Lever Actions with Excessive Headspace?

Picher

New member
I used to do gunsmithing for a local sporting goods store in Central Maine. Once, a Winchester 94 came in for cleaning and sighting-in the factory sights.

I took it to the range and, upon firing, the lever kicked-open somewhat, hurting my fingers. Another shot did the same thing, so I stopped shooting and returned the rifle (after cleaning) to the store with the diagnosis.

Has anyone else here experienced such headspace problems with older lever guns?
 
Virtually all lever actions will open the action slightly upon firing. It happens less often with Marlins than Winchesters. I seriously doubt there is anything wrong with the rifle. What you describe is normal.
 
I have never had a Marlin kick open, and I own one or two more than 100 years old...

My 1912 vintage Model 1893 in .30-30 has the most headspace, but neck sizing my brass takes care of the case stretching...
 
jmr40 said:
Virtually all lever actions will open the action slightly upon firing. It happens less often with Marlins than Winchesters. I seriously doubt there is anything wrong with the rifle. What you describe is normal.
It is very much NOT normal.
If it is something that you experience or witness regularly, then you should get your leverguns, or those of the guys shooting near you, checked by someone that understands how leverguns actually work.

Levers kicking open generally come down to one of two things:
1. Worn parts and bad (incomplete) lockup.
2. Excessive headspace.
C. Shooter's hand remaining stationary (due to a loose grip) while the rifle recoils, and 'pushing' the lever open via recoil.


Has anyone else here experienced such headspace problems with older lever guns?
Cornbush (my brother and a member here) recently had to fit a new locking bolt to his well worn Marlin 336 that he and I converted to a 444. Lockup was bad to begin with, but when paired with the new .444 Marlin barrel, headspace was extremely long. We did test fire it in that condition and it was prone to kicking open, as well.
In deciding how to remedy the issue, we discovered a previously over-looked issue: Some Bubba had previously "polished" and altered the original locking bolt as a "fix" (bandaid on a bullet would :rolleyes:) for other action parts that were worn and in need of replacement (finger lever and cartridge lifter).

Now she's tighter than a ... ;)
 
The lever kicking open somewhat isn't necessarily headspace. Especially old lever actions. You check the headspace with proper gauges?
 
Why and how does excessive headspace open the action?
The Marlins, in particular, use angled faces on the locking bolts. Since the rifle isn't actually locked at the moment of ignition (the hammer pushes the bolt forward against the case head), the bolt slams backward when the case expands. When it his the angled face of the locking bolt, it kicks the locking bolt down and into the lever. Thus, popping the lever open.
Reasonable illustration of the Marlin action: Marlin 336

With REALLY bad headspace, severely worn parts, and overly-hot loads, several members on the MarlinOwners forums have had their fingers injured superficially (nasty abrasions or even cuts).


The Winchester 94s use a different method for lockup, but the situation is similar. The engagement surfaces are angled and the locking block can be forced downward (pushing the lever and lower link ahead of it) if the bolt slams into it - particularly if the rifle is well worn, is severely battered from being fired in that condition for some time, or has been 'improved' by some idiot filing the locking bolt in their shed.
(I can't find a satisfactory image of the '94 action.)


With Volcanic style (toggle-link) lever guns, such as the Winchester 73, Burgess, Volcanics, and more, the excessive headspace is usually caused by worn links or link pins, which result in improper lockup. (Actually creating an "out of battery" condition, even if only slightly.) Those worn links and incomplete lockup can have the same end result: Levers getting kicked open.
It happens in the Volcanic style actions, because the toggle links get worn enough that they're no longer forming a straight line and mechanical lock between the rear link that's attached to the receiver, and the front link that's attached to the bolt. Rather, they're "sagging" in a shallow "V" shape, and they direct the bolt thrust into the center pivot (which is where the lever attaches). When that center pivot gets forced down, the lever opens.
Decent video of a Volcanic style action (Win 73): YouTube Video
 
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Yup seen one of those quite some time ago..
The use of factory Federal 150s would open this rifles receiver a good 1/2" or better upon firing. Loose Post 64 model having a (really thin) blued carrier. After experiencing its shooting. (couple shots.) I'm glad I didn't own it.
 
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