Browning Auto-5 troubleshooting

[Pitch]

I picked up my "new" Auto-5 12-gauge from my FFL today. It was made approximately 1934 in Belgium, and is in good cosmetic condition. I tested all the controls and they worked fine. My problem showed up the second time I tried to use the bolt release button. Now the bolt is locked back, and the button will not release it. It will not come forward if I try to trip the release by pushing the barrel back against the bolt. I am sure that it released just fine earlier this morning, and didn't make any obvious noises of something breaking.

I'm also not sure that it's loading from the magazine correctly. The owner's manual from Browning describes a speed loading feature, where loading the magazine with the bolt open will automatically chamber a shell. That doesn't happen with mine. It also doesn't attempt to load when I try to cycle it by pushing the barrel. I can reach into the chamber and depress the carrier with my thumb, in which case it does begin to load a shell. The shell doesn't come out of the magazine far enough for the carrier to raise it, but I'm not sure if that's an issue with it catching on something or with the magazine spring.

Where should I begin? I haven't opened it up yet, because I still need to buy some screwdrivers to grind down for those narrow-slotted screws. The best case is that my problem is just a misunderstanding with how the gun works. If not, then I hope it's only one or two minor pieces that need replacing.

Edit: Well, I'm embarrassed for using my first post for this. I think I found the problem. The Auto-5 has what I think is a loaded chamber indicator on the left side of the receiver. It sticks just a little too far in, and the shells get caught on it when trying to load from the magazine. Some part of the mechanism will not allow the bolt forward when it's not loading properly.

Now, how do I fix it?

 

[zinj]

The Auto-5 has what I think is a loaded chamber indicator on the left side of the receiver. It sticks just a little too far in, and the shells get caught on it when trying to load from the magazine.

That is not a loaded chamber indicator. It is a magazine cutoff. Flip it forward to turn it off.

I'm also not sure that it's loading from the magazine correctly. The owner's manual from Browning describes a speed loading feature, where loading the magazine with the bolt open will automatically chamber a shell. That doesn't happen with mine.

Auto-5s made before the 1950's have a one piece carrier, not the two piece "Speed Load" carrier. The bolt release must be pushed in to release the carrier and allow the loading of the magazine.

It also doesn't attempt to load when I try to cycle it by pushing the barrel.

DO NOT DO THAT WITH A LOADED AUTO-5! It is a good way to accidentally blow your head off. The Winchester 1911 was an early competitor to the Auto-5 that required the user to depress the barrel to chamber or eject a round (Browning held the patent to the charging handle), and got the nicknames "Widowmaker" and "Head-buster" for this reason.

The shell doesn't come out of the magazine far enough for the carrier to raise it, but I'm not sure if that's an issue with it catching on something or with the magazine spring.

Weak magazine spring.

Where should I begin? I haven't opened it up yet, because I still need to buy some screwdrivers to grind down for those narrow-slotted screws. The best case is that my problem is just a misunderstanding with how the gun works. If not, then I hope it's only one or two minor pieces that need replacing.

No offense, but you don't have enough experience with this model to be taking it apart. They are like a Swiss watch inside. If you still cannot get the bolt to close bring it to a gunsmith.

 

[Pitch]

Thanks for the safety advice. I'll definitely remember it, but in this case the "shells" I was mucking about with were actually snap caps.

That is not a loaded chamber indicator. It is a magazine cutoff. Flip it forward to turn it off.

That's not the piece causing the problem. I think that it's the "cartridge stop", judging from the Owner's Manual schematic. I have to admit I have no idea what it does, or if my problem is actually what it's supposed to do. When the gun tries to load from the magazine, the shell is pushed a half-inch out, at which point it just barely gets caught up on the cartridge stop. The "problem" with the bolt release seems to be the gun saving me from my own stupidity by refusing to close with a shell in the process of loading. I made the educational mistake of reaching in and giving the cartridge stop a slight push to move it out of the shell's way. Once I did that the snap cap popped into the chamber and the bolt closed on my finger.

Does my cartridge stop need adjustment of some sort? Or is it really the weak magazine spring, and the normal operation of the Auto-5 is for the force of the spring to just push the stop out of the way?

 

[zinj]

It is the weak mag spring, my own gun (which does need the mag spring replaced) will do this on the last two rounds if you are hand-cycling it, but feeds them fine when the gun is fired. Replace the mag spring (the retainer will pry out the same way as an 870) and it should fix the problem.

 

[Big Az Al]

The cartridge stop

Is in the left side with, a tab that sticks up barrel high, you see the tab showing thru the left side of the frame a little above and behind the magizine cut off.

If it is worn it will not let the shell move far enough back to trip the carrier release, and let the bolt close.

I have replaced and retimed several of the cartridge stops, they can wear out, or sometimes a new barrel won't move it enough to work.

 

[Pitch]

I have another newbie's question. I bought a new magazine spring from Brownells. It's marked as a 12-gauge mag spring, but it's about a quarter-inch narrower than the old spring, and it fits right through the center of the retainer. Am I right in thinking that it's probably a 16- or 20-gauge spring in the wrong package?