[waldonbuddy]

I have heard this term used a lot on gun forums so I decided to check it out.

From what I gather reading online articles about how to do a head space check, is that if there is a problem with the spacing its due to the barrel. Is this correct?

In other words even if I had a head space kit there would be nothing that I could do myself to correct the problem unless I had a lathe with the special bits to bore or chamfer the chamber...........

[fguffey]

for me the chamber is not adjustable, head space is fixed, my dies and presses have threads, this make case length adfjustable, case length has an effect on head space, so I make a gage that checks head space when measured with gages I also make, after sizing a case I measure the effect the case has on head space with the same gage.



Again: I have an Eddystone M1917 that has .016 head space, I form 280 Remington cases for this rifles by controlling the lenmgth of the case from the head of the case to the shoulder.I form first then fire.



F. Guffey

[rcmodel]

Excess headspace can be caused by several things.
A too deep chamber is one.
Bolt set-back or peening in the receiver locking recesses is more common in old mil-sup rifles.

In any case, setting the barrel back a thread and re-cutting the chamber with a reamer to correct headspace again is a common way to correct the problem.

It is not something the average hobbyist is equipped to do as it involves a barrel vice & action wrench, lathe work, a chamber reamer, and headspace gages.

rc

[NCsmitty]

In other words even if I had a head space kit there would be nothing that I could do myself to correct the problem unless I had a lathe with the special bits to bore or chamfer the chamber.

That's true, but with headspace gauges, you can at least check the headspace.
In simplest terms, headspace gauges are machined to SAAMI specifications for that caliber.
On rimless bottleneck cases, you usually are measuring from a specific point in the chamber(a point on the shoulder area)to the boltface.
The Go-Gauge should fit with the bolt closed. The NO-GO is usually .006 longer than the Go-Gauge and the best case scenario is to close the bolt about 1/4 of the way without forcing the bolt. If it closes on the No-Go, then the headspace is too long and may indicate a problem.
There are some calibers, usually military, that have a Field-Gauge and that's usually .010 larger than the Go-Gauge. Some military rifles may close on a NO-GO Gauge but not on a Field-Gauge and usually are allowed to be used without incident.
Rimmed cartrides are most often based on the rim to boltface dimension.
Belted (magnum) cases are usually based on the belt to boltface dimension.

There are other factors that can affect headspace, such as bolt and bolt lug setback.
I'm tired of typing right now.


NCsmitty

[waldonbuddy]

So, lets say I buy the tools, check head space on a rifle, and find it has too little, or too much, what are my options {outside of weapons with lifetime warranty's}.

Obviously if its too much then as someone said, if the barrel threads in then if you could turn it in, or out if HS is too tight.

Can a reaming tool be used with just a drill press, or does it have to be done on a lathe?

[LongRifles, Inc.]

Head spacing questions.........
I have heard this term used a lot on gun forums so I decided to check it out.

From what I gather reading online articles about how to do a head space check, is that if there is a problem with the spacing its due to the barrel. Is this correct?

In other words even if I had a head space kit there would be nothing that I could do myself to correct the problem unless I had a lathe with the special bits to bore or chamfer the chamber...........


First question:

As mentioned, there's a small variety of things that cause headspace to change.

2nd question:

You are correct, unless a person has the ability and access to a machine shop that is tooled up to perform gun work, altering a rifle's headspace is going to be a daunting task.

Light at the end of the tunnel.

This will almost surely stir up the bee hive a bit, but it's rock solid truth. Headspace is important as if it's grossly excessive it can lead to all sorts of problems to include case heads being decapitated from cartridge case bodies. This can lead to trips to the ER with gun parts buried in people parts. Not cool.

HOWEVER if a guy is a handloader and knows what he's doing, a headspace problem can be very easily dealt with. You just back your dies off a bit so that your not resizing brass back to the standard chamber size. Essentially your almost "kinda sorta" fireforming just like you would for an Ackley improved cartridge. The only difference is your working from the web back towards the case head instead of blowing out the shoulder.

This DOES stretch the brass in the critical web/case head area but again this CAN BE dealt with if a guy is on his game. If your hand loading, simply start with virgin brass and seat your bullets long with a good bite into the lands, this will ensure the case head is butted up against the bolt face, now your fire forming just like an Ackley cartridge. Your pushing the shoulder forward to accommodate the growth in cartridge length due to the headspace being long.

Now this must be tempered with a dosage of common sense. If your the type who insists on loading 338 Lapua Magnums with H110 pistol powder in the quest for "ultimate velocity" then chances are good that your action suffers some deeply rooted fundamental problems and you shouldn't be using it for anything other than a tomato stake out in the garden. If however you have a gun that's seen a whole lot of use then it's not uncommon for the lugs to peen back a little and throw things out of tolerance. For this kind of application what I suggest is perfectly acceptable. (assuming the gun still shoots well, otherwise either sell it or send it to a guy like me to be gone through.)

The Sporting Arms Ammunition Manufacturer's Institute (SAAMI) says the difference between "GO" and "NO GO" is .006" for most high power centerfire rimless cartridges. We are talking two human hairs laid side by side. The BEST way to determine where a rifle is in this tolerance is with the use of a GO gauge and a strip of .001" thick shim stock. You pull the fire control out of the bolt and strip the ejector/extractor also. Drop the gauge into the chamber and send the bolt home. The handle should rotate into battery with the force of gravity. Once you do this cut a small square of the shim stock that is small enough to fit inside the face of the bolt. Use a dab of grease to hold it there. Now close the bolt again. Repeat until the bolt doesn't want to close. You now have an actual dimension to reference to. This is a process I began using over ten years ago and it's worked on everything from world championship winning 1000 yard target rifles to heavy magnum sniper rifles currently in the middle east. The term to go with this process is "GO plus whatever the shim stock adds up to." this is a great tool because if a guy does this check on DAY ONE of owning a new gun he/she can track any changes due to wear or a "whoops" from stuffing H110 powder in a 338 Lapua. (No, I've not done this, it's just an example) If for example your new 300 Rem Ultra is at GO+.003" on day one and two years and a 1000 rounds later its at GO+.007" then you know that over the course of that 1000 rounds your gun peened in .004". Adjust your dies accordingly and continue to march-although your barrel is probably close to being shot out by that time as the 300RUM is not a forgiving cartridge to barrel throats.

Hope this helped and didn't confuse too much.

Cheers,

Chad


Chad Dixon
Gunmaker
LongRifles, Inc.

[waldonbuddy]

Not confusing at all, good reply. Thanks to all who replied.

[dmazur]

Obviously if its too much then as someone said, if the barrel threads in then if you could turn it in, or out if HS is too tight.

I believe the shoulder of the barrel has to contact the receiver, so the shoulder can turned down for rifles with excessive headspace. This is usually far too little headspace, so the chamber is then reamed to the correct headspace.

For rifles with insufficient headspace, careful reaming can restore proper headspace. However, you can't unscrew the barrel or you lose shoulder contact.

Now Savage's are a whole 'nuther story, with their clever adjustable barrel nut. :)

[scratcherky]

You can easily adjust headspace on Stevens and Savage centerfire rifles.