Using 10m target for the 25m

[jerber]

Does anyone tried using 10m AP target to practice for the 25m?
I was at the range today and forgot to refill my bag with 25 m targets
I also have some 10m AP target and decided to use them
Set it at 10m and finished my session
I did OK, shots were a little high but I guess I can adjust the rear sight
So I was thinking that since I have a lots of 10m targets, I could use them
Does anyone think that's a bad idea?
Is there a distance that I should set the target that would be the equivalent to the 25m?
Thanks jerry

[shaky hands]

Provided you want to practice precision stage of the standard pistol, the distance would have to be about 7.7 meters to ensure that your 10-ring shot at that distance would be equivalent to the 10-ring at 25 meters. The distance is calculated from the formula

L = LL * (D+d)/(DD+d)

where LL = 25 m, DD = 50 mm (diameter of the 25 meter precision pistol target's 10-ring), D=11.5 mm (diameter of the 10-ring of the air pistol target), d = 5.56 mm, diameter of the bullet.

[jerber]

Thanks shaky hands
That's what I needed to know
I'll try it at that distance and maybe I wouldn't need to adjust my sight

[jliston48]

Although it doesn't change the result that much, rather than comparing the sizes of the 10-ring, it is more effective to compare the sizes of the "black" because it is the black area that you see when you are setting your sight picture. The 25m black is 200mm and the size of the air pistol black is 60mm, so the shooting distance using the same formula would be 7.5 metres.

It is difficult to compare scores, firstly because of the disproportionate sizes of air pistol scoring rings compared to the proportionate sizes of the 25-m target (AP "10"-ring is 12mm and each other ring increases diameter by 16mm whereas 25-m target has 50mm "10"-ring with each successive ring increasing by 25mm). Also, you can't really compare 22cal scores with 17cal (air pistol) scores on the AP target. You can with a bit of maths, working from points of impact, and readjusting the calibre size. Anyway, training is about points of impact and groups, not scores, isn't it?

[OTD]

Thanks in advance for accepting my smart-assness. I think there’s two basic errors. 25m pistol targets have a different ring diameter proportions than 10 m AP targets. For the calculation of the proportions the Intercept Theorem applies: d1 : s1 = d2 : s2 and because of the different proportions there is not ONE correct distance. It depends of what you want.

If you want to have the AP target diameters to be proportional to a pistol target it’s

59.5mm x 25m / 200mm = 7.43m -> 8.04 ft.

If the diameter of the 10 ring shall be proportional it’s:

11.5mm x 25m / 50mm = 5.75m -> 6.28 ft.

And if you want to have the inner 10 to be proportional, it’s:

5mm x 25m / 25mm = 5m -> 5.46ft.

[David Levene]

d = 5.56 mm, diameter of the bullet.

I think you mean 5.6mm (for .22), or 9.65mm for centre fire.

[David Levene]

Thanks in advance for accepting my smart-assness. I think there’s two basic errors.

I'm afraid that you have left out an important factor if live firing, the constant (non-scaleable) diameter of the gauged shot hole; 5.6mm for smallbore or 9.65mm for C/F.

[shaky hands]

Thanks in advance for accepting my smart-assness. I think there’s two basic errors.

No worries, there was no smart-assness. Only two basic errors.

If you want to have the AP target diameters to be proportional to a pistol target it’s
59.5mm x 25m / 200mm = 7.43m -> 8.04 ft.

1) What David said. See my formula above.
2) You are also confusing feet with yards.

[jerber]

Thanks everyone
I'm just going to set it at 7.5m
It's just for practicing
Just looking for groups

[tpambau]

Stupid question:

If you suggest to use bullet-size containing formula for scoring rings, then bulls-eye size must be taken from simple formula (e.g. 200*10/25=80 cm for resizing 25m target to 10m) and be bigger than 7th ring to keep the same angular size for sighting.

Is it right?

[jliston48]

Stupid question:

If you suggest to use bullet-size containing formula for scoring rings, then bulls-eye size must be taken from simple formula (e.g. 200*10/25=80 cm for resizing 25m target to 10m) and be bigger than 7th ring to keep the same angular size for sighting.

Is it right?

The answer of 80mm here is an equivalent size of the black when shooting at 10 metres, to a 200mm black when shooting at 25 metres.

The calculation we did before was to determine the shooting distance (7.5 metres) using an air pistol target to replicate the 200mm black at 25 metres.

This was done so that the sight picture (target/front sight/rear sight relationship) is the same while dry firing at 7.5 metres. If you actually fire projectiles at the target, the scores are not comparable because of the relative differences in size of the scoring rings between air pistol targets and precision targets - and the calibre sizes of the projectiles. If live firing is contemplated for score comparison, you will have to design your own target with a 60mm diameter black and 10-ring = 15mm dia (not 12mm as on the air pistol target), 9-ring = 30mm (not 28mm), 8-ring = 45mm (not 44mm), 7-ring = 60 (also the size of the black), 6-ring = 75mm (not 76mm), 5-ring = 90mm (not 92mm), 4-ring = 105mm (not 108mm), 3-ring = 120mm (not 124mm), 2-ring = 135mm (not 140mm) and 1-ring = 150mm (not 156mm). Phew! - nothing better to do on Christmas Day!

Then there is the calibre issue!

If you live fire at 7.5 metres on your "new" target, to score the shot accurately, you will have to determine the point of impact of the shot then add a hole size of 1.67mm diameter to scale for 22cal ammo.

I think the whole exercise of live fire under these conditions may not be a good training strategy.

As I said before, practice is NOT about scores it is about technique - hence the dry firing. Live firing merely confirms that the technique is correct. And the scores? Well they are for the people in the Scoring Room to determine! We competitive shooters strive for good technique, not scores, don't we? If the technique is good, the scores will happen.

[PaulT]

An easy cheat for this......
Download and install the latest SCATT software on your PC. [totally Free]
from the menu, select TOOLS, then PRINT TARGET
Select your discipline target diagram and the distance you intend to shoot it.
You can optionally print the scoring rings and the outline of the official target size.
My local club shoots at 22.5m so I print out 50m ISSF scaled to 22.5m on normal target board for use with my free pistol.

I rarely bother with scoring rings as I train using group size and other routines.
Angular –v- parallel error with short-distance shooting of marginal relevance at best.

You may like to take a look at the SCATT catalogues for the disciplines that you are interested and open the files. It could spark an interest in using SCATT to help your training but the above is totally free of charge.

[jerber]

Stupid question:

If you suggest to use bullet-size containing formula for scoring rings, then bulls-eye size must be taken from simple formula (e.g. 200*10/25=80 cm for resizing 25m target to 10m) and be bigger than 7th ring to keep the same angular size for sighting.

Is it right?

It's not about scoring
But more about using the target for training at a reduced distance

[tpambau]

Well, I do understand this.

But concerning practical aspects: there are two useful kinds (for me!) of shorter-distance training - dry firing and grouping.

Concerning dry fire everything is clear - we can just scale black ring.

Concerning grouping - something unclear, e.g. if I my shots group within 8(ok, 7 :))-ring at 25 m, what size of group is desirable for me at 10m? Just scaling 150mm of 8-ring to 60 mm is incorrect, therefore it must be (150-5.7)*10/25+5.7 = 63.4 mm for the same angular dissipation. Right?

[David Levene]

Your formula is correct for groupng within the 8 ring.

For shots scoring a minimum of 8 then it's:-

((150+5.6)*10/25)-5.6) = 56.64