I recently acquired a Winchester 101 3-barrel set (20, 28, 410) that was probably manufactured around 1970.

The receiver and all three barrels and fore ends are in great shape--no marks of any consequence on the wood and bluing looks almost new.

I took it to the skeet range this past Wednesday and discovered the action is very difficult to break open--the release lever won't thumb over to the right easily, and I had to hold the gun in my right hand and push the lever hard with my left.

At home I oiled all parts with RemOil and let it sit for a day, but the lever is still very hard to operate--almost as though it's locked up, but with enough pressure it will open.

When the action is closed the lever sits exactly in the middle (not to the right like on a new gun) so it's obvious that, despite appearances, the gun has seen some use.

Any suggestion on ways to remedy this problem, or do I need to take it to a gunsmith?

Thanks in advance for your assistance.

Take it apart could very well have dried and harden oil residue on the parts.

You do not say if the action is hard to open after firing or before firing.

Presumably you would have opened and closed the action prior to taking to the skeet range, did you not notice the issue then?

Or has this just manifested itself at the range on firing the gun. If this is so i.e. only hard to open after firing, then could be firing pin drag or worn locking bar or hinge pin which is causing the locking bar to bind in it's bite under recoil.

Remove the barrel set and check the operation of the top lever and locking bar. If the top lever is still stiff to operate then it needs freeing with a penetrating fluid/oil and/or the locking bar needs the same. If the operation is light and smooth then this highlights that it is an issue when the locking bar is trying to release from the bite on the barrel lumps.

Once the locking bar is retracted correctly then anything making it hard to break the gun could be firing pin drag, hammer cocking rods/mechanisms bent, damaged or seized extractor/s.

Remove the stock to better observe all the actions that take place when opening an U/O shotgun to pin point just what is causing the problem. This is what a gunsmith will do.

Does the problem arise with all three barrel sets, the answer to this question may help pinpoint where the trouble lies.

If you going to remove the release lever it is a left hand thread.

#1, you shouldn't be taking an O/U apart unless you know what you are doing. Things can get farked up in a hurry.

First, isolate the issue. Start with removing the barrels and working the lever. If it feels smooth, proceed to testing it with each set of barrels on it. Determine if each set of barrels produces the same result. If it is just one set, then likely the problem could be in the lockup/cocking interfaces on that set. If consistent, then the issue likely resides in the cocking or ejection trains. Sometimes cocking/ejection plungers and levers get jammed up. Locking blocks too. Remove the stock and inspect. If full of dried lube or no lube, clean and oil. Re-assemble and try again. If in doubt, take it or send it to a qualified 'smith.

Eagle27: I purchased the set online (Gunbroker.com) from a gun store with many A+ ratings and outstanding comments.

I did assemble the 28 ga barrel when I picked it up and don't recall noticing any difficulty with the release. Two days later I went to the skeet range and immediately on Station One had trouble opening the action. From then on breaking the action, either after firing or at home when cleaning, has been a problem.

I've tried all three barrels & each presents the same issue.

p dog shooter & Bobster: I don't feel competent to disassemble the gun further than removing the barrel and lubricating the working parts. I would not attempt to take the stock off the receiver; even if I did, I wouldn't know what I was looking for/at.

I guess I'll either learn to live with it or try to find a local gunsmith who knows 101s.

Removing the stock is simple on an U/O shotgun and should be done occasionally to check for corrosion and to lube all the internal parts of the action.

Remove any screws that hold the trigger guard to the stock, lube a screw driver with detergent and poke into screw holes in the recoil pad and remove the pad. Use either a large long screw driver or small socket on end of extension and remove the stock thru bolt. Wriggle stock and pull back off action.
Everything will be nicely exposed and easy to see what is happening when the top lever, safety/selector, and cocking mechanisms are operated and much easier to lubricate things this way.

U/O shotgun actions are much simpler and more contained than SxS guns so their stocks just slip straight off to the rear, no fiddly little cutouts in the wood that can get damaged during removal.