Headspace guage for M305 - .308 Win Ok ?

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dukeNukem

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I am looking to buy a headspace guage for my rifle. Is a .308 Winchester ok or do i need a special 7.62 x 51 one ?

This whole thing confuses me a bit and i know i need to do a bit more research but would like to start with the correct equipment.

Brownells have these in 308 win ??

thanks
 
I don't think you'll find a headspace guage in 7.62 X 51 mm. If you are really concerned about headspace, fire 5 rounds in your M305 and mail the empties to Hungry or Skullboy. They'll tell you where your M305 sits as far as headspace.

Hungry is in Ontario and Skullboy is in British Columbia.

Ripstop

(At least I believe Skullboy does this. Hungry has made the offer before.)
 
Save your money. Out of the dozens of people that had brass mic'd by Hungry and Skullboy, only 1 or 2 that I can recall were under .308 saami no-go spec. These things have generous headspace, 15 to 20 thou over saami min spec for .308 and will swallow a no-go guage. No problem shooting factory or military surplus ammo though, just don't full length size reload for them or you could risk head seperation. Send 5 fired cases to hungry or skullboy and they will mic them for you, add a couple thou for brass springback and you will have a good idea of what the headspace is to the thousandth of an inch.
 
Small point but checking the headspace on a selfloader like the M305 is a little more challenging than a bolt action. Ideally you should use a gauge designed for the firearm eg (USGI type - with a cut-out for the extractor) or dismantle the bolt and remove the op rod spring so that you are not placing unreasonable pressure on the gauge or chamber.

The easiest (and I think most accurate) method is to take Hungry's offer and get a reading that way. Too much headspace isn't great but depending on the amount can be quite acceptable... similarly too tight a headspace with these types of firearms can be just as much trouble.

Headspace on these firearms does not seem to be an issue fwiw. At least not on the rifles I have seen/fired ---- fwiw Ap
 
I have both .308 and Mil Spec 7.62 gauges, and a set of feeler gauges, which are required to get exact dimensions at the right side lug. Hopefully, the bolt is straight, the lugs are bearing even for both sides.
.....Hopefully .....

The 7.62 Military Gauge is cut out for the ejector, so you don't have to strip the bolt for a quick and dirty check. the .308 Gauge is of course .0055" shorter [ and a few other dimensional differences that you dson't care about ]. I use it when i am lapping in a STRIPPED bolt for first fit.

More important than headspace is EVEN wear on the lugs, with MAXIMUM bearing on BOTH lugs.

Too many new Chinese M-305 rifles have the left lug cut improperly.
 
I have both .308 and Mil Spec 7.62 gauges, and a set of feeler gauges, which are required to get exact dimensions at the right side lug.
Click to expand...

Lazarus - can you please elaborate on the correct procedure with the feeler guages? Also - is the cut issue with the left lug, or is it the locking area that's out of spec?
 
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