TargetTalk

I just decided today to change from a center hold to a sub-6 hold. I got the air pistol out and resighted it and shot about 40 rounds. I started to call my shots and was surprised how bad I called the shot and still had a scratch 9. It sure saved a lot of .22 ammo learning where I was most comfortable holding and using the air instead of the free pistol.

I was starting to get some good tens and then shot an 8 shot group at about 2 o'clock on the 9 line and in the 8 ring. I wasn't sure what caused it except I changed the light on the target a little. Now I am wondering if I had the pistol canted slightly. It seems to me that a cant would really be detrimental sub-6 compared to center hold. Do you sub-6 shooters find that to be the case? Do you have any tips to make the change successful?
Thanks!
Ben

You might want to play with your front sight width. When I changed from sub 6 to center hold, I found that decreasing my front sight width a little helped. With sub 6 my front sight was somewhat wider than then bull, with center hold my front sight is somewhat narrower than the bull.

Freepistol wrote:I just decided today to change from a center hold to a sub-6 hold. I got the air pistol out and resighted it and shot about 40 rounds. I started to call my shots and was surprised how bad I called the shot and still had a scratch 9. It sure saved a lot of .22 ammo learning where I was most comfortable holding and using the air instead of the free pistol.

I was starting to get some good tens and then shot an 8 shot group at about 2 o'clock on the 9 line and in the 8 ring. I wasn't sure what caused it except I changed the light on the target a little. Now I am wondering if I had the pistol canted slightly. It seems to me that a cant would really be detrimental sub-6 compared to center hold. Do you sub-6 shooters find that to be the case? Do you have any tips to make the change successful?
Thanks!
Ben

Cant is no more of an issue sub-6 than centre hold. My cant sometimes varies and it doesn't appear to affect the POI of my shots. I would say that if you have just tried it for one session, carry on working with it for at least a month. You can't really make any assessments as to which would be best for you without a fairly lengthy tryout spell.

Rob.

I played around with the sub-6 and couldn't get myself to hold on "nothing" when I had such a small ten ring on the 50 ft. free pistol target. I went back to the center hold, but still questioned my sanity.

A few days ago, I decided to do the blank paper excercise and kept thinking that if I shoot center I should shoot at a black paper instead of white.

What an eye opener!

My sights were getting lost in the huge black area. Even my rear sight was hard to see.

I'm now a former center hold shooter.

Ben

Freepistol wrote:I played around with the sub-6 and couldn't get myself to hold on "nothing" when I had such a small ten ring on the 50 ft. free pistol target. I went back to the center hold, but still questioned my sanity.

I work with kids on this (coach PPP) and use a different explanation for your point of focus. It follows the idea behind this:



Do you see a black Vase, or 2 white Faces? You're looking at the same thing, but you shift focus. So instead of focusing on the Black parts (rear sight, front sight, bull), focus on the White parts (gap between the front and rear sight on the sides, and between the bottom of the bull and the top of the front sight). All 3 spaces should be the same width (my side to side never changes, just up and down, so I adjust the distance between the top of the front sight and bottom of the bull till it matches the other 2 white spaces).

I know it helps some people to information presented in a different way, so maybe this will help.

Cheers,

Brian

ShootingAir.com

Been shooting sub-6 for 20 years. First in NRA Bullseye now with air pistol. Brian is right. The space between the black and front should be same as the width on the sides. What helps me is to keep repeating "Trust your sight, trust your sight....." as I prepare to fire. Also the light will affect your groups. I've heard it said "pellet follows the light"! It's really true.

Thanks Brian and Sail, I can see how that technique will be more accurate than trying to judge the black distance while the front sight is fading into the bull with a center hold. The greatest gain will be the ability to keep the front sight in focus on the white. My old eyes weren't able to see it anymore.
Thanks again!
Ben

Cant is no more of an issue sub-6 than centre hold. My cant sometimes varies and it doesn't appear to affect the POI of my shots. I would say that if you have just tried it for one session, carry on working with it for at least a month. You can't really make any assessments as to which would be best for you without a fairly lengthy tryout spell.

Rob.


This is completely wrong. Hold a pencil vertically in your hand at arms length facing a blank wall. The tip of the pencil will be yourPOI using area hold [ aiming in the white beneath the black ].....now cant your hand to the right or left and watch the arc created by the movement. This will be the new POI as a result of canting.
Area aim is used to make the sight picture more visible on a white background, and to minimise concious trigger squeeze caused by moving backwards and forwards over such a small target as the centre of the black.
The only potential problem with area hols is CANTING, and particular attention MUST be paid to the vertical orientation of the pistol for each shot.

All holds are "area holds."

If you pretend you have a point hold, well, great. The facts are, your muzzle is continuously moving over the face of the target. No matter what you are personally focusing on.

As to the effect of cant on variously centered area holds, well now, that is indeed worth talking about.

Assume a normally distributed pattern of wobble centered on any particular point.

Assume also that you are canting uniformly (I have never seen anyone who canted in different directions for each shot; everyone cants in one direction at one angle fairly constantly).

Consider the "offset" of the center, 6, and sub-six holds . . . each is centered on the ten ring, the normally distributed pattern of wobble is simply translated from the tip of the (aligned) front sight to whatever the visual reference point is.

Would it matter if you held the gun upside down? Or sideways?

Once sighted in properly, for whatever visual picture you are using, the wobble area will continue to wobble over the POI *offset* from the POA.

Now, if you are canting the gun in different directions for each shot, going from sideways, to upisde down, to rightside up, etc. well, you have much bigger problems than the effect of "cant" on POI vs. POA.

Steve

deadeyedick wrote:...This is completely wrong. Hold a pencil vertically in your hand at arms length facing a blank wall. The tip of the pencil will be yourPOI using area hold [ aiming in the white beneath the black ].....now cant your hand to the right or left and watch the arc created by the movement. This will be the new POI as a result of canting...

I am not sure that this intuitive example holds up on the firing line.

There was an ISSF article a few years ago about the POI effect of canting (yes it was on 50m Rifle, but however) and that quite a lot of cant had little affect at the target.

There is a difference between a consistent cant (a transparent factor when adjusting the sights) and a change of cant during a stage or event. Change of cant might bring a change of POI - a cant that is consistent will not.

Spencer

Canting will have no effect on POI if the shooter has his/her rifle/pistol sighted in on the point they wish to impact [point of aim], but does have a huge say in where the projectile lands depending on the amount of cant, and how low in the target the area aim is set to.
If a shooter has their sights set somewhere in the white, below the black, so the bullet passes through the 10 ring and was set that way by a person who shoots with a constant cant, or position, then the impact point will not change. However in the 20 odd years of coaching pistil shooters, I have not seen one that accurately repeats the cant. Now , with that being said, if the sights are at point of aim, as I said earlier, there will be virtually no discernible change in POI. However with the sights set to an area hold position, because of the arc effect produced by the sights being set to approx. six inches below the actual POI, then the necessity to keep the pistol in the SAME [preferably vertical] position becomes even greater.
That is why some shooters believe they shoot better with the sights in the point of aim position [ they do not repeat the shot execution exactly as before ]. The area hold has many virtues that are not being exploited by most, mainly because of this . In fact, the lower on the target the sights are set to impact the ten ring, then the more disasterous the miss will be unless the gun is fired in exactly the same orientation as previously.

A picture is worth a thousand words

Or maybe two

Ed Hall has given a good discussion of this subject: http://www.geocities.com/ed_ka2fwj/12PPC12.html

He has calculated that a 850 fps bullet will drop ~ 6" at 50 yd. A pistol with a red dot scope (which would be a center hold for iron sights) sighted in to give POI=POA with no cant, will put the POI about 6" to the left of center and 6" down from center if the gun is canted 90 deg counterclockwise, that is about 7:30 on an 8.5" diagonal from center.
If I apply this model to a sub 6 hold with a POA 6" below POI, a pistol canted 90 deg counterclockwise will give a POI about 12" to the left of POA and about 6" down from POA, i.e. 12" to the left of center (POI) and 12" below center (POI).

.....and to add that cant does matter unless the gun is sighted in for the degree of cant at that distance.

Further, the greater the distance from the line of bore to the line of sights the more the cant matters, i.e. iron sights on barrel vs a scope mounted 1.75 " above bore.

Quick obvious example. Sight in gun at known distance with vertical hold. Shoot a group. Turn gun 90 degrees holding at same place and shoot a group. Now, going back to vertical make an elevation adjustment that will cause the gun to shoot 6" high. Shoot a group which should be 6" higher than first vertical hold group. Now turn the gun 90 degrees to left (cant). Shoot a group holding at same place. This group will be 6" to the left of previous canted group. Why because an elevation change is not pure elevation (at the sights) if the gun is canted.

Gravity effects the bullet during its flight time constantly. Ed Halls detailed comments on this topic are quite good.

Martin

From Ben's original post (re shifting from center to sub 6 hold):

"Now I am wondering if I had the pistol canted slightly. It seems to me that a cant would really be detrimental sub-6 compared to center hold. Do you sub-6 shooters find that to be the case? Do you have any tips to make the change successful?"

No, Ben, as we have demonstrated here, the difference between cant effects on a center hold (which isn't really a center hold at all- the muzzle is offset from the sight line by 15 mm or so) vs. a sub six hold (where the muzzle is offset from the sight line by maybe 40mm) is trivial. Ed's excellent example of 185 gr 45 ACPs at 50 yards is instructive for 10m AP, but not definitive. You can translate his methods, but not his conclusions. [To determine the "real" effect of cant, you must first establish how much variation in cant is reasonable. +-30 degrees? +-60 degrees? How much variation is actually seen in the real world? That will drive the amount of offset- not the absolute value of the cant, but the amount of shot-shot variation in cant. With a fairly sloppy amount of cant variation- +-5 degrees- the shot-shot offset between 15mm at 40mm isn't that great.]

I think the most important point out of all of this discussion is somewhat subtle- to the point of being ignored by most of the contributors to this thread.

Sorry to be "Johnny One Note" here but what about TECHNIQUE?

The *only* time this matters is if your cant angle changes SIGNIFICANTLY between shots.

I'm sorry if I'm "changing the subject" back to the issue at hand.

If you are unable to control your cant inside of a +30 <-> -30 degree range in between shots, then where to center your aiming area is perhaps not the element of technique you should be focusing on!

Steve

Steve,
What is the subtlety that I am overlooking? The issue at hand is the effect of shot to shot variations in cant on POI for a center hold vs a sub 6 hold.

Where, in this thread, has it been demonstrated that the difference between cant effects on a center hold (which isn't really a center hold at all- the muzzle is offset from the sight line by 15 mm or so) vs. a sub six hold (where the muzzle is offset from the sight line by maybe 40mm) is trivial.?

Time of flight for a 22 traveling 50m is close to time of flight for a 45 bullet traveling 50 yd. (Ben's original concern was using a sub 6 hold for FP. The AP was used as a stand in). Scoring rings for the ISSF precision target are smaller than for the NRA 50 yd Slow Fire. So, back up your statement. What is the effect of a +-5 deg change in cant? How many scoring rings? AP? FP?

Fred

Using Ed's assumptions and math, we get drop in mm at target:

AP@500 fps: drop 21.1 mm ~21 mm
FP@1200 fps: drop 91.7 mm ~ 92 mm

Continuing with Ed's assumptions and method, we assume there is no offset from the muzzle-top of front sight, and only add "drop line" to the six o'clock (ymmv for sub-6 depending on how low you choose to hold) holds to get "effective drops" of

AP, C: 21 + 0 = 21 mm
AP, 6: 21 + 30 = 51 mm

FP, C: 92 + 0 = 92 mm
FP, 6: 92 + 100 = 192 mm

These "effective drops" represent the distances between the point of boreline (BL) and point of aim (PoA) on the target face.

Departing now from Ed's example, we have the angle formed by the boreline and sight line, assuming a vertex at the firing line (assuming away length of shooter's arm, boreline-sightline offset).

So we are looking at the amount of POI shift given an angular shift of 5 degrees from vertical. Using the formula Tan(A) = a/b where A is the angular shift, a is the amount of shift on the target, and b is the length of the "drop line" (BL-PoA distance) we get:

AP, C: Tan(5) = a/21; a=1.8 mm
AP, 6: Tan(5) = a/51; a= 4.5 mm
FP, C: Tan(5) = a/92; a= 8.0 mm
FP, 6: Tan(5) = a/192; a= 16.8 mm

To recap: assuming the amount of cant would rotate the BL around the POA on the target (keeping the POA fixed at either center or six o'clock hold), a 5 degree cant (rotation) of the vertical "dropline" would displace the BL end of the vertical drop line by the indicated amount.

If the logic holds, then, assuming the assumptions are all assumable, and assuming the math is at least reasonable, it would appear that we should expect to see 2-5 mm of displacement in AP and 8-16 mm of displacement in FP as a result of canting from 0 degrees to 5 degrees.

This seems high actually; looking for flaws in my logic . . .

Steve

We have really wandered way off the subject of the orriginal post. Back to it, have you considered the possibility that you were never focused on the front sight to start with ? And , even worse could you be silloueting the front sight against the target white and still not looking [focusing] on it even now ? A consistant cant does not seem to cause any considerable damage to the shot grouping But why would you want to do it in the first place? I once watched a free pistol shooter fire a 580 in a warm up match who turned the piston on its right side with the sights mounted on the left side of the pistol . Please dont ask me to explain this process as I didn't understand what he was doing at the time and still have no idea why he arrived at this strange configeration. Good Shooting Bill Horton

Fooling around with my Rika the other day I found that a 1-2 degree cant was easily detectable . . . and a 5 degree cant looked obviously "crooked."

What say you all?

Obviously, the effect of a 1 degree cant will be much less than the effect of a 5 degree cant:

Offset, Center hold/6 hold, in mm

1 deg 5 deg
AP 0.37/0.89 1.8/4.5
FP 1.61/3.35 8.0/16.8


And the assumptions of the calculations above still bug me as well.

O.K., time to get a bench vise mounted at eye level and a protractor and see what happens in reality . . .

Steve