Monday, July 25, 2016

Beretta A400 Excel Piston Ring

I ran onto a shooter that had a piece broken off his Piston Ring (part of the piston assembly) . 

He said his gun was still working. 

I did some reading on the subject, as always interested in what spare parts to carry.

First off.  The piston assembly on the A400 needs to be inserted into the barrel cylinder before inserting the barrel into the receiver.  If not, you can bend the ring. 

Will something else cause it to deform?  Have no idea. 

I've read some have a habit of sliding the barrel cylinder on the part where the forearm cap attaches and not into the barrel cylinder.  They marry up once the barrel is installed, but I guess not always 100%.  If I hadn't read this could be a problem I wouldn't have never given it a second thought.

The piston ring bending (deformed) is not common.  If your at a shoot you can try to bend it back into shape and you should be able to finish.

My readings didn't come across a broken ring, but seeing is believing.

You can remove the old ring and install the new one yourself.

The serrated ring needs to be squeezed to reduce the diameter before inserting back into the gas cylinder.

A replacement ring at Cole Guns is $18.05.  Shop around you may save a few bucks.  If you have an A400 Xtreme it's a different part number.  Make sure you purchase the part for your model.

Speaking of Barrel Cylinder.  Next time you clean your A400 take a light (I took mine outdoors) and shine it on the area of the gas port.  I found a good bit of buildup.  After given it a good cleaning I made sure the gas port was clear.  Nothing fancy in regard to the gas port, used a large toothpick.  You may feel safer using a thin drill bit.


2 comments:

  1. The left side of the ring opening seems to be shape like a L .. if right side was shape the same but inverted and the pistom slam into the cylinder without being seated correctly it could snap.
    Best advise NEVER take the ring off the piston,it is not made of spring metal and will deform if you take it off. For cleaning just soak the entire assembly in solvent and be carefull when you wipe it dry .

    P.G.

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    1. I just take a tooth brush and solvent. Couple of minutes of brushing and done.

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