The rear goes back to the bolt face. In the middle, brass gets stretched. Now, in the microsecond in which this happens, it can proceed in several different ways, but the end result is the same: the case gets stretched in the middle, weakening it. This matters only to reloaders. The effective service life of your brass depends on how much stretching, and how much bumping you subject it to.
If your headspace headspace is within accepted limits, you can get 10 or more loadings out of your brass before you start seeing neck cracks from work-hardening. If the headspace is excessive, you may only get two or three. An example of this is the SMLE in. The British Army cared not a whit about reloadability, only for reliability.
I gave up reloading ammo for my various SMLEs because I could not get cases to last more than three loadings in any of them. The U. As long as the brass holds together and is ejected in a single piece, they are happy.
And that is where the Field gauge comes into play. The Field gauge has been developed with one thing in mind — how large can the chamber be and still have a rifle that can be used in a wartime situation? And that is why military armorers have a Field gauge that they use commonly, rarely reaching for their Go and No-Go gauges.
An armorer may have a rack filled with rifles and carbines that would easily gobble up a No-Go gauge. Use of the Field gauge only applied to used rifles and carbines. If a brand new, fresh out of the box unfired rifle is tested, and the bolt partially closes or locks on a Field gauge, it should be sent back, even in military use. Why then is a Field gauge not a good choice for you?
You will likely be using reloaded ammo. You have an interest in making that brass last as long as possible. What of the others? The cognoscenti argue over the commercial. I talked to Dave Manson, a maker of headspace gauges about this. How much can these vary? So, if you have a rifle chamber just over the max size, call it 1. Unload your rifle and separate the upper from the lower. Use the chamber brush to scrub the chamber.
Clean the bore with a patch to extricate any crud you scoured out of the chamber. Remove the extractor from the bolt. Use the bolt fixture to remove the ejector. Scrub the bolt and dry it. The closing bolt has enough mass and leverage to close the bolt on even a No-Go gauge if you are forceful enough or let it crash forward under full spring force. That is the wrong way to be doing it.
The right way is as follows. If you have the barrel out of the receiver, life is easy. Drop the Go gauge into the chamber. Hold the bolt by the tail, and see if you can insert it into the barrel extension, rotating it in front of the locking lugs. You should be able to do this. Which is at fault? There is no way of telling with the tools at hand.
To find out, you need at a bare minimum a surface plate, standing calipers and a bolt face cylinder. The cylinder is simply smaller in diameter than the bolt face opening, and a known thickness.
Put the cylinder on the surface plate. Stand the bolt on the cylinder, and measure the distance from the surface plate which is flat to a millionth of an inch, if you bought the good one and then consult the bolt drawing to see what that measurement should be.
If the bolt and chamber accepted the Go gauge, then remove the bolt and gauge, and replace the Go with the No-Go. Try again. The bolt should not, must not, rotate to the closed position. A quick answer, in both instances is, both of them. What if you have the barrel already installed in an upper receiver? Go to the store and buy yourself a foot of PVC tubing.
You want a piece that has a quarter-inch inside diameter, or ID. The first thing to do, if you have the gear and parts, is check the headspace on a rifle that has worked.
Vote count: No votes so far! Your rating will help us continue to provide valuable and interesting content. Follow us on social for first dibs on brand new content! Started with some handloads at the minimum load spec, and noticed the primer was beyond flat flowing actually , the case head was showing imprint from the bolt face, and to boot, the case separated.
Re-visiting, making sure I did not make any errors with the charge weight or powder used, I shot again, and the case showed the same symptoms, with a crack where the case started to separate. If you want to be among the first to know when we release new content, your best bet is to sign up via email:. Email address:. View this post on Instagram. Did you find this article useful? Let the author know with a 5 star rating! Since you found this post useful We are sorry that this post was not useful for you!
Let us improve this post! Tell us how we can improve this post? Submit Feedback. Issues with feed ramps can be more common than many builders…. All you need is to have gauges to measure the headspace. Although they are a bit pricey, you should try and get your hands on any of the suitable options. The risks involved are just too great, especially if you are not a seasoned rifleman.
But make sure that the metal part of the gun is taken through proper metal maintenance chores. We may get commissions for purchases made through links in this post. Table Of Contents. Author Recent Posts. Richard Allen. By profession, I've been a Cytogenetic Technologist for about 24 years of my career.
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