2400x1800mm (8'x6') targets

[ger]

I might regret this.

With advances in rifle technology, optical assistance, electronic targets, and general skill levels increasing to the point where we have the SuperV, do we really need to have the subject sized targets?

They are covered in SSR's from 700M onwards, or 800Y onwards. But nowadays, do we really need them?

A 1200x1200mm (4'x4') is also allowed at 300/400 M/Y. I see, I think without exception 1800x1800mm (6'x6') targets used at these shorter ranges.

The big targets cost a bit, and certainly add to the cost of running a range (if long enough to require them). From the ET perspective, they represent the largest area at the longest ranges, where the weakest signals (.223) are expected to provide clear definintion at the centre of the target where the distance to the sensors is greatest. Even though I am finding the accuracy of weak (.223/5.56) shots at 900M and beyond challenging due to poor definition of the shockwave when trans-sonic, I feel other reasons are present that justify the question.

But that aside, with current technology, and skill levels, can the cost of these targets in addition to the 1800x1800 ones, really be justified?

The differences between ICFRA and the NRAA rules may have a bearing on this also.

Is this a topic worthy of some discussion and/or debate?

Geoff.

[Woody_rod]

Good question ger. Maybe go with the std 6 foot square (1800mm) targets as per long range in the USA.

[RDavies]

So, what you are saying is that the smaller 4x4 targets are more reliable at reading shots from smaller calibers.

[AlanF]

...But nowadays, do we really need them?...

Very good question Geoff. Quite apart from the ET aspect, there could be considerable advantages in not having to cope with the greater wind forces, extra weight and extra cost of the 8' x 6's.

I think a good way of selling the idea would be to look at the ballistics of the older TR gear e.g. .303s at the maximum range they were used on the 8' x 6' targets. If someone can find MV and BC figures for the old military .303 target ammo, I could work out wind drift figures. This could be compared with the current situation, and if we found that wind drift is less than ¾ of what it used to be, then there is a good case, particularly when you factor in the higher accuracy standards of today.

So, can anyone give me reliable .303 BC and MV, or alternatively, the wind drift figures from a VERY OLD full bore scorebook?

Alan

[ger]

So, what you are saying is that the smaller 4x4 targets are more reliable at reading shots from smaller calibers.

I'm not sure if you mean 6x6 targets (1800x1800mm roughly).

With these targets (6x6) at 900M I have had to really crank up the gain of the sensor microphones in order to reliably detect the [.223] projectile going through the centre - where the sound has to travel the longest distance. Things were fine at 800M. With the high gain the sensors became very sensitive rendering them prone to extraneous noise such as the target rattling around in a very old and loose frame. This resulted in false sensor triggering. And when a shot did go though with all 4 sensors registering, the error level was unacceptable (the loss of definition I refer to).

I haven't bothered with the .308 yet at this range, taking the view that it's better to concentrate on the smaller bullet.

When Mike and Lyle get home we are going to conduct some more experiments. I have a new target design in which the sound chamber is virtually airtight and has thicker walls, with scope for additional soundproofing internally. That may improve things.

And this was with the 6x6 target. The problem would be worse with the 8x6.

While it is likely that we can get the 8x6 to reliably measure accurate shot positions (by our methods and procedures anyway) I started thinking about the general requirement for them in the first place. They are large, heavy, expensive to build, and difficult to manhandle. Quite aside from the technical challenges appearing in the context of the electronic target system I have. Hence my posting above.

Ultimately, for the time being, we (Brian, the boys, and I) have to persevere with the large targets at the long ranges (900M+) with the small calibre.

Geoff.

[Barry Davies]

I rather think the FB shooters may not particularly like 6 ft square targets at beyond 600. I know it's only 12" per side but thats better than 1moa at 1000yds.
Geoff, if you used a 6x8 target and positioned the sensors as for a 6x6 target -- this would be no worse than using a 6x6 would it. Would the sensors work positioned at 6x6 in a 8x6 sound chamber?

Barry

[ger]

8x6 targets are not going to disappear overnight under any circumstances so I have to consider them during the design process.

At the moment I am investigating the viability of 4 sensors in each corner but with the expectation that we will have to reduce the gain of each individual amplifier and adopt a system along the lines Barry suggests. Only with 6 or 8 sensors located around the perimeter of the target. This will most likely allow for a reduction in gain on each sensor amplifier but at the expense of additional timers, and CPU resources (computing power). Worthy of thought.

It is possible that 4 sensors located as Barry suggests could work. Depending on the method used to resolve the shot posistion based on TDOA's, shots outside the "square" can be resolved.

A scenario was put to me today that apparently occured recently at a 700 range. Low shots were apparently hitting the mantlet and the grit thrown up was not only hitting the target face but registering shots - albeit bad ones but I doubt if the error was being determined - or reported. This is the sort of problem that can be expected when having to resort to high gain (sensitivity) sensors - they can pick up all sorts of things in addition to the bullets they are supposed to.

But taking ET's completely out of the equation, I still question whether or not the large targets are really justified for our sort of shooting from 700M/800Y to 1000M - TR & FC - with the levels of technology and skills of today. To me the argument is similar to any about ring diameters (not sure if there is one at the moment...). We're not shooting 303's any more.

Geoff.

[aelowyn]

That kind of sensor configuration (1800x1800) in a 1800x2400 target would be fine. In fact, it might actually be better to use that kind of configuration to reduce the distance between shot and sensors.

I always wondered why we had wider targets at long range

[AlanF]

Further to my post above, I have found some figures for .303 MK VII military ammo : 174gn BTHP, 2440fps, BC 0.425.

If these (unconfirmed) figures are correct, then my calculations show a 10mph cross-wind at 1000 yds will cause 12.1 MOA drift.

Compare this with a 7.62 and 155gn HBC at 2950fps, and the drift is about 8.9 MOA.

So the drift is now approximately ¾ of what it was in the .303 days. This appears to support serious consideration of reducing targets to ¾ width.

Alan

[IanP]

I might regret this.

With advances in rifle technology, optical assistance, electronic targets, and general skill levels increasing to the point where we have the SuperV, do we really need to have the subject sized targets?

They are covered in SSR's from 700M onwards, or 800Y onwards. But nowadays, do we really need them?

A 1200x1200mm (4'x4') is also allowed at 300/400 M/Y. I see, I think without exception 1800x1800mm (6'x6') targets used at these shorter ranges.

The big targets cost a bit, and certainly add to the cost of running a range (if long enough to require them). From the ET perspective, they represent the largest area at the longest ranges, where the weakest signals (.223) are expected to provide clear definintion at the centre of the target where the distance to the sensors is greatest. Even though I am finding the accuracy of weak (.223/5.56) shots at 900M and beyond challenging due to poor definition of the shockwave when trans-sonic, I feel other reasons are present that justify the question.

But that aside, with current technology, and skill levels, can the cost of these targets in addition to the 1800x1800 ones, really be justified?

The differences between ICFRA and the NRAA rules may have a bearing on this also.

Is this a topic worthy of some discussion and/or debate?

Geoff.

Geoff, you did say you might regret bringing this up so just a little criticism of your concept and logic.

If you cant get your system to work well with small calibres on existing targets you suggest changing the targets (make the target smaller).

Listed below is the frame sizes copied and pasted from our SSRs these are based on the ICFRA standard, not a modified to suit a targeting system standard.

Your system is either up to the task or its not! If its not, then I suggest you find a fix that allows target shooters to keep their existing target sizes to the ICFRA standard.

Maybe you could explore using 8 sensors to overcome your current systems difficulties. It seems these guys have done just that http://www.hexsystems.com.au/

National Rifle Association of Australia Limited
Standard Shooting Rules Page 31 of 62 Revision: 18 March 2009
CHAPTER 13
TARGETS
13.1 Target Dimensions [Standard]
All target dimensions are in millimetres

Third Class
1200 square

Second Class
1800 square

First Class
2400 x 1800


The dimensions shown below are copied and pasted from the ICFRA website.

DIMENSIONS OF ICFRA TARGETS.

D1. Targets: General
D1.1. Form. All targets will consist of a circular black aiming mark centred on a white or off-white background.
D1.2. Frame Sizes. The standard dimensions are (height x width):
300yds/m: 1.2 x 1.2 metres (4 x 4 foot)
500-700yds: 1.8 x 1.8 metres (6 x 6 foot)
Long Range: 1.8 x 2.4 metres (6 x 8 foot)

Alternatives: The 300yds/m target may also be mounted on a 1.8 x 1.8m frame, centred in a
marked 1.2 x 1.2m. square. Long Range targets may be mounted on 1.8 x 1.8m or 1.8 x
3.0m frames if domestic practice so prescribes.

IanP

[ger]

Geoff, you did say you might regret bringing this up so just a little criticism of your concept and logic.

If you cant get your system to work well with small calibres on existing targets you suggest changing the targets (make the target smaller).

Yes, I knew that someone would raise this but it didn't stop me from doing so, did it. Sometimes one has to allow others a few free kicks, just to get a point across. You didn't disappoint me!

My questioning of the continuing justification of use of the 8x6 targets is not because of difficulties I may have. Is is more to do with the expense associated with building, purchasing and maintaining these extra targets, and the difficulties in manhandling them, in today's shooting environment.

Listed below is the frame sizes copied and pasted from our SSRs these are based on the ICFRA standard, not a modified to suit a targeting system standard.

In raising this I obviously don't give a toss about what ICFRA or the NRAA, or any other authority provides by way of guidence or whatever. It's a clear cut question about whether or not maintenance of the status quo can be justified. Pure and simple. So I discount all your fancy cutting and pasting of the "rules" below. Sorry.

Your system is either up to the task or its not! If its not, then I suggest you find a fix that allows target shooters to keep their existing target sizes to the ICFRA standard.

You didn't read what I said very well, did you?

I stated that :

"Ultimately, for the time being, we (Brian, the boys, and I) have to persevere with the large targets at the long ranges (900M+) with the small calibre."

Of course we're going to address this. And resolve it.

Maybe you could explore using 8 sensors to overcome your current systems difficulties. It seems these guys have done just that http://www.hexsystems.com.au/

I'm not sure if they have shot at their target from beyond 800M. I don't know what their reasoning was for going to an 8 sensor system. I'm not sure if they just happened to quess that the longer ranges would cause some issues or not or whether they simply thought that 8 sensors are better than 4. They're not likely to tell me their rationale for doing anything so I don't bother trying to second guess them or anyone else.

I would sumbit that all of us working with electronic targets have to grapple with similar issues, but we all probably look to resolve them in different ways. I suppose that is natural - we don't all think alike.

We may indeed increase the numbers of sensors (gee, I think I said that also somewhere...) - whatever it takes. But the question still remains! There are others reading this forum who obviously agree with the thrust of my question.

At least I (and Rod Gray and to some extent Aschera) have come out and explained a lot of how our systems work, our observations (good and bad) and importantly have attempted to clear up some of the apparent mysticism that seems to surround acoustic targets in the long range environment. Rod has written an complete paper on the subject - published on the NSW F-class website I think. Would you prefer that we were not so open - as has been the trend for the last 15+ years or so?

I could simply shut up and not expose myself to the sorts of comments I am currently addressing. Much less grief. Would you prefer that? But as I said at the start of this response, I was fully expecting this so I guess I shouldn't complain too much.

Geoff.



Geoff.

[M12LRPV]

With advances in rifle technology, optical assistance, electronic targets, and general skill levels increasing to the point where we have the SuperV, do we really need to have the subject sized targets?

Unfortunately the skill level improvements have not extended to everyone and shots falling in those outer areas of the targets are not uncommon.

Mind you adopting the smaller target might be the kick in the pants that a few people need

[Woody_rod]

Just keep going Geoff, there will always be people that can't see a way forward other than what they are doing now. I know this all too well.

Talk about 8 x 6 targets is purely historical, and has nothing to do with the current target shooting environment. When was the last time a serious competitor shot anywhere near the white with a zeroed rifle at any distance?

The USA has been doing this for many years, but we have to stay with the 1900's thinking with our larger target face. It is not necessary, and what Geoff is proposing makes very good sense. People should not get caught up with history when another proposal comes along.

The SSR's from a target face dimension point of view is more a recommendation than something chipped in granite. I have shot on variations, and it really makes no difference to the shooter. I also don't agree with the "cut and paste" of rules: people need to try and go with the proposal as it is written, and think about it in the absence of other concepts.

Staying with what we have at all times, leads to out of date rules like we have now. Things evolve; particularly reactionary, long winded processes like review of the SSR's, when the front line technology has gone ahead as it has lately.

At least we have gone as far as discussing this issue, and related issues in our sport. If we only had a reactive and historical perspective, as some do, our sport will be dead in a few short years.

[Woody_rod]

With advances in rifle technology, optical assistance, electronic targets, and general skill levels increasing to the point where we have the SuperV, do we really need to have the subject sized targets?

Unfortunately the skill level improvements have not extended to everyone and shots falling in those outer areas of the targets are not uncommon.

Mind you adopting the smaller target might be the kick in the pants that a few people need

The score is only 1 (one) point difference between a one and a miss. Not like that is going to change the standing of the leader board, nor will it make the shooter any better or worse.

[M12LRPV]

The score is only 1 (one) point difference between a one and a miss. Not like that is going to change the standing of the leader board, nor will it make the shooter any better or worse.

It's more a point of where the first shot goes than the final score.