Article 5 – 2017

Question: I am looking to reduce the recoil in my field shotgun, as it tends to boot me quite a lot especially with 32 gram hunting loads. I don’t want to spend a lot of money and purchase a fancy recoil reducing stock, but I was told there is a new recoil reducing device available which is filled with mercury that I can simply screw into to the back of the stock. Can you advice me that in your opinion does this type of thing work?

Jason Stockdale, Altona VIC

Answer: There have been many recoil reducing devices such as the one you are referring to that have been available on the market for many years Jason. Despite what you think this is certainly not new technology and believe it or not they do work, but probably not for the magical reasons may think. They work simply due to principle in a simple recoil equation. I will give you a quick lesson on the mathematical on the laws of physics in relation to this matter. For the purposes of explanation let;

M=mass of the gun

m=mass of a bullet

u=velocity of the gun

v=velocity of the bullet

Solving for u tells us the recoil speed is -mv/M. Initially the gun is at rest so the total momentum is zero. So momentum becomes Mu+mv =0. Solving the recoil speed is -mv/M. Therefore we use momentum to derive the recoil of gun.

With all of that we can get the result;

recoil speed=(mass of bullet*velocity of bullet)/mass of gun

To simplify this equation in laymen’s terms Jason by increasing the mass of the gun (for instance adding a 250 gram recoil reducer) you are simply adding weight to the gun that reduces recoil speed or the amount the gun is booting your face or shoulder.

We can make up fancy marketing rhetoric about the benefits of recoil devices to the end of time, but simply nothing can alter the laws of physics and that simple mathematical equation.

The positive side of your recoil reducer is that it will certainly help once the mercury filled device has been added to the interior of your stock, the downside is that it the balance point of the shotgun will have been altered significantly and the shotgun will now probably be balanced very much towards the rear of the gun or “stock heavy” which will make the firearm more difficult to control. Adding weight to the front of the gun to achieve perfect balance will probably have to happen. You can do this by adding a barrel weight that of course will further decrease the shotguns recoil.

This is a subject we have visited many times over the past decade in different forms. The other ways to reduce recoil may be to use a slower shot shell or one with less shot. These factors are again simply components of the mathematical equation of recoil. There is no magic in this I am afraid.

Question: I have a Miroku model 10. I bought it second hand and it was in pretty new condition. I estimate in total it has fired about 5,000 rounds. I was told the barrel life of most shotguns is between 50,000 to 100,000 rounds. Not that I think I will get to this amount any time soon, but I was wondering if that was true?

James Catling, Ipswich QLD

Answer: Personally I have never seen any brand of barrel worn out. I have met some American trap shooters that claim their barrels have fired over 500,000 rounds and have never missed a beat and still shoot as straight as the day the firearm was purchased. I have no doubt this is true. The hinge pins holding the barrel to the mechanism of the shotgun do suffer from wear and tear and will need replacing from time to time, but never the barrels. Miroku have always been a very good brand with barrels made to last a lifetime. The shotgun will probably outlive you James.