|
S |
M |
T |
W |
T |
F |
S |
|
|
|
|
1
|
2
|
3
|
4
|
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
|
12
|
13
|
14
|
15
|
16
|
17
|
18
|
|
19
|
20
|
21
|
22
|
23
|
24
|
25
|
|
26
|
27
|
28
|
29
|
30
|
31
|
|
|
|
0 members (),
384
guests, and
6
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
Forums10
Topics38,501
Posts545,497
Members14,414
| |
Most Online1,344
Apr 29th, 2024
|
|
|
|
Joined: Jun 2002
Posts: 9,350
Sidelock
|
Sidelock
Joined: Jun 2002
Posts: 9,350 |
I wouldn't have expected more recoil from the shorter shells. Assuming similar light loads, why, please?
|
|
|
|
|
Joined: Aug 2008
Posts: 960 Likes: 12
Sidelock
|
|
OP
Sidelock
Joined: Aug 2008
Posts: 960 Likes: 12 |
Thank you all for your opinions, which is all I can ask. Last Dollar, that's very interesting that the short shells recoiled more. Hmmm... Which powder are you using in your recipe and how many grains? I'm using Longshot, but may switch because it does produce the most recoil from what I understand. I agree with revdoc, that is hard on 100 yr. old wood. I'll be heading to the range soon with a bunch of different 2.5" handloads and a few of the 2 3/4" lp shells and let you all know how it turns out. It will of course be an extremely scientific undertaking, using the most rigorous and statistical analysis available. I'm sure you all know what I mean 
|
|
|
|
|
Joined: Sep 2007
Posts: 2,814 Likes: 1
Sidelock
|
|
Sidelock
Joined: Sep 2007
Posts: 2,814 Likes: 1 |
King, I wouldnt have a clue as to why we "perceived" less recoil, but we all seemed to. I dont think we can assume similar loads becsue I have no stats on the short shells ...Mark,I am loading 800x, you will have to consult your manual for the recipe...
|
|
|
|
|
Joined: Feb 2006
Posts: 3,733 Likes: 52
Sidelock
|
|
Sidelock
Joined: Feb 2006
Posts: 3,733 Likes: 52 |
As Pete said low pressue doesn't increase or dercrease recoil, velocity does. Now if you have a low pressure of 7000 psi and velocity of 1,050 the recoil will be less than 7000 psi and 1250 fps.
So really it should be stated low pressure, low velocity = low recoil.
David
|
|
|
|
|
Joined: Jan 2002
Posts: 5,983
Sidelock
|
|
Sidelock
Joined: Jan 2002
Posts: 5,983 |
Just my recollection of Bell's article, but I thought he said he tested paper hulls as well and they didn't show an increased pressure outside of the average of the plastic hulls. Also, my memory says that he got between 0 and 15% increased pressure from 2 3/4" shells in a 2 1/2" very short (1/2"???) forcing cone chamber. My personal experience with only one load in a couple damascus guns is that my 2 3/4" Federal paper hull loaded to what a manual says should be mid 7K psi is actually coming out to mid 6K psi measured in a short chamber. I feel no significant recoil and velocities are super consistant at 1150 fps. So, from all the above I've formed the opinion that short chambers (mainly 2 9/16 to 2 5/8" in American guns as I understand it) is not a reason to change my reloader setup to load 2 1/2" shells. It's inconvenient to change to shorter shells and I see no benefit at this time. However, if someone has convincing evidence that my information is wrong, I'm always willing to change that opinion. I do have to take exception to the statement that pressure has nothing to do with recoil. I believe it is one of several key components in acceleration of the payload in a gun, the others being time and weight of the payload, and surface area of the payload upon which the pressure and time work to accelerate the payload and conversely, the gun in the opposite direction. I'm no physicist or ballistician, but I think that covers the basic physics of a gun. Sorry Pete.  Pete is correct in that pressure has nothing to do with recoil, period. If you increase pressure on a given load AND that pressure increase also causes an increase in velocity, you might indeed experience some increased recoil. BUT, big BUT, the recoil increased because of the velocity increase, NOT because of the increased pressure. If shooting a long shell in a short chamber caused a pressure increase without a velocity increase, There would not be a recoil increase. OCYFTBAYWT (Of Course You're Free To Believe Anything You Want To. Sorry Chuck, I thought YOU knew better.
> Jim Legg <
|
|
|
|
|
Joined: Nov 2005
Posts: 4,598
Sidelock
|
|
Sidelock
Joined: Nov 2005
Posts: 4,598 |
To measure actual recoil, you need to know the velocity of the projectile, the mass of the projectile, the mass of the charge and the mass of the gun.
To measure pressure, you also need to know the burn rate of the propellant, the size the chamber, the plasticity of the barrel, the size the bore, etc.
It is the simple physics.
Bell essentially showed that given a momentary constriction and the plasticity of a shot shell, pressure increase is negligible. But recoil did not change. Increasing the bore size immediately after the chamber will decrease the pressure some what, but again it does not affect recoil.
Pete
|
|
|
|
|
Joined: Feb 2004
Posts: 13,880 Likes: 16
Sidelock
|
|
Sidelock
Joined: Feb 2004
Posts: 13,880 Likes: 16 |
David,
As I posted; I believe pressure is one of several key components in what makes up recoil, not the only one. You can't have recoil without pressure. Sure, one can take the total ejecta and the MV and gun weight come up with a total energy of recoil. But that is a very simplistic answer that ignores the "time" element of recoil. It does not include answering what peak force is generated. And some have argued that peak force in recoil is irrelavent and maybe some think that peak force won't change if velocity and weight of ejecta doesn't change. Maybe. But, I don't believe that.
I think the point at which opinions start diverge is on the definition of the term "recoil". The simple definition is the total energy of the gun movement. That's not wrong. But there are other defineable elements like peak force and time of the forces. I believe peak force is an element of recoil that most shooters can feel. Others don't believe that. So, we disagree. That's o.k. it's just what I believe, not something everyone needs to believe.
Last edited by Chuck H; 09/03/08 05:49 PM.
|
|
|
|
|
Joined: Mar 2002
Posts: 1,815 Likes: 4
Sidelock
|
|
Sidelock
Joined: Mar 2002
Posts: 1,815 Likes: 4 |
I have shot both in my 2.5 Guns and have never noticed the difference in recoil or pressure signs on the primers. The S.Bell article is in the Winter 1992 DGJ if I remember right.
|
|
|
|
|
Joined: Jan 2006
Posts: 9,427 Likes: 315
Sidelock
|
|
Sidelock
Joined: Jan 2006
Posts: 9,427 Likes: 315 |
So if the ejecta slams into a retained wad just past the forcing cone, there will be no increase in the recoil before the barrel blows, compared to the ejecta exiting the barrel without obstruction? Took some physics once, and it was never very simple to me.
|
|
|
|
|
Joined: Feb 2006
Posts: 3,733 Likes: 52
Sidelock
|
|
Sidelock
Joined: Feb 2006
Posts: 3,733 Likes: 52 |
Chuck,
If my statement sounded like I was disagreeing with you, I was not. It is hard to believe that pressure, psi, which is force has nothing to do with recoil. In my opinion the force is going two ways forwards and backwards, and the backwards would be felt recoil. I know what people say but I have a problem trying to deal with the equation.
Still again my opinion, I reload 2 1/2" 20 ga. and 2 1/2" 16 ga. for short chambered "elsies" and I would not put 2 3/4" shells in it even though thousands have been fired that way.
David
|
|
|
|
|
