Headspace gauge question

[RonS]

Guys, I'm not a gunsmith but i have changed a few Savage barrels with no problems until now. I installed a new barrel on a friends rifle, when I inserted the go gauge and tightened the barrel nut the bolt operate normally. I always insert my no-go gauge to check my work. This is the first time using my Forster 222REM gauges. So when I inserted the no-go gauge the bolt closed. I repeated the complete process three times with the same result. I have a Remington 788 in 222REM with less than 500 rounds through the barrel and when I inserted the go gauge in the chamber and tried to close the bolt it would not close nor would the no-go gauge. I called Forster and explained the situation to them, they asked me to send them the gauges so they could do a measurement test on them. After a few days they called me and said the gauges are the proper lengths and my problems in my rifles and insist I should use a field gauge to check my headspace. I have several sets of headspace gauges from PT&G which work flawlessly but this is the only set I have from Forster. Besides buying another set from PT&G can someone give me an opinion of what I should do to finish my friend's barrel change.

 

[fguffey]

I am a reloader, I form cases, I make comparators.

I measure head space gages for length from the shoulder/datum to the head of the gage. I do not assume.

I do not know what you are doing with the extractor, first I would make sure the extractor is not holding the gage off of the bolt face. If for some reason the go/no go gage was not working I would use a factory over the counter new ammo, I would compare the length of the minimum length new ammo with the go gage.

F. Guffey

 

[RonS]

Guffey, I get what you're saying, I removed the extractor before inserting the go gauge, ran the barrel all the way in until it was tight against the gauge, locked down on the barrel nut, opened and closed the bolt several times with the go gauge still in the chamber. Then removed the go gauge and put in the no-go gauge and the bolt closed. So am I crazy or is there a problem with the gauges? Seeing how they won't function properly in my factory original Remington 788.

 

[shortgrass]

I'd try those gauges in several more chambers before I'd claim there was a problem with them. A old model 788 is hardly the "standard".

 

[shortgrass]

Out of curiousity, I pulled my .223 gauges (they were made by Forester). As per the etched measurements on each gauge, there's .003" between GO & NO-GO. I'd say your problem lies with the difference between the threads in the action and the threads on the barrel, they're not as good a fit as needed to install the barrel with the method you're using. I'd say there's more than .003" slack between the action and barrel threads. You turn the barrel in until it's against the GO gauge and when you tighten the nut, it pulls the barrel away from the bolt, thus increasing headspace, and the bolt will then close on the NO-GO. Just a guess, without having it in my own hands to see for myself.

 

[OTTER264]

I'd say your problem lies with the difference between the threads in the action and the threads on the barrel, they're not as good a fit as needed to install the barrel with the method you're using. I'd say there's more than .003" slack between the action and barrel threads. You turn the barrel in until it's against the GO gauge and when you tighten the nut, it pulls the barrel away from the bolt, thus increasing headspace, and the bolt will then close on the NO-GO. Just a guess, without having it in my own hands to see for myself.

+1
Another thing that could be happening is the barrel nut is unscrewing the action when you tighten it. Clamp the barrel in a barrel-vise and use an action wrench to hold the action in position when you tighten the barrel nut.
And also, you mentioned that you removed the extractor. Good. The ejector pin needs to also be removed, in fact it wont hurt a thing to finish stripping the bolt.( remove the firing pin and spring)
If you are still having trouble with getting proper headspace, when you screw the action up on the barrel with the bolt closed and hand tight on the go guage, take a sharpie and make a line up mark on the barrel and action.
Open the bolt and screw the action on to the barrel just a little bit. Using the mark as a reference just turn it enough to split the mark.
Try closing the bolt. Keep doing this (screwing he action on with the bolt open and closing on the go guage) untill the bolt closes with some resistance. With the bolt closed on the guage then tighten the nut on the barrel. If there is still a little resistance closing on the go guage after tightening the nut(and the nogo won't go), check a full length resized case to make sure it chambers without resistance.
Hope this helps.
Ron
.

 

[RonS]

As soon as I get my gauges back from Forster I will check them again. And yes I have a barrel vise and action wrench, I would not attempt to do this without one. As far as my Rem 788 if the chamber were worn that much, the bolt would close on both gauges but the bolt will not close on either gauge. Can someone explain that to me?

 

[Bert]

The chamber is smaller than the gauge. Just because it is a factory chamber doesn't mean it is to print.

 

[RonS]

Bert, the factory chamber is correct, factory ammo chambers without issues. I received my gauges back this evening. I noticed the base of the go gauge had been machined and now fits my Rem 788 and the bolt now closes but is stiff.

 

[Kodiak99317]

Ok, the cheap man's no-go gauge, take you go gauge and put a piece of scotch tape the the base and trim with a sharp knife, it is now a no go! Remember to take the tape off after!! The scotch tape will add approx 3-6 thou to your go gauge, depending on it's thickness I myself use a fired case from the rifle and it works the same.

 

[Bert]

While your factory chamber excepts factory ammo you cant use that as a standard to call it correct. Does it functions ? yes. Does the chamber measure to spec? Don't know. It could be the gauge. Or the factory chamber could have something else going on but if it shoots and is safe it doesn't matter.

Now how to fix your savage. If your threads are loose like previously mentioned screw the barrel on with go gauge. Then remove go gauge and screw barrel in about .003 or what ever the difference is of the go and no go gauge. I am not sure of the thread pitch for a savage so I don't know how much of a turn? Something like 1/20 of a turn. or use some shims. Mark action and barrel with a sharpy then turn a little and try. Then lock barrel nut. And check with go and no go gauge. The barrel might move a little when you lock it down so it may take a couple tries to get it correct.

Now if you still don't trust the gauge measure then your self. Or buy new.

 

[RonS]

Bert, as far as the Savage goes, with the go gauge being machined the gauges work better. And when I use my bullet comparator to measure the lengths again, they are now different. But the thing I don't understand is why they would send me a field gauge to check my chambers if the go and no-go gauges would not allow the bolts to close......?

 

[X Ring Accuracy]

In my experience, and Shortgrass hit the nail on the head. Tightening the barrel nut pulls the barrel away from the bolt taking up the slack in the the threads. It's not a biggie as long as you know thats what happens. Cutting perfect threads on a Savage barrel isn't the answer, the action is still what the factory produced. Thats why Savage rifles are built the way they are. If it were mine I would lock down on the go guage, mark the action (fine pencil mark), extract go guage, rotate action in to split the mark, hold action with action wrench, and lock down the barrel nut. You should be good to go.