I have a question concerning a custom 6.5x55 built on a Wz.29 polish mauser: I measured the headspace with forster gauges. The go went as expected. I was able to close the bolt on the no-go, but not the field gauge. This rifle has had only approx 150 rounds fired through it since a re-barrel. The barrel was short chambered and required the gunsmith to finish it. My concern is that either the gunsmith cut the chamber too much, or possibly the receiver lugs are soft/setting back? Should I look for other possibilities?

Thanks,
Regards,

US Military armorers would not reject a rifle if it didn't close on the field gauge. Having said that, I wouldn't have the "warm fuzzies" with my rifle closing on the NO-GO gauge. Your brass will fail prematurely or you will have to neck new brass up to .270/.280/.30 cal and size it back down until your bolt will close with feel on the case and never set the fired case shoulder back when resizing. This is simply a work-around and not a fix. I would take it back to the smith and ask him to make it right.

Should have added that the 6.5 Swede as normally loaded probably would not set the lugs back. I would have the smith pull the barrel, check for lug setback and if that is not present, I would say that he cut the chamber too deep and would need to make it right.

If the bolt lugs are set back into the receiver after firing a standard load you will feel a harder bolt lift.From what you are describing the set back would have to be more than.003".That really would be severe.I would think if that is the case you would have ran into other high pressure indications. roger

Thanks for the responses. So quick... Anyway, I thought that setting back of the lugs was reaching. When the rifle was an 8MM, it worked fine. The bolt got a little stiff once in a while but nothing to be concerned about. There were no apparent high pressure signs. I do believe that the gunsmith cut it a little deeper than necessary. My thoughts were to have another gunsmith take a look at it. Thanks, Regards,

No-Go means just that. Unless you want to fireform the brass just for that chamber, have a good smith fix it. For a mauser, the headspacing is not a huge task for anyone good. Heck, Brownell's even sells long chambered barrels for mausers that you can finish yourself, with proper tools. A good smith will make sure all is straight and fully contacted though.

a4m1d6,
The industry standard SAAMI headspace is MIN (go) to MAX (no-go). The MAX dimension is the MIN dimension +.010". If I remember correctly, the Forester no-go is the MIN dimension +.006 with a tolerence of +/-.0005". That means that the no-go Forester guage could be MIN +.0055". The industry usually holds there headspace from MIN to MIN +.007.

Your chamber is good as long as it doesn't take the field guage.

Headache

Headache,

Thanks for the explanation. I see it is possible to fall within these tolerances. I guess what raised is little concern was measurement on my M96 was different than on my custom 6.5. I could not close the bolt on the no-go and field gauges on my M96. I guess it would also depend on what gauges the gunsmith was using when the chamber was cut.
Thanks,
Regards,

Just a little more info....I took the rifle back to the gunsmith shop. They took a look at the headspace and determined that it was excessive. This rifle has had approx 100 rounds fired through it since being built. I had no signs of high pressure from any of my reloads. This is mainly because I stayed at the minimum/starting grains. In addition most of the ammo was factory ammo. I was breaking in the barrel. Anyway....They are going to determine what is the reason for the excessive headspace. My question is...If the lugs are set back should I consider this a scrape project or should I have them correct this and send the action out to be re-heat treated. Appreciate the responses.

Regards,

Did you have the action hardness tested?

Jaywalker

Jaywalker

When I first had the rifle done, I didn't know the questions to ask. I talked with the smith who never offered any either. My bad I guess. I did ask while he was doing the work, whether he thought the action was strong enough for the conversion. He said that he thought it was. Again, probably my bad.

Regards,

at first glance, I would say it's too long.. BUT

put a piece of scotch tape on the back of the no-go and see what you get.. will it close, will it not even start, or anything in between

how does the brass resize, btw?

here's my concerns.. I normally don't have a no-go and a field... usually go and no-go, so i would read the gages to make sure it's no-go and field.

second, take a new case .this should be a fill length resized EMPTY case. DO not use a live case EVER

put it in the chamber.. work the bolt.. see if you can feel anything..

then put ONE piece of scotch tape on the face of the brass...

try again.....

if you can close the bolt AT ALL without being "mongo" then put another piece of tape on it...

SHOULD not close without STRONG effort.

if it closes on the first piece, the headspace is too long

if it takes or nearly takes 2, it's dangerous

jeffe

jeffeosso

It is definitely long. The gunsmith agreed. It swallowed the no-go with no problem. In addition, I used a dial indicator on the back of the bolt with the go gauge in the chamber. I measured the amount of fore and aft movement with the bolt closed. It was .003-.004 movement. The gunsmith is not sure why. This smith is not the same one who cut the chamber. My thought - The smith doing the work cut the chamber too long.
Thanks,
Regards,

I'm wondering if the action's too soft and the lug/lug recesses are wearing. That would explain both observations. Aren't these actions mostly dependent upon the surface hardening?

Jaywalker

quote:

They are going to determine what is the reason for the excessive headspace. My question is...If the lugs are set back should I consider this a scrape project or should I have them correct this and send the action out to be re-heat treated. Appreciate the responses.

Lug setback cannot be measured by headspace gauges. In order for headspace gauges to work one must feed them into the chamber and rorate the bolt 90 degrees. Setback only inpacts the action in the fully rotated position.

It's reasonably safe to say that your excess headspace problem is not caused by setback. It was machined that way day-1

Regarding your question about reheattreating should setback occurr.....I would discard the action and look for a VZ-24 or commercial Mauser to replace it. I beleive it'll cost less and you'll have a better product in the end.