In this Tech Tip, Brownells gun tech Steve Ostrem walks users step-by-step through the process of checking headspace on their AR-15 rifles, but new and used. Learn more here www.brownellsvi...
You have literally explained in simple Laymen's terms that anyone can understand, within 4 minutes, what dozens of other posts, articles and websites could not. This isn't something I should be impressed by, yet here we are.
When using a head space gauge, NEVER let the action slam shut on the gauge, you can easily jam the bolt /BCG where the chamber was just a little too small for the gauge and now it may be near impossible to get it out! Only use your thumb to push the bolt carrier forward! Saw it happen!
Mmpi For All You live a boring life. I say cover the gauge in red loctite, let her slam forward, and jam that forward assist with a mallet. Let sit for 24 hours, and go from there.
From Brownells website: "The GO gauge corresponds to the SAAMI (Sporting Arms & Ammunition Manufacturer's Institute) minimum chamber length, while the FIELD gauge usually matches the maximum chamber depth, or slightly less. NO-GO gauges are an intermediate length between minimum and maximum, that, technically, is a voluntary dimension." There is really no need to bother with a NO-GO gauge, get a GO and FIELD to test min/max.
Yes, but a no go gauge is a good test to adhere to if a person reloads and wants the longest life out of their brass..Accuracy can also fade the closer the chamber nears the max.. It is more important to use the correct 1.4646 go gauge for 5.56 NATO chambers instead of the incorrect 1.4636 223 go gauge many manufacturers call 5.56 NATO...
@hairydogstail Do you suppose they do that because they are accounting 5.56 users will also shoot .223? Any logic in doing so. I don't know enough to say.
I wish I wasn't so impatient. All I wanna do is go to the range with my self-built AR! Guess I should check the head-spacing first! Got the gauges and ready to go. Thanks Brownells.
Should all new builds with new parts, be checked for good headspace? Most videos talk about using used with used, or used with new. I have ALL new parts.
What gauges (and specs) for a wylde barrel? I know they have their own specific throat erosion gage so I am wondering if the headspace gauge is specific to it as well? Thank you
Too Brownells has stopped providing the great gunsmithing tools they used to sell. now it's almost all for 1911 or ar's no more plating supplies drilling fixtures etc. Hope Midway will pick up the slack.
Ok I have a problem. I did a no go and my bolt still went all the way forward. And end up getting a other bolt and the no go stop the bolt so is the problem is the bolt right? I just want to be safe and I switch the same bolt to the other upper and it still went forward. Is it still safe to use that bolt ?
The explanation of the “Colt” gauge is a little confusing. I think they are referring to a 5.56 max gauge which would be used for any NATO 5.56 chamber (as opposed to .223) ...not just Colt. Colt is the technically the spec for 5.56 but many other companies chamber for true 5.56 (BCM, LMT, etc)
The mill spec go gauge for 5.56 chamber is 1.4646, not the often but incorrectly marked 1.4636 go gauge.. 1.4636 marked go gauges are for 223 chambers, not 5.56 NATO..
Be sure to use the 1.4646 go gauge for barrels marked 5.56 NATO and the go gauge of 1.4636 for 223 commercial marked barrels. Many manufacturers will label their 1.4636 go gauge as a 5.56 go gauge which is not correct..The military requires a 1.4646 go gauge to pass their head space requirement...
If it was from a reputable company where the barrel and bcg was installed as a complete upper, I'd assume head spacing was verified. Call and ask or just check it if you or someone you know has gauges
Do to manufacturing defects and out of tolerance parts that slip out from a manufacturer it should always be checked. Doesn't matter who made it. If it's mil spec, it's made to the specifications of the military. That's why you can buy anything mil spec and it should work. And most companies check for function not a perfect assembly. So the headspace may be ok, or slightly off and still function. But it's not optimum for accuracy or brass life
@@JosephHuver No, always head space when changing bolts. For 5.56 marked chambers you need to use the 1.4646 go gauge and not the 1.4636 go gauge many head space gauge manufacturers label 5.56 go gauge..
I've got a question. I'm beginning to start reloading. Can I just start off by setting my sizing die to flush, or slightly backed out, and check the brass in the chamber, to see if the headspace is correct? And then, if it isn't, slightly start screwing the die down, until it's perfect? This will simply bump the shoulder back to an exact dimension, without causing excessive headspace. From what I understand, each chamber is gonna be slightly different, as far as headspace dimensions. So, it wouldn't even do any good to check your case with a headspace gauge, because YOUR specific chamber may be a little shorter, or longer than the standard gauge. I hope this makes sense, and I would REALLY appreciate your opinion on this. Thanks.
You should be measuring your brass to make sure it's within spec. You should also be measuring overall cartridge length to make sure it's within spec as well. You shouldn't have to check headspace with a reloaded cartridge. That's what go/no go gauges are for.
If you are using 5.56 NATO pressure ammunition then you need to use the 1.4646 go gauge and not the 1.4636 go gauge many manufacturers incorrectly mark as 5.56..
what kind of reading does get if the bolt is not fully disassembled? say you only removed the extractor and then performed the test? can the resistance from the ejector give a false reading?
I test headspace with ejector AND extractor in the bolt. I operrn the action via the takedown pin, and position the bolt carrier so the bolt is near the chamber. then tilt the gauge under the extractor and pull it into the bolt so the ejector collapses. I then slide it part way into the chamber as I'm holding it in position -- usually it's very easy, and once the gauge gets started into the chamber you don't have to worry about the ejector. I then push on the back of the BCG to perform the test. I can't see where this can be wrong, because it's what's done with the actual cartridge in firing. If the go, goes and the no-go doesn't (with a good push with the hand), then I can't see why that isn't enough. There could be "close" situations, where you would then want to remove ejector/extractor to get a clearer test -- but, again, with my test, if the go goes and the no go doesn't (with a good push) I can't see how headspace can be wrong. Doing this, I've seen mostly passes -- and a couple of no-go failures. More or less what one might expect looking at many rifles.
Nothing wrong with doing it how you want but for precision accurate measurement you would remove the ejector at the least. You ideally want the parts to be under no external tension so you can feel how tight or loose the fitment is is you're going for precision fit. If it just has to be ballpark then you can cut corners to save time.
"can the resistance from the ejector give a false reading?" Absolutely, YES! Remove the ejector! The ejector spring can go "coil bound" if too long, giving a false reading. Ejector springs can be very stiff, thus giving a false reading. The ejector plunger can bind in the hole, thus giving false readings. All the above will lead you to believe that the bolt is properly headspaced, while in reality there can be a gross amount of excessive headspace. Upon firing the case head is stretched rearwards as the case body grips the chamber walls. Chamber pressure is somewhere around 55,000 PSI. More force is applied to the ejector that you can apply with your hands. IF any of the above conditions have affected your headspace test, they will be overcome by the massive force applied to the rearward moving case head. The resulting excessive headspace can lead to a case head separation. IF a case head separates, gas pressure can/will move around the bolt nose and into the receiver, possibly destroying the gun.
@@Stephen-br6il Use the correct 1.4646 go gauge if using 5.56 NATO ammunition..If you are only using 223 pressured ammunition then the standard 1.4636 go gauge will work..To check the 223 throat you must have a 223 Wylde function gauge..
If you're buying from a reputable manufacturer with good quality control, not really... But if you decide not to just know that you're taking a risk. A very small risk, but still a risk
What size punch or roll pin did you use to get the pins out of the bolt? Don't use 1/16th...it goes right through the middle of the pins and jams in there, and I think by bolt is trashed b/c of it. Grrr.
513-100-241WB for GO, 513-100-240WB for NO GO. These are SAAMI spec .223 Remington gauges. www.brownells.com/gunsmith-tools-supplies/measuring-tools/headspace-gauges/rimless-rifle-shotgun-cartridge-headspace-gauges-prod25179.aspx
Hello, I have an upper that uses the Pantheon Arms Dolos kit (barrel quick change system). I use the upper between a .50 beowulf barrel and a .300 AAC Blackout barrel. I think the Blackout barrel might not be head spaced correctly since it didn't come with its own bolt and I was just using my regular 5.56 bolt with it. It's slightly crimping one side of the lip of the casings after ejection. What can I do if it is a head space issue? I have several other 5.56 bolts, should I just try the other bolts? If none of the other bolts perform better, what would a gunsmith do to fix the issue?
Under no circumstances should you ever attempt to fire a round in a firearm without checking the headspace if a headspaced bolt has not been provided with the barrel. You will need to take this to a qualified gunsmith and have it checked out.
WOW. Damn people are stupid and spread terrible information constantly. Ignore the idiots that commented on your question and do THIS ---> "If a rifle closes on a NO-GO gage, it may still be within SAAMI specifications, or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gage. If a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI-specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin." - Forester. IMHO there is no need for a NO-GO gauge, get a GO and FIELD to test min/max.
@@MoragTong_ People are not stupid and are just trying to learn so lighten up slick. It is more important to use the correct go gauge of 1.4646 if the barrel is marked 5.56 and not use the 223 commercial go gauge 1.4636 as short chambers are much more of a problem than over sized chambers. The no go is a good gauge for reloaders who want to get the most life out of their brass and are seeking better accuracy..
So my .223 wylde barrel is brand new from CMC. I have checked bolt and the barrel and the barrel seems to have a bit of a spacing issue when testing it with the go gauge, it doesnt close flush. Could this be the finisher coating? I dont want to fire it if its going to explode on mez
It could possibly be a short chamber which is much more common than a long chamber. I would send it back..If you are shooting 5.56 pressured ammunition, you need to use the 1.4646 chamber go gauge and not the 223 commercial 1.4636 go gauge..
Question regarding headspace on a AeroPrecision M5 Build: Yesterday I swapped out barrels on my M5E1 and put on a Ballistic Advantage 20" 308 Bull Barrel. I checked headspace with Forester Go & NoGo Gauges. The interesting part is when I checked the headspace with the barrel out of the upper, both gauges worked as expected indicating headspace is safe. However when I assembled the upper, I put the NoGo gauge in and the bolt closed completely on the NoGo gauge. Wondering if anyone has experienced this before. The assembled upper method with the NoGo gauge forcing the bolt to stay out of battery is what I saw on Brownell's tutorial section. Would you guys say the rifle is safe to shoot considering headspace gauges passed the test with the barrel removed? Thanks, B
If you performed the test correctly with the barrel removed, and the bolt DID NOT go into the barrel extension deep enough to turn and engage the locking lugs on the NO-GO gauge, then it passed headspace. If the bolt closes COMPLETELY on a NO GO gauge, regardless whether the barrel is installed or not, it has FAILED headspace. IF the first check was performed correctly, something has changed the distance from the locking lugs in the barrel extension (and thus the bolt face) to the shoulder in the chamber. That distance has to have gotten longer. How could this happen? One likely reason is that the barrel extension has become unscrewed slightly. Far less likely, but could otherwise contribute to changing headspace would be that the chamber has been deepened, the locking lugs are damaged or worn, or the bolt face has been polished or machined backwards. If you failed to remove the ejector (or extractor) when checking headspace, there is a possibility that you your initial headspace check gave you an incorrect reading. It is possible that the ejector made it appear that the NO GO wouldn't fit, but the ejector was fouling to test. In this case it would appear that the bolt doesn't close on the NO GO, while in reality the ejector or extractor are causing the bolt not to go into lockup. Later, the extra force and weight of the bolt carrier over-ride the ejector/extractor and allow the bolt to go into full lock up, because headspace was in excess of a NO GO to start with.
You have literally explained in simple Laymen's terms that anyone can understand, within 4 minutes, what dozens of other posts, articles and websites could not.
This isn't something I should be impressed by, yet here we are.
That Brownells, thats what they do.
When using a head space gauge, NEVER let the action slam shut on the gauge, you can easily jam the bolt /BCG where the chamber was just a little too small for the gauge and now it may be near impossible to get it out! Only use your thumb to push the bolt carrier forward! Saw it happen!
Mmpi For All You live a boring life. I say cover the gauge in red loctite, let her slam forward, and jam that forward assist with a mallet. Let sit for 24 hours, and go from there.
@@dylconnaway9976 Hahahahahaha
Nothing a dowel down the bore can't take care of...
@@dylconnaway9976 wow so funny ..
You are correct and should never use over 8 pounds of pressure when using go- no go- field gauges..
Love these video. Brownells is pure American Gold! I could watch these all evening next to a fire.
From Brownells website: "The GO gauge corresponds to the SAAMI (Sporting Arms & Ammunition Manufacturer's Institute) minimum chamber length, while the FIELD gauge usually matches the maximum chamber depth, or slightly less. NO-GO gauges are an intermediate length between minimum and maximum, that, technically, is a voluntary dimension." There is really no need to bother with a NO-GO gauge, get a GO and FIELD to test min/max.
Yes, but a no go gauge is a good test to adhere to if a person reloads and wants the longest life out of their brass..Accuracy can also fade the closer the chamber nears the max.. It is more important to use the correct 1.4646 go gauge for 5.56 NATO chambers instead of the incorrect 1.4636 223 go gauge many manufacturers call 5.56 NATO...
@hairydogstail Do you suppose they do that because they are accounting 5.56 users will also shoot .223? Any logic in doing so. I don't know enough to say.
I wish I wasn't so impatient. All I wanna do is go to the range with my self-built AR!
Guess I should check the head-spacing first! Got the gauges and ready to go.
Thanks Brownells.
Good luck! be safe out there!
Good thing you did the safest thing for you and your friends at the range thank you!! ❤️
Hey,,, you only do this one time,,, so take your time
Please start listing part numbers.
Cool just checked my aero/midwest ind./Radian build I completed just to make sure everything's kosher
Should all new builds with new parts, be checked for good headspace? Most videos talk about using used with used, or used with new. I have ALL new parts.
Should be coming soon Jeff Williams!
Solid post, here.
Great information here from Brownells......thanks for all your videos..!
So what is the part numbers for the 1.4646 go gauge for 5.56, the no go gauge and field gauge from Brownells?
I would have liked more explanation of what headspace is and how to correct bad headspace.
I guess it's nice to know if there is a head space problem. But with the ar style system there isn't much you can do about it.
I checked my headspace with reinstalling the firing pin. I should be good right?
Which gauges do u recommend
What gauges (and specs) for a wylde barrel? I know they have their own specific throat erosion gage so I am wondering if the headspace gauge is specific to it as well? Thank you
It's the cleaning rod eject for me
My new Aero Precission as well as my new Bravo Company both close on the no go gauge....what now
Did you figure it out?
Too Brownells has stopped providing the great gunsmithing tools they used to sell. now it's almost all for 1911 or ar's no more plating supplies drilling fixtures etc. Hope Midway will pick up the slack.
Do you need to check the headspace if you get a new Bolt Carrier only?
Ok I have a problem. I did a no go and my bolt still went all the way forward. And end up getting a other bolt and the no go stop the bolt so is the problem is the bolt right? I just want to be safe and I switch the same bolt to the other upper and it still went forward. Is it still safe to use that bolt ?
If you're going to buy just one gauge should it be a go or no go?
I just tried those and wouldn't close, but the bolt still had the ejector and extractor on it... would that stop it from turning on a 5.56 gauge???
The explanation of the “Colt” gauge is a little confusing. I think they are referring to a 5.56 max gauge which would be used for any NATO 5.56 chamber (as opposed to .223) ...not just Colt. Colt is the technically the spec for 5.56 but many other companies chamber for true 5.56 (BCM, LMT, etc)
The mill spec go gauge for 5.56 chamber is 1.4646, not the often but incorrectly marked 1.4636 go gauge.. 1.4636 marked go gauges are for 223 chambers, not 5.56 NATO..
Be sure to use the 1.4646 go gauge for barrels marked 5.56 NATO and the go gauge of 1.4636 for 223 commercial marked barrels. Many manufacturers will label their 1.4636 go gauge as a 5.56 go gauge which is not correct..The military requires a 1.4646 go gauge to pass their head space requirement...
So a factory assembled upper doesn’t need to have the head space check, even if the bcg was ordered separately both from same manufacturer?
If it was from a reputable company where the barrel and bcg was installed as a complete upper, I'd assume head spacing was verified. Call and ask or just check it if you or someone you know has gauges
Do to manufacturing defects and out of tolerance parts that slip out from a manufacturer it should always be checked. Doesn't matter who made it. If it's mil spec, it's made to the specifications of the military. That's why you can buy anything mil spec and it should work. And most companies check for function not a perfect assembly. So the headspace may be ok, or slightly off and still function. But it's not optimum for accuracy or brass life
@@JosephHuver No, always head space when changing bolts. For 5.56 marked chambers you need to use the 1.4646 go gauge and not the 1.4636 go gauge many head space gauge manufacturers label 5.56 go gauge..
Always good info will the 223/5.56 headspace gauge work on a 223 wylde?
Yes, since the length is the same.
Thanks for the info.
THANKS
I've got a question. I'm beginning to start reloading. Can I just start off by setting my sizing die to flush, or slightly backed out, and check the brass in the chamber, to see if the headspace is correct? And then, if it isn't, slightly start screwing the die down, until it's perfect? This will simply bump the shoulder back to an exact dimension, without causing excessive headspace. From what I understand, each chamber is gonna be slightly different, as far as headspace dimensions. So, it wouldn't even do any good to check your case with a headspace gauge, because YOUR specific chamber may be a little shorter, or longer than the standard gauge. I hope this makes sense, and I would REALLY appreciate your opinion on this. Thanks.
You should be measuring your brass to make sure it's within spec. You should also be measuring overall cartridge length to make sure it's within spec as well. You shouldn't have to check headspace with a reloaded cartridge. That's what go/no go gauges are for.
NATO or WILDE or .223 ? .. Same gauges for ALL?
What gauges do you use if you have a .223 Wylde barrel or a ar-15 lower receiver marked 556/223? Want to buy the correct gauges.
If you are using 5.56 NATO pressure ammunition then you need to use the 1.4646 go gauge and not the 1.4636 go gauge many manufacturers incorrectly mark as 5.56..
what kind of reading does get if the bolt is not fully disassembled? say you only removed the extractor and then performed the test? can the resistance from the ejector give a false reading?
I test headspace with ejector AND extractor in the bolt. I operrn the action via the takedown pin, and position the bolt carrier so the bolt is near the chamber. then tilt the gauge under the extractor and pull it into the bolt so the ejector collapses. I then slide it part way into the chamber as I'm holding it in position -- usually it's very easy, and once the gauge gets started into the chamber you don't have to worry about the ejector. I then push on the back of the BCG to perform the test. I can't see where this can be wrong, because it's what's done with the actual cartridge in firing. If the go, goes and the no-go doesn't (with a good push with the hand), then I can't see why that isn't enough. There could be "close" situations, where you would then want to remove ejector/extractor to get a clearer test -- but, again, with my test, if the go goes and the no go doesn't (with a good push) I can't see how headspace can be wrong.
Doing this, I've seen mostly passes -- and a couple of no-go failures. More or less what one might expect looking at many rifles.
Nothing wrong with doing it how you want but for precision accurate measurement you would remove the ejector at the least. You ideally want the parts to be under no external tension so you can feel how tight or loose the fitment is is you're going for precision fit. If it just has to be ballpark then you can cut corners to save time.
"can the resistance from the ejector give a false reading?"
Absolutely, YES! Remove the ejector!
The ejector spring can go "coil bound" if too long, giving a false reading.
Ejector springs can be very stiff, thus giving a false reading.
The ejector plunger can bind in the hole, thus giving false readings.
All the above will lead you to believe that the bolt is properly headspaced, while in reality there can be a gross amount of excessive headspace.
Upon firing the case head is stretched rearwards as the case body grips the chamber walls. Chamber pressure is somewhere around 55,000 PSI. More force is applied to the ejector that you can apply with your hands. IF any of the above conditions have affected your headspace test, they will be overcome by the massive force applied to the rearward moving case head. The resulting excessive headspace can lead to a case head separation. IF a case head separates, gas pressure can/will move around the bolt nose and into the receiver, possibly destroying the gun.
Is it really too much to ask for consistency from firearms manufacturers?
I have a .223 Wylde barrel..can I use either 5.56 or .223 gauges to check the headspace?
.223 wylde barrels can safely fire 5.56, & .223
@@Stephen-br6il Use the correct 1.4646 go gauge if using 5.56 NATO ammunition..If you are only using 223 pressured ammunition then the standard 1.4636 go gauge will work..To check the 223 throat you must have a 223 Wylde function gauge..
Id love to find out the length of the go/no-go gauges.
I have Clymer 5.56 set.
GO - 1.4636
NOGO - 1.4696
@@ddm3548 The 1.4636 is not the correct go gauge for the 5.56 NATO..1.4646 is the correct go gauge..
Is checking headspace really necessary on a brand new factory barrel?
If you're buying from a reputable manufacturer with good quality control, not really... But if you decide not to just know that you're taking a risk. A very small risk, but still a risk
What size punch or roll pin did you use to get the pins out of the bolt?
Don't use 1/16th...it goes right through the middle of the pins and jams in there, and I think by bolt is trashed b/c of it. Grrr.
What to do if the bolt turns on both go and no go guages? And also seats flush on both also?any smiths out there know how to fix this?
If it turns on the no go gauge, then you have excessive headspace.
could not find the gauges at Brownells what is the part #
513-100-241WB for GO, 513-100-240WB for NO GO. These are SAAMI spec .223 Remington gauges.
www.brownells.com/gunsmith-tools-supplies/measuring-tools/headspace-gauges/rimless-rifle-shotgun-cartridge-headspace-gauges-prod25179.aspx
@@John4566442 You need the correct 5.56 go gauge that is 1.4646, not the 223 1.4636 go gauge if using 5.56 pressured ammunition..
Hello, I have an upper that uses the Pantheon Arms Dolos kit (barrel quick change system). I use the upper between a .50 beowulf barrel and a .300 AAC Blackout barrel. I think the Blackout barrel might not be head spaced correctly since it didn't come with its own bolt and I was just using my regular 5.56 bolt with it. It's slightly crimping one side of the lip of the casings after ejection. What can I do if it is a head space issue? I have several other 5.56 bolts, should I just try the other bolts? If none of the other bolts perform better, what would a gunsmith do to fix the issue?
Under no circumstances should you ever attempt to fire a round in a firearm without checking the headspace if a headspaced bolt has not been provided with the barrel. You will need to take this to a qualified gunsmith and have it checked out.
I knew I should have gone for the barrel/bolt kit! Thanks for the reply!
So there is no way to measure this without these gauges?
that's correct. You need a headspace gauge to measure headspace. Just like to need a ruler to measure your eggplant.
What about a 223 wylde?
👍
What is the fix if it closes on the no-go gauge ??
Take it to a gunsmith.
barrel --> trash can
WOW. Damn people are stupid and spread terrible information constantly. Ignore the idiots that commented on your question and do THIS ---> "If a rifle closes on a NO-GO gage, it may still be within SAAMI specifications, or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gage. If a rifle closes on a FIELD gage, its chamber is dangerously close to, or longer than, SAAMI-specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gages are slightly shorter than the SAAMI maximum in order to give a small safety margin." - Forester. IMHO there is no need for a NO-GO gauge, get a GO and FIELD to test min/max.
@@MoragTong_ People are not stupid and are just trying to learn so lighten up slick. It is more important to use the correct go gauge of 1.4646 if the barrel is marked 5.56 and not use the 223 commercial go gauge 1.4636 as short chambers are much more of a problem than over sized chambers. The no go is a good gauge for reloaders who want to get the most life out of their brass and are seeking better accuracy..
So my .223 wylde barrel is brand new from CMC. I have checked bolt and the barrel and the barrel seems to have a bit of a spacing issue when testing it with the go gauge, it doesnt close flush. Could this be the finisher coating? I dont want to fire it if its going to explode on mez
It could possibly be a short chamber which is much more common than a long chamber. I would send it back..If you are shooting 5.56 pressured ammunition, you need to use the 1.4646 chamber go gauge and not the 223 commercial 1.4636 go gauge..
If your rifle is going to blow on shot 1 it's probably not going to happen because the case is a single thou too long 🤔
Bought a brand new AR and then went out and bought an upgraded bolt, is a headspace required?
Yes as the bolt has been changed.
@@moshedayan9253 roger that
Hope you used the correct 1.4646 NATO go gauge. Many manufacturers label the 1.4636 223 go gauge as 5.56.
so if i have changed my upper but not my bolt or barrel would i need to check head-space or should that still be the same?
You do not have to check headspace if you only changed the upper and reused the same barrel and bolt. :)
Brownells, Inc. Cool, thank you very much
You got it Cameron!
Question regarding headspace on a AeroPrecision M5 Build:
Yesterday I swapped out barrels on my M5E1 and put on a Ballistic Advantage 20" 308 Bull Barrel. I checked headspace with Forester Go & NoGo Gauges. The interesting part is when I checked the headspace with the barrel out of the upper, both gauges worked as expected indicating headspace is safe. However when I assembled the upper, I put the NoGo gauge in and the bolt closed completely on the NoGo gauge. Wondering if anyone has experienced this before. The assembled upper method with the NoGo gauge forcing the bolt to stay out of battery is what I saw on Brownell's tutorial section.
Would you guys say the rifle is safe to shoot considering headspace gauges passed the test with the barrel removed?
Thanks,
B
If you performed the test correctly with the barrel removed, and the bolt DID NOT go into the barrel extension deep enough to turn and engage the locking lugs on the NO-GO gauge, then it passed headspace. If the bolt closes COMPLETELY on a NO GO gauge, regardless whether the barrel is installed or not, it has FAILED headspace.
IF the first check was performed correctly, something has changed the distance from the locking lugs in the barrel extension (and thus the bolt face) to the shoulder in the chamber. That distance has to have gotten longer.
How could this happen? One likely reason is that the barrel extension has become unscrewed slightly. Far less likely, but could otherwise contribute to changing headspace would be that the chamber has been deepened, the locking lugs are damaged or worn, or the bolt face has been polished or machined backwards.
If you failed to remove the ejector (or extractor) when checking headspace, there is a possibility that you your initial headspace check gave you an incorrect reading. It is possible that the ejector made it appear that the NO GO wouldn't fit, but the ejector was fouling to test. In this case it would appear that the bolt doesn't close on the NO GO, while in reality the ejector or extractor are causing the bolt not to go into lockup. Later, the extra force and weight of the bolt carrier over-ride the ejector/extractor and allow the bolt to go into full lock up, because headspace was in excess of a NO GO to start with.
Well dammm got you're ANSWER.... ME TOO
No-go means you're getting sloppy but still usable headspace. However, to be sure it shouldn't be fired if it closes on a Field guage.
@@John4566442church
Question - I bought 2 complete uppers from your company. I'm curious if you check the headspace before shipping?
They don't check anything before they ship it.
first