of the gauge. Stack the shims until it won't go. Now you have an idea
of what you have. Foil will work, a dab of grease keeps it in place.
Just watch out for compressible stuff, you will get a false read.

Well, contacted the seller and outta luck there....but honestly, no hard feelings toward seller. I don't have any record of the sell and it was purchased several years ago.
Have an offer from a friend who is going to send me a different set of gauges in .223 to try. Mine are 5.56 so we'll see if that makes a difference.
rookie

It won't.

Read the chart I posted.................it's titled 5.56 / .223. HS dimensions are the same.

The only way it might make a very small difference is if the manufacturers are different & that would be very small.

But, per the chart, Military No-Go gauges (dimensions) are considerably larger, if his set happens to be Military by some enchanted stroke of luck.

You really should make an effort to find out exactly where you are on HS.

Use masking tape in layers, carefully trimmed to the HS gauge head & see how much more thickness it takes to not allow the bolt to turn, assuming you've removed the ejector & the extractor.

If it falls within the Military spec, that will give you some valuable info & it it does, then you can feel more or less OK with it, & then just keep the brass separate.

Maybe not ideal, but usable; otherwise, it's trash.

MM

Good on the op for checking the headspace. Some do not. I'm also glad MM started a thread a while back on this. Kudos to both... Something that I've heard is unnecessary because you rarely have issues with headspace on an AR15. I always err on the side of caution and check. Even when I get a new barrel with matched bolt, I check..

The barrel in question has a new home.
I took it to a gunsmith who checked it and said he'd buy it from me if I wasn't comfortable using it so it be gone!
rookie

I fire a case or three. Then read headspace with a gauge. Has not let me down so far. Obviously next build could. But I've not seen dangerous headspace and I don't always buy the very best parts, I buy whats needed for a particular job.