I'm a little confused about head spacing when I change ammo mfgs. If I go from LC 72 to CMP Greek do I have to rehead space? I've had the 1919 apart several times and reset the head space at 2 clicks and it runs fine on the LC. Haven't shoot the Greek yet.
Head spacing question
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re:headspacing
From what i have learned so far, yes, different surplus ammo,need to reheadspace as the tolerances really vary. I pull three bullets in a collet press,fire the primer, and then, reseat and crimp to the same length of all the others. These stay in a box, and are used as headspace rounds. It seems safer to me than using live rounds! Greek is good ammo from my experience in the past, but I have never fired any out of a 1919 yet. I am currently using British surplus,it's okay.
From what i have learned so far, yes, different surplus ammo,need to reheadspace as the tolerances really vary. I pull three bullets in a collet press,fire the primer, and then, reseat and crimp to the same length of all the others. These stay in a box, and are used as headspace rounds. It seems safer to me than using live rounds! Greek is good ammo from my experience in the past, but I have never fired any out of a 1919 yet. I am currently using British surplus,it's okay.
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8,751 Posts
The key is to bear in mind that, since ammo can vary, you want to check the headspace anytime you change ammo. It is a good thing to check it every time you go shooting, even if you don't think anything has moved. As to LC 72 vs the CMP Greek, they might very well use the same setting. But the way to determine that is to set the headspace when switching. I find with 30-06 that two clicks out- from the first position that allows the action to go into full battery, as per the field method- works just dandy with everything so far, including some reloads I got from a friend. But that's my particular experience. That is always a good starting point, then watch the function of the gun and examine the brass for the first few rounds. I don't shoot the volume that some on this board do, but I have never suffered a kaboom yet!
Ditto on checking headspace every time you shoot. In the military it was SOP. It's a good thing to do this at the range if possible. Then you know that no one has screwed with it or it didn't get out of adjustment while cleaning or disassembling. You can make the task easier by getting a headspace gage but as was stated different ammo may cause variations.
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801 Posts
its generally a good idea to reset the HS especially with surplus ammo from varying countries, even if its just for peace of mind. Make it easy on yourself, if you have an izzy gun - grind the barrel retainer (i forget what its really called at 3am) down to a point that it matches the usgi ones and get a jjcustom HS wrench - then HS'ing only takes a quick minute and you wont dread doing it. hell, on one of my guns it was necessary to grind the barrel spring, as the izzy tang didnt have enough room from the LSP to disengage the barrel notches - after grinding them to usgi style i cant imagine going back.
what was i talking about? damn them sam adams will sneak up on ya
GR OUT!
what was i talking about? damn them sam adams will sneak up on ya
GR OUT!
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5,337 Posts
Double trippe safety check
I use different head spacing for LC USGI and my handloads. The handloads are one click tighter than the GI. I also have prick punched the top of the barrel ext and a punch next to each barrel notch so I can visually confirm that nothing has been moved. When I get some Greek I will reheadspace.
"Send "Want2race" a member here a email or PM, As he made a video showing how too head space without a gauge. Do to a forum crash last month we are unable to get it from the forum directly."
I remove the firing pin from the bolt and headspace it with the bolt, barrel and barrel extention removed from the gun and use the actual ammo you are using. You will be right on with this method everytime. I read it in a military booklet years ago and the video is only a slight variation of that.
I remove the firing pin from the bolt and headspace it with the bolt, barrel and barrel extention removed from the gun and use the actual ammo you are using. You will be right on with this method everytime. I read it in a military booklet years ago and the video is only a slight variation of that.
Everytime I open this board there is a question about headspacing. It is amazing.
Here's what works for me. Throw the headspacing gauges away. Screw the barrel into the extention until the gun will not close into battery. Screw it out one click at a time till it goes all the way into battery. Then screw it out an additional two clicks. Bingo! Now, when you go to the range with your new ammo chamber a round. Does the gun still go all the way into battery? If it does open the top cover and look for any gap between the bolt face and the end of the barrel. if there is more than a couple thousandths. Dont use that ammo. It surfices to say that bad timing is more likely to destroy your gun than a headspacing error. This is where the gages come in. If the firing pin will fall with the thicker of the two gauges in place do not fire the gun till this issue is corrected. Never, ever.
Here's what works for me. Throw the headspacing gauges away. Screw the barrel into the extention until the gun will not close into battery. Screw it out one click at a time till it goes all the way into battery. Then screw it out an additional two clicks. Bingo! Now, when you go to the range with your new ammo chamber a round. Does the gun still go all the way into battery? If it does open the top cover and look for any gap between the bolt face and the end of the barrel. if there is more than a couple thousandths. Dont use that ammo. It surfices to say that bad timing is more likely to destroy your gun than a headspacing error. This is where the gages come in. If the firing pin will fall with the thicker of the two gauges in place do not fire the gun till this issue is corrected. Never, ever.
B.A.R. gunner
Master Gunner Join Date: May 2006
Posts: 322
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make a reference mark on your barrel and barrel extension with a dot of white out at the point where you think headspace is correct.
Next
pull the guts out of the gun
remove the firing pin - very important
open the barrel 3 clicks from your witness marks
slide a live round down the t slot of your bolt and move the bolt forward in the barrel extension until the round is seated in the chamber
flip the assembly upside down with the bolt facing the floor and slide the breach lock down locking the bolt to the barrel extension
slowly screw the barrel in one click at a time until it comes to rest against the ammo removing all slop - at this point the chamber is pressing against the ammo, the ammo is pressing against the bolt face, and the bolt face is touching the breach lock and there is no slop in the assembly. this is the point of perfect headspace for that brand type ammo if all of the ammo in your lot is exactly the same
you would probably want to open it up 1 click from that point to allow reliable feeding, but flip it over and compare it to your witness marks you made with the white out - is it close?
I cut and pasted this from BAR because he described how I do mine and I know we've fired hundreds of thousands of rounds in my little shooting group and we do it this way.
Master Gunner Join Date: May 2006
Posts: 322
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make a reference mark on your barrel and barrel extension with a dot of white out at the point where you think headspace is correct.
Next
pull the guts out of the gun
remove the firing pin - very important
open the barrel 3 clicks from your witness marks
slide a live round down the t slot of your bolt and move the bolt forward in the barrel extension until the round is seated in the chamber
flip the assembly upside down with the bolt facing the floor and slide the breach lock down locking the bolt to the barrel extension
slowly screw the barrel in one click at a time until it comes to rest against the ammo removing all slop - at this point the chamber is pressing against the ammo, the ammo is pressing against the bolt face, and the bolt face is touching the breach lock and there is no slop in the assembly. this is the point of perfect headspace for that brand type ammo if all of the ammo in your lot is exactly the same
you would probably want to open it up 1 click from that point to allow reliable feeding, but flip it over and compare it to your witness marks you made with the white out - is it close?
I cut and pasted this from BAR because he described how I do mine and I know we've fired hundreds of thousands of rounds in my little shooting group and we do it this way.
A case length gage can change your life. Really, I shot for years without a gage worrying about this ammo or that ammo. Resizing dies and different ammo manufacturers can leave you scatching your head. A case length gage will take a lot of the guesswork out of the picture. A lot of help for so little money.
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2,700 Posts
Now after reading all this, I gotta ask... how many of these guns are full-auto?
I'm not trying to be a snob. I truly believe there is some sort of difference between the semis and the full-auto guns in the trigger mechanisms, because I don't do any of the things you guys are calling Gospel here, and I've been blowing through cases and cases of ANY brand 8mm, 308, 30-06, etc and I'm not having any of the problems reported here.
I'm not trying to be a snob. I truly believe there is some sort of difference between the semis and the full-auto guns in the trigger mechanisms, because I don't do any of the things you guys are calling Gospel here, and I've been blowing through cases and cases of ANY brand 8mm, 308, 30-06, etc and I'm not having any of the problems reported here.
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479 Posts
Not yet !!! , I think this is the key word. ( If you always do what you always did, you always get what you always got. ) doesn't apply here. I just hope that day never comes for you. Good luck
Shattered;
I agree. I haven't been running my A4 as long as you have, but have dumped many cases of ammo downrange since buying it with no troubles that weren't ammo-derived. I presume it was timed by Dougie when he built it and I haven't timed it since. I headspace whenever I install a new barrel, but once it's confirmed as being right and marked with a prick punch- that's it. It doesn't get re-headspaced until the rifling is gone and it becomes a tomato stake.
Some of these guys act like the Browning is made out of crystal and it'll shatter if you look at it wrong. With the possible exception of the Degtyarev series of MGs, I can't think of a more rugged and robust gun.
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I think if you buy Nato spec ammo(quality control and manufacturing tolerance are tight) you will not have problems with headspacing(using the guage procedure). But by using the different types of surplus ammo even in different calibers you are asking for problems. I've had 7.62X39 from different sources where the bolt closes consistently on one type of ammo but another type of ammo a huge proportion of it will not allow the bolt to close. I've fired over a thousand rounds of 7.62X54R of Russsian ammo and the use a different headstamp of the Russian ammo and I experience case separation issues. 8mm same issues, where even the chamber of the barrel had to be slightly reamed(using Yugo ammo). I have used the method of headspacing by taking the barrel, bolt(removing the firing pin) and barrel extention out of the gun for years. The technique of using the guage makes an assumption that your ammo was manufactured to close tolerances(ie. nato spec). The other way takes your actual ammo and "custom" headspaces the gun to it. I've been not mixing different types of ammo for years and I've not used the guage technique ever and it works perfectly. I read(can't remember where) the heaspacing way in a military manual years ago and it has served me well.
I think if you buy Nato spec ammo(quality control and manufacturing tolerance are tight) you will not have problems with headspacing(using the guage procedure). But by using the different types of surplus ammo even in different calibers you are asking for problems. I've had 7.62X39 from different sources where the bolt closes consistently on one type of ammo but another type of ammo a huge proportion of it will not allow the bolt to close. I've fired over a thousand rounds of 7.62X54R of Russsian ammo and the use a different headstamp of the Russian ammo and I experience case separation issues. 8mm same issues, where even the chamber of the barrel had to be slightly reamed(using Yugo ammo). I have used the method of headspacing by taking the barrel, bolt(removing the firing pin) and barrel extention out of the gun for years. The technique of using the guage makes an assumption that your ammo was manufactured to close tolerances(ie. nato spec). The other way takes your actual ammo and "custom" headspaces the gun to it. I've been not mixing different types of ammo for years and I've not used the guage technique ever and it works perfectly. I read(can't remember where) the heaspacing way in a military manual years ago and it has served me well.
Shattered, there is a difference between the f/a and semi guns. In a f/a only when the first round;in a string; is fired are the recoil groups actually fully forward. In f/a the gun actually fires about 1/16th of an inch before recoil groups are fully forward. (At the instant of firing, the parts are in battery , but not fully forward. ) A semi fires fully forward every time. This is why timing is critical on a f/a and not on a semi. On a 1919 the timing is achieved by bending the trigger bar. It should be checked for safety reasons. As an example remove the breech lock completly from the gun and go shoot it. NO, DON'T REALLY DO THIS, JUST THINK ABOUT IT. HTH
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