Rule of 96

[frontgate1]

Is anyone familiar with the "rule of 96" and is it still applicable to today's powders?

The rule of 96 tells you that your shotgun needs to be at least 96 times heavier than the weight of the shot charge it fires to ensure:

-the shooter's shoulder is not battered black and blue
-the tightest and most consistent patterns
-the gun is not destroyed by shock and vibration from recoil

My Win 1300 12 ga. weighs 8 1/2 lbs. by the bathroom scale.
I shoot Federal game loads with 1 oz. #8 shot.
The formula- 96 x 1 oz. = 96 oz. or 6 lb.

According to this I am 2 1/2 lbs to the positive and should not suffer excess recoil, shock or vibration, correct?

 

[Hungry Seagull]

Well let's see. I dont know anything about the rule.

But I am still standing after having fire my first 3 inch magnum round... staggering... but still standing.

 

[Badger Arms]

-the shooter's shoulder is not battered black and blue
-the tightest and most consistent patterns
-the gun is not destroyed by shock and vibration from recoil

The weight of the shot charge vs. the weight of the shotgun do not directly correlate to bruising. I bruise with a .223. Moreso, patterning is NOT in any way, shape, or form related to the weight of the gun. Finally, the "shock and vibration" of firing have nothing to do with the weight of the gun. Where did you read this?

 

[JWF III]

Don't really think it has any relevance with anything listed.

If it did, a 3.5" 12 ga. or 10 ga. would have to weigh 13.5 lbs to fire the 2.25 oz. turkey loads. My old Moss. 835 has well over 200 of these fired through it, plus some 00 buck, but only weighs in at 7.5 lbs. Granted, nearly doubling the weight would help with recoil, that thing's a beast. But I'd rather hike all day with the shotgun that weighs half as much, because it really doesn't get fired near as much as it gets toted.

Wyman

 

[Leaky Waders]

Since Dave hasn't responded yet...here's a link...

http://www.gunshopfinder.com/articles/shotgunrecoilandkick.html

 

[oneounceload]

The rule of 96 was used by British gunmakers to build a double - the formula as mentioned is correct - the weight of the charge x 96 = the design weight of the gun....many older field guns were designed around this principle and while a joy to carry, can be a PITA to shoot a lot

 

[rcmodel]

The "Rule of 96" leaves out one very important part of the equation.
Velocity.

Black powder was sorta self limiting as to how much velocity you could get.
Not so much with smokeless powder.

A 1oz load at 1,450 FPS will kick much harder then a 1oz load at 1,200 FPS.

In a 7 pound gun for instance:
Recoil energy = 15.49 F/P vis 22.59 F/P

Recoil velocity of gun = 11.94 FPS vis 14.42 FPS.

SO, just adding 250 FPS to the same shot charge makes the gun both kick harder and faster.

rc

 

[Virginian]

Now I know what they used to design those boat anchor 10 gauges.

 

[Dave McCracken]

A couple things...

BP velocities ran pretty close to what modern R/R loads do. Around 1200 FPS seems to do the trick even today. Heck, I ruined some Doves' day last fall with some 7/8 oz, 1150 FPS loads of 7.5s.

The Brits had custom fitted guns in mind with the Rule of 96. Fit can make more difference than 100 FPS more/less speed.

And a load of 1 oz at standard speed in a shotgun weighing over 8 lbs should be a joy, given decent fit and form.

 

[earlthegoat2]

The rule of 96 is not the end all be all of shotgun design. It is however a good starting point. True it does not take velocity into account as I would not want a 6 lb gun shooting some of the hotter 1oz slug loads. Custom gun builders even today use the rule of 96 even today as a baseline for their guns. It is a distinctly British idea and I do believe the British have their wits about them when it comes to the design and building of fine guns. I believe weight to be the number one factor in perceived recoil but gun fit is probably just as.

 

[oneounceload]

except eaerthgoat - I do not believe they were talking about slugs - they were talking about driven birds and at the time, mostly 2-1/2" shells and loads

 

[earlthegoat2]

Right you are oneounce, and it would be a grave mistake indeed if one were to use the rule of 96 in such a way. If one were to analyze it a little further and take into account a Benelli Super Black Eagle at 7.2 lbs and figure a 3 1/2" load of 2oz then this translates to a gun that should be 12 lbs. No wonder there are so many people complaining about the recoil of those brutal 3 1/2" shells.

 

[WardenWolf]

The Rule of 96 also comes from before modern metallurgy. Modern alloys and tempering easily overcome this. It also comes from before modern recoil management techniques such as recoil-damping semi-auto actions, muzzle brakes, and Limbsaver pads. A fixed action shotgun such as a single shot or pump can take note of this old rule for purposes of shooter comfort, but modern semi-auto shotguns can discard it entirely.

 

[JohnBT]

You can dampen recoil and spread it around, but you can't repeal the laws of physics. There's a reason those SBEs show up regularly on the used gun rack. They hurt you if you shoot enough of the big shells.