I may have to give it a try. I might have a one hole rifle!Guys, my sole passion is group shooting at long range. This is why 1k benchrest has been the hobby that has "stuck". I LOVE testing this stuff more than the actual match shooting, it is what is fun for me. TRUST me, this has been tested every which way... If you can dream it up, I've tested it. I've put about 40,000 rounds on paper at 1k since 2008, and attempt to learn from each one. Here's where I'm at on the subject...
I would give up an organ if I knew it would make me shoot smaller. I full length size because it shoots smaller.
I've never worn out the brass for a barrel before the barrel was toast.
Tom
Brass Separation Above Belt
- Thread starter curtiscd
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J E Custom
Well-Known Member
I don't know what to say about checking head space this way. First a rimed case does not headspace on anything but the rim and measuring the case fired or not Is asking for trouble.
There is only one proper way to set or check head space, And that is with a HEAD SPACE GAUGE. It is based on the SAMME dimensions for that cartridge and does not re bound or spring back like brass does. Anyone that headspaces using the brass is not a gunsmith and should not be allowed to touch anyone's rifle except his own.
It is always best to buy the head space gauge from the same reamer manufacture so they match. the reamer does not set the head space, the head space gauge does, Different Gun Smiths will head space differently within a few thousandths depending on the rifles purpose and if it will be reloaded for or factory ammo is to be used.
A ridged gauge is the only way to measure head space and I recommend that the ejector be removed before head spacing to prevent false readings.
A Go Gauge will work for both setting head space and checking head space by placing shims between the bolt face and the go gauge until the locking lugs show a slight resistance. Then measure the thickness of the shims and that will tell you the amount of head space you have.
(How much more than the minimum for this cartridge) it should not be more than .006 or it may fail.
If the weapon is very old and used, a No go gauge will tell you if it has to much head space. No go gauges are normally .006 to .008 thousandths longer than the SAMME specification and/or the Go Gauge.
Most "Gunsmiths" will head space from .0005 to .004 max depending on the intended use for an all round head space, most will set head space at .002 to .003. But, after it is fired once, the amount of head space for some types of cases are dependent on the Reloader and the setting of his dies. Rimed cases retain the head space originally set by the smith.
On a rimed case the length of the case has nothing to do with head space. Primers are not reliable ways of checking head space for many reason one being Primer pockets vary in depth and so do primers so The back of the case head is the starting point no matter what type of cartage case is used the only other point from the back of the case head is the front of the case head on a rimed case, the front of the belt on a belted case, and the Datum line of the shouldered case with no belt . the only exception is rimless cases that use the case mouth trim length to head space on (like the 45 ACP and other rimless cases) this still requires a Go gauge to do properly.
If a go gauge is used properly for head spacing, the first firing should not cause/create case head separation. If it was head spaced incorrectly, It can/may cause case head separation on the first firing.
Correct head space will not prevent separation if the case is oversized many times and served with high pressures it is not uncommon to see.
I cant stress the importance of proper head space enough. please do not use anything but the proper head space gauge for safety and function.
J E CUSTOM
There is only one proper way to set or check head space, And that is with a HEAD SPACE GAUGE. It is based on the SAMME dimensions for that cartridge and does not re bound or spring back like brass does. Anyone that headspaces using the brass is not a gunsmith and should not be allowed to touch anyone's rifle except his own.
It is always best to buy the head space gauge from the same reamer manufacture so they match. the reamer does not set the head space, the head space gauge does, Different Gun Smiths will head space differently within a few thousandths depending on the rifles purpose and if it will be reloaded for or factory ammo is to be used.
A ridged gauge is the only way to measure head space and I recommend that the ejector be removed before head spacing to prevent false readings.
A Go Gauge will work for both setting head space and checking head space by placing shims between the bolt face and the go gauge until the locking lugs show a slight resistance. Then measure the thickness of the shims and that will tell you the amount of head space you have.
(How much more than the minimum for this cartridge) it should not be more than .006 or it may fail.
If the weapon is very old and used, a No go gauge will tell you if it has to much head space. No go gauges are normally .006 to .008 thousandths longer than the SAMME specification and/or the Go Gauge.
Most "Gunsmiths" will head space from .0005 to .004 max depending on the intended use for an all round head space, most will set head space at .002 to .003. But, after it is fired once, the amount of head space for some types of cases are dependent on the Reloader and the setting of his dies. Rimed cases retain the head space originally set by the smith.
On a rimed case the length of the case has nothing to do with head space. Primers are not reliable ways of checking head space for many reason one being Primer pockets vary in depth and so do primers so The back of the case head is the starting point no matter what type of cartage case is used the only other point from the back of the case head is the front of the case head on a rimed case, the front of the belt on a belted case, and the Datum line of the shouldered case with no belt . the only exception is rimless cases that use the case mouth trim length to head space on (like the 45 ACP and other rimless cases) this still requires a Go gauge to do properly.
If a go gauge is used properly for head spacing, the first firing should not cause/create case head separation. If it was head spaced incorrectly, It can/may cause case head separation on the first firing.
Correct head space will not prevent separation if the case is oversized many times and served with high pressures it is not uncommon to see.
I cant stress the importance of proper head space enough. please do not use anything but the proper head space gauge for safety and function.
J E CUSTOM
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LoneTraveler
Well-Known Member
A question curtiscd. What type of action does the problem rifle have??? If the action happens to be a Shultz and Larsen, ITS THE NATURE OF THE BEAST. The S&L action has its locking lugs in the back of the action, and on the back of the bolt. Under firing pressure the action stretched and the bolt sort of compressed ever so little but enough. At about 3 reloads the 7mm Sharp and Hart cartridge I have dealt with would separate. This happened with a friends rifle years ago, He actually had a broken case extractor he carried when at range or hunting just to be safe.
H&H style belted cases are head spaced on the belt.
SAAMI specs. call for headspace of .220 to .227 on the belt itself. It sounds like the chamber in front of the belt may be out of specs., Measure a fired case against a new case and SAAMI specs. A chamber cast may need to be made and measures taken to find the problem. If a new case or new factory shell is changing length on firing, The chamber may be the problem. Good Luck on finding the problem and getting it cured, Be Safe.
H&H style belted cases are head spaced on the belt.
SAAMI specs. call for headspace of .220 to .227 on the belt itself. It sounds like the chamber in front of the belt may be out of specs., Measure a fired case against a new case and SAAMI specs. A chamber cast may need to be made and measures taken to find the problem. If a new case or new factory shell is changing length on firing, The chamber may be the problem. Good Luck on finding the problem and getting it cured, Be Safe.
bigedp51
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I have headspace gauges for most of the rifles I own and what I described was a way to check headspace or head clearance for anyone without headspace gauges. And excessive head clearance is what causes case head seperations.
The only difference between a rimmed, belted or a case that headspaces on it shoulder is the distance from the bolt face to the reference datum headspace point.
And the gunsmith who rebarreled the rifle in this posting screwed up and this rifle with brand new cases was having case head separations. And if the owner of this problem rifle in this posting had used the primer method he would have known he had a headspace problem and excessive head clearance.
I collected the British .303 Enfield rifle and it had removable bolt heads to adjust headspace. And the primer method was a very good method to check the rifles headspace without actual headspace gauges. And when you added your primer measurement to your rim thickness you had your rifles actual headspace
All a headspace gauge will tell you is if the bolt will close or not and you would need headspace gauges in .001 increments to know your approximate headspace within .001 of actual headspace. And you want to tell people that a headspace gauge is more accurate than the primer method.
Below a set of .308 headspace gauges in .001 increments.
The rifle in this posting was not within normal headspace limits and had excessive head clearance. And this excessive head clearance is what caused the cases to stretch and separate.
And it doesn't matter how the rifle headspaces or where the datum point is, it is the head clearance that causes case head separations.
And the reloading dies for a belted cases push the case shoulder back too far when its better to let the belted case headspace on its shoulder.
Headspace is also the distance between your ears and how you use use this space.
The only difference between a rimmed, belted or a case that headspaces on it shoulder is the distance from the bolt face to the reference datum headspace point.
And the gunsmith who rebarreled the rifle in this posting screwed up and this rifle with brand new cases was having case head separations. And if the owner of this problem rifle in this posting had used the primer method he would have known he had a headspace problem and excessive head clearance.
I collected the British .303 Enfield rifle and it had removable bolt heads to adjust headspace. And the primer method was a very good method to check the rifles headspace without actual headspace gauges. And when you added your primer measurement to your rim thickness you had your rifles actual headspace
All a headspace gauge will tell you is if the bolt will close or not and you would need headspace gauges in .001 increments to know your approximate headspace within .001 of actual headspace. And you want to tell people that a headspace gauge is more accurate than the primer method.
Below a set of .308 headspace gauges in .001 increments.
The rifle in this posting was not within normal headspace limits and had excessive head clearance. And this excessive head clearance is what caused the cases to stretch and separate.
And it doesn't matter how the rifle headspaces or where the datum point is, it is the head clearance that causes case head separations.
And the reloading dies for a belted cases push the case shoulder back too far when its better to let the belted case headspace on its shoulder.
Headspace is also the distance between your ears and how you use use this space.
Unless there is something I don't know, on a belted case, the reamer "is" what determines the length from the front of the belt to the shoulder. The Gunsmith determines headspace by how far he pushes the reamer into the barrel but he can't control both measurements on a belted case. If he sets the distance from the bolt face to the front of the belt with the gauge, the distance from the front of the belt to the shoulder is determined by the reamer.
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J E Custom
Well-Known Member
I have headspace gauges for most of the rifles I own and what I described was a way to check headspace or head clearance for anyone without headspace gauges. And excessive head clearance is what causes case head seperations.
The only difference between a rimmed, belted or a case that headspaces on it shoulder is the distance from the bolt face to the reference datum headspace point.
And the gunsmith who rebarreled the rifle in this posting screwed up and this rifle with brand new cases was having case head separations. And if the owner of this problem rifle in this posting had used the primer method he would have known he had a headspace problem and excessive head clearance.
I collected the British .303 Enfield rifle and it had removable bolt heads to adjust headspace. And the primer method was a very good method to check the rifles headspace without actual headspace gauges. And when you added your primer measurement to your rim thickness you had your rifles actual headspace
All a headspace gauge will tell you is if the bolt will close or not and you would need headspace gauges in .001 increments to know your approximate headspace within .001 of actual headspace. And you want to tell people that a headspace gauge is more accurate than the primer method.
Below a set of .308 headspace gauges in .001 increments.
The rifle in this posting was not within normal headspace limits and had excessive head clearance. And this excessive head clearance is what caused the cases to stretch and separate.
And it doesn't matter how the rifle headspaces or where the datum point is, it is the head clearance that causes case head separations.
And the reloading dies for a belted cases push the case shoulder back too far when its better to let the belted case headspace on its shoulder.
Headspace is also the distance between your ears and how you use use this space.
Thanks for the great pictures, It should help those that don't understand how and where head space is measured.
It also totally agrees with my description, Except for some snide comments at the end.
The only part I don't agree with is that a head space does/cant tell you exactly what the head space actually Is. Measuring with anything else
is not as consistent reading to reading and I personally think we should not tell new members to take short cuts when checking head space.
It is ok for a good gunsmith to use some other method just to se if there may be a problem, but he will still use the proper gauges for final proof as to what the actual head space is, Not close.
Just my opinion
J E CUSTOM
Scooterbum
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- Jan 23, 2016
- Messages
- 89
Nice diagram. However,...
the base can't display that much lateral if you have tight clearance at the web, like what might be desired.
If u have a very loose web, that moves into willis territory during launch, how much does hs increase, prior to setback?
Scooterbum
Well-Known Member
- Joined
- Jan 23, 2016
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- 89
This is true. If your case fits the chamber tightly at the back, it does much more for alignment with the bore than the freebore.
Most of this discussion ih about reloading. You can headspace on both when loading a fired case. The length to the front of the belt stays at whatever the Gunsmith set it at. The reloader determines the distance to the shoulder. If your Gunsmith did a good job and you do a good job, it is headspaced correctly at both places.
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Scooterbum
Well-Known Member
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- Messages
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U didn't mention case dimensions, which can b all over the map. At prime strike, one or the other will determine hs.
Alex Wheeler
Well-Known Member
Guys, my sole passion is group shooting at long range. This is why 1k benchrest has been the hobby that has "stuck". I LOVE testing this stuff more than the actual match shooting, it is what is fun for me. TRUST me, this has been tested every which way... If you can dream it up, I've tested it
I would give up an organ if I knew it would make me shoot smaller. I full length size because it shoots smaller.
I've never worn out the brass for a barrel before the barrel was toast.
Tom
This is NO place for testing, proof, or facts sir! Take those 40k rounds, records, match wins, years of proving it, ext. and stick it. We dont want to hear it! LOL
bigedp51
Well-Known Member
- Joined
- Dec 10, 2010
- Messages
- 1,022
Out of all the headspace gauges I have there is only .003 between the GO and NO-GO gauge. And this is for setting up new or re-barreled rifles and the SAAMI cartridge and chamber diagrams show .010 between minimum and maximum headspace.
And when people collect 30 or more older type milsurp rifles they need a simple and less costly method of checking headspace. Military headspace on a Enfield rifle is .064 minimum and .074 maximum. And SAAMI headspace is .064 GO and .067 NO-GO for initial headspace setup.
Below my .303 British Headspace gauges, with SAAMI and military gauges. So do not tell me there is something wrong with using the primer method to check headspace/head clearance.
And even if these older rifles exceed maximum headspace if the cases are fire formed to the chamber they can be safely fired with reasonable loads.
And this posting is about a rifle that a so called gunsmith screwed up re-barreling and gave it back to the owner grossly out of headspace limits. And again if this person had used the primer method I described he would have seen how much head clearance the rifle had.
Below using the primer method on a Enfield rifle grossly out of headspace limits. And the amount the primer is protruding is the amount of head clearance this rifle had. And the amount of head clearance should be equal to the amount of shoulder bump. Meaning on a bolt action rifle .001 to .002 to insure the case does not stretch beyond its elastic limits.
So again headspace is also the distance between your ears and how you use this space.
And when people collect 30 or more older type milsurp rifles they need a simple and less costly method of checking headspace. Military headspace on a Enfield rifle is .064 minimum and .074 maximum. And SAAMI headspace is .064 GO and .067 NO-GO for initial headspace setup.
Below my .303 British Headspace gauges, with SAAMI and military gauges. So do not tell me there is something wrong with using the primer method to check headspace/head clearance.
And even if these older rifles exceed maximum headspace if the cases are fire formed to the chamber they can be safely fired with reasonable loads.
And this posting is about a rifle that a so called gunsmith screwed up re-barreling and gave it back to the owner grossly out of headspace limits. And again if this person had used the primer method I described he would have seen how much head clearance the rifle had.
Below using the primer method on a Enfield rifle grossly out of headspace limits. And the amount the primer is protruding is the amount of head clearance this rifle had. And the amount of head clearance should be equal to the amount of shoulder bump. Meaning on a bolt action rifle .001 to .002 to insure the case does not stretch beyond its elastic limits.
So again headspace is also the distance between your ears and how you use this space.
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