doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com OT: Recoil

I have a 12 gauge Merkel with 3" chambers that weighs 6 pounds 12 ounces. A three inch shell produces pretty good recoil but manageable. Does anyone know how this shotgun recoil compares with the recoil of a big double rifle, say 470 Nitro Express? Is there a table with this information available? I was bird hunting in Africa last month and I sort of got hooked on shooting plains game also. A double rifle isn't really necessary but would be great fun.

Richard,

If you can find all of the particulars, this calculator may assit with your question. http:www.handloads.com/calc/recoil.asp

Good luck,

Kurt

Here's another one: http://www.zknives.com/bali/brcstgn.shtml
I'm not sure if shotguns and rifles are figured the same but if you have the charge wt., bullet wt. velocity and gun wt. It will be close enough to compare to a shotgun you have the praticulars on. JL

between shotguns and rifles they would be figured exactly the same except the velocity of the escaping powder in a shotgun should be quite a bit less than in a rifle. rifles are usually taken to be 4700fps for the powder but this is a working average and going from extremes like 45-70 to 378 wby they'll be way off to either side of that.

for shotshells, the weight of the powder charge is so small compared to the weight (well, mass actually) of the shot that the velocity of the powder is of little significance. not like in the case of say a 416 rigby where the powder charge is 1/4 that of the projectile.

i looked on champlins site and he's got 470 class dr's ranging from a few oz over 10# to right at 12# which will change the recoil quite a bit but as a rough #, a 3" magnum 12 of that weight will be around 30ftlbs. an 11# 470 class rifle will be abt 70. these #'s can vary widely depending on load used and gun weight. rough #, figure 2.5x the 3" mag 12.

roger

Hatcher suggests a method for figuring recoil in which muzzle velocity only is used but the powder charge weight is given a compensating figure. He recommends using from +25% to +75% depending upon muzzle pressures. Shotguns would be on the low side with high intensity rifles on the high end. I suspect that a lot of the big double rifle sartridges which operate at somewhat lower pressures than more "Modern" rounds would be sort of middle of the road @ about +50%. Another thing of consideration is the velocity of recoil. A 9lb gun recoiling at the same velocity as a 6lb one will have 50% more recoil energy. However if two 6lb guns were loaded to give one 50% more recoil velocity the energy would be increased by 125%.
Miller

i've long felt that aspect of recoil isn't given enough attention. rather all the emphasis is on the raw # of ftlbs. but just as the math for kinetic energy of the projectile (bullet, shot, whatever) is biased towards velocity, so is it for the gun. 50ftlbs of recoil in a light gun compared to the same 50 in a heavy gun is going to feel totally different and my impression has been more uncomfortable. the light gun being a much more abrupt, harsher jab and the heavier being a slower, longer drawn-out shove.

i happened to realize when i said 30ftlbs for a 6.75# 12 ga i was basing that on 1-1/4oz and 3-3/4 dram loads. that's not really 3" mag. i've got an excel spread sheet done up to calculate recoil energy, gun velocity, and gun momentum and only have to input the projectile weight, powder weight, muzzle velocity and gun weight. don't have load data handy for 3" magnum 12 but i'm betting between a 3" mag 12 at 6.75# and an 11# 470 the difference will be less than twice and i'd not be surprised if the actual "felt" recoil difference were even less than that. i'd expect a 6.75# gun firing 3" mags would have rather brisk recoil. in fact, it looked like the velocity of the recoiling firearm would be almost the same for both. the rifle would still have a faster acceleration to that velocity but also has almost double the inertia to overcome before it even starts moving.

roger

For handguns a rule of thumb is powder velocity is 1.5 times bullet velocity.

Stock fit has a GREAT deal to do with perceived recoil. My Wm. Evans double rifle is quite comfortable to shoot, the Brits knew how to design a stock. But my Winchester M1894 whacks one all out of proportion to the actual recoil as the stock is designed more to fit a scabbard than a shoulder.

No, but do try some of those 3.5" turkey loads in early (unported) Mossberg Ultimag or Multimag,... or whatever the name of that supid thing is. Funny thing is if you shoot qod the first week is painful, but after couple of weeks of steady shooting your shoulder will likely get used to it, but your mind may not!

QUOTE FROM ABOVE---"Funny thing is if you shoot qod the first week is painful..."

huh?

Is that god or is that not quite God? ....Oh, it is qod.... hmmm... what is qod? At first I thought it was God.... Wow, I thought that was one enigmatic post.... hahahahaa

Anyway, regarding recoil, all I can say is it is FELT recoil that matters (to me) and all those charts and numbers do not do a useful job (In my humble opinion) of accurately predicting how hard or sharp it hurts or how much it doesn't hurt. I shoot the identical slugs in two different slug guns and while the guns are almost the same in weight you would think one was a 20 gauge shooting #7 shot and one was a cannon with a mule hoof built in the butt plate.

gents:

The equations are simple, some of the implications are complex.

For instance, use a load which produces 20 foot pounds of Ke recoil in a gun with a short narrow, butt. Now try the same load in an identical gun, except for having a wide, thick, butt.

You wont believe its the same load.


Regards

GKT