On a Winchester Model 97 pump shotgun what is meant by the term
"slipping threads" when referring to the magazine tube?? Does it mean
the tube is loose and has too much play in it? If so, what can be done
to remedy the problem??
Back the vast wasteland of my mind, I recall that the Model 1897 magazine tube screws into the frame??
The term might mean that the magazine tube is loose and needs to be tighten.
DO NOT BET THE RENT MONEY THAT JIMMY's ANSWER IS CORRECT!
It's been a while since I pulled the barrel on my dads 97 (now my brothers) but I think they are referring to what a machinist would call interrupted threads. The threads cover half the circumference of the barrel in two quarter circumference sections. You can slid the barrel almost all the way home then give it a 1/4 turn to tighten the threads. Not unlike the breach of a howitzer.
Like I said though, my memory on this may be faulty or I may be thinking of another shotgun. Several makers used this system.
Yes, I know about the interrupted thread system that was used on
the Winchester Models 97 and 12. I was just wondering if the threads
on my 97 are excessively worn causing looseness in the tube when I
put the gun back together. Could the magazine band be too loose and
cause this? I have tightened the band screws sufficiently with no luck.
The magazine band screws have nothing to do with the looseness of the magazine tube threads. If the magazine tube is reassembled with the tube a half turn out of proper position, the magazine tube can slip by the threads when the slide is worked. Make sure the tube is assembled in the correct orientation. I have found that on those 97s that have been used hard a certain amount of looseness is to be expected.FWIW
They just get worn over the years from constant take down use. The end of the tube was supposed to make some contact on the receiver when the takedown lock pin was tightened up. That made the tube a firm fit against the receiver and the large square threads kept it from wearing out too awful quickly.
But those guns are anything from 100+ yrs old to just less than 60. The sheet metal tube end has just plain worn or in some cases been rolled slightly inward from pressure aginst the receiver and allowed the tube to twist loosly in place.
There is supposed to be a slight rolled lip at the end to contain the mag follower in the tube, but too much pressure against the receiver can increase the curl to the point where it can cause feeding problems catching the shell rims.
A balancing act that opts for light pressure to avoid turning that lip inward causing feeding problems. But that allows the mag tube to loosen up after some use and rock slightly in it's locked position.
Solid frame 97s have their tube screwed into the frame with a very fine 'v' thread and held into position with a set screw on the right side of the frame. I've never seen one stripped and loose/turning free in the recv'r. But if it's not turned all the way in it can cause feeding problems as the shell rims can catch on in the slight void between the end of the tube and the receiver edge.