Trapshooters Forum banner

Status
Not open for further replies.
1 - 11 of 11 Posts

·
Registered
Joined
·
1,207 Posts
Discussion Starter #1
A friend said," POI off a rest will be lower than the POI when shot offhand" considering the fact that the beads are stacked exactly the same and shot by an "Expert" shooter. Do you think there will be a difference? John
 

·
Registered
Joined
·
10,782 Posts
John, if there's a difference, I've never seen it, like 410 says.

I sandbag my rifles with a scope off sandbags too and none there either when I shoot from different positions. The only thing that changes is a two bit aim now n then, maybe that's what your friend was meaning or implying? :) Hap
 

·
Registered
Joined
·
11,024 Posts
If the gun is allowed to recoil the same in each position the POI will be the same. If muzzle jump is restricted in one and not the other the POI will be affected. HMB
 

·
Registered
Joined
·
4,113 Posts
adding to what hmb said, your stance can make a difference. Recoil from any shoulder fired shotgun is not straight back. There is some upward rotation, with the amount determined by stock dimensions, barrel position and shooting form. That upward rotation can affect POI vis a vis a bench.

I used to test barrel convergence and choke tubes from a low bench rest table. I was forced to lean forward and down, while sitting, to look down the rib. If I shot for POI in that position I got a lower POI than when I stood and shot. The difference was 3" @ 40 yds.

Acting on tips I got at a trap clinic last fall, I have been gripping the pistol grip more tightly, placing more weight on my left (front) foot, and leaning a little forward. With that stance, the difference all but disappeared. If there still is a difference it is less than 1" @ 40 yds- too small to tell.

So your friend is correct, for him. When you try it, and you should, you'll see if there is any difference for you.
 

·
Registered
Joined
·
9,941 Posts
My experience is that even off a rest at 13 yard, a distance at which you can tell what's going on, the full-choke holes are not all in the same place, not by a long shot. Over a string of 10, you will have "pattern" of POI's much like you get from a BB-gun at a similar distance. The pattern is sure to be bigger than two inches, counting the diameter of that hole as part of the measurement.

So how, I've always wondered, can anyone nail down POI at 40 yards to three inches? When you add what seems to me to be a basic uncertainly of at least 3 inches, then add

1) "wobble" introduced by not using a rest &

2) the uncertainty of placing the center of any pattern shot at 40 yards

and I'd say, biff, that your friend was guessing.

And even if it were testable, which I doubt it is, it makes no difference anyway. What you are trying to do is relate the POI results off a rest to scoring results on the field, not two POI results.

Neil
 

·
Registered
Joined
·
10,782 Posts
ZZT, if you got a different reading as much as 3 inches at 40 yards, either your table was too low or the bead alignment was off. With a shotgun patterned at 40 yards, how can you say your hold was that exact with a primitive bead and off-hand to boot? I've patterned my shotgun using a 1.75 power scope mounted on it too, to say I was off an inch at 40 yards with a shotguns erratic pattern tendencies and I certainly can't make that statement. Now, at 16 yards, that's a different ballgame because of pattern size. At that distance, it makes no difference. This is almost the same as saying my rifle sighted in on the sandbags from a sitting position at the bench will shoot (somewhere) different than shooting it off a much higher bench using a rest from a standing position? Shooting off sandbags tell the story, not a guess hold when the gun goes off, especially at 40 yards shooting off-hand. Hap
 

·
Registered
Joined
·
4,276 Posts
Neil, You have my attention and interest in your testing system. Do you super impose any of your shots, or are they 10 seperate ones side by side. I have 2 O/U barrels that I am trying to regulate to shoot the same as the unsingle, or try and get all 5 barrels to shoot to the same POI. At least that is what I think I should be attempting to do.
#1. Is this the correct goal?
#2. I believe that I need to start the work with the 2 top barrels, which seem to be similar,and then bring everything to that.
#3. While I have your attention, I'd like to thank you for all of the time and effort that you take to try and give good advice to this site.
Thank you, Bob Hawkes
 

·
Registered
Joined
·
4,113 Posts
Hap, the table was too low. I use a different method now. Bead line up was the same. I don't shoot for POI at 40 yards. I shoot at 13.33 yards from muzzle to target, then multiply by 3 to get offset at 40 yards.

I use a 40" wide sheet of paper and draw a tic-tac-toe frame on it with an extra plus sign in the middle. That gives me 9 intersections to aim at. I shoot at each in turn, measure and average the results. From a rest I stop at 9. Standing I'll do more if I pull too many shots. I've never seen 2" of variation from a rest unless the wad in that load doesn't shoot straight and enlarges the hole.

Anyway, now that my shooting stance is more "correct" the discrepancy has disappeared. As I said above, if there is a difference now, it is too small to matter.
 

·
Registered
Joined
·
1,207 Posts
Discussion Starter #11
Thanks all for the responses. I am thinking more about what Neil said that a smoothe bore barrel can give variables much like a BB gun. It spins my mind that a shotgun barrel which is smoothe,like a BB gun, may have even more variables due to wad construction, loose round pellets, amount of pressure to close the hull packing the shot in, the burn rate of the powder, how fast the primer ignites the powder, and other factors unknown like X. No wonder I sometimes miss when I send only a thimble full of round small spheres through unfriendly atmosphere; I thought all the time it was ME just plain missing the target!

I also guess my friend is right that HIS gun will shoot higher off his shoulder than when he sandbags it. I'll tell him that, no sense putting doubt in anyone's trapshooting beliefs. My gun has a tendency to shoot right or left or high or low when I try to find it's POI off handed, that's why I shoot off a bag at 26.6 yards; that way I see both POI and an idea of how the pattern is. Thanks, John
 
1 - 11 of 11 Posts
Status
Not open for further replies.
Top