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391 End Cap Seizure

Discussion in 'Shooting Related Threads' started by rogertc, Sep 3, 2009.

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  1. rogertc

    rogertc Member

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    Gentlemen
    I'm a new 391 owner and need your help.

    I see it on Briley's site and posted on this site where if the spring and plunger seize inside a 391 End Cap it will cause the cap to be very difficult, to impossible, to remove. I see recommendations to replace the guts in the end cap with a stainless plunger to eliminate the problem.

    I really can't see how, if the cap internals seize up, it causes the cap to seize on the threads. How are those two related?

    I can imagine a scenario where the internals of the cap have seized up and the barrel is hot and has expanded putting a load on the cap threads because the seized spring and plunger won't allow the barrel to expand. Theoretically the problem would go away when the gun cooled. Anybody know if this is the real problem?

    Has anyone coated the internal parts and the threads with anti-seize? Did it work?
     
  2. BigM-Perazzi

    BigM-Perazzi Well-Known Member

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    As a new 391 shooter, I would recommend discussing this with Tron on this board. The issue is very real, and is recognizable by the channel lock and vice grip marks on the end cap......
     
  3. mike campbell

    mike campbell Active Member

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    It's true and you have to find a way to deal with it, whether you understand it or not. I've tried every lubricant in my shop as well as never-seize. Doesn't matter what I put in there, if I shoot 50 rounds and put it away, it WILL seize....every time. OTHO, if I simply loosen the cap immediately after shooting there's no problem. The trick is to loosen it a great deal,so the forend is so loose you can't possibly miss the fact next time you go to shoot it. On those occasions when I forget and it seizes, I use a plastic strap wrench to break it free.
     
  4. 635 G

    635 G Well-Known Member

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    Angleport sells a great cap, it will not seize. I used CLP when I shot a 391. Never seized up.

    Phil Berkowitz
     
  5. Mike Battista

    Mike Battista Well-Known Member Supporting Vendor

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    I(f the end cap has seized up it likely is rust. You have to keep grease on the threads. You will most likely have to cut through the cap stem. You will have to replace the cap stem and cap. We have tried soaking a seized 391 cap in everything here at the Silver Dollar with no success. You are probably looking at about $50.00 in parts from Beretta.
    Mike Battista
     
  6. Mark S

    Mark S TS Member

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    If you shoot thousands of rounds a year with your 391, or you shoot dirty ammo,you need to modify the end cap. Works like a charm. All the instructions are in a book called "Beretta 391 Disassembly" by Seamus O'Casiside. (1007 Christie Rd., Richmond, Va 23226) Appendix #3, page 41. "Simplified Forend Nut" It is a simple fix and turns the inside of the cap into a model 390 cap. End of the frozen cap problems. Works like a charm.
     
  7. Dickgshot

    Dickgshot Well-Known Member

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    If you shoot a 391 you absolutely should buy the book Mark S. is referring to it. It's what an owners manual should be. Nevertheless, to modify the cap, click onto this link which is the excerpt from the book:

    http://www.shotgunworld.com/bbs/viewtopic.php?t=79775
     
  8. Tron

    Tron Supporting Vendor Supporting Vendor

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    The endcap problems were caused by corrosion and incompatable materials. The new caps are made from a different steel and the guts are stainless with a stainless sleave that the plunger rides one. Most of the problems would be caused by people putting their 391's away in one piece in a sock or soft case and not cleaning/lubing the cap and threads. Also, if the plunger froze up, the cap would not seat the forearm properly and the forearm could move slightly forward, gas could escape and the forearm could crack/splinter.

    In the picture, there is the old style cap on top and new style on the bottom labeled A-F. Also note the stainless sleave between C&D that is only with the new design.

    <a href="http://smg.photobucket.com/albums/v712/Tronspace/?action=view┬Ąt=100_2749.jpg" target="_blank">[​IMG]</a>
     
  9. Rick Barker

    Rick Barker Well-Known Member

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    If you don't have a strap wrench, use an old leather belt or length of one, and put between the jaws of the pliers and the end cap.
     
  10. rogertc

    rogertc Member

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    Gentlemen

    Thanks for all the great responses. A special thanks to Tron for the picture of the new and old caps and his explanation of the problem. Seems my new 391 has the old style cap (an accident waiting for a place to happen)! Seamus book is on order. The Angleport cap is aluminum as are the threads. Screwing an aluminum cap on a steel rod in a high heat area is not a very good idea. Looks like the new style Beretta cap with the stainless guts would be a better way to go. Anyone had problems with the new style cap?

    Roger
     
  11. Shady Creek

    Shady Creek TS Member

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    As Tron said,it is part of the gas system. I've got the old style on my 391's and about once a year I take them apart to clean. I use a dab of wheel bearing grease (boat trailer)and the rest of the year I use Break Free, turn it upside down on the table and compress the spring several times to make sure it's free.

    Another thing, make sure the end cap is tight before you start shooting and DO NOT re-tighten when when the gun gets hot.......You will think it seized up on you.

    I hope this helps, it has worked for me and my old end caps. GOOD LUCK
     
  12. rogertc

    rogertc Member

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    Coles has the new style caps with the stainless guts (plunger and sleeve) for $32 + shipping. Got one on its way. Thanks for the heads up about the new style Tron. This and some of my 2600 degree LPS anti-seize should prevent any problems.
     
  13. Dickgshot

    Dickgshot Well-Known Member

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    I just ordered one by phone but the guy who took the call didn't seem to know that there was an old one and a new one. How did you know you are getting the new one?
     
  14. Frank C

    Frank C Well-Known Member

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    SO, for what appears to be such a common problem, and relatively simple solution........why isn't Beretta listening?? (And I SHOOT a Beretta and own several)
     
  15. Tron

    Tron Supporting Vendor Supporting Vendor

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    Beretta doesn't always listen....they are STILL putting the straight carriers on after all. Just plain stupid sometimes.
     
  16. rogertc

    rogertc Member

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    dickgtax

    The office staff was out to lunch when I called so the gunsmiths were answering the phone. The guy I talked to (a gunsmith) knew there was an old and new cap. Thanks to Tron I knew the plunger was either blue steel (old style) or shiny stainless steel (new style). The one he pulled for me had the shiny stainless plunger so I ordered it. Angleport has their aluminum cap (stainless guts) for $75 or their replacement stainless plunger for $35. The Beretta steel cap with the stainless guts seems like a bargain at $32!

    Roger
     
  17. BIGDON

    BIGDON Well-Known Member

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    A pipe wrench and a small sledge works great.

    Don
     
  18. Spanky

    Spanky Active Member

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    Posts like this are great posts. I'm a Beretta owner, AL 391 Urika Trap Optima I use as a back up gun and an AL 391 Urika 2 Sporting Optima. Cleaning is a bit extensive vs. a Remington or Browning but, in the long run as far as a quality target auto goes they are better than the fore mentioned. To me the cleaning is well worth the effort. I'm a big Remington and Browning fan but I have no negatives about the Beretta autos. I clean mine thoroughly every 400-500 rounds and use high temp grease in the threads. Note, new from the factory there was grease on those threads. Seamus's book is top shelf. Beretta's owners manual isn't for sh!#. You need to have a few special tools to clean a Beretta properly. Longer reach snap ring pliers, o-ring picks, X-tra fine Scotch Brite Pads, small brass bristle brush and a small 1/4 " plastic dowl rod w/ a slit cut in it. These tools will not set you back very much and will be around as long or longer than the gun.

    Also, another big no no is. Don't forget to install the red plastic bushing in the fore end if storing your gun in 2 pieces. End cap and fore end could be damaged just as bad or worse.

    Going out and shooting 100-200 rounds than throwing your gun in a slip for a week or so until you get it out again isn't too good especially in wide temperature variations. There are a few good things about having a break down style case. The plastic Beretta case is no prize but, there are a few aftermarket ones that are not too expensive.
     
  19. rogertc

    rogertc Member

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    You gotta love this forum! You can ask for the time and end up knowing how to build a watch.
     
  20. Spanky

    Spanky Active Member

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    I know there are alot of guys on here that are not mechanically inclined and could use some help. Beretta maintenance isn't 1100 maintenance.
     
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