Recoil question

[bikerbeans]

Does it make since that with the same bullet & same powder type, but with 20 to 30 percent more powder by weight, that a 45 120 would kick less than a 45 70?  I am shooting 500 grain gas checked lead RNFP with H4198.  My shoulder gave up around 36 to 37 grains in the 22" 45/70. I shoot this same bullet in the 45 120 and 50 grains is less of a pounding.  A lot less, the scope never even things about punching my forehead.  The 45 120 barrel is 32", the 45 70 is 22".  Exact same receiver & stock set, including the bolt channel full of #4 shot.

BB

[quickdtoo]

Rifle weight is the other factor in calculating recoil, the heavier the rifle, the less recoil, all else being equal.

Tim

http://www.handloads.com/calc/recoil.asp

[PawPaw]

Does it make since that with the same bullet & same powder type, but with 20 to 30 percent more powder by weight, that a 45 120 would kick less than a 45 70?  I am shooting 500 grain gas checked lead RNFP with H4198.  My shoulder gave up around 36 to 37 grains in the 22" 45/70. I shoot this same bullet in the 45 120 and 50 grains is less of a pounding.  A lot less, the scope never even things about punching my forehead.  The 45 120 barrel is 32", the 45 70 is 22".  Exact same receiver & stock set, including the bolt channel full of #4 shot.
BB

Along with what Quick said, you've also got to figure the velocity of the projectile.  Momentum won't go away.  Recoil goes the other way.  If you're at the velocity limit of the barrel and projectile, the recoil impulse will be the same.  SO, as you increase the velocity of the bullet, recoil will increase.  As you increase the weight of the rifle, felt recoil will decrease.  Stock design often plays a big part in felt recoil.

Strange, ain't it?

[bikerbeans]

The only weight differential between my 45-70 & 45-120 is the 10" of barrel, which isn't a whole lot.  I haven't chrono the loads, but per published data the 45-120 velocity, with 13 extra grains of H4198, should be 200 to 300 fps faster than the same bullet in 45 70. Just wondering if the extra air space in a 45 120 case somehow dampens the recoil?

bb

[dpe.ahoy]

If you are running less pressure at the same bullet weight and more speed, that can decrease the rate of recoil speed which will feel like less recoil.  Black powder gives more a "push" than a "punch" even when pushing the same weight bullet at the same speed.  I really think it's how you hold yer mouth when you squeeze the trigger.   DP

[Rustyinfla]

    10" of barrel weighs something. Do a Google search for "barrel weight calculator" and you can find  out how much weight is involved in the difference.

[S.E.Ak]

Just weigh the barrel and divide the inchs into it to get weight per inch

[RB1235]

More case volume left over in the 120 can be less pressure than the 70. To me a 40 pistol kicks harder than a 45acp. Bigger bullet and more powder in a 45, but generally higher pressure in a 40. The 45 pushes like the guy above said. The 40 snaps.

[gcrank1]

BB, If I was you I wouldnt over-analize this...you might find out that what seems like less recoil isnt and then what are you gonna do with it? (Ha....bet there would be more than a few potential buyers here).
Be happy and go with it....sounds like you got what you wanted!

[bikerbeans]

gcrank1,

I guess what it going around in what is left of my mind is if I can get more velocity with less recoil with the same bullet in the longer case, then maybe I ream out my shorty to 45 120.  Going to have to shoot the 32" model for awhile and get a new chrony to seem what is what.  Probably need to switch between the 32 & 22 inch barrels on the same frame and see the velocity difference and recoil difference.  Maybe I am just infatuated with the 3.25" brass?

BB

[gcrank1]

Aint love grand ?! They are SOOOO 'purposeful' looking that the stubby little 45-70s look just puny....

[bikerbeans]

Rustyinfl,

You are correct sir, 10" of 458 cal. barrel does weigh somthing.  Here is what I found:

10" of barrel weighs 1 lb 1oz.  Calculated by weighing the 3.5" barrel chunk that I had previously hacked off of a 22" 45/70 and determining the weight per inch.   I then weighed the complete 45/120 with sling, lead in the stock, scope etc., unloaded and it is exactly 11 pounds.  So with a 22" 45-70 barrel the gun should weigh 9 lb 15oz.  So the mass of the 45 120 is approx. 10% more.   Explains some of the recoil difference, but not all. 

BB

[LaOtto222]

Part of the recoil is when the bullet leaves the case, part of it is when it leaves the barrel. When you have a longer barrel, the recoil is over a longer period of time, so it feels like less when in fact it is not. Try shooting your old load for the 45-70 in this gun, I bet you will find it feels like a pussy cat.

[USSColorado]

Also most of the weight differance is at the very end, reducing muzzle flip more than the weight differance alone would suggest.  Less cheek slap equals less felt recoil.  The shorter barrel would hurt much more if rechambered then it does now.

[NFG]

The easiest way to get a rifle weight is to use a postal or bathroom DIGITAL scale...I bought a grocery store scale at a yard sale way back when and it's paid for itself many times over.

There is actual recoil and perceived recoil...actual recoil is just physics...a certain mass at a certain velocity calculated by many recoil programs...basically Kinetic energy...factors are rifle weight, bullet weight, powder weight and velocity, and the results are usually given in recoil energy in ft lbs, recoil velocity in ft/sec and "Apparent felt" recoil in ft lbs.

"Perceived recoil" is a whole 'nother ballgame...and recoil velocity has a lot to do with it.  The faster the rifle hits you, the "harder" is the perceived recoil.  Different powders burn at different velocities...some of the recoil programs take this into consideration, others just use the powder weight.

The bullet AND powder are considered ejecta...the more powder, the more gas, the higher the recoil velocity.

I have a friend that has a 7mmRM and a 300WM...he swears the 7mmRM "kicks" harder than the 300 WM even though he uses a 150 gr bullet in the RM and a 200 gr bullet in the WM...recoil calculations says different EXCEPT the recoil VELOCITY is  aboput 10ft/sec faster in the 7mm due to his load parameters...both rifles are Savage 110's and weight within a few oz of each other on my scale.  I can't convince him to try a few 150 gr bullets in the WM just to see...nor will he believe that my recoil program says doing so will give almost the SAME recoil velocity and recoil energy with both 150 gr bullets but adjusting the parameters to give equal balance.

My 45-120 "seems" to kick less in with the 720 gr bullet than 400-450 gr bullets in my 458 WM or 416 Taylor...the 45-120 weighs 12#, the 458 9# and the 416 10#...so the 45-120 should actually kick a LOT more, but perceived recoil says different...a big shove vs a sharp stick in the eye...er shoulder. 

Some rifles give a good, relatively smooth shove...others slap the stuffing out of you quickly and sharply...one is perceived to "not kick much" while the other gives moans and groans.

Here are some figures for a 9#, 10# and 11# rifle using the same load parameters...I just used one of my 458 450gr/2000fs loads.

 9# rifle-20.4 ft/sec recoil velocity/58.4 ft lb recoil energy...Apparent recoil...OUCH, SEVERE
10# rifle-18.4 ft/sec recoil velocity/52.6 ft lb recoil energy...Apparent recoil...OUCH, SEVERE
11# rifle-16.7 ft/sec recoil velocity/47.8 ft lb recoil energy...Apparent recoil...OUCH, SEVERE


There are many ways to mitigate recoil by adding weight, adding a better recoil pad, having a better fitting or shaped stock and modifying the load parameters.

Luck

[PawPaw]

The faster the rifle hits you, the "harder" is the perceived recoil.

Quite right.  I recall an article many years ago where Jeff Cooper talked about having a .30-378 rifle on one of his Africa trips.  They got out to the hunting lease and posted some targets to verify zero on the rifles.  His rifle recoiled so quickly that it sheared the screws that held the scope bases and the scope fell off the rifle.  He said that he was "considerably distressed" and had to borrow a rifle for the hunt.

[bikerbeans]

NFG,

My 12 year old as a Wii with a balance beam which accurately measures weight.  Kid weighs herself with & without the gun, and I get my gun weight.

10-4 on the stock design. Went shooting saturday with my 22" 45/70 that has the BC Furniture.  Curved steel buttplate, no pad.  Shooting 330 grain Lyman 457122 over 25 grains of H4198 and the gun tore me up.  Didn't notice much at the time I was shooting it but the next day, I have a huge bruise that is still expanding.  I have no experience shooting a gun with the old style stock/butt plate so I am assuming my injury is from operator error.  Live and learn.

BB

[Mac11700]

BB:

 My thoughts on this is actually a 2 part issue your dealing with.

Part of this is indeed perceived recoil..Perceived recoil is shooter dependent,in other words it is felt differently for several different reasons...Stock dimensions do play a significant role in this..and the best way to do it is to have the stock fit to you..but..most won't spend any money doing this..FYI...the primary place perceived recoil comes from is the shooters face since this is the first place any recoil is felt provided a proper cheek weld is used....I know lots of grown men who can't shoot heavy recoiling rifles,and it really bothers them mentally and physically because of it..You don't have to have a heavy 45-70 load to feel this,heck I've heard folks complain about 30-30's and 243's as well..This can be often cured with a simple add on that will take almost all face slap out of the stock..and that is a good padded cheek piece.Since no 2 people have the same physiology..some may have bad teeth..or high cheek bones,others my just be more prone to pain from the jaw bone area...For me it seemed the older I got..I found the less I could tolerate heavy kicking shotguns or rifles,and it did bother me..so I went looking for a simple solution and actually found it at my local trap range..Trap shooters have been adding soft stick on sorbathaen comb pads for eons for people like me..they also are more likely to have folks actually fit their stocks if they shoot competitively..so..once I stuck one on my O/U..and I went from pain to fun again..This translates over to light weight rifles and sharp kicking loads as well..For your rifle if you can't find any of these pads locally and want to do a quick fix, just add any shell holder with some soft foam under on your stock it will let you know right away if this is part of your problem..It may look ugly..but if you want to find out if real quick..then try it..I've recommended this before to you and don't know if you ever tried it.Sure..having extra weight and a damn good recoil pad helps..but once the pain is gone from the face..the perceived recoil is practically eliminated..if the stock really fits you and it is sitting in your shoulder pocket correctly..I've found most factory stocks for rifles are just too damn long..and this forces the rifle out onto the bones which over time begin to hurt..

 Now..the second part of this is the difference in the loads and length of the barrel.One of the main things to remember is the burn time and how fast the rifle is recoiling rearward.This is were having extra weight and a longer burn time of your 45-120 come into the equation, The burn time difference, even though the stock set is the same,it is allowing the shorter barrel to slam your face harder,than the longer barrel does..Pressures are higher with the 45-70 as opposed to the 45-120 and the harmonics is all different..I would bet that the shorter barrel 45-70 has 30-40% more muzzle climb than the 32" 45-120 with the loads you are talking about.That muzzle rise is crushing your face each time you pull the trigger and your 45-120 doesn't.Even though you are pulling it in tight..it still is slamming into your face.. Sure their are physical differences in pressure and..there will always be with a longer barrel vs a shorter barrel..a longer cartridge and shorter cartridge and even though your using more powder the bullet has a longer time in the barrel to aid in the powder burn.It takes longer for the bullet in the 45-120 to get up to the same speed as the 45-70.The extra weight and the longer barrel does change the harmonics by allowing most of the powder to burn completely as opposed to getting a complete burn with the shorter barrel.so you shouldn't get near the muzzle rise with it.Try shooting both at dark and see which one has the biggest fireball out of the muzzle..the shorter barrel will have the largest in most cases..

Mac

[NFG]

Roger, roger on that BB...you got more hair than I with that curved butt plate...FIRST thing I did with my BC...BEFORE shooting it... was pull that nasty thing off, square it up and install a Limbsaver.  Curved butt plates might look cool but the have absolutely NO give.

You're definitely right about the face thing Mac...even the puff of air from a muzzle break will make some people jumpy...and getting slapped in the nose with your own thumb when you don't get your cheek welded to the stock or hammered by a mis-shaped comb is NOT the best way to get acquainted with a hard kicker.

Finding the right shaped stock or reshaping one to fit your hand and face is a very good thing to learn...I don't have a rifle OR shotgun stock that I haven't modified to fit my hand and cheek one way or another...

My Rem870 knocked the stuff out of me every time I cranked off one of those extra stout slug loads I worked up until I put on one of the 1/4" foam cheek protectors...Not sure if it was the extra quarter inch or the foam softening, but it sure helped.  There are some very nice 1 1/2" thick shotgun recoil pads, but for some reason not many seem to go for them...I will put one on my 510 Makatak for sure or a Grind to fit Limbsaver AND a slip on one... 

My Mossy 500 with a synthetic stock slaps me good but the wood stock doesn't even though the synthetic one weighs more(full of lead shot).  I bought a Mossy 535 combo for the rifled barrel and extra length shotshell more than anything, then put on a thumbhole stock, Limbsaver AND foam cheek piece and the combination makes it almost pleasant to shoot the heavy slug loads.

The aftermarket Gun Stocks Inc thunmbhole stock makes shooting the 45-120 or 12GaFH much more pleasant(?).  I camo'ed the 12GaFH including the thumbhole stock and heavy forend so it doesn't go too well hanging off the 45-120, but I will remedy that some day.

Part and parcel of this game is to get YOUR shooter to fit YOU and to do whatever is required to make your toy a pleasure to shoot.  Looking at some of the synthetic monstrosities being produced makes me cringe just thinking about how hurt you can get if they were on a hard hitter...you can get away with having them on a 223 or such, but anything much more and you're asking for cheek knots.

When you are working up load you need to consider the barrel length and use a powder that will burn in that length...that will produce the highest velocity and NO loss of pressure due to the powder burning OUTSIDE the barrel...i.e., BIG FLASH AND FIREBALL.  If the powder burn is too slow that's what will occure and some powders just make a lot of flash.  Use a reloading manual that shows velocity and presssure and pick a powder that gives the highest velocity and lowest pressures which was developed in a rifle with the same length barrel as your shooter...if possible.  Many times, but NOT always...there will be a couple that match those parameters for you to try

Luck

[gcrank1]

A quick try on the suggestion of the foam under an ammo sleeve is to use a bit of computer mouse pad. The foam is about the right density and thickness.
As much a traditionalist as I am on the 'look', that BC buttplate is a bite. Not that my 38-55TM was a kicker, but once I swapped my UV lam wood onto it (wanted to try the BC wood on another) the architecture change (and a bit more weight) made that TM work really well. Now that Im used to the look it is just fine.

[CoyoteSniper]

Are you serious man i never thought to do that. I ususlly use a calibrated pelouze viking slide scale that reads to 50#

[bobcat billy]

Try a dead mule recoil reducer in the stock it should kill the kick.
If I was worried about the gun kicking that bad I would nt shot it 
I'm to old to shoot somthing that kicks  like that.

You guys are right that Vicking scale works great you can also use it to weight your trigger pull