Got a 16 ga. JC Higgins that shoots well, but is hard to open. I think it may be the cocking lugs. Any suggestions for lubing/cleaning them? It's a Savage 5100.

Is it hard all the time or just when you shoot it ?

Check for firing pin drag on fired primers.

Has the buttstock ever been off & the action cleaned & lubricated? If so, then better chance that the firing pins are dragging. If it has never had the buttstock removed, then now is the time to do so. The NRA published a series of books on firearms assembly of most hunting guns. I believe a version of your gun is covered in either volume 1 or 2, but not sure which.

Irrespective, first thing I would look for is any deformation showing on the fired primers of the cartridges you are using. They will clearly bear drag marks, if one or both are the culprit. No marks would indicate the need for a good strip & clean.

w/drag marks:

If you are using reloads, some primers have harder cup material than others, so you might be able to avoid the issue by using a published appropriate recipe that calls for a dif primer.

Same may be said of different factory loaded ammunition; some brands will have harder primer cups than others.

OTOH, you may wish to look closely at the firing pin holes and also the ends of the firing pins to see if the holes are worn or the firing pin ends are eroded or broken. Using a tough material [hardwood or horn] held against the standing breech you can fire both bbls and then check the projection of the firing pins. They should project 1.5mm or .060" maximum through the standing breech. If it is more than that they need to be stoned back to that or a bit less, keeping them hemispherical rather than sharp. Less than 1mm or .040" is considered too little for reliable ignition, so go easy & don't over doit. Too much firing pin projection can cause dragging i.e, hard opening.

Hope something here helps you out. All easy enough to check. Not a big deal to a qualified gunsmith, so shouldn't be overly expensive to get repaired if you do not wish to tackle it yourself.

kind regards, tw

Just when I shoot it. It probably needs cleaning.

I have a Spanish 20 gauge (low priced gun) that I bought new in 1970. It was so hard to open after shooting it that I had to break it open over my knee. The firing pins were protruding too far. I filed them back and the problem was solved. But as mentioned, you should see evidence of drag marks on the shell casing.

No drag marks on the primers, but the primer holes are pretty deep.

Gene,try different brands of shells.Could be the primers causing it. Bobby

The pressure might be too high.

It's a near minimum load.

I once had a Sauer that was hard to open after firing. The extractors did not have full free travel; starting to get tight just before seating in the breech recess.

Filed the ends of the extractors and worked fine. Too tight a fit;; needed more clearance.

Gene..is that you 3 grains over max plus a different shellcase load ?
franc

Before you get too involved in mechanical reasons the gun is hard to open, clean the chambers really well. Use some scotch brite on the end of your cleaning tool along with some solvent/oil and really scour it clean. I have cured two doubles of really stiff opening problems with nothing more. If the chambers are not clean it is possible for them to retain the hulls requiring quite a bit of leverage to get the gun open. Also cured a couple of semi autos which wouldn't properly function the same way.

First thing I'd do would be to look at my ammo.

The Stevens doubles are pretty simple and if it opens fine before fired, then it should open fine after firing (in theory).
If the pins are not sticking in the primers, then you can rule that out.

Another thing to check would be if it is in fact the cocking mechanism. The Stevens 5100 (311) cocks by the barrels lifting an arm in the base of the action. What I would do is uncock it (by dry firing it against a block of wood as to not chance breaking the pins), and then assemble the gun and open it (to cock it) without anything in the chambers. If it opens fine at that time, then the issue is related to the shells being in the chambers.

What type of ammo are you using? I have found that some of the cheap Winchester target loads (from walmart) what to expand the matal base when fired and make them stick up in the chambers of some guns. This also loosens the metal base on the shell as well. I have had some guns where I cannot put a fired shell back into the chamber due to the expansion of the shell base.
I also once had an ejector single shot that would not eject the shell due to this issue as well. Talk about a pain in the ass at the trap range...

Thanks to all who responded. The shotgun will indeed open, it's not locked, but it's difficult to fully open it.

I'm using Fiochi hulls with 16.5 gr. of Green Dot.

Me too.
It could be ejector-extractor wear. In this case it's possible to see some tracks/swellings on hull cooper.

Genelang, you may be talking about the built in limit in the gape of the 311 which is there on purpose to prevent your shells from falling out when you carry it open. That's a pretty handy feature IMHO, and I wouldn't try to change it. There is a way to do something with the cocking rods to allow the 311 to gape fully open...Geo