Head Space
- Thread starter 270BBR
- Start date
No.
You would not be measuring headspace, you would be measuring the head clearance of that particular case.
Headspace is a fixed figure when the barrel is assembled to that action. It is measured with steel gauges.
Any measurements with brass cases are measurements of cartridge head clearance.
You would not be measuring headspace, you would be measuring the head clearance of that particular case.
Headspace is a fixed figure when the barrel is assembled to that action. It is measured with steel gauges.
Any measurements with brass cases are measurements of cartridge head clearance.
Even if the case you were using was exactly head space length, the brass case is so soft it will make feeling the resistance to bolt closing very difficult. Head space gauges are made of hardened steel.
You can check the fit of that brass case to your rifle in this manner. If you measure the thickness of the tape you can get a good numerical estimate of the clearance involved. It should not be more that 2-3 thous.
It is important to take out the firing pin spring to get a feel for the fit. The ejector spring also causes a drag that could mask the feel of the fit a bit. The bolt should not flop down with no pressure (cartridge too short), nor should it be extremely tight (cartridge too long). You should feel the bolt close smoothly. Vary the thickness/type of tape to get an estimate of clearance. If reloading, adjust you sizing die to give a nice smooth closing of the bolt on a re-sized case.
NormB
I've seen that tape trick done before on one of those youtube gunsmithing videos. The guy reamed the chamber until the bolt would just close on the gauge, then put a thin piece of sticky tape onto the end of the gauge to show that if done correctly, the bolt should not be able to close.
That would be using a steel go gauge... and perfectly acceptable... not using a case as asked - "I have been told that an easy way to check head space is put a piece of masking tape on the rim of a new case and see if the bolt will close, is this true? "
I totally agree with Guntech. Elastic material does not tell anything, not even gives you an idea of headspace, as you have no idea how much pressure the tape will take to crush and how much it will back after being compressed.
Feeler gauges and other metal sheeting gauges are made of hard steel and won't compress (not under the pressure you may put by hand) and won't spring back for the same reason.
Headspace is a safety tolerance, not a funny thing we can play with.
Feeler gauges and other metal sheeting gauges are made of hard steel and won't compress (not under the pressure you may put by hand) and won't spring back for the same reason.
Headspace is a safety tolerance, not a funny thing we can play with.
Last edited:
It isn't as much that an elastic material could not be used as a headspace gauge.. it could be if it was made to an exact dimension as a steel gauge is made... it is because cases are made quite inaccurately.
My point is a steel head space gauge is made to an exact dimension and a factory cartridge case is not... it is made to large plus or minus specifications so it will fit in any saami chamber... from minimum chambers on up to large chambers...
I am also trying to make a point that head space is not adjustable - it is a fixed measurement when the gunsmith assembles the firearm.
People talk about hand loading to correct headspace when in reality they are adjusting the cartridge head clearance on a reloaded round... the headspace of the rifle is unchanged.
You can make a case to fit a chamber very closely - and if you do the cartridge head clearance measurement would be very close to the head space measurement of the rifle.
My point is a steel head space gauge is made to an exact dimension and a factory cartridge case is not... it is made to large plus or minus specifications so it will fit in any saami chamber... from minimum chambers on up to large chambers...
I am also trying to make a point that head space is not adjustable - it is a fixed measurement when the gunsmith assembles the firearm.
People talk about hand loading to correct headspace when in reality they are adjusting the cartridge head clearance on a reloaded round... the headspace of the rifle is unchanged.
You can make a case to fit a chamber very closely - and if you do the cartridge head clearance measurement would be very close to the head space measurement of the rifle.
