Accurizing the AR-15 - Part 1: Checking Headspace
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- čas přidán 12. 09. 2024
- Josh and Michael discuss what headspace is, how it impacts barrel performance and function, and offer a brief tutorial on how to check headspace with a set of gauges and a bolt disassembly fixture.
Wonderful company to do business with. Outstanding quality and customer service. And, no, I am not getting paid for this. Just a very satisfied customer.
Glad to hear and see the cutter bolts YOUR NOW MAKING IN HOUSE, that are chrome where they need to be and nitride where they need it. Seen a batch Chad had on The School Of American Rifle and they are so consistent and such tight tolerances..... Nothing but amazing stuff from you guys.. still wanting to test out a real barrel or BCG from the highest quality manufacturing company...YOU GUYS
Where do they need to be nitride?
3:36 is when it starts
The correct TDP go gauge for the US military M-4 - M-16 is 1.4646, not the commercial 223 1.4636..Many channels don't know this, good job...Many manufacturers don't correctly make a true 5.56 or 223 Wylde throats.. Using a throat or function gauge is an easy way to test any new barrel's chamber...
Watched many videos on ar15 head spacing…..have never seen one fail the test….
We find out of tolerance bolts on a daily basis from a wide range of well-respected companies. Checking headspace is similar to leveling the foundation before building a house. It is critical to long term accuracy and reliability as it directly controls the consistency of the chamber pressures and seating depths. Millions of structures have been built without first leveling the foundation... still a terrible practice. If one cares about performance (reliability/accuracy) and understands how these rifles operate, it is not debatable, headspace is critical.
Can I send you my AR15 bolt for head spacing. My bolt is Sharps reliabolt. I suspect it is very spec. But do you make any additional tolerance adjustments to the barrel? Ty.
Josh or Michael, if a 5.56 barrel takes a NoGo .223 guage, but not a 5.56 field guage, is it safe to shoot .223 ammo through it?
While the likelihood of any injury is extremely low, I would recommend finding a larger bolt to tighten up headspace. Headspace is critical to function as is it directly responsible for the consistency of the chamber pressures and seating depths. Getting set up correctly from the beginning will produce better accuracy and reliability for the life of the barrel. I recommend finding a bolt that closes tightly on a 1.4646 go gauge (meaning you can feel the lugs engaging inside the barrel extension as you turn the bolt). I like to see no movement at all with a 1.4676 no go gauge. If you have any issues finding a properly paired bolt, feel free to git in contact with us and we can get you set up with one if you send your barrel or complete upper receiver in for a head-spaced bolt.
If you got no free turn on the no go then your chambers are very nicely cut. Many AR barrels spin bolts on no go as well.
So any videos about how to chwck headspace but no videos explain what cause improper headspace
Jeff Gao 1. Out of spec barrel.
2.out of spec bolt
3. Used bolt with new barrel or vice versa
@@echofoxtrotwhiskey1595 Thanks for that answer. How common is out of spec bolts or barrels?
@@michaelmappin4425 Not very common if you’re buying good parts.
So you are saying the barrel is not at fault for having an incorrect headspace?
Where can I buy head space tool one you have
how to fix if your new rifle has excessive headspace?how do you actualy make it correct?
Ultimately, you would need to find a bolt that properly head-spaces. It is quite common to find significant variations in bolts even from reputable sources. This is one of the reasons we offer head-spaced bolts that are hand fit to approximately .001 of clearance between the bolt and the barrel for optimal chamber pressures and seating depths. It removes the headache that some customers experience... in theory you could try several bolts and none would be an ideal fitment. Because head-space is so critical to performance, we like to offer properly fit bolts for the benefit to our customers.
I'm looking for a 22 creedmoor Barrel for my Ruger M77 M2 Target rifle
Great video, thank you!
Assuming you're chambered in 5.56 NATO (apologies if I missed this), why are you using a 1.4676" NO GO Gauge instead of 1.4696? Is it simply that you (Criterion) want that tight of tolerances for "accurately" shooting groups? For the weekend warrior/home builder, maybe building a CQB or similar, who doesn't care about THAT tight of a grouping, is 1.4696 the proper dimension for a NO GO gauge in 5.56 NATO?
I'm by no means trying to relay that I am some sort of expert and know something you don't. Quite the opposite. I'm learning and there is a plethora of [differing] information that I'm trying to sort through. My current understanding/belief is that 1.4636 is the mil-spec Go, 1.4646 is the Colt accepted GO, 1.4696 is the "No-Go", and 1.4736 is the NATO "Max", or what I would consider to be the Field.
The US military TDP go gauge is 1.4646
So what happens if the bolt doesn't headspace properly? Do you need to adjust the barrel nut until it does? Is this something a customer can do?
A barrel extension can be modified to headspace properly but it takes a few hours of machine and labor time to get it effectively dialed in. The most cost effective fix is to get a new bolt that features the proper tolerance spec.
Another option would be to send us the bolt and new barrel out to us and we could try to find a replacement barrel that is on the high or low side of the tolerance (depending on how the bolt gauged). Sometimes you can get lucky and find one that matches (if you can find a barrel and bolt that have overlapping tolerance ranges).
What do you mean by "headspacing a bolt"? Are you just checking the headspace incase it's off or is there a process that you do to fix it?
Headspacing insures the bolt twists all the way home into battery so the gun will fire, but there is no slop in the fit which could result in the base of the cartridge separating and essentially backfiring into the receiver.
Right, but how do you correct it...trash the Bolt and get a different one?
@@unapologetic7900 barrel extension
Please get some microphones the audio is terrible. Love your new sunglasses
Any recommendations for BCG compatibility with Criterion Barrels? I just bought one of your .308 Hybrid CL Barrels from Brownells, was about to use it with an Aero BCG, but now that you mention it...maybe I should just go ahead and get another BCG specifically for your barrel.
What if you already assembled your upper receiver?
Is there a 5.56 specific set of gauges or the 223 rem works for both barrels?
I recommend gauges for either chamber with a GO spec of 1.4646 and a NO GO spec of 1.4676. If you look for a tight closure on a GO gauge you will achieve approximately .001 of clearance between the bolt and barrel for the most consistent chamber pressures and seating depths.
@@CriterionbarrelsInc, thanks for the reply. I’m new to headspacing so trying to learn correctly. I assume the same gauges you mentioned for your 223 wylde barrels too?
@@atox4957 That is correct, the distance is the same between .223 Rem/5.56/.223 Wylde!
@@CriterionbarrelsInc These videos are awesome. I've been looking for go/no go gauges with the specs listed above (1.4646 & 1.4676) and can find the 1.4646" listed as the Colt spec on Brownells but can't find a no go that's 1.4676". Can you point me in the right direction to find this?
Hello I recently assemble a faxon upper. Barrel reciver. Bcg. Do I need to check head space
Yes. Checking headspace is similar to leveling the foundation before building a house. Despite what anyone may say, checking headspace is essential to maximizing performance from your rifle. Headspace dictates the consistency of your chamber pressures and seating depths. This goes a very long way in ensuring that your rifle will be accurate and reduces wear and tear on internal parts and components.
Great video, very informative. Audio could use some work though!
who makes head space gauges with the hole milled out in the back?
You can't mill a hole. Holes are drilled, bored or reamed but never milled.
@@brianmorrison9066 boring is done with a boring bar, reaming is done with a reamer, and drilling is done with a drill bit. If I put a hole in a work surface with an end mill, I did indeed perform a milling action.
Jesus Christ there are so many fudds in this comment section
who makes that little block for disassembling the bolt?
What do you do if it's too tight and what do you do if it's too loose?
The easiest solution is to just change out the bolt. The rifle will likely function just fine if the headspace runs a bit long (our internal tolerance is significantly tighter than the USGI no-go or field gauge spec), but for optimal accuracy it is usually best to have it fit the prescribed range.
If you have a Criterion barrel you would like mated to a headspaced bolt, all you need to do is give us a call and send the barrel in to us. We'll pair it with a BCM bolt that shares the correct headspace specification.
Too loose means you're not packing enough heat.
What gauges do
you suggest be used for the hybrid profile .308 ar barrels?
Gauges from PTG, JGS, Forster, and many others work very well. We hold production tolerances well inside SAMMI specs with a GO spec of 1.631 and a NO GO spec of 1.634. When we pair a bolt to our barrel we can generally obtain around .001 of clearance for a very tight head-space which makes for extremely consistent chamber pressures and seating depths... all good for accuracy and overall performance.
What head space gauges do you use in your 223 wylde barrel
We use a mix of gauges from either PTG or JGS.
@@CriterionbarrelsInc using 223 or 5.56 gauges?
Either one will work, so long as it measures out to 1.4646 or 1.4676. You can go a bit longer on the no-go gauge if you prefer, but that's what we typically hold our internal tolerance to.
Appreciate the effort. Unfortunately your audio sounds like you're working inside of a tin can. The benchtop work on the barrels is really hard to see. Not close enough and too dark. In 30 years of film and video I have never seen (heard?) one man narrate another man's hands. It just feels weird. More nice, soft light bounced off of a white ceiling or sheets of artboard ( foam core) , however you can hang it, and you will be rocking . You guys are both well spoken, again thanks for your efforts.
You all need to talk louder or move your Mike closer
Damn you gotta remake this with better audio. Can't even finish this video it's so bad
Acoustics and or microphone absolutely terrible!
It's tough to filter out background noise in a machine shop. This room was the best option in drowning out the various shop sounds, although it does tend to generate a bit of an echo. We're planning an office expansion over the next couple months that should allow room for a video studio with better acoustic properties.
Criterion Barrels, Inc. , sir if l buy ar-15 hbar 5,56/223 barrel from you can l use my sharps XPB complete bolt carrier directly ? Or l have to buy BCM bolt from your Web? Thanks ,
@@CriterionbarrelsInc A cheap fix, get some matress egg crates and tape them to to wall, will help kill any sound bouncing around. Heck, even actual egg crates will work
@@CriterionbarrelsInc excuse excuse, the guy shooted a bullet off the group he blamed to the wind.