J series headspace issues/questions

[handirifle]

I have a J series, that I bought new, so no one else has worked on it. Some time back I converted it from 243 (factory) to 308. I have since decided to go back to it's original barrel, which is a 20" 243, that was cut and drilled for sights.

Now the issue comes when I set the headspace with my Forester gauges. If I align the sights to be centered as they were from the factory, then I can close the bolt on the no-go gauge. It takes force to close, but not much.

Now keep in mind I put a few hundred rounds through the factory setup, both factory ammo and handloads, with no apparent headspace issues.

Is it a difference in how they set headspace (1974) or is my gauge off, or was it off from the factory, or is it fine the way they had it set? I want to leave the factory barrel on it for nostalgia but not with the dovetail setting crooked, and not if it's unsafe properly aligned.

Could headspace specs have changed since then?

[sharpshooter]

Head space gauges have a tolerance also. Roll it back where the sights line up.

[Uncle Jack]

Did you ever check headspace while the rifle was in the original condition?

uj

[handirifle]

Ok thanks, i will do.

Now I just had another weird issue. I was doing a swap on an accutrigger model and once everything was badk together, the safety was hard to get to engage. Wellbafter almost an hour of swaping the bolt around thinking I had put something back in wrong, I discovered the adjustment screw for the trigger pull had fallen out, somewhere! I have no clue where or when, and I dont have anything close. So tomorrow I guess I putb in a call to Savage for a new one. Also discovered my retaining pin for the ejector rod had snapped the little head off when I tapped it out.

Maybe I need to call Brownells orMidway

[handirifle]

Did you ever check headspace while the rifle was in the original condition?

uj

No I never did, so I had nothing to go by.

[bigedp51]

Now the issue comes when I set the headspace with my Forester gauges. If I align the sights to be centered as they were from the factory, then I can close the bolt on the no-go gauge. It takes force to close, but not much.


You "NEVER" force a headspace gauge closed, as soon as it makes contact you "STOP".

Between GO and NO-GO is normally .003 and anything in between these two gauges is normal for a factory headspaced rifle.
Look at the SAAMI drawing below there is .010 between minimum headspace and maximum.
You can also have new cartridge cases .007 shorter than the GO gauge and I have seen new cases that were .009 shorter than the GO gauge.

http://i122.photobucket.com/albums/o254/bigedp51/SAAMI308.jpg

You can buy a .308/7.62 NATO set of 10 gauges in one thousands increments for a M1A and M14 rifle. A military type M1A will have longer factory headspace settings than your bolt action and still be OK. Line up your sights, shoot your rifle and only bump the shoulder back .001 to .002 and your brass will be a custom fit to your chamber.

If your cases are thinning on the first firing you have two choices, set your headspace closer or fireform your cases to your chamber using a false shoulder or by jamming the bullets into the lands. With ether method your cases will be a custom fit to your chamber.

You do not need perfectly zero headspace as close to the GO gauge as possible, you need to know how far to bump your shoulder back on a fired case and not let it stretch in the web area when fired.

http://i122.photobucket.com/albums/o254/bigedp51/RCBSCMG.jpg

Below I use a GO gauge to establish a reference zero point to measure new and fired cases and know how far I'm actually pushing the shoulder back on a fired case in reference to actual rifle headspace.

http://i122.photobucket.com/albums/o254/bigedp51/Picture009.jpg

I have old milsurp rifles with .017 head clearance and with careful fireforming all excess cartridge headspace is eliminated with custom fitted cartridge cases. NOT all rifles can be adjusted and you can compensate for. And remember that headspace increases due to bolt thrust and lug wear and if your rifle really did increase in headspace it normally means hot loads or oil in the chamber which doubles the bolt thrust.

[handirifle]

Well "forced" might have been the wrong word to use. I didn't really force it, it felt more like a case that had been sized tight. Either way, I have set the sights straight up, and will adjust dies accordingly.

I will end up with 2 sets of 243 dies cause I plan on making one rifle a long range rifle, and will not want to mix the brass. Will prob go with a different brand of brass for that one, either Lapua or Norma, to keep it simple.

Thanks for the good feedback.

[BillPa]

Ok thanks, i will do.

Now I just had another weird issue.

I discovered the adjustment screw for the trigger pull had fallen out, somewhere!

Also discovered my retaining pin for the ejector rod had snapped the little head off when I tapped it out.

Maybe I need to call Brownells orMidway

I dunno, I think if I had your run of luck I'd call a gunsmith before fix'n anything else! :p

Bill

[handirifle]

Yea it has been one of those days. Just ran into an issue on my 375 Win big bore 307 conversion. Still some more parts needed I think.