G'Day Wombat,
You just need to wait a little while longer. We hope we can have something available soon which may help you. But it is a bigger task than you may expect because unfortunately things have deteriated rather badly in this area.
Scoring of score shooting targets has been a problem for a few years really. Probably because people who run matches and other people who happen to do the target scoring either
A) Just do not know or understand rules (may not be their fault) or have poor training/help.
B) Have lost the skills and knowledge about how to do this job properly
C) Never understood some very critical issues with need attention right at the beginning to prevent errors. In other words...process.
Then the net result is: shooters get unhappy and run around like angry chooks and...well sad feelings. Understandably people get pissed off and can feel the results are just not fair.

That's the biggest issue. The scoring of targets need to be carried in a way to gain the utmost credibility. It's an important task and EVERYBODIES responsibility really if we all want to see this important issue advanced. Our rulebooks do not provde good information and in some cases no information.

Of course a competitor may always place a protest if they feel a shot or shots are incorrectly scored. Yet they often do not do that due to other reasons. In my opinion if the scoring is correctly carried out then a protest should never be needed.
Its always true that shooters may not be happy the position of their own shots which did not make the higher ring score BUT at least they should feel it was because its WHERE THEY ACTUALLY PLACED THAT SHOT, rather than how the scorers interpreted it's position. The scoring should be done consistently and with process that allows cross checking and recall (for official protests).
Having to protest a score is a difficult thing to consider. Many people feel agreived but in the end decide not to make a fuss with a formal protest which also includes a fee. Buy they, and maybe some others who agree with them, go away very unhappy with the whole situation and may feel things are unresolved. Even start to wonder if other targets were correctly scored and therefore are any results credible.
Also, on the flip side, sometimes the people doing that scoring may actually assume they did things right due to no protests being received. Not necassarily so.

So for a while now myself and few others have been looking at these problems. Why us? Well someone has too. We have made a bit of noise about it and no one else does anything so we thought we had better investigate and see if we can produce some better ways. We hope many others contribute also but we have not been over run with contributors yet. This is not a closed group by any means. It's not neccassarily about changing rules but looking at what boundaries we can work in and improve the lot.
We have focused on the target scoring of the Benchrest events. This involves events like:
SSAA Benchrest for Score (Hunterclass) in Rimfire and Centrefire
SSAA Benchrest Fly Shoot in Rimfire and Centrefire.
SSAA Benchrest IRB ( supposedly as per rules of the World Benchrest Federation Rimfire championships (WBSF)
TRA Rimfire and Air Rifle (also known as RBA and part of the World Air Rifle and Rimfire Benchrest Federation (WRABF)
TRA Benchrest which is basically smallbore off a bench. Much of this is on electronic targets.

So for myself, I do not claim to be an expert in anything. But I do have some scoring experience over many years in a large variaty of scoring matches and situations and locations. I think the first time I assisted scoring targets was in 1981 where I organised ran the National Benchrest Championships in Canberra. The last half day of 5 days was Hunterclass. 2 targets at 100 and 2 at 200. I checked scored with Max Coady. But over the years myself and Annie ended up doing a lot of scoring one way or another. In early 1990 when BR-50 International come along it was the first big world wide benchrest score shooting event. We were the Australian co-ordinators of these matches. I think 13 clubs up and down the east coast were involved back then. Whilst centrefire was included that got dropped after year 1. It ended up being strong in Rimfire and Air Rifle for 10 years. It was the start of all these events like IRB and WRABF etc.
The target had 50 bulls and was worst edge scoring. Very difficult and lots and lots of scoring to do. So we learnt lots of things and processes to settle all that. We always shot Hunterclass too and organised many Matches from club to State to Nationals. When we started the IRB in the early 2000's things really started to take off with Rimfire benchrest world. Then the other organisation started (RBA) and the rest is history. Two organisatioon with pathways to world championships. But yet, even at these World events we have experinced some very poor scoring and the ways they tried (or didn't) to resolve them failed. Usually because of the three main causes listed above under A,B and C

So back to now, our little group started by looking at rulebooks. We found a big variations. Then we looked at the recommended sizes of scoring plugs. A bit of a variation also. Then we looked at electronic scoring used in RBA (WRABF) "True Score" scanning system and many of us have noted a number of big problems there. In can be quite accurate. But also can be very poor. So we looked into why. Neil Digweed and myself started looking at that in particular. In the end Neil has found a new love in his life of retirement called ...code writing for scoring programs. haha. He has put a lot of work and expertise in and we will see the fruits of his labour over the next few months I think as he will be able to demonstrate how his software system works to score targets. We did build into this target scanning system a way which identifies those shots which are close (within a certain tollerence) and those identified shots will then be manually plugged with the correct gauge as per rules and also a photo stored showing this to either confirm of deny the score given by the scan system.

I have been focusing more of equipment (tools) and skills experince of people doing manual scoring. Manual scoring is what happens most of the time in many clubs. So as mentioned above, the rulebooks need to be examined. The scoring plugs types and sizes need to be discussed and also other equipment like magnifyers which can assist the process. I also have had help from Phil Jones as also is an exeirenced scorer himself and between the two of us we will be making a range of scoring plugs, calibrated to size for sale. We are still experimenting with shape on that one. We have found other commercial available stuff scarse and not calibrated. Many people's idea of checking the size on the rim of a scoring plug is to use a shitty old caliper. It is not. A good micrometer is needed.
Some people may think this is overkill about the actual size of scoring plugs (gauges), BUT, the fact is that MANY events including World Championships are very often won and lost on one point or one dot and that will boil down to those "plugged shots" from both competitors to determine the winner.

All organisations do not really have very well written rules, or guidelines or system of training to give match organisers and therefore people doing the scoring of score targets much info.
So, you mentioned scoring gauges and that in itself is a major issue. It should not be this way as it should be reletively straight forward but it isn't.

Issue 1: The sizes. Some scoring gauges are commerially available. But hard to find. The size varies. So lets just talk about Rimfire scoring plugs for a start. centrefire size is reletively easy as it is the caliber size. Eg 22cal centrefire bores are .224", 6mm ones are 0.243" etc.
But 22 Rimfire has a lot of controversy. One organisation the World Air Rifle and Benchrest Federation ( WRABF through TRA Australia) has within its rulebook a plug size of 0.224". So that is incorrect technically for 22 Rimfire. 224 as I indicated above is for centrefire 22cal bullet holes because the bore size is 224.
The ISSF world body in their rules say a 22 Rimfire scoring plug should be between 0.2015" and 0.2225". That's a wide range really.
The WBSF Rimfire Benchrest rulebook lists the scoring plus size ar 0.222" actually. Rule 8.c See http://www.worldbenchrest.com/documents/rulebooks/2018_WBSF_Rimfire_RULE...

I actually think this is a correct call. If you look at the SAMMI specs for rifle barrel bore sizes that is about the range for 22 Rimfire. Remember at the end of the day it is the barrels bore size that determinbes the size of the bullet exiting.
OK, so now lets look at the SSAA IRB rulebook. Which is supposed to mirror the rules of the World Body in most regards. WBSF Rimfire. At least as rifle specs, range specs and you would think scoring specs. In fact in those rule at the very start it talks about standardising rules on an international basis. Rule 1.1.2 Here is that rule
1.1.2 To standardise, where practical, on an International basis, the entire benchrest
shooting program so that targets, ranges, scoring methods, records and match
procedures will be uniform and compatible.
Yet when we look at what the rule actually says about scoring plugs in the SSAA IRB rulebok, it says in rule 6.8.3 quote:
6.8.3 Scoring Plugs
All shots which cannot be scored by visual scoring, will be checked by using a .22
ISSF / USAS Inward Gauge (5.60-5.65 mm or .2205- .2225”) and marked with a
“P” to so indicate.

So that doesn't align with the rules International Body that SSAA IRB is connected with.
It's wording aligns with another International body which SSAA has no connection with. Therefore: Go figure???? Who wrote that?

Anyway that's way too much ramble to start with here. But summary is, we nearly have a software system ready (Neils) to demonstrate for RBA and IRB. We soon hope to have scoring plugs which will be hand finished and with a calibration size confirmed. We have a magnifyer system which projects onto a screen (usually laptop) over the scoring plug in a bullet hole to assist in making determinations and record a screen shot for future refence. I will talk in more detail about its use later.

Any contributions welcome.

Stuart Elliott

A Newcastle member can make these for about $100 but you would need your own calliper. Any calliper will suit (cheap or expensive)
Kim