An Experiment in reducing recoil....

D

Dave McC

Staff In Memoriam
As some of you may have noted by now, I like to tinker. All of my shotguns have been modified, some extensively, and the process never stops.

Along with this, I'm a bit of a tightwad. Having a fixed income and three McCs in college will do that. I wear clothes and cars out before getting new ones, go around the house turning off lights and so on.

My latest(and newest) 870 is the TB that's a claycrunching death ray for trap birds. I've messed with the fit, added a Morgan Pad( A gift, told you I'm tight), learned to reload to save money, and so on.Thanks to the Hull Elf, who periodically leaves a bag of 500 once fired AA or STS hulls under my pillow, reloading costs are minimal.

And since I'm now shooting more than ever, I'm worried about building a flinch. Had one, fought to lose it, and don't want it back. And while I'm shooting light loads in a heavy gun, I'm shooting LOTS of them, and old trapshooters keep telling me how a flinch snuck up on them.

So, some of my obsession lately with tinkering has to do with kick reduction,on the Oz of Prevention Principle.

Anyway, I was on my way home from a good session with the Geezer League at AGC, when I started musing on the high priced recoil reducers like GraCoil,PFS,Edwards, etc. All of these do work, some better than others, and what they have in common is a weight, a spring or hydraulics to return the weight to the starting position, and a 3 to 4 figure price tag.

So, the little light bulb went off over my head. Weight, spring, weight, spring.....

After dinner, I sat in the room where most of my sports equipment is stored. With me I had....

A couple of trash hulls filled with shot and crimped.These are handy weights for getting shotguns balanced. A 2 3/4" hull filled with shot and crimped runs close to 4 oz.

A old 870 magazine spring left over from a makeover.

A set of wire cutters.

Both standard and Phillip's head screwdrivers.

The first hull went in the mag tube, just under the retaining ring. The mag spring was unaltered.

The second hull went in the cavity in the stock that accesses the throughbolt. Behind it, a piece of spring just a little longer than the cavity,so very slight compression was needed to get the pad back on.

The reason a gas auto has less felt recoil,per Brister, is the kick is spread out over a longer time interval. Instead of one big kick it hits like three smaller kicks, and as a result, FEELS lighter. Same idea here.

As the shotgun recoils, the shoulder and hands offer resistance,so the weighted shells keep moving just a little and are then slowed by the springs. These compress,storing energy and releasing it some milliseconds after the main recoil pulse. Result, some lessening of felt recoil.

So, now I need to figure out if the weight and spring really do cut the kick(felt recoil) more than just the added weight would, and there's a problem.

When shooting at something moving, like clay birds or game, I don't notice the kick.And I'm fortunately quite recoil tolerant. So, it's going to be difficult for me to tell the difference. Here's where YOU might come in....

This setup would have advantages when testing and zeroing slugs. Same for patterning turkey or waterfowl loads. Using both, fore and aft, means the balance stays more or less the same. Using just the aft one would not be a prob when using a pre mounted gun, or if one wanted a more muzzle light feel.

Anyways, I hope some folks out there will try this, and post their results. If this does what I think it does, lots of folks can benefit a lot from a minumum cost. What's the price of a new mag spring these days? of course, one needs some shot and access to a loader to crimp with, but that's not hard for most of us.

Thanks.....
 
Not bein an avid pump or autoloader banger, never thought of puttin it in the mag tube. While back played with a prototype that did what you talkin bout except it was overengineered and thus expensive to make. Went into the buttstock. Seemed to work. Expense made it seem unmarketable and I don't think it ever went into production.

I think you are on to sumpin Dave.

Sam
 
Thanks, Sam, an endorsement from you is indeed a compliment.

Shot two rounds today with it. The kick feels less, but I cannot quantify how much is due to the spring action and how much is just the extra weight. The weight did slow me down just a hair, and that's welcome in this case. I've been shooting a bit fast lately, and this will work better than moving my support hand forward.

I hope someone out there more sensitive to recoil than I tries this, and posts the results. Gotta hunch this can help lots of folks, and at minimum expense....
 
I suggest trying it with the weight behind the spring, such that the inertia of the weight compresses the spring. The way you have it set up now, the weights recoil with the gun and compress the spring as it comes to a stop against the resistance of your shoulder. See if that makes a difference.
 
Good idea, Jim, and I hope to try it out at some point. Meanwhile, gonna play with this a bit. A pair of trap rounds is hardly an extensive test.

With over a hundred views in less than 24 hours, obviously some folks are interested in this. Maybe some engineer/shotgunner out there is rigging up a machine rest to measure the changes, even as we type.

My hunch is there's something to it. Just adding 7 oz of weight to an 8 lb gun should cut the kick by roughly 5%.I doubt I can tell the difference. SO, since I did note the difference, ergo it's more than just 5%. Basically, it made the 1 1/8 oz handicap load I was using feel like a 1 oz, that's more on the order of 12%.

All the folks with muzzle heavy,"Serious", shotguns could benefit from the butt unit. Much as I like mine, I note they swing a bit faster with some weight in the butt, and cutting recoil on fast crisis resolution shots is a good thing. I imagine I'll set up my deer 870 with a butt unit soon, and try a fast COF with and without.
 
Reducing Recoil

Have you considered using a rod to displace the "lead dummy"
in your magazine so that it is directly over your hand ? That
may be of interest if your leading hand is far out enough to
still have room in the mag tube for some of the spring .

Hawkaaa53
 
I could put the dummy on the back end of the spring, right behind the follower. But I'm going to stay with this a while before any other mods or changes, just to see how it goes.

Still hoping some other folks will try this out....
 
Dummy Location

Dave ,

I believe your initial idea about having the "dummies" against a solid part of the gun (on the muzzle end) will be more effective
in that will allow the recoil to be absorbed over a few more miliseconds .

But , it is true that when the gun fires , the dummies will tend to
remain at rest until the spring(s) compress enough to overcome the inertia (and any friction - yada yada) of the dummies .

An interesting study , Hawkaaa53
 
It'd take a better engineer than I to chart the curves on this, but my gut feeling's that the method with the weight forward of the spring will elongate the recoil pulse more than the other way around, but that the weight behind the spring way may provide more of a reduction quicker. I doubt any of us can tell the difference. We're talking milliseconds here.

And, I wanted to keep this on the low tech side. By the time we start talking about what strength spring to use, lots of folks will lose interest.

But anyone can take it from here, any way they want to.This sure as heck isn't patentable, and I'm not trying to make a dime off it....
 
Dave,

I've got a question about the magazine spring used for the shell in the buttstock. I can't seem to find spares anywhere around town in gun/sporting goods shops. I also don't see any online. Where should I look for one?

Sincerely,
Adam
 
I had some leftovers from when I converted two of mine to extended mags. Or, try Brownell's. If all else fails, PM me with an address and I'll send the remnants of this one.

BTW, for this purpose, any pump shotgun mag spring oughta do...
 
Good idea Hawk. The spring from my TP tube is the perfect length for the hole w/ 2 20 ga. shells. My 1300 Def.'s hole is just barelly too small for 12 ga. hulls so instead of making it bigger I just downed one shell size. I'm also trying the 2 shells because I doubt the spring will compress more than a few inches, so it might be better to have 2 shells and 4 inches of spring instead of 1 shell and 7 inches of spring. I'll have to see how it works.

Sincerely,
Adam
 
An update....

I went to PGC this AM for practice and further testing. I had a mixed bag of loads with me, the 1 oz load of 8 1/2s, one box of 1 1/8 oz of same, and two boxes of the handicap trap/dove load I concocted, 1 1/8 of 7 1/2s. I shot them in no particular order. Scores ran 23,23,21,23 for a
90/100. a little lower than I'd been shooting. I blame this on lack of practice, I had to go out and get a real job last week.

It also could be I'm not grooved into this setup yet. Adding a half lb of weight, even if balance is close to what it was,does change the swing, and the laws of inertia are merciless.

Anyways, I noted that the thump was not only lessened, but after the kick there was a distinct "Click" and small thud as the springs and dummy shells returned to their starting point.IOW, some recoil was delayed enough for this to be noticed, in a process that took small increments of a second.IMO, that's a significant reduction. Felt recoil, of course, isn't much in this setup. Let's do some numbers, and remember I'm not really good at this.Anyone that is, PLEASE jump in here. And I'm guessimating,a semi wild eyed but educated guess.

Adding a half lb of weight to an 8 lb shotgun should cut the FELT recoil about 1/16th, or 6%. Let's pretend that adding the spring setup on two dummy rounds delays 1/16th(6%) of the kick long enough that it doesn't add to what's felt in the initial thrust. Voila!! A 12% reduction, about what I think I feel in that it makes a 1 1/8 oz load feel like a 1 oz, subjectively speaking.

And what's a good use here?

High volume shooters like trapshooters and those sporting Yuppies go for all the kick reduction they can find, which is why Gracoil, KickEez, etc sell.

Other shooters who are recoil sensitive, including smaller framed folks.

All of us who test heavy kicking loads, including waterfowl, turkey, slugs, and "Serious" buck. Heck, anyone who wants to benchtest and zero would like this,even my fillings get loosened sometimes when testing slugs.

Now, like that loudmouth on the Food Channel, let's kick it up a notch....

I'm gonna make another dummy round, a trash hull filled with shot and heavily crimped. T'will take but a moment to install same in the magazine, just behind the follower. Like Jim said a little while ago, this may be a better way to do this. And, with the weight in between my hands, it should alter the balance and swing little. Since the TB would still be somewhat lighter than my HD 870 with all those bells and whistles, I know I can handle it. Will advise...

And, I sure would love to hear from other folks trying this. Thanks....
 
Dave ,

If the "click" is annoying , what about putting a 1/8", or so, thick rubber 'buffer' --- something like the seal from a garden hose or
an item from a pack of seals/gaskets .

I have only auto-loaders with return spring/tube in the stock , so , I can't "play" with you pump-gunners , Hawkaaa53
 
Hawk,it's not annoying,just noticable. I could put a buffer in and I may at some point. This is still a test in progress.

Also, note that part of the stuff goes in the mag tube. You can still play(G)...
 
Went to PGC this morning and shot 4 rounds with all three "reducers" in place. Using the 1 oz, 1150 FPS standard load, I felt VERY little kick. And, I remember what that "Click" sounds like, a Ruger 10-22 firing when I'm wearing muffs.

I consider this experiment a success. It's effective, cheap, durable, and easy to install or take out.And, I bet this is as effective as all the fancy and expensive recoil reducers, back boring, porting, forcing cone stuff, etc.

So, if kick has driven you to a gas gun, with all the bbl mods and so on, this can be added to REALLY cut the kick!

I am pushing the envelope with all three installed. While it balances pretty much like it did pre test,it's much heavier(maybe 13 oz) and has inertia. I shot over some straightaways because of it, but I'm sure I'll adapt.

Waiting to hear from y'all about this, thanks...
 
You must log in or register to reply here.
Back
Top