Trapshooters Forum banner

1 - 20 of 63 Posts

·
Premium Member
Joined
·
1,281 Posts
Discussion Starter · #1 ·
I have a fairly good understanding of velocity and mass of the payload can have an effect on recoil (real or perceived) but I am in the fog about the psi reported on the reloading tables.

When comparing load formulas, would lower psi (same fps and payload) deliver less recoil?
 

·
Premium Member
Joined
·
1,281 Posts
Discussion Starter · #4 ·
How many times are you going to try this troll?

NO BITES.

Pool is sterilized.
Is flashmax suggesting that grandpasarms is trolling for something? Also, what does that mean -exactly?
I am honestly interested in selecting a recipe and I want to know how different psi numbers relate to recoil.
 

·
Premium Member
Joined
·
602 Posts
The reason powder companies include chamber pressure for a load recipe is to show that - according to their testing - the pressure a given load creates doesn't exceed safe limits.

Recoil is determined by the weight of the shot load, the velocity at which it leaves your gun, the weight of your gun and - to some extent - how much the operation of the action of the gun absorbs recoil energy. Chamber pressure has no correlation to recoil.
 

·
Registered
Joined
·
32,283 Posts
I think the guy who started this thread below, had it figured out, posted just a couple months ago.

https://www.trapshooters.com/threads/actual-recoil-vs-perceived-recoil.859023/

“The weight of the shot and the muzzle velocity determine the amount of rearward energy generated when a shell is fired. The energy is measured in foot-pounds.”



Which makes today’s thread scratching our head.

.
 
  • Like
Reactions: Kazer and pbansen

·
Premium Member
Joined
·
742 Posts

·
Registered
Joined
·
198 Posts
To test the theory, fire a few shots with full choke and a few with improved cylinder and see if you perceive any difference in recoil. The more open the choke, the less pressure. I have an auto loader that will eject 1 oz shells just fine with a full choke, but barely ejects the same shells with a modified choke (sometimes even fails to eject). I sense no difference in recoil, but then again, it’s an auto loader.
 

·
Premium Member
Joined
·
1,281 Posts
Discussion Starter · #12 ·
I think the guy who started this thread below, had it figured out, posted just a couple months ago.

https://www.trapshooters.com/threads/actual-recoil-vs-perceived-recoil.859023/

“The weight of the shot and the muzzle velocity determine the amount of rearward energy generated when a shell is fired. The energy is measured in foot-pounds.”



Which makes today’s thread scratching our head.

.
The discussion last October - yeah, that was also me - was grounded in velocity and weight and there wasn't a mention of psi. The reload tables post psi and I am honestly interested in how that number might have an influence on recoil (actual or perceived). I remain on the trail of adjustments that can help me continue shooting comfortably. If asking legitimate questions makes me a TROLL then so be it.
 

·
Premium Member
Joined
·
410 Posts
The PSI shown in the manual is the peak pressure that combo of components reaches. That peak pressure only exists for a very short time and occurs before the shot leaves the chamber. The total time that peak pressure exists is too small for it to affect the velocity. Look at a pressure versus time curve. So just checking the peak pressure of different combos of components tells you nothing about velocity but it does tell you the peak pressure which tells you if the load is safe and relatively good burning.

However, if you just look at one load with the same components but differing amounts of powder then the peak pressure actually does follow velocity. But that is the trivial case.
 

·
Registered
Joined
·
1,725 Posts
To look further at capabilities of human perception - response time in humans is way slower than peak pressure in shotshells.
The fastest human response time is visual at about 13 milliseconds, and response to physical stimulus is about 100 milliseconds.
Peak pressure in shotshells is under 1 millisecond, which says to me that the concept of human detection of fast or slow powder in recoil perception is nonsense.
I remain open to more educated opinions regarding human response to stimulus - speculation not so much.
 

·
Registered
Joined
·
3,977 Posts
To test the theory, fire a few shots with full choke and a few with improved cylinder and see if you perceive any difference in recoil. The more open the choke, the less pressure. I have an auto loader that will eject 1 oz shells just fine with a full choke, but barely ejects the same shells with a modified choke (sometimes even fails to eject). I sense no difference in recoil, but then again, it’s an auto loader.

By the time the shot and wad get down the barrel to where the choke is the pressure is only in the 100’s of psi. That’s why ports on a shotgun are useless. Here is a pressure chart from 3 different loads shot and like already mentioned in a above post, the peak pressure is less then a millisecond then it’s all down hill.
5505AEE1-A5B3-48E8-8683-8096B5EF3244.jpeg
 

·
Ya can't miss with a shotgun
Joined
·
2,763 Posts
I have a fairly good understanding of velocity and mass of the payload can have an effect on recoil (real or perceived) but I am in the fog about the psi reported on the reloading tables.

When comparing load formulas, would lower psi (same fps and payload) deliver less recoil?
I honestly think that if you really did have a good grasp of the physical laws around velocity, mass, and recoil, you would know that pressure has zero influence on recoil...... equal and opposite reaction. Zero. Period.

A barge at float at sea launches a tug boat out the rear cargo deck. The barge will have an equal and opposite reaction by moving in the opposite direction of the released tug..... that's the recoil, and with zero pressure. A larger tug will move the barge further in the opposite direction and still, zero pressure, even with a change in ejecta weight and velocity.

Ejecta weight, ejecta velocity, and weight of what's doing the launching are all there is.

You'll find many, many, loads in reloading manuals that show higher velocity with the same payload weight, expressing lower pressure, than that same load at lower velocity, but with a higher pressure using a different powder.

.
 

·
Ya can't miss with a shotgun
Joined
·
2,763 Posts
Jaburg has done tons of research in this area so I am going to go with what he says.




View attachment 1655157
Very wise of you.......Thank you for the support Doc, and yes, I’ve conducted exhaustive field research, and have my work published in several key peer-reviewed journals of mechanical engineering, of which you served on the review board. You even donated a couple of the bath tubs used in testing simulated, scale model, tug boat recoil.

.
 
1 - 20 of 63 Posts
Top