I was reading my old reloading book and brushing up on procedures and precautions and thought i read somwhere that a fast powder will spike recoil faster and will make the recoil seem shorter & not as bad vs a slow powder recoil spike which is a little longer.Is this correct?Can powder burn time make a differance in felt recoil impulse?Do you try to use the fastest powder you can as a rule on loads first when experminting with differnt powders?I have never read this or hear of it before....

If you can feel events in the miliseconds long duration of a recoiling rile you might just be able to tell. I can`t seperate the stages myself. (primer ignition, powder ignition, bullet inertia being overcome, bullet exiting the muzzle, ect)

I doubt it. Slower powders normally require more powder to reach the same vel. More powder equals more recoil. You can try an experiment yourself by loading identical bullets w/ the same charge weight of med. rate powder & a slow powder & fire them side by side. The slower powder will likely yield less vel. & this should actually recoil a bit less.

It's my understanding that velocity and bullet weight are the two critira that determines recoil all things being equal. Of course the weight of the rifle plays a big part. Five pound rifles recoil more then 12 pound rifles using the same load.
Jim

I doubt that you can "feel" the different stages of cartridge ignition.

Once upon a time we took data on .223 cartridges during firing and that indicated that the bore residence time of 55 grain ball ammo was about 3.5 milliseconds. That is, it was 3.5 ms from the time pressure started to rise until the pressure drop as the bullet left the 20" barrel.

Most of us mere mortals can't discriminate between events occuring on that time scale.

On the other hand, physics tells us that the mass of the propellent contributes to the recoil. Thus, in shooting two lots of ammo generating the save velocity with the same bullets but using different powders we'll see greater recoil from the ammo using the heavier powder charge.

Sometimes this is VERY perceptable! My .470 NE Searcy generates about 2250 fps with 500 gr Woodleigh bullets with both 108 grains of IMR-4831 and 89 grains of RL-15 using the same cases (BeLL) and primers (Fed 215). Even though the RL-15 load also uses 5 grains of dacron as a filler, its felt recoil is significantly less than the IMR 4831 load.

The calculation for free recoil requires bullet weight, bullet velocity, charge weight, and rifle weight.

quote:

Originally posted by arkypete:
It's my understanding that velocity and bullet weight are the two critira that determines recoil all things being equal. Of course the weight of the rifle plays a big part. Five pound rifles recoil more then 12 pound rifles using the same load.
Jim

Agreed....powder burn rate may be reflected in velocity.....but isn't a component in recoil.

Beg to differ. Please see this recoil calculator link:

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

Ain't just me that thinks propellent charge weight is a factor. The difference between the free recoil calculated for the loads given in my previous post is about 10%! Absolutely enough to feel.

I agree with the explanation that faster powders usually require less powder to yield a given velocity as compared to a slower powder. The difference will definately be noticed as in the example given above, the .470 NE. 108 grains is an 18% increase over 89 grains and I can assure you, I can tell the difference 100% of the time in my rifle by recoil alone!

Geronimo

quote:

Originally posted by mstarling:
The calculation for free recoil requires bullet weight, bullet velocity, charge weight, and rifle weight.

Rifle mas X it's velocity = powder mass X it's velocity + bullet mass X it's velocity.

There are other smaller factors but this is the lions share.

one other thing-- CHARGE VELOCITY The occurring rifle velocity in the Impulse equation than reflects the felt recoil. roger

The largest factor in felt recoil is determined by the pressure level in the barrel at the moment the bullet uncorks from the crown of the barrel. Lower pressure at that moment translates to lower felt recoil. To lower muzzle pressure, use lighter bullets and/or faster powder.

Interesting discussion
In some rifles as the bullet weight goes up I've reduced the powder charge in consideration of pressures. Yet the recoil seems to be more then the recoil generated by the much lighter weight bullet with greater powder charge.
For example:
I mostly shoot a 208 grain cast bullet in my mod 95 Winchester. The load is loafing along at 2200 fps. The other load I worked up was a 155 grain jacketed bullet at, I'm guessing, 2800 - 2900 fps. I had a bunch of Sierra 155 Palma left over from testing.
I've got the powder charges down in loading shed, but I used IMR 4895 with the cast bullet and 4064 and 4350 with the 155.
That 208 cast still pops me better the the 155.
Jim

(W1Vp+4700W2)SQUARED/64.348Wg = recoil energy

W1 = wgt of bullet in lbs
W2 = wgt of power in lbs
Wg = gun wgt / lbs
Vp = muzzle vel in fps

This gives free recoil ENERGY in ft/lbs. I believe Barsche gave the formula for free recoil VELOCITY.
Might be wrong though I`ve seen a couple of formulas for the same thing and there are more then 1 part of recoil that formulas are given for.

Gerard is probably on the right track. The "jet" effect of the muzzle blast is higher when muzzle pressure is higher. Recoil of the jet occors when the gasses accelerate from 1/2 muzzle velocity to somthing in excess ofmuzzle velovity. Muzzle brakes rely on the gas velocity.
Good Luck!

This is not a formula for foot pounds--just a formula for recoil factor and I find it very good for getting a comparison. Bullet weigh+powder charge X muzzle velocity divided by 3500(constant)divided by rifle weight=recoil factor.

quote:

Originally posted by Ol` Joe:
( I believe Barsche gave the formula for free recoil VELOCITY. .

You are absolutely correct. That Velocity times the MASS of the rifle in slugs gives you the Impulse.

1/2 that velocity squared times the mass in slugs gives you the energy of the recoil in ft.Lbs.

The thing that has always puzzeled me is what part of the bolt thrust adds to felt recoil, if at all. Is this an additve quantity or resolved in the moment of impulse? Than I say to myself, "Self does anyone but you really care?" back to your cave roger.

quote:

The thing that has always puzzeled me is what part of the bolt thrust adds to felt recoil, if at all.

Roger....It don't....bolt thrust is completely countered by the opposite and equal thrust of the receiver on the bolt......caused obviously by bolt thrust.

If it wasn't thew bolt would come thru the receiver and the gun will be ruined.....or worse.

Does a 2320 swift have greater or ewual recoil to the 30-06?.....the Swift operates at greater bolt thrust than the old '06!

quote:

Agreed....powder burn rate may be reflected in velocity.....but isn't a component in recoil.

My original post.....still applies!

Gerard has the correct answer ! After the bullet leaves the barrel burning powder inside the barrel creates a rocket effect adding to the recoil ,as much as 25% it is said.The purpose of porting is to bleed off those gases and that's why porting reduces recoil !Remington made reduced recoil shotgun target loads by choosing a powder that would burn completely by the time the shot charge left the barrel !!

For a 200 gr bullet to accelerate to 3000 fps down the bore 24", in free recoil the 8 pound gun will accelerate back to 10.7 fps over a distance of .086".

The compliance of the recoil pad, clothing, flesh, and bones is such that only a tiny fraction of the peak pressure per square inch on the flesh will occur during the first .086".

For someone to feel the difference between powders over that period is hard to believe.

The faster powder will make less noise, and noise is a small part of perceived recoil.

What does it all mean?
You cannot feel the difference.

Want to feel pain?
A semi auto pistol that throws the brass 30 feet has the slide slamming into the frame. The slide bounces off the frame much faster than a bullet can accelerate in a revolver, but that speed is not why it hurts so much. It could be 10 times slower and still hurt the same. The reason is because the frame is already pushed tightly against the hand from the recoil springs at the time of slide slam. One shot from a small 9mm with stock springs and 357 mag loads makes my hand hurt for an hour.

quote:

Originally posted by tnekkcc:
...What does it all mean?
You cannot feel the difference. ...

Hey tnekkcc, Do you believe the same thing applies to Shotguns for people shooting Trap with Fast Powders vs. Slow Powders - over the course of a days shooting? Maybe 300-1000 shots.

This is probably the only time that I have come out publicly to agree with Hot Core. I have read threads on shotgunworld.com of the benefits of using slower burning powders to reduce the cumulative recoil effects of many rounds of clays shooting.

quote:

Originally posted by tnekkcc:
For a 200 gr bullet to accelerate to 3000 fps down the bore 24", in free recoil the 8 pound gun will accelerate back to 10.7 fps over a distance of .086"..

Right on ! Your my Superman. roger

I thought such statements were bunk, but I can gurantee in my 350 rigby if I load 66gr varget under a 250 gr for 2700 fps, and 71-72gr(it's been awhile since I did load work) of H4350 under the same 250 gr for the same 2700 fps, you'll have absolutely no problem telling which load is which

I don't know if it's the recoil pulse occuring further down the barrel that causes the gun to rotate more in recoil and hence the cheekpiece to slap you silly, but there is a night and day difference between the loads. The Varget load is just a goodly push back, the H-4350 load is a slappy bitch, and makes the gun feel much more than it should on recoil. Fortunately the varget loads were sub moa and 4350 was about 1 1/4 moa, so I never had to debate shootability vs accuracy.

In the smaller bores you won't notice it, but I can gurantee in the bigger rounds you can deffinately feel the difference in various powders.

Almost forgot, worked up a load with VVN550 in the 458 lott w/ 500 gr bullets, even though recoil was a good 100 fps slower than the RL15 load, the VVN550 load was much stouter in recoil.

Paul,

It is my experience that I can tell the recoil difference between slow and fast powders too, with the slower burning ones seeming to produce more "felt" recoil.

I have seen this explained by the NRA years ago as being the result of the heavier charge-weight of the slower powders.

To exaggerate the explanation they gave: if a one is using a charge of 40 grains of a quite fast powder and 60 grains of a very slow powder, the additional 20 grains of the slower powder is claimed to act just like an additional 20 grains of bullet weight. Thus with the application of the old "equal and opposite reaction" law, more recoil is produced.

Everything in front of the primer is ejected during firing, whether as gas, or solids, or both. So what is being blown out the bore IS 20 grains heavier.

I have trouble believing that is the whole explanation, but I am just a shooter, not a scientest.

quote:

It is my experience that I can tell the recoil difference between slow and fast powders too, with the slower burning ones seeming to produce more "felt" recoil.

I've experienced the same thing.

quote:

Originally posted by Hot Core:

quote:

Originally posted by tnekkcc:
...What does it all mean?
You cannot feel the difference. ...

Hey tnekkcc, Do you believe the same thing applies to Shotguns for people shooting Trap with Fast Powders vs. Slow Powders - over the course of a days shooting? Maybe 300-1000 shots.

Hotcore, your post scares me.
I could be wrong.
I am often wrong, but I send them an invoice anyway

The gun may get more excited and ring like a tuning fork.
I have an Enfield No4 mark 1 that makes a buzzing sound for a few seconds after shooting.

A very fast rise time powder would make the gun shake more side to side.

This would explain Paul H getting his face slapped.

A slow powder would have more recoil at the same bullet velocity, as it takes more powder and we must could the gas mass momentum [ same as powder mass] as part of the recoil.

quote:

Originally posted by Alberta Canuck:
Paul,

to act just like an additional 20 grains of bullet weight. Thus with the application of the old "equal and opposite reaction" law, more recoil is produced.

Everything in front of the primer is ejected during firing, whether as gas, or solids, or both. So what is being blown out the bore IS 20 grains heavier..

AC, It really is a fact,but the additional 20 grains of powder gas isn't taveling at the speed of the bullet; it's much faster incurring greater impulse than if it were traveling at bullet speed. roger

It has been my experience that the slower burning powder will result is more perceived recoil.

I have experienced this when working up loads in my 416 Rem Mag. BLC-2 powder pushing a 350 grain projectile had more recoil than Rel 15.

I noticed that the slower burning powder also had more muzzle blast, contributing to the perception of higher recoil.

quote:

AC, It really is a fact,but the additional 20 grains of powder gas isn't taveling at the speed of the bullet; it's much faster incurring greater impulse than if it were traveling at bullet speed. roger

Roger-

You're quite right...I ahould have thought of that, but sometimes I'm not so sure I think at all anymore. Of course the gas impulse has an additive effect to recoil...and more of it too! Good point.

BTW, yes, am very interested in seeing your Mannlicher project pictures when you get to that point....I might even try to copy it with one of my own.

Best wishes.....

Hey tnekkcc, Back in my youth, I shot a lot of Trap. I noticed one of the Elders I shot "against" seemed to be somehow fresher. less tired, more alert (whatever) at the end of the day than his peers and those of us much younger. Just figured he was a Tough old Coot with a focus like steel.

Time passed and for some reason I ended up shooting some of his cartridges at the end of a day. He said he suspected I'd need to lead just a bit less than normal. So, I was figuring it had to be a Faster, harder kicking Load. It soon became apparent to me he had something different in his shells than I was using, because the recoil "seemed" to be less and keeping the same Lead as normal, I was actually smoking them better than usual.

I originally thought it might be "less shot", but the smoked clays did not support that. So, I managed to "pocket" a couple of his shells.

Weighing what all I found inside made no sense at all(back then), because he had the same amount of shot as I was using, but more Powder.

I did a bit of Reverse Engineering(before that term was dreamed up) and looked through the Reloading Manuals to see what Powder fit that Hull, Wad, weight of Shot and weight of Powder.

His components were essentially the same as mine except for the Wad and Powder. I was using Red Dot and 700X back then and I "think" he was using SR 4756. The Load shown for that Powder in the old IMR Handout matched what I found in his shells. He had a lot more Powder(something close to 2/3 more) with less chamber Pressure and a Higher velocity than the Loads I was using. But the amazing thing was it "felt" like less recoil.

Today I see it as the longer Burn Duration, plus less Pressure, spred the recoil over a bit more time and gave the "sensation" of less of a kick.

Easy enough for anyone that loads their own and shoots Trap to try for themselves if they would like to experience the difference.

quote:

Originally posted by Alberta Canuck:
[QUOTE]AC,


BTW, yes, am very interested in seeing your Mannlicher project pictures when you get to that point....I might even try to copy it with one of my own.

Best wishes.....

I have some photos of the finished MAS Mannlicher sned me your E -Mail address and I'll send them to you. roger

quote:

Originally posted by Hot Core:
Easy enough for anyone that loads their own and shoots Trap to try for themselves if they would like to experience the difference.

Trap is for them that can still see. roger

Well I can tell you that the recoil from an M1 Garand does not "feel" as sharp as the recoil from a M1903A3, even when both weight about the same. The bullets are of the same velocity out of the rifle but somehow the recoiling Garand action does something.

But in terms of bolt guns, well my experience firing 300 Rapid fire with a Match 30-06 bolt rifle. I have two excellent loads that chronograph at close to the same velocities, 168 Sierra 47.0 IMR 4895 and 168 Sierra 56.0 H4350. Well the IMR load always felt softer. I would have thought it would not have made a difference but the H4350 load kicked more, and the difference in powder weight should not have been enough to feel anything.

Fred and Geronomo got it right. All things being equal more powder weight mease more recoil at the same muzzle velocity. Try a .300 Win. mag., with a 180gr. bullet at 2700 fps and a .308 Win. also with a 180 gr. bullet at 2700. You will very quickly notice the difference. This was also very apparent to me with a .50cal. blackpowder rifle with a 22in barrel and 130 gr. of pyrodex, 300gr bullet, at 1530 fps and later I cronographed a .44 mag load with the same bullet the went 1520 fps at a fraction of the recoil. The physical weight of the powder does at to the recoil.

My father designed guns with a copy of the book "Hayes Elements of Ordinance".

The formula he used for recoil mechanism design was the gas velocity was 1.5 times that of the projectile.

So the gun recoil velocity was = [[bullet velocity] [bullet mass] + [1.5 X bullet velocity ][powder mass]]/ [gun mass]


This gun, the M110, had a 480,000 pound recoil reaction.
The recoil was absorbed with hydraulics, but the recoil springs that just returned the gun to battery were huge.

quote:

Originally posted by JBoutfishn:
It has been my experience that the slower burning powder will result is more perceived recoil.

I have experienced this when working up loads in my 416 Rem Mag. BLC-2 powder pushing a 350 grain projectile had more recoil than Rel 15.

I noticed that the slower burning powder also had more muzzle blast, contributing to the perception of higher recoil.

I had a similar experience working up loads for my bolt action 45-70, using a 500 grain cast bullet. My experience was the reverse of yours.
I was working with IMR 3031 and IMR 4064. both powders were generating some where around 1,500 fps and the IMR 3031 load hurt and the IMR 4064 load became my standard for that bullet.
My perception was the 3031 load was a sharp jab and the 4064 was a push.
Don't know if it makes any difference, i was testing the loads shooting prone using a sand bag. I was laying on dry side of a farm pond shooting across the pond to a bank 100 yards away.
Jim