Author Topic: Gun Design and Recoil  (Read 10182 times)

Daryl

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Gun Design and Recoil
« on: August 27, 2009, 03:33:49 PM »
Note the shooting form - cheek down hard on the comb of this English Styled rifle for a perfect sight picture.




Note that during recoil, the gun rotates up, but the butt stockseems to drop slightly, with the comb dropping from the face so there is no impact on the cheek bone. Wonder if they've got stock design down right for heavy recoilers?  The same thing is apparent with both offhand and sitting shooting.  In both pictures, the recoil hasn't stopped yet. The actual height attained by the rifle is slightly higher than shown.





Any coments?
« Last Edit: August 27, 2009, 03:41:23 PM by Daryl »

Offline Roger Fisher

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Re: Gun Design and Recoil
« Reply #1 on: August 27, 2009, 04:33:21 PM »
Yes, I do ;D

Since your x stix are too low and you rested the rifle in your hand in turn resting on said stix I assume you took this position simply for the photo session to show the rise in the piece from recoil ???  Right?

For hitting the target the rifle should rest in the stix at a level and comfy positon to the target and not on your hand (for accuracy) Digging in your heels helps but little tough on that concrete.  IMHO only ;D

Offline hanshi

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Re: Gun Design and Recoil
« Reply #2 on: August 27, 2009, 05:55:44 PM »
What kind of load is being fired here?  That's some recoil!  You'd have to have a well designed stock to keep from breaking a shoulder from the looks of it!  Maybe it's just perspective.
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J.D.

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Re: Gun Design and Recoil
« Reply #3 on: August 27, 2009, 05:59:06 PM »
No comment, but a coupla questions.

 What does pitch have to do with the stock dropping away from the shooters face?

What characteristics of the butt design are conducive to absorbing heavy recoil.

Last and probably least, how long/high should X sticks be. Never used them and only seen them in use one time, so don't know anything about them.

Thanks and God bless
« Last Edit: August 27, 2009, 06:00:38 PM by J.D. »

Offline Roger Fisher

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Re: Gun Design and Recoil
« Reply #4 on: August 27, 2009, 06:19:54 PM »
No comment, but a coupla questions.

 What does pitch have to do with the stock dropping away from the shooters face?

What characteristics of the butt design are conducive to absorbing heavy recoil.

Last and probably least, how long/high should X sticks be. Never used them and only seen them in use one time, so don't know anything about them.

Thanks and God bless
I'll throw this answer in here since  I shoot over the stix someetimes.....
I don't know squat abt stock pitch etc but to handle recoil you want a wide butt but not as wide as the neighbor ladies!

Your stix should be long enough that after adjusting them you sit behind them on a pad of some sort so your butt is a bit higher than your heels..... Stix should be set so you are comfy behind them with no straining of your back and legs.  Should be level on with your target.  Did I say you should be comfy.  That is very important in shooting over those stix.
If the clubs allow be certain you drive heavy nails in the bottom end of said stix so they stay put when you drive them into the ground.....  I go for stix that are at least and 1 and a quarter inch thick - I have a thing about vibration on ignition.   Shaders help fairly heavy rifle also.........If you have enough years the young girls may think you are a buffalo hunter survivor! ;) ;D  Can't hurt to leave your gray beard grow also since you can use it as a wind flag ::) 

Offline James Rogers

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Re: Gun Design and Recoil
« Reply #5 on: August 27, 2009, 06:20:50 PM »

 What does pitch have to do with the stock dropping away from the shooters face?

What characteristics of the butt design are conducive to absorbing heavy recoil.


Correct pitch keeps the butt of the gun in solid contact with the shoulder area concentrating on the top 3/4 of the butt. Incorrect pitch is usually the main cause of a whack up to the cheek as it works in coordination with a good solid mount of the cheekbone on the comb. A gun that does not have enough pitch for a shooter will rise on recoil more on the toe of the butt causing excessive barrel rise. This condition will cause a shoote to prematurely raise the head anticipating recoil as if left mounted, it will bust the cheek. With correct pitch and a good cheekbone mount, the shooter and gun will recoil as one unit.
The sitting pictures show it more clearly but the shooter's head is rising off the stock with the shot as much as the barrel is rising. This may be purely because of some powerful elephant load.  :D

A wide butt design, pitched to suit a shooter's stance, mount and body structure so that the top 3/4 of the butt is transferring recoil is best. The more parallel the comb is with the stock, the better the felt recoil.
Certain body types benefit with some toe-out as well.

James
« Last Edit: August 27, 2009, 06:27:41 PM by Capt. Jas. »

Offline Dphariss

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Re: Gun Design and Recoil
« Reply #6 on: August 27, 2009, 06:48:51 PM »
This is a couple of of photos of the the first shots with the 16 bore.
With the load here is is moving a 1 ounce ball at 1700-1750 for about 3000 ME.
I have another with less muzzle rise but don't know when in the recoil sequence it was taken. Also I am shooting uphill so the initial angle is already above horizontal.
With the current load at 1600-1650 its less.
The rifle never causes any bruising, never contacts the cheek bone etc at all. But if it slides off the shoulder from improper holding its WILL briuse the arm.









Dan
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Offline Dphariss

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Re: Gun Design and Recoil
« Reply #7 on: August 27, 2009, 09:23:09 PM »
Pitch can be negative or positive. Excessive pitch can really increase the pain level by not spreading the recoil over the entire buttplate. 
In making BPCRs for competition I used to use zero pitch or close to it. Better recoil characteristics.
The 16 bore is pretty close to this. Many traditional kentuckys have a lot of pitch but it goes with the look and the buttplate design. They generally have pretty mild recoil compared to bigger bore RB guns or BPCRs.

Dan
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BrownBear

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Re: Gun Design and Recoil
« Reply #8 on: August 27, 2009, 10:18:17 PM »
I'm with you all the way Daryl, if I can add fit to the list. 

I'm 6'4" and 220, with a 78" (6'6") wing span from fingertip to fingertip with my arms spread.  My wife is 5'6" with suitable reductions in weight and wing span.  Rifles and shotguns she shoots comfortably eat me alive, and visaversa.  I've got three cartridge guns that recoil as much as your third photo, and I shoot them well.  One hunting pard is a fair bit smaller than me, and he can't even bring himself to pick them up again after shooting them once each. 

Daryl

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Re: Gun Design and Recoil
« Reply #9 on: August 28, 2009, 03:19:36 AM »
Excellent- the sitting recoil does show my head rising - timing of the photo - the shot is gone and I am raising my head - but - the recoil is absorbed by the butt- over 2" wide on this rifle.

Roger's coments are interesting - if not held by the left hand, the point of impact is not the same as offhand shooting. This is a hunting rifle and must be held - you cannot let it bounce off a rest or it will throw it's shots high.  My .40 and .45 rifles don't do this, but then, they don't recoil.

Load was a piddling 140gr. 2F with a .684" pure lead ball weighing 484gr.  That load is 25gr. less than my normal hunting load. I did this as the second leaf is zero'd for 165gr. at 200 meters - which puts the shots some 8" or a bit higher at 200 yards.  I reduced the charge to 140gr. to obtain a mere 4" elevation height with the second leaf due to the closer 200 yard range.

 Even with 225gr. of 2F, the comb does not strike the face at all - but the shoulder knows it's fired a heavyier charge.

As Dan's photos show, the English design has a very straight comb - not a raising angle as with American designed guns of the period and earlier - but - the drop at the comb is low enough that when cheeked, the cheek bone itself rests just over the comb with the face hard against the side of the stock.


jmforge

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Re: Gun Design and Recoil
« Reply #10 on: August 28, 2009, 06:47:04 AM »
Very nice.  You have to figure that the English gunmakers had to get the stock design right because most of the guns that I have seen from the earlier percussion era were 20-14 bore!!!!  I guess they wanted a rifle that would not only take big red deer in Scotland but also tigers and perhaps the occasional gaur or water buf in India.

Offline Dphariss

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Re: Gun Design and Recoil
« Reply #11 on: August 28, 2009, 07:31:06 AM »
Very nice.  You have to figure that the English gunmakers had to get the stock design right because most of the guns that I have seen from the earlier percussion era were 20-14 bore!!!!  I guess they wanted a rifle that would not only take big red deer in Scotland but also tigers and perhaps the occasional gaur or water buf in India.

They considered the 54 cal to be a small caliber for deer hunting.
They did not think animals should run off after being shot. The Americans were less concerned with this.
Stewart stated that his 20 bore rifle killed more game on less powder and lead than any rifle at the 1833(?) rendezvous.

16 bore, according to Forsythe, was about as small as anyone would use for dangerous game. He hunted India, a 16 was too small for Africa and I think the 12 or 10 was thought to be minimum there.

Dan
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northmn

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Re: Gun Design and Recoil
« Reply #12 on: August 28, 2009, 06:52:06 PM »
A question arose about the proper way to use X sticks.  Yes Daryl is doing it very wrong.  I got the technique from photos used by Don Davis in the book Muzzleloading and Shooting with the Champions and used to enjoy teaching it to wives shooting so they could beat their husbands (they didn't know it all).  First you rest barrel in the crotch of the sticks right behind the front thimble.  The left hand for a right hander is often held at the bottom of the buttstock as in the toe plate area.  The sticks need to be high enough so that the knees can be used for support of the trigger hand and the sights naturally aquire the target.  If done correctly X sticks are about as good as a bench rest.  I have used them for sight ins and have taken deer with them even with modern high powders and scopes.  I carry period correct electricians tape and cut the sticks out in the field to place in my blinds.  A true X sticks rifle is a half stock as afull stock tends to "bounce".  As to recoil, Tennessee rifles, late period Pennsylvania rifles and Hawkens are designed to kick the worst.  It is a matter of individual fitting.  For a big bore the English rifle utilized a WIDE butt plate.  Length is important as too short tends to create a gap at the shoulder and punch instead of push.  The drop at the comb and angle of the cheek piece are very critical.  I always recommend to beginners not to finish the rifle until they have shot it to look at things like that.  The angle of the butt plate or pitch as you call it plays in also. Theories used in trap guns.


DP
« Last Edit: August 28, 2009, 06:55:49 PM by northmn »

BrownBear

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Re: Gun Design and Recoil
« Reply #13 on: August 28, 2009, 07:06:53 PM »
A question arose about the proper way to use X sticks.  Yes Daryl is doing it very wrong.

I let the rifle decide right and wrong.  Several of mine, especially with lighter loads, demand shooting as Daryl does.  Rested right on the sticks, they throw shots noticeably higher.  And they're half stocks.  Heavier guns and heavier loads are approximately the same with our without the hand on the sticks and cradling the rifle. 

I prefer to be "wrong" too, because I don't want to develop the habit or instinct of resting the rifle on anything but my hand.  Doing so with my rifles is a loser from almost any rest other than the almost-special case of crossed sticks.

That's a field shooter and hunter talking, and not a match shooter. 

Leatherbelly

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Re: Gun Design and Recoil
« Reply #14 on: August 28, 2009, 07:16:57 PM »
  My centerfire high powers don't jump like Daryls or Dan's do. They push straight back with minimum of rise.(jump) Any rifles or smoothies that "jump",  I get rid of. A gun that jumps,IMHO,doesn't fit or has the wrong stock/pitch design for me. A lot of drop at the butt or the comb or both are gonna jump! That's OK with the small bores because the recoil is minimum. The bigger bores,say a fifty or larger..no good for me. I hate it when my thumb bashes into my protruding breathing apparatus! Makes it very hard to follow through.

Offline Dphariss

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Re: Gun Design and Recoil
« Reply #15 on: August 29, 2009, 08:18:05 AM »
I suspect that your centerfire HPs don't generate the recoil either of these rifles do.
The 16 bore uses a similar powder charge and produces similar velocity to a 50-140 Sharps.  It will move me more than a 375 H&H. And don't fall for the old ME determines the recoil, BP generates more recoil for a given ME than smokeless.
The rifle pictured is not a lot of fun to shoot off the bench and requires getting in shape for if shooting over 110-120 grains of powder.
Much of the muzzle rise is the result of rotation of the body backward.
So far as muzzle rise goes my AR-15 H-bar is actually pretty heavy with a 30 rnd mag, its about as heavy as an M-1 or seems like it, has a bore centerline near the comb line, a light recoiling cartridge and it requires a pretty firm hold to shoot a double tap without too much muzzle rise.
I know I shot about 60 rounds through it today in close range speed drills.
I used to build BPCRs for silhouette using prone X-sticks and stocked similar to this 16 bore these would hardly, if at all, move off the sticks.  The one that sticks in my mind was a 40-70BN moving a 380 gr bullet at 1400-1425. But it was also about 2 pounds heavier than the flintlock with FAR less recoil impulse.

Dan
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northmn

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Re: Gun Design and Recoil
« Reply #16 on: August 29, 2009, 05:39:19 PM »
A question arose about the proper way to use X sticks.  Yes Daryl is doing it very wrong.
I let the rifle decide right and wrong.  Several of mine, especially with lighter loads, demand shooting as Daryl does.  Rested right on the sticks, they throw shots noticeably higher.  And they're half stocks.  Heavier guns and heavier loads are approximately the same with our without the hand on the sticks and cradling the rifle.  

I prefer to be "wrong" too, because I don't want to develop the habit or instinct of resting the rifle on anything but my hand.  Doing so with my rifles is a loser from almost any rest other than the almost-special case of crossed sticks.

That's a field shooter and hunter talking, and not a match shooter.  

X sticks can be padded to help somewhat with the rise.  Match shooters use the method I described.  When I used them hunting I would put a hat or something in the crotch.  Even in the field and resting on the forestock there is no reason to need use of the non trigger hand anymore than on a bench rest.  My description is more accurate for a match rifle designed to be used on X sticks.  They now used 6 bull targets at 50 yards for X sticks.  I took the comment to be that of match use.

DP
« Last Edit: August 29, 2009, 05:42:34 PM by northmn »

Offline Dphariss

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Re: Gun Design and Recoil
« Reply #17 on: August 29, 2009, 05:50:36 PM »
Where the barrel is rested on the X-sticks will change how well the gun will group.
Putting down pressure at the forend, 5-10 pounds or just the weight of the shooter's arm, can change how the rifle groups. If really serious a lot of serious shooting with record kept has to be done.
Many MLs like to be rested well out toward the muzzle. But it requires testing. To prove. To the point of putting tape on the gun and testing then moving the tape a couple of inches and shooting again.
How stiff the sticks are, leather "sling" type x-sticks etc can all effect how the rifle will group.
I was shooting a pistol from the bench yesterday resting at the muzzle and was pretty proud of how I had guessed at the sights. Elevation was perfect. Then I shot it resting my hands on the rest and offhand and it shot about 4" lower at 25 yards.

Dan
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northmn

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Re: Gun Design and Recoil
« Reply #18 on: August 29, 2009, 05:55:16 PM »
For some reason I have problems with my computer writing longer windy comments which is likely a good thing.  Rifle recoil control is related to the engineering term called ergonomics.  The rather radical m-16 when introduced to the military drew a lot of comments on its design and was explained as being designed with ergonomics in mind.  Before anyone gets going on personal experiances against the design, it is also designed to fit a majority of people.  A true design would have included adjustability.  Recoil control is a factor in that type of rifle as it pushes straight back and there is no torque and of course the grip does not require any bending to the wrist.  Of course we are not going to build a M-16 flintlock, but the design does deserve mention.  Double shotguns have moved to O/U a lot because of the fact that the recoil is straight back as well as the sighting plane. S/S tend to torque to the side and give less controllable recoil.  Weight is also the great recoil tamer.  I heard a person describe shooting one of the modern marvels in a muzzle loader as about like touching off a 458.  150 Grains of 777 or something behind a heavy slug in a 7-8 pound rifle.  

DP

bs2

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Re: Gun Design and Recoil
« Reply #19 on: August 30, 2009, 02:51:06 AM »
Brought up shooting 12 ga and slugs for deer, thought me early to kneel at the shooting bench.

Keep your back straight, and rock with the recoil!

Straight stocks with WIDE pads are your friend.

My first BP rifle was a TC Hawken.......[skinny curved plates are not your friend]..............my second was more like an English Sporter...........even before I had ever seen a picture of one, I understood the design.

2.1/2"s of drop, wide plate..................and a trigger guard that doesn't smack the middle finger.  :'(Them Jaeger folks have that figured out ;D..........when your fingers all fit all in a row, and not behind the guard, it feels much better.

The ole 7ga smooth bore with 180ff and a 1000 grain ball shoot about 1100 fps.......10.5 pounds of gun, and you get a nice big push, from standing or kneeling, it's all in the stock design...........up the load to 240+ grains an.............it just KICKS..............UP and Back!!, but no bruises or marks, can't imagine what a skinny plate with a lot of drop would feel like, or do to the ole body!

I have shot my .73 cal barrel [28"] in both a 7 and 8 pound rifles, and cannot tell the difference in shooting 125ff-175ff and a 550 grain balls.

I have back down in caliber as I get older, my next rifle barrel is only a .690 bore 1.1/8 x 1.0 x 29"s.

Bruce









northmn

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Re: Gun Design and Recoil
« Reply #20 on: August 30, 2009, 05:04:33 AM »
Reason I find the designs so interesting is that I have a preference for larger bore fowlers and muskets.  The Brown Bess was a beautiful gun but it nailed me in the cheek.  Saw a few originals with the cheek scooped out.  Natives used to complain that the NWTG were built too straight (not enough drop).  As I understand it they were getting hit in the cheek.  I built a 12 ga along Brown Bess lines that had adequate drop and was much more pleasant to shoot.  The big problem with fowlers is that they are light weight and do not have some of the built in control of rifles.  A Hawken rifle would weigh over 10 pounds a fowler close to 8 or less.  Hawkens are 54 bore, or so, fowlers are 20 ga or so.  Even though a Hawken has that slim curved butt plate it has weight.  Even the 20 ga can belt you if built wrong.  If I were retired with enough time and money I would look into the French Fusil de chasse as that curved design looks like it might jump up at you.  Its possible that the negative pitch at the heel might have it drop away from the face?  A round ball shot out of a large bore fowler recoils, but can be tamed with proper drop and a large straight buttplate.

DP

Leatherbelly

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Re: Gun Design and Recoil
« Reply #21 on: August 30, 2009, 09:14:56 PM »
  I have a beautifully ,well made Fowler made from a kit by a very reputable maker and builder. This post takes nothing away from both but,dangit ,it doesn't  fit me. It cheeks me and bangs my nose on recoil. I can shoot it 6 or 8 times before I'm flinching. After fifty or more shots,well it feels like I've gone three rounds with Mike Tyson!...and haven't hit much.(maybe 30%) So the quest for a perfect fitting gun goes on. Sure wish there was a sure fire way to get measured up for a rifle living away up here in the north. Just can't make the shows etc. to try a bunch of different guns.

northmn

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Re: Gun Design and Recoil
« Reply #22 on: August 31, 2009, 09:41:25 PM »
Modern shotguns, W/O ribs offer a good way to test fit.  Getting banged in the nose sounds like too short of stock, getting cheeked is either not enough drop or an angle on the comb that is not proper.  A slip on recoil pad, if one can be found to fit, would be a good test item.  You could always rig up some sort of beaded leather thing to hold in an extension if that helps.  While some like cast off it can also be a culprit as when you look at it, it angles the front of the comb into your face.  They actually used to build a slight "cast on" to help with recoil.  As I mentioned, at Fort William by Thunder Bay, I saw a collection of Brown Bess muskets and a few had the cheek piece scooped out.  My repo Bess nailed me in the cheek also. 

DP

Daryl

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Re: Gun Design and Recoil
« Reply #23 on: September 08, 2009, 05:58:26 AM »
A question arose about the proper way to use X sticks.  Yes Daryl is doing it very wrong.

I let the rifle decide right and wrong.  Several of mine, especially with lighter loads, demand shooting as Daryl does.  Rested right on the sticks, they throw shots noticeably higher.  And they're half stocks.  Heavier guns and heavier loads are approximately the same with our without the hand on the sticks and cradling the rifle. 

I prefer to be "wrong" too, because I don't want to develop the habit or instinct of resting the rifle on anything but my hand.  Doing so with my rifles is a loser from almost any rest other than the almost-special case of crossed sticks.

That's a field shooter and hunter talking, and not a match shooter. 

Thought I'd noted why the hand hold, maybe forgot to.  If a heavy recoiling gun is allowed to jump, it will cause high AND erratic shots. Holding onto the forearm makes it shoot the same from all postitions.

 - Too - As to face postion before and after recoil - when mounted and sighted, the cheek is against the stock and that shoulder (right) is higher than the other. Upon recoil, the rifle shoulder is driven down, which pulls the face away from the stock - my fault - I thought that was obvious in the pics.

northmn

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Re: Gun Design and Recoil
« Reply #24 on: September 08, 2009, 02:11:52 PM »
Actually an English sporting rifle is not a X stick gun anyway.  But with a typical medium bore rifle the method I described does work quite well.  My reference was also to the question of form for X sticks.  An X stick rifle is typically built slightly under 13 pounds with a 1 1/8 inch 50-54 cal barrel about 38" long.  I do remember a 50-90 Rolling block I had that was built too light.  Shooting it off of X sticks was not a pleasant experience.  The position does not permit much body movement to give with the recoil.  With padded sticks its shot, but that gun was more fun to give to others to shoot than shoot yourself.

DP