Do I really need a headspace gauge?

Thats what ive done with several mausers. I prefer cutting pieces of feeler gauges and putting that under the case head. .006 is your “no-go”. Yes, try a few different factory brands.

A. When I bought a replacement bolt on eBay, for my Remington 03-A3 that had a junk bolt, I found a site online that rented headspace gauges. Sorry, I didn't save a link. Try that route.

B. It depends. If you shoot factory ammo, too much headspace can be an issue. Too little may mean the ammo won't chamber. If you reload you can adjust your dies to accommodate almost any discrepancy.

Most all new ammo/brass is a little under size so it will fit most any chamber. I have head space gauges for most all the barrels I fit.

I've seen bolts for AR-15 vary 0.002-0.003" between mfg. So depending on where your at in the chamber it may or may not work.

I would check the chamber. Other wise you will not know if it's in spec or not.

Bayourambler said:

Is there something wrong with using a brand new case for a gauge.

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2 thing may happen?

1. Factory ammo may not chamber.
2. The fl die may not push the shoulder back far enough on fired brass, for it to chamber.

Bayourambler said:

Is there something wrong with using a brand new case for a gauge.

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Yes. You are assuming that the new brass is correctly sized, when it may not be.

Col. Harrumph said:

I found a site online that rented headspace gauges. Sorry, I didn't save a link.

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https://www.reamerrentals.com/ProductDetails.asp?ProductCode=6.5Crd.g

Case will give you a ball park. But Bill makes a good point.

For my AR builds, I use a field gauge only. But for my bolt guns, I use a go and .002”-.003” feeler gauge spacer.

I would rent the gauge's . I have to admit I have used shimming cases to determine headspace, but that was simply to see how it compared. I happen to be dead on. I don't have the proper tooling to do rifle barreling. I know how, but never did any. I have re-barreled revolvers, but that's something different.

I wouldn’t use just an empty case, would prefer a loaded round.

Same reason I don’t just start loading new brass and run them through the same reloading process as once fired cases after they are clean.

Dissemble the bolt and drop half way method is generally how I set my sizers for sizing to a particular rifle as brass lasts the longest if moved the least.



If you have more than one rifle in the caliber I would use a round loaded for it and the above method.

As someone who did it for a paying hobby, (well, for a living in the Army also) I use the proper set of headspace gauges. They are available for rent, as mentioned; I have borrowed them from local gunsmiths, especially the one I used to work for.

The ONLY way that I would not use gauges is if I were sizing and loading for a specific gun where the brass was sized differently from print specs and would only be used in that specific gun. Then you are left with the question of what happens when your gun gets passed on the the next fellow. Will the loading info go with it? Will he be knowledgeable enough to understand that he essentially has a wildcat for which he MUST load non standard ammo? Will the gun be marked as such or left for someone to guess?

Ya go with head space gauges, you can get by with only the go gauge, just go slowly.

Go gauges are only needed for setting barrels; for testing a gun, the no- go is the better one, field is also handy for milsurps.