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Low Recoil Loading Data needed for S&W 40


mastergunner

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sd, my reference for the 4000 is Ed Lowry, Winchester's famed ballistician.  The math does not say a heavy bullet will generate less recoil than a light bullet pushed to the same power factor.  While that is certainly the case sometimes, it is not always.  If you use small amount of a fast powder for the 180 and gobs of slow powder for the light bullet, things may reverse.

 

mg, I came up with the data because an individual had the powder tested at a lab (cartridge manufacturer) to see what the limits were.  He reports the loading is the same as Clays, but without the pressure spikes.  He also says that at higher pressures, e3 acts like it is a slightly slower powder.  e3 exhibits no temperature sensitivity.  In my chrono testing e3 gives the same velocity grain for grain the Clays or Clay Dot does.

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38 minutes ago, zzt said:

sd, my reference for the 4000 is Ed Lowry, Winchester's famed ballistician.  

 

The math does not say a heavy bullet will generate less recoil than a light bullet pushed to the same power factor.  While that is certainly the case sometimes, it is not always.  If you use small amount of a fast powder for the 180 and gobs of slow powder for the light bullet, things may reverse.

 

 

Sorry, I should have been more specific.  A heavy bullet will produce less recoil than a light bullet if pushed to the same power factor with the same gunpowder.

 

If you use different gunpowders, everything changes, but then it's a different type of comparison because you've added another variable (different gunpowders). 

 

Did Ed Lowry publish this information, or is this by word of mouth?

 

 

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Es Lowry did publish this information in his Windows Ballistic Programmed called Shotgun Ballistics for Windows.  Since I cannot cut and paste, I'll quote the relevant passage.  BTW, Ed uses "...average velocity (at the muzzle) of the propellant gasses" in his description of the formula for recoil, but later clarifies by saying, "The seventh, the gas velocity (actually the velocity of sound in the propellant gasses), is approximately 4000 for shotshell propellants".

 

Hodgdon uses 4700 in their formula, as an approximation for rifle powders.

 

The comparison does not change when using different gunpowders.

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The comparison changes if you're using different gunpowders for different bullet weights. In other words, if you use gunpowder A for a 180 grain bullet and gunpowder B for a 150 grain bullet.  You can't make a fair recoil comparison under those conditions. For a fair recoil comparison for different bullet weights, use the same gunpowder. 

 

I repeat, a heavy bullet produces less recoil force than a light bullet if they are pushed to the same power factor with the same gunpowder.

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2 hours ago, zzt said:

sd, my reference for the 4000 is Ed Lowry, Winchester's famed ballistician.  The math does not say a heavy bullet will generate less recoil than a light bullet pushed to the same power factor.  While that is certainly the case sometimes, it is not always.  If you use small amount of a fast powder for the 180 and gobs of slow powder for the light bullet, things may reverse.

 

mg, I came up with the data because an individual had the powder tested at a lab (cartridge manufacturer) to see what the limits were.  He reports the loading is the same as Clays, but without the pressure spikes.  He also says that at higher pressures, e3 acts like it is a slightly slower powder.  e3 exhibits no temperature sensitivity.  In my chrono testing e3 gives the same velocity grain for grain the Clays or Clay Dot does.

 

zzt so I would use the Clay or Clay Dot loading data for the particular grain I need for the velocity I want?

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sd, you are talking about "felt" recoil.  Actual recoil calculations are based on the weight of the powder, not its composition or burn rate.  As such, recoil comparisons are accurate and valid.

 

mg, yes for 40sw and 45ACP.  I don't know about 9mm, because I don't reload it.  The person who had the testing does use it for 9mm and says it works fine and is safe.

 

BTW, I gave my Major and Minor loads for Limited in an earlier post.  I also developed a soft load for Steel Challenge.  It is 3.3gr e3 under a Rainier 135gr TC bullet.  It makes 109PF and shoots like a dream in my CZ TS.  For Steel with my Open upper for the TS I load 3.5gr e3 under a 155ge Rainier TC bullet for 131PF.  It works the comp and there is zero muzzle rise.

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36 minutes ago, zzt said:

sd, you are talking about "felt" recoil.  Actual recoil calculations are based on the weight of the powder, not its composition or burn rate.  As such, recoil comparisons are accurate and valid.

 

mg, yes for 40sw and 45ACP.  I don't know about 9mm, because I don't reload it.  The person who had the testing does use it for 9mm and says it works fine and is safe.

 

BTW, I gave my Major and Minor loads for Limited in an earlier post.  I also developed a soft load for Steel Challenge.  It is 3.3gr e3 under a Rainier 135gr TC bullet.  It makes 109PF and shoots like a dream in my CZ TS.  For Steel with my Open upper for the TS I load 3.5gr e3 under a 155ge Rainier TC bullet for 131PF.  It works the comp and there is zero muzzle rise.

 

zzt I thought those loads were for a 180gn bullet. Did you have one for a 155gn bullet?

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2 hours ago, zzt said:

sd, you are talking about "felt" recoil.  Actual recoil calculations are based on the weight of the powder, not its composition or burn rate.  As such, recoil comparisons are accurate and valid.

 

 

No, I'm talking about actual recoil force based on calculations that include the weight of the powder. 

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mg, yes you can, but if you use a fast powder for Major PF under a 155 it will hit your hand hard, and you'll be up around max pressure.  You said you wanted a light recoiling load. If that is still the case, using nothing lighter than 165.  There is a reason a majority of Limited shooters shoot 180s.  Many also like the softer (but slower) feel of 200s.

 

For 172PF, keeping everything the same, including the powder charge, but excepting the bullet weight, a 155gr bullet and a 200gr bullet have the same recoil in a 2.35lb gun.  This is to illustrate that increases in velocity count for more than increases in bullet weight, because the results are squared.  If you entered the correct powder weight for the 155gr slug, you would end up with a higher recoil, because you used more powder to get the 155 up to 172PF.  The 155gr slug will have more actual recoil, and it will feel sharper to your hand.

 

sd, the recoil formula gives you Momentum.  Components do not matter.  Only weight of the ejecta, velocity, 4000, twice the acceleration of gravity and the weight of the gun.  If the formula returns a higher value, there is more Momentum (recoil) than a lower value, regardless of the components that made up the loads.

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The power factor is a momentum value while recoil is more commonly an energy value.  Momentum id mass times velocity.  Energy is one-half mass times velocity squared.

 

The value of 4000 for the powder gas velocity is a more recent figure.  Hatcher, in his book, listed 4700 for the powder gas.  As someone stated, either can be used as it will still rank the relative values.  I tend to stay with the 4700 value, since that is what I've been more used to.

 

The powder charge is a significant portion of the recoil.  As an example, the recoil due only to the bullet for a 200 grain bullet at 850 fps gives a recoil value of 3.1 ft-lbs.  Using 5 grains of powder brings the recoil to 4 ft-lbs, comprising 13% of the total.  In rifles the powder may produce more recoil than the bullet.

 

Guy

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On 3/13/2017 at 4:44 PM, outerlimits said:

want another variable?  try this recipe with 180 lead vs 180 jacketed.

+1

(IMHO) ... Absolutely!! It takes a lot less powder to push a coated or pure lead bullet than it does to push that Berry ... even FMJ move faster.

I can make 170pf w/ a 180 blue bullet and 4gr of Bullseye ... it takes 4.6 Bullseye (for me) to get the same velocity with an Extreme plated. 

Can only find this old article in this book now ... hope link works ...

 

https://books.google.com/books?id=datxDAAAQBAJ&pg=PA237&lpg=PA237&dq=fastest+bullets+coated+lead+jacketed&source=bl&ots=HMOtlOwTjB&sig=g5xvPsLHbEY1PNoRZHV6nacM5WM&hl=en&sa=X&ved=0ahUKEwiCyMzaj9_SAhVJKWMKHeTbAbQ4ChDoAQgzMAQ#v=onepage&q=fastest bullets coated lead jacketed&f=false

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There is disagreement about the value used for the escaping gas' velocity. SAAMI suggests using a multiplication factor of the bullet's velocity instead of the 4000/4700 values.  

 

http://www.saami.org/PubResources/GunRecoilFormulae.pdf

 

"The effective velocity of the propellant gas, a much more difficult measurement, varies, in general, with the muzzle pressure and projectile velocity."

 

High powered rifles  x 1.75

Shotguns (average length)  x 1.50

Shotguns (long barrel)  x 1.25

Pistol & revolvers  x 1.50

 

"The above velocity relationships were derived from extensive experiments by the British, published in "British Text Book of SmallArms" published in 1929 and confirmed by later work in this country."

 

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As you quote, the multipliers come from the British Textbook of Small Arms 1929.  Hatcher's 4700 value comes from his latter 1950's book.  Quickly scanning the book, I do not see teh individual factors as listed by SAAMI, but the statement that the value will be between 1 and 2, to be determined by experiment, but generally as 1.5.

 

It has been said the 4700 value is applicable to artillery, and the 4000 to small arms.  I've also seen recommendations to use 2000 for black powder.

 

Which is "best"?  I don't know, but as long as one system is used for side by side comparison, it should give a relative comparison.

 

As a comparison, let's look at the aforementioned 20gr bullet at 850 with 5 grains of powders versus a 250gr bullet at 680 fps with 4.2gr of powder.

 

     Bullet          Bullet           Powder          Recoil          Recoil          Recoil          Bullet Only

     Weight       Velocity        Charge          4700           4000            SAAMI          Recoil

----------------------------------------------------------------------------------------------------------------

     200             850             5.0                 4.0              3.8              3.8                3.1

     250             680             4.2                 3.8              3.7              3.7                3.1

 

These have equal momentum (power factor) but we see the heavier bullet gives less recoil energy through the use of less powder.

 

Guy

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Guy, does Hatcher explain how he came about the 4700 value?

 

It seems that the speed of the escaping gas could be measured with some form of high speed photography. In any case, I suspect that there will be variation in gas speed, and that the quote "The effective velocity of the propellant gas, a much more difficult measurement, varies, in general, with the muzzle pressure and projectile velocity." will be right since muzzle pressure and projectile velocity varies.

 

The gas speed is used as a  constant, so as you say, the relative difference in recoil will be evident, and that's the question that is asked when comparing recoil between different bullet weights.

 

 

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Guys this is an awesome discussion though I guess what I thought was a simple question really isn't. What I have noticed is that the calculations provided by a few here on PF are not jiving with most online PF calculators. If I wanted to shoot Major with my .40 I need to shoot a 180gr bullet at almost 900fps. Some of you are showing a way lower velocity so I am really confused.

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8 minutes ago, mastergunner said:

Guys this is an awesome discussion though I guess what I thought was a simple question really isn't. What I have noticed is that the calculations provided by a few here on PF are not jiving with most online PF calculators. If I wanted to shoot Major with my .40 I need to shoot a 180gr bullet at almost 900fps. Some of you are showing a way lower velocity so I am really confused.

 

165000/180 = 916 fps minimum.  most folks will load to a higher power factor for a margin of error.

 

170 power factor:  170000/180 = 944.4 fps.

 

 

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On 3/12/2017 at 7:32 PM, mastergunner said:

I am shooting USPSA using my S&W M&P 40. I have shot 180 gr bullets but thought if I went to a 155gr bullet I would have less recoil. I am using CFE Pistol powder and would like to get some help on a real lite load for a 155gr bullet. Is there such a thing or do I have to go back to a heavier bullet. I also have Win 231 powder that I could use if necessary. Thanks for the help.

I would use the w231 over the cfe if you are trying to soften up the recoil. Heavier bullets is the way to go for softer shooting too. I would also go with a coated bullet if I were you. It will require less powder to make power factor. That will help soften the recoil too.

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