Headspace in a Lever Action with a Straight-wall Case

[Old No7]

Yes, I could have a qualified gunsmith check it over but...

But... The 1892 Winchester (made in 1910) that I picked up recently is just begging to be shot!

It was rebarreled to .357 Mag and still has the original "blackpowder" firing pin, but I've been advised by the best (a forum member here) that it should be OK with lead loads, as long as I see no primer leakage.

The headspace though, as measured by seating a once-fired primer very shallow, and then letting the closing of the action seat it (with extractor and ejector still on the bolt) -- comes out at 0.018"...

Now I understand that with a bottleneck round, I'd risk stretching the brass and having a casehead separation -- which would not be fun...

But in a straight-walled case like 357 brass, using 4.5 gr of Universal reloads with lead bullets... Is that headspace OK?

And if it's not... What's the fix?

Thanks all!

Old No7

[rbertalotto]

I'm not going to say it's "OK".........................





But I'd shoot it all day long with light Cowboy Loads.................Just my opinion.

[earlmck]

Yeah, that seems like quite a bit of excess headspace, No7. But I'm with Roy B -- go ahead and shoot it and I'd bet you don't have any trouble with it. Just saying that 'cause I've never seen a head separation with a straight-wall pistol case. And also I've experienced varying degrees of "badness" with the old blackpowder firing pin. That also may not be a problem with any normal load. And if you get some primer piercing (that's what you'll see -- a hole in your primer that makes you think the firing pin was too long and sharp) you can try switching to Remington primers. I've never gotten a hole in a Remington 7 1/2 primer and I have a couple rifles that have those big sloppy firing pin holes and won't let me use a CCI or Winchester small pistol primer...

So now you've got a couple votes from the "try it and see how it goes" crowd.

[Old Time Hunter]

Before you shoot it, build up .007 to 010" of masking tape on the back of a spent shell and see how easy it cycles. Have seen quite a few bolts with the center concave.

[Nate Kiowa Jones]

Yes, I could have a qualified gunsmith check it over but...

But... The 1892 Winchester (made in 1910) that I picked up recently is just begging to be shot!

It was rebarreled to .357 Mag and still has the original "blackpowder" firing pin, but I've been advised by the best (a forum member here) that it should be OK with lead loads, as long as I see no primer leakage.

The headspace though, as measured by seating a once-fired primer very shallow, and then letting the closing of the action seat it (with extractor and ejector still on the bolt) -- comes out at 0.018"...

Now I understand that with a bottleneck round, I'd risk stretching the brass and having a casehead separation -- which would not be fun...

But in a straight-walled case like 357 brass, using 4.5 gr of Universal reloads with lead bullets... Is that headspace OK?

And if it's not... What's the fix?

Thanks all!

Old No7

I do feel you will be ok with the BP firing pin and any load that doesn't flow the primer back into the hole. But, at .018 headspace if you shoot it much it's only going to get worse. in the black powder era .010 was considered acceptable. Now days .005 or less is the norm for smokeless. What you need to do is find where the slack is.
What you might try is take it apart and then use feeler gages to measure the gap between the locking bolts in their frame cuts.If there is excess front to back play you can tighten them some by forging the locking bolts wider where they engage the breech bolt. If you can't get it close to .010 you may have to set the barrel back.

The problem with excessive headspace isn't just case damage. Think of it as if it's a bowlong ball in the back of your pickup. as long as it's contained in a ball bag or box it can't do much damage but if it loose back there it's gonna leave some marks.

[Buck Elliott]

Case stretching, and eventual head seperation is almost guaranteed, with that much headspace, firing loads at "normal" .357 pressures...
It's going to happen somewhere down the line, even if everything locks up tight, and headspace is at a minimum, but with that much "running room," it's going to occur much sooner, rather than later, and will continue to batter the old action, increasing the wear and tear...

[gundownunder]

Just in case it's an important question,

Is anything nasty likely to happen if a seriously heavy 357 magnum load gets put in that old gun by mistake?

[Nate Kiowa Jones]

Just in case it's an important question,

Is anything nasty likely to happen if a seriously heavy 357 magnum load gets put in that old gun by mistake?

Because the 92 action is a strong design anything short of an overload will probably not cause a catastrophic failure. The gun is going to just get looser and looser. Particularly with the pre-WWI metal being suspect, too. It has been my experience that the post WWI guns converted to 357mag tend to hold up better if set up with correct headspace. However, the ones converted to 44mag tend to shoot loose regardless. Of the ones I’ve seen I don’t have any way to know how well they were set up initially so it’s possible they too started with excessive headspace.

[WyrTwister]

Years ago I bought a cheap automotive feeler gauge . I cut shims from it and use them between the bolt face and a no-go head space gauge .

If you try to determine the space between the front of the bolt & the back of the case , I suggest you use something like that , instead of tape .

If you determine the rifle needs major work , consider the cost vs the cost of a Rossi M92 clone . And make the old gun a wall hanger .

God bless
Wyr

[Don McDowell]

Try some small rifle primers in those cases. Those big ol rifle firing pins sometimes mash the stuff out of pistol primers and it looks like either headspace or pressure issues , when it really isn't.
Also try a real headspace guage. Using fired primers , you might as well be using the rule on your leatherman as far as accurate measures are concerned.