wow was my cap froze up. i tried to remove it this past weekend only to find it not wanting to turn. i had to use a set of channel locks and rubber pad to grip and remove the cap. the inside of my threads on the cap are rather rough looking. what i'm saying is the steel in the cap is definatly prone to corrosion as noted above. i have the internal threads filled with some kroil as i type. i'll let it soak over night and clean tomorrow.
if they are still pretty bad looking should i inquire with Beretta about a new cap? or just make sure i use a greese on the threads and check & clean the cap assembly often?

I'd say clean it up, grease it, and give it a try. If there is enough thread left to let it screw down to compress the spring inside, and stay that way while you are shooting, then it should be OK.

Seamus; Thank you for the disassembly manual. This is a terrific resource for Beretta 391 owner's. Have you tried placing the 391 fore-end cap in an ultrasonic parts cleaner? I wonder if this method would clean out the cap without taking it apart?

Scott

By accident I found the simplest way to clean it. Don't use it! I bought the Briley aftermarket weighted cap to counteract the weight of a recoil reducer. It is simplicity in itself. Four parts; only two move. Unscrew the two outer parts and the spring and a sliding sleeve are easily removed and cleaned.

Just my 2¢ worth.

Amen Benedict1. This is the best cure. The Briley is KISS simple and works great for me. Dont know why Shamus wants to stick with the OEM.

I have to agree with Seamus. Why should I spend money on a new Briley fore-end cap? Should I toss out the entire gun just because it needs to be cleaned? The OEM cap works just fine if it is properly maintained. I cleaned the threads with a Dremel tool and applied a little bit of anti-seize compound. I'm not convinced the fore-end cap design is Beretta's fault if I choose to use loads with powder that does not burn cleanly.

I solved two problems with the Briley cap. I have a recoil reducer on this gun for high volume trap shooting and it needed a counterweight. The easiest solution is add weight to the forend cap. Only other alterantive is a barrel weight which looks kinda weird. I chose the cap and got a bonus.

I don't have a Dremel tool and don't need to spend $$ to get one with this.

What "clean" burning powder do you recommend, BTW? I have shot scatterguns for 45 years and haven't found one yet that doesn't foul a gun sooner or later.

I agree that the clamp-on barrel weights don't look so great. I can see where the Briley Cap makes sense in your case if you are using it as a counterweight. But for $60 plus shipping, I'll stick with the OEM cap. Does using a Briley cap void the warantee on a new Beretta?

I've owned my Dremel tool for many years and did not purchase it to solve this problem, though most of what I use it for is usually related to guns. It takes off really stubborn powder residue faster and more efficiently than Break-free Powder Blaster or PB Blaster.

No powder burns completely clean, but with 45 years experience, you obviously know that some powders leave a lot more residue than others, and that powder residue is corrosive.

I shoot about 6'000 rounds through my 391 each year, and I never have a problem with seizing of the forend nut. How come? simple, I didnt reinstall the retaining circlip after I first cleaned it! each time I clean the gun the forend nut comes off allready disasembled, making it simplicity itself to wipe and clean the parts... No need to struggle to get the D**M thing out and back in !

Sounds good Wolfie. How often do you clean the 391?

Sorry for the delay there Bell, I have only just revisited this thread ! I shoot 100 competition each week

and clean my gun each time, after the nut had started to seize the first time I stripped it down, cleaned

it and reinstalled it without the circlip. after all the circlip only holds it together when off the gun. once on,

it cant come apart.

Had my cap seize up. I turned the gun upside down and put liquid wrench on it for about two days......no go.
I took my shrink tube heat gun (400 deg. output) heated the cap until HOT used a pair of slip joint pliers and a cotton rag covering the cap and it screwed right off with NO problem.
Lucky? Maybe............but it did work for me...........

I have the new Beretta A400 Xplor. Do I need to monitor/maintain the fore-end cap/nut as well...seems it is made of some kind of hi-technopolymer. Again, there is no note in owners manual in the maintenance or special maintenance sections referencing the fore-end cap; other than "screw it on tightly", or "unscrew it counter-clockwise". Thank you for your kind assistance!

I have no experience with the A400. Beretta says the fore-end cap on the A400 never needs maintenance, but then again, they didn't tell you that the fore-end cap on the 391 does need maintenance, did they?

Just bought a 391 20 ga that the cap is froze up solid. I soaked it for 6 days now in PB Blaster and still solid I tried some heat and was going to replace internals but still solid even with heat and melting the inside plastic or nylon piece. I think I will check into the briley cap as some have said. Any other ideas?

Yeah. Get a new factory cap, swap out the retaining ring to make it easier to get apart, and clean it now and then.

It does not need to be cleaned often, but it should be checked often to make sure it is not locking up.

I wouldn't buy a Briley cap just for the hell of it, but if I needed a replacement cap I would pick up the Briley. Much easier to deal with from a maintenance standpoint. That's just my pref though. Both do the job.

Seamus,

Great article. I only wish I had seen it before my barrel lug weld came apart as in your picture. I oiled it regularly but as your illustration showed, cleaning and oiling m,ay not be enough and dismantilling is the key.
It's really a shame they have such a poor design and for get about any help from berreta if it's out of warranty.
Sad how companys tought how superb their craftsmanship is until it breaks and they have a 1 or 2 year warranty when clearly a barrel should be manufactured for longer and to sustain.
No more berretas for me, But for now, anyone having a 30" mobilchoke barrel, plz IM me

OR

DON'T buy a 391!

I'm new to skeet and sporting clays having just started 6 months ago at our local gun club. I bought the Beretta AL391 and have only 1500 rounds through it. My forend cap seized up already and using pliers and a cloth, managed to get it off but not easily. The cap got scratched up from the pliers slipping and when pushed against the table top, it does not give at all. I ordered a replacement cap (OEM) from Cole Gunsmithing and put a few drops of oil before screwing it on.

After reading this article, I am going to try cleaning the original cap IF I can take it apart.