Automatic Shotguns - Recoil vs Gas Operation

If you've looked into automatic shotguns at all, you may or may not have noticed that there are 2 different operating types.

The first and oldest type is the long recoil principle of operation.  When the shot is fired, the barrel and bolt recoil into the receiver.  The barrel then moves back forward into its normal position.  The spent shell is ejected as the bolt continues its rearward movement.  At this point the barrel has returned to its normal position.  The bolt now moves forward, picks up a new shell from the magazine, pushes it into the breach, and locks to the barrel.  All this happens in the blink of an eye.

Our old friend John Browning made it all look so simple, but there is a lot going on.  In the following diagram you will see arrows pointing to 2 springs.  The fat spring on top is the barrel's recoil spring.  This is what the barrel acts against under recoil.  Just ahead of that spring you will notice a bronze friction ring.  This ring acts like a brake to take some of the shock out of heavy loads.  The skinny spring handles the recoil for the bolt.

I am unaware of any recoil operated shotguns currently in production, however there are millions of them on the used market.  You can spend as little as $150 or several thousand.  Some people say that these recoil shotguns kick like mules.  Indeed they will if heavy loads are used without adjusting the friction ring.  It's important to understand your gun and follow the instructions so that it will cycle the shells you plan to use in it.  There is nothing wrong with the recoil guns.  Some, like my 11-48 actually cycle all shells without adjustment.  Most, like the Browning Auto 5, require adjustment of the rings to operate reliably yet not tear your shoulder off.  

The second, and most recent, operating system is gas.  Gas operated rifles had been around for many years before shotguns began to use the system.  Basically, drill a hole in the barrel (gas port) and vent some of the gas from the burning gunpowder to push the bolt backwards.  Gas guns have the advantage of cycling all loads well, while not having a recoil spring on the barrel.  The barrel doesn't move either.  One example is the Remington 1100.

My arrow is pointing to the gas piston of a Remington 1100.  This piston is pushed backwards by the gas siphoned off of the barrel.  The 2 action bars look very similar to the ones on a pump shotgun.  Indeed they both cycle the action, but the autoloader does it automatically and the pump uses your muscle power.  You may be wondering about the spring labeled #3.  It is not a recoil spring, it just returns the piston to its position after the shot is fired.

Gas guns are the current standard of automatics and generally work very well.  They must be kept clean, as powder fouling will clog up the works.  Also, you must keep an eye on your o rings.  These rubber seals are essential to the operation of the gun.  If they are damaged or hardened, you will have issues.  

Personally, I have shot gas guns and I think they are just great.  It all depends on the manufacturer and how good their design handles different loads.  I've shot the Remington 1100, 11-87, and the Mossberg autos.  I like all of them, but I do not own any gas operated shotguns.  Instead I have gone to the recoil gun.  Honestly, the Remington 11-48 that I have has served me well.  I didn't buy it because I prefered a recoil gun, I bought it cause it was cheap.  But, it has been a great gun.  My Dad has enjoyed his Browning Auto 5 magnum for years now.  Call us old fashioned if you will, but these old recoil guns treat us well.  Set them up properly and recoil is not an issue.    

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