Gunsmithing Remage bbl 6.5 CM closes on both go and no go. Professional advice?

[Pastureman98]

Gun shoots .5-.6 MOA out to 940yds. Shows no pressure signs. I couldn't find any go or no go gauges when we put it together, so we headspace it on a new, unfired Lapua case. I know there is a very small difference between go and no go, that's why I listed it on this particular forum hoping for some feedback from professional gunsmiths. It shoots fine, I just wanted it to be safe. I have a couple of older rifles that were professionally built using the old method of a new unfired case, and they have shot very well for years.

Thanks for the advice in advance.

Remington 700 SA 6.5 CM
Crittendon 24" pre chambered barrel
Lapua Brass

 

[Eagle1899]

If you have a case gauge... measure a new unfired Lapua case and an unsized once fired Lapua case... What is the difference between the two?

 

[cast1]

DANGER!!! You have excessive headspace. Sounds as if you have a go gauge now. Snug your barrel down on it with a closed bolt and tighten the barrel nut to spec. Make sure it has cleared the extractor. You can hear it click over the rim of the go gauge as you snug the barrel. Then confirm it won't close on the no go. Make sure you remove your ejector for the job. No reason to think it won't still shoot.

The distance between your bolt face and shoulder of your chamber is too long. Impossible to say by how much. Your brass is having to stretch too much at the web where it is unsupported. Increased chance of case head separation and a stream of plasma hot gas in your face. No bueno. Unlikely that it will show pressure signs.

 

[Supersubes]

Of the three brands of 6.5 CM brass ive played with, the lapua is the shortest. About .002-.003 shorter than "go". Your particular lot may be different, but kinda odd it will close on a no-go having been set off a virgin lapua case. If you have a headspace comparator setup like he hornady, you can easily measure both of your gauges, as well as virgin and fired cases to get an idea of where your at.

 

[CharlieNC]

Measure a sized brass with your HS comparator. Partially insert a primer, chamber it, and slowly close the bolt to finish seating the primer. Remove and measure again, the difference vs the original length is the HS. I've shot up to .010in with no problems, but the safety margin is up to you. Ideally set the rifle for .002in vs your virgin brass to maximize brass life.

 

[hunter223]

Chamber reamer may have been inserted too far into barrel. One option to determine how much headspace you actually have is to take your go gage and get some cellophane tape and add a piece to the ass end and trim the outside of it to math the head of the go gage. The tape should measure right at .002" and keep stacking it until the bolt doesn't want to close. It's not the best method but will give you an idea of where you are. I think badger designed the m2013 to allow up to .006"-.008" over go gage. Could be wrong but I think that's what Marty told me. Also, if you have a depth mic, measure how much protrusion you have on the go gage to the face of the barrel

 

[Pastureman98]

Gents, thanks for the advice. I re-checked the headspace today, re-set it, tightened it up, will try it tomorrow. Will not close on no go gauge now. Not even close. Hopefully this will fix the issue, if not I will be back in touch here. Thanks for the advice from all of you.