Handload recoil question......

[Rick James]

Quick question for you guys.....

Is recoil affected only by pressure?

Reason I'm asking.....right now I've found that my 5.5" Bisley in .45 seems to only like hot loads. I've only experimented with HS-6. Using Linebaugh's loading data, I loaded in half grain increments from 13-15 grains of HS-6 behind a 265gr cast performance bullet. 13 grains accuracy was pretty terrible, and it' didn't start cleaning up until I got to the 14 grain loads. 15 grains (max) was consistently the best load by a long margin. I went from 5-7" groups with the 13gr loads at 25 yards to a 2" or so group when I hit the 15gr max load.

What I'm wondering is if I switch over to H-110, and try to push the loads faster.......will I have more recoil? Linebaugh's writing indicates I'm around 1225fps right now and 30,000CUP. If I swap over to H-110 I can start at a 25.5gr load and expect 1350ish and load up to 27gr and 1450fps @ 30,600CUP.

Since the pressures are almost the same at max load, despite how much more velocity I'll be getting from H-110, will there be a perceived increase in recoil? The max loads I shot today with HS-6 were hot but bearable, I'm not sure I really want too much more recoil. If I could gain more accuracy, it might be worth it though.

Any thoughts?

 

[Tellico]

Recoil will increase with velocity increase if bullet weight is constant. Same velocity with heavier bullet will increase recoil also. An increase of powder weight will even increase recoil with the same velocity and bullet as you must add the powder weight to the bullet weight as ejecta. The increase will be negligible with the powder weight increase but will be there and could be measured. Recoil is subjective and momentum will have and effect on perceived recoil also. people say a .40 feels like more recoil than a .45ACP because of the sharper feel to the .40 but in foot/lbs the .45 has more but slower momentum makes it feel like less. IMHO.
Fred

 

[Rick Courtright]

Hi,

Recoil's both subjective AND objective...

The objective part can be covered by a decent high school physics class (if there are such things these days?) You can look up "gun recoil" and find formulae to plug your figures into to get that. You'll need the gun weight, bullet weight, powder ("ejecta") weight and velocity. That'll give you a solid figure that increases w/ velocity and/or bullet-charge weight combination and isn't really pressure dependent.

Then there's the subjective part. While pressure isn't really a part of that recoil number generated above, a load that accelerates more quickly (which IS often a function of pressure) will "seem" to kick harder than one which achieves the same muzzle velocity but does so a tiny bit more slowly due to a different rise in the pressure curve. A good ballistician w/ the right test equipment can generate pressure/velocity curves which will "suggest" how folks "might" react to the load upon firing, but, in the end, each shooter's gonna have loads that feel better or worse in a particular gun.

Clear as mud, huh?

Rick C

 

[Jimbo357mag]

I have found that a slower burning powder will give a softer felt recoil compared to a faster powder for the same cartridge pressure and even more so for the same velocity .

Example
- (1) Same bullet loaded to the same max pressure with two different powders. The slower powder will have the softer felt recoil, more of a push.
- (2) The same bullet loaded to the same velocity with two different powders. The slower powder will have a much softer felt recoil because of the slowness of the powder plus the pressure is less.

 

[m657]

I've read considerable about such perceived recoil changes with otherwise comparable given muzzle velocity of a given weight slug.

Agree with the notion the 'rate of acceleration'---otherwise known as 'burn rate' etc of the powder---is a factor in that 'perception'....and given all else is 'the same', recoil measured in a longer slower peak pressure curve vs sharper faster peak pressure curve, can and does affect that perception.

Example: think of a running shoe with a given athlete generating a given downward moment-impulse during heel-strike phase. The last study I saw years ago listed something on the order of .5 microseconds of compression before the heel-bone hit the effect end of the cushioning material---transmitting a given physical shock to the calcaneus, eventually resulting in pain and/or heel spur. The designers came up with a then-new material which spread the same vertical load over a longer compression time, producing a subjectively more comfortable heel-strike which also decreased both pain and heel spur formation.

My contention is the longer impulse-loading phase may produce a runner and/or slug traveling unaffected objective speed rates while the subjective sensation is beneficially changed.

If I haven't confused the question, this produces the same pressure wave but over a longer time period. Recoil as measured by straight-back as well as muzzle-rise forces, the subjective part, is modified. Projectile FPS across a chrony, is the same. IMHO.

 

[powder smoke]

I ignore recoil don't even think about it! Seems to make me a better shooter! ps