Setting head space

[wisconsinteacher]

I just set the head space and torqued the barrel nut on the action. I used a go and no-go gauge. The go gauge allows the bolt to close with a little pressure but is smooth while the no-go gauge allows the bolt to close 1/4 of the entire throw. I used a torque wrench and put 32 ft/lbs on the nut. I figure if I add the length of the nut wrench, I am close to 35 ft/lbs on the nut. I have check with both gauges about 10 times each and I get the same results every time. I dropped some virgin brass in and they close with ease. I think I did it right. Does it sound right to you?

 

[DeltaBravo]

teacher,

I do it the same way with the firing pin removed. I get about 1/3 to 1/2 turn on the no-go, so not much different. How's it shoot?

Dennis

 

[wisconsinteacher]

I just set the head space tonight after work. I am going to pillar bed it and reload for it over Christmas break. I hope to shoot it around the new year if the weather works out.

 

[jonbearman]

Hey teach,remember to break the barrel in correctly and clean all the garbage out of it before you ever think of shooting one round.This is just a reminder,I am sure you know it anyways.

 

[M-61]

I do not know the length of your barrel nut wrench, however take a look at this:
http://www.belknaptools.com/support-library/extensions-calculator/
I think you will find you are higher than you say. Either way that amount in my opinion is sufficient. There does not seem to be (that I can find) a torque value published by Savage.
The one thing I do besides the firing pin removal is remove the extractor. I have found it can get damaged sometimes on the headspace gauge. That little detent ball loves to go flying. They are somewhere in my shop never to be found so I always have a couple in stock.

 

[wisconsinteacher]

I guess I was over on my ft/lbs. Using that webpage, I am closer to 55 ft/lbs. I guess it is tight. I know it is not as tight as the factory nut.

 

[M-61]

I guess I was over on my ft/lbs. Using that webpage, I am closer to 55 ft/lbs. I guess it is tight. I know it is not as tight as the factory nut.

And the factory nut not only is there no torque value stated there are some who say they use Loctite. I never have seen any trace of that (which only means I haven't seen it...not that they don't use it). Some factory nuts are tightened by gorillas! My opinion you are fine. Also that extractor can be a pain to remove because of the ball (no tools really needed)....good eyesight.... and when the extractor is slid to the side PRIOR to fully removed that is when that ball is ready to launch!

 

[pdog2062]

I always put the bolt in a large baggie to save the flying parts

 

[M-61]

I always put the bolt in a large baggie to save the flying parts

Great idea!! Clear plastic?

 

[DCRYDER]

Don't forget the anti-sieze!!!

 

[M-61]

Don't forget the anti-sieze!!!

+1

 

[wisconsinteacher]

The anti-sieze was on the barrel when I put it together.

 

[Rustystud]

Two things come to mind. Always remove the ejector before setting the head spacing.

I don't use anti-seize, I use high temperature bearing grease.

It provided greater lubricity, therefore better metal to metal fit.

It provides protection from moisture.

It prevents gauling.

Nat Lambeth

 

[wisconsinteacher]

Darn, I did not remove the ejector when I set the headspace. :-\ I guess I need to do it over.

 

[Outrider27]

Two things come to mind. Always remove the ejector before setting the head spacing.

I don't use anti-seize, I use high temperature bearing grease.

It provided greater lubricity, therefore better metal to metal fit.

It provides protection from moisture.

It prevents gauling.

Nat Lambeth

Based on a whole bunch of threaded fastener friction coefficient research my employer was kind enough to fund for me over a period of several years (a bit over $250,000 worth, so it wasn't a series of trivial projects), I can say that there are a lot of myths about the use of high temperature bearing grease in threaded joints, so we need to be careful. The reason it works more or less OK in this application is that the stress in the threads isn't as high as, say, the cylinder head bolts on a car.

To address the issues one at a time:

It does not supply better lubricity; the mean friction coefficient for an alloy steel and alloy steel joint using common graphite based antisieze compunds is in the 0.10 - 0.12 range (it's about 0.07 for Moly based antiseize compounds). High temperature bearing grease (and automotive lube oils) have a mean friction coefficient essentially the same as unlubed, which for alloy steel and alloy steel is 0.20. It is slightly higher for stainless steels than alloy steels when an antisieze compound is used, an a lot higher for hi-temp bearing grease, on the order of 0.28.

Since both antiseize compounds and hi-temp bearing grease have similar petroleum compounds as a base/carrier, moisture protection is similar (many of the applications we tested for were for bolting external to the pressure hull on a submarine, so moisture resistance was a consideration).

The high pressure additives in bearing greases are not the right type for preventing galling at the high specific psi loads in the threads of a threaded joint; this is not a major issue with chromoly actions and barrels, as alloy steel and alloy steel threaded joints are very good players with regard to galling, probably the best behaved out there. This is NOT the case with a stainless/stainless combination - stainless/stainless is not the most galling prone combination out there, but it is one of the three or four worst. The worst we have encountered is titanium/titanium, the next worst is stainless/monel, with monel/monel about the same or slightly more galling prone than stainless/stainless. The microfine ball bearings (for lack of any better description) supplied by the microfine powdered graphite (or MoS2) and various microfine powdered metallic additives found in antiseize compounds (copper, aluminum and zinc are probably the most common - the ones that use copper are easy to spot, the rest require referencing a Material Product Safety Data Sheet) are what give the antiseize compounds their much lower friction coefficient and the anti-galling abilities at the high contact loadings in threaded joints that are not present when bearing greases and motor oils are used for a thread lube - bearing greases and motor oils have pressure additive packages keyed to a totally different environment.

All of which is not to say that hi-temp bearing grease will not work fine as a thread lube for mating a barrel to an action if the material combination is alloy steel/alloy steel, it just means that any specific torque applied will give a greatly different final preload (considerably lower), than if an antisieze is used. The actual preload achieved doesn't seem to be a major issue with the assembly of barrels to actions, and an experienced technician will feel the end result and end up in the proper range of final preload anyway, regardless of which type of thread lube is used, if they don't use a torque wrench. Since steel/steel isn't particularly galling prone, bearing grease should work fine at the relatively low preloads used here, and even at preloads over 50% of yield, galling shouldn't be a problem. We're really more interested in dimensional issues (headspace) here than achieving a specific preload, so, again, use of bearing grease or antisieze isn't really an issue - just don't put it up dry/unlubed.

When we get to assembling stainless barrels to stainless actions, it gets a little stickier, as stainless/stainless can gall at quite low preloads; depending on which end of the dimensional tolerances the male and female threads are at, even just running the threads up by hand before contact is made and real preloading begins can result in galling. While bearing greases will help a little in this situation, for stainless actions and barrels antiseize is a much better choice than bearing grease, as bearing grease offers essentially no protection against galling in threaded joints once you get much beyond finger tight, and sometimes, as stated earlier, even before that.

All in all, neither lubricity or moisture resistance is much of an issue in our application - one choice is about as good as the other where the threads are concerned. Galling, however, can be a real player, so outside of alloy steel/alloy steel, you need to play very carefully with the choice of thread lubes, as bearing greases used with stainless/stainless or titanium/anything work more by luck than design with respect to galling resistance, and our luck can run out very quickly where galling is concerned.

Mike Gifford

 

[memilanuk]

Darn, I did not remove the ejector when I set the headspace. :-\ I guess I need to do it over.

Don't sweat it; it'll be fine.

 

[DennisH]

??? Mike, thanks for the info. Very informative.

I use never seize and just put a good snug on the bolt wrench when installing a barrel. I know some of the best who do the same with no issues. I was taught by one of these individuals.

Removing the ejector and extractor is the best way to set headspace, but being honest, I done many without removing the ejector.

Dennis

 

[Nomad47]

Same here. I don't remove either ejector or extractor. No problems, just be careful. And make sure the go gauge was against the bolt face when headspace was set.

 

[wisconsinteacher]

Thanks for all the help. When I put the gauges in the chamber and ran the bolt, I could feel it move the ejector. To me, it was then making contact with the bolt face. I sure hope I did it right.

 

[ragsflh]

it will be alright