The Firing Line Forums

Go Back   The Firing Line Forums > The Hide > The Dave McCracken Memorial Shotgun Forum

Reply
 
Thread Tools
Old June 7, 2011, 08:44 AM   #1
Lance1
Member
 
Join Date: October 15, 2008
Posts: 25
What is the theory of recoil reduction in stock?

Looking on the web for ideas to reduce recoil for my 12GA, I've come across a few ideas, some very expensive.

Two cheap ideas was a steel weight with springs on both sides inserted in the stock hole. And the other fill a container with lead with no springs and inserted in the stock hole (can't tell if it's meant to slide or just add weight). Then there is the Edwards mercury, etc.

Is this weight suppose to slide? If so, is the weight best to start at the back by the pad and slide forward on recoil?

Would this few ounces of weight help much with magnum loads?

Any homemade recoil reduction ideas?
Lance1 is offline  
Old June 7, 2011, 10:27 AM   #2
oneounceload
Junior member
 
Join Date: April 18, 2008
Location: N. Central Florida
Posts: 8,518
The BEST way to reduce recoil is to:

Shoot the HEAVIEST gun with the LIGHTEST loads in a gun that FITS.

There are 2 types of recoil - actual, which is a math equation based on weight of the gun, mass and velocity of the payload

and perceived or felt, recoil which is based entirely on gun fit

If your gun doesn't fit, then adding gizmos and weight and springs will do nothing to stop the bruise to your cheek or shoulder.

All of the recoil pads, hydraulic/spring/air cushion devices do is spread the recoil pulse over a longer period of time (measured in milliseconds).

If you are going to only add weight to the buttstock, you will upset ANY semblance of balance unless you also add weight forward as in under the forearm

Which recoil are you trying to reduce?
oneounceload is offline  
Old June 7, 2011, 11:39 AM   #3
Dave McC
Staff In Memoriam
 
Join Date: October 13, 1999
Location: Columbia, Md, USA
Posts: 8,812
An old thread here "An Experiment in Reducing Recoil" I wrote way back may help you.
Dave McC is offline  
Old June 7, 2011, 03:46 PM   #4
John L. Smith
Member
 
Join Date: March 3, 2010
Posts: 40
One Ounce is right, the heavier the gun is the less it will kick you. As an example I bought one grandson a Chas. Daley youth 20 ga pump and it has a pretty good kick. I finally got him to shoot my Maverick 88 and he told me it didn't kick as hard as his 20 ga. Well right then I needed a new shotgun. I bought a Mossberg 535 which weighs 12 oz. less than the 88 and it lets you know the difference. I put about 6-7 oz of weight in the stock( locked down ) and it makes a big difference. I haven't noticed any difference in the balance. Am sure if I would have put more weight in stock it would effect the balance.
My patent is, I took a piece of 3/4" PVC pipe cut to the length of the hollow stock and inserted 3- 2 oz lead sinkers. Hot glued the ends and the back end of pipe to stock. Guess you would call this redneck engineering.
John L. Smith is offline  
Old June 7, 2011, 04:12 PM   #5
oneounceload
Junior member
 
Join Date: April 18, 2008
Location: N. Central Florida
Posts: 8,518
John - IF you find your forward balance now disturbed, what many with pumps are doing is taking an empty hull, filling it completely with lead shot and inserting it behind the mag stop so that it does not sit in your magazine ready to go into your action - downside is you lose 1 capacity - upside is your gun might balance and fit somewhat better
oneounceload is offline  
Old June 7, 2011, 04:59 PM   #6
idek
Senior Member
 
Join Date: August 20, 2009
Posts: 602
It doesn't look like anyone specifically addressed "mercury recoil reducers." I believe the theory behind them is that when recoil pushes the gun back, the mercury initially stays in the same place ("an object at rest remains at rest" kind of deal). A fraction of a second later, the mercury's momentum moves back in the direction of the gun, but the idea is that the recoil is being spread out of a longer period of time and multiple, lesser recoil impulses instead of one sharp one.

Perhaps the best way to visualize this is to think of a gallon jug of water, 1/4 full. If you try to slide it across a table, it won't slide in one smooth motion. It will move a few halting jerks as the liquid shoshes back an forth within the container. With the mercury recoil reducer, the gun is the container, and the mercury is the liquid. Obviously, 14 oz of mercury in a 7 lb. gun is different than 32 oz. of water in a 6 oz. jug, but the premise is the same. I suspect putting a weight between two springs in a stock is supposed to work along the same theory--objects shifting at slightly different times.

As oneounceload said, more weight can reduce free (or actual) recoil. Adding 14 oz. to a 7 lb. gun, for example, would reduce free recoil (or actual recoil) by about 11%, whether it's a $70 recoil reducer or <$1 worth of lead shot. Whether or not the the recoil reducer does much more than add weight is questioned by a lot of people.

Last edited by idek; June 7, 2011 at 05:05 PM.
idek is offline  
Old June 7, 2011, 05:57 PM   #7
zippy13
Senior Member
 
Join Date: August 23, 2008
Location: SoCal
Posts: 6,405
It's about time...

Most shooters don't give a hoot about the mechanical calculations required to determine a gun's recoil force, but they are concerned about reducing felt recoil, or kick. It's fairly easy to understand when you know what's involved. There is only one factor that your body reacts to, and that's what's known as unit stress. Stress is simply the force divided by the area resisting the force (we commonly use PSI). The greater the area you have resisting a specific force, stress and kick are reduced. There is also another, often overlooked, factor involved which is time, or the duration of the event. Time makes the difference between a punch and a push.

There are some basic ways reduce kick:
  • One way is to maximize the gun's contact area with your body. This is were a proper fitting stock is important. You want the recoil to be balanced across the body parts that are in contact with the gun -- taking the majority of the recoil in your face is no fun. Your goal is to have the recoil absorbed by as much tissue as possible. A proper fit must be accompanied by a firm grip in the gun.
  • As my friend oneounceload mentioned, reducing the load (mass and/or velocity) and/or increasing the gun's weight will reduce recoil and kick. But, this can be taken to the absurd -- who want's to shoot a 20-pound BB-gun?
  • Recoil can be reduced by energy energy absorption and/or redirection. Porting and compensators redirect some of gas energy. Other devices convert recoil energy to other forms (heat).
  • The most effective way to reduce kick is by buffering, or increasing the time involved. While elastic materials, inertia masses, air cylinders, and springs may convert a little energy to heat, they are most effective in increasing the recoil event. They effectively turn the recoil punch into a push.
  • Another factor to consider is basic geometry. The higher the bore line is above the butt plate, the more the gun will want to rise the muzzle. A stock with a lot of drop may be the reason you're getting whacked in the face.
When I started competitive shotgunning (after many years of casual shooting), the cumulative kick from more rounds got me looking for some help. After trying various methods, I finally found relieve using air cushion systems. A key factor with these rigs (JS and Shockmaster) is the cheek contacts the gun after the buffering (telescoping stocks). Some of the other systems buffer your shoulder, but not your face.
zippy13 is offline  
Old June 7, 2011, 06:31 PM   #8
BigJimP
Senior Member
 
Join Date: February 23, 2005
Posts: 11,340
You've gotten all the technical answers ... but keep it simple ....increase the weight of your gun ( yes you can tape a spent shell full of shot into the stock of your gun ) ....but don't let it move around. Get it set / so the balance point of the gun remains the same. Ideally, I like to add about 8 oz under or inside the forend / and 8 oz in the stock ... and adding 1 lb will reduce the recoil about 20%.

Shoot shells with 1 oz or 7/8 oz of shot ....and keep the velocity down to around 1200 fps or even drop it to 1150 fps ... If you reload - that's easy to do.

Expensive ..?? is relative ..../ personally, I've added a GraCoil system to my primary Trap gun - and it helps a lot. Mercury reducers work pretty well ...but so do the homemade solutions.
BigJimP is offline  
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 02:03 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2014 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Contact Us
Page generated in 0.07310 seconds with 7 queries