Jim,
Average aggregates are actually getting smaller overall, but in recent years falling at a pretty slow rate. I think most of it can be explained by the law of diminishing returns. Years ago when the average aggregate was say a .370" it is relatively easy to see that aggregates can get smaller as the shooters and equipment improve. The problem is that as the groups and aggregates go into the "ones" it is harder to get them smaller. There were hot shooters in decades past that set records. Heck, Pat McMillan's .1605" LV100 IBS aggregate record set in 1978 was only broken in 2008! What you may want to examine is what the average shooter is doing.
I don't have the data, but a telling statistic would be the number of teen aggs shot in a per year in, say the last 30 years. That would be a simple snapshot or bellwether of the level of accuracy that is showing up on the targets year-by-year.
Jim, another interesting examination would be the average 2-gun agg shot at your Super Shoot. Averaging 300 to 400 shooters' performances at each SS over many years at the same range would be real interesting...my guess is the trend line would look a lot like the one attached.
Directly below is a post I made a couple of years ago. Please check out the attached .xls spreadsheets. I think the trend lines are interesting and bear out my comment above.
jks
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(post from 2005)
"I have an outlook on benchrest akin to Rip Van Winkle in that I shot from 1976 to 1986, then got back in the game in 2003. Despite the long hiatus, I did manage to keep all my shoot reports-and they are pretty interesting. Over several evenings, I pored over the data and was able to create a spreadsheet showing the winning and median aggregates for LV and HV 100, 200 and grands, as well as the 2-gun aggregates. I used the median rather than average to represent "Joe Shooter" in the middle of the pack-the top of the bell curve.
The "shrinking aggregates.xls" file is solely for shoots I attended starting in the Southeast Region of the NBRSA since I lived in GA in the early days. In late 1977 I moved to PA, so the rest of the data is primarily IBS with a number of Super Shoots thrown in. The chart in the spreadsheet is for HV100 only. The second file is the IBS Champion multi-gun aggregates from 1970 through 2005, and is "IBS Champion Aggregates.xls". This data was secured from the IBS website. You Excel wonks can play with the data all you want to develop better charts.
Here are my general observations:
::There was a paradigm shift in this game from 1977 to 1978. In '77 at the NBRSA Nationals the HV Top 20 showed one 22PPC and a solitary 6PPC. Fast forward a mere 12 months. At the 1978 IBS Nationals HV competition had 18 6PPCs in the top twenty and one 22PPC! A die hard with a 223/45 came in 20th place. If you examine the data there is a decided drop in aggregates at the same time.
::Teen aggs were quite rare in the mid 70's. If shot, they were usually records. In fact, Pat McMillan's .1605 LV 100 aggregate shot at the 1978 IBS Nationals still stands. By the early to mid-80's teen aggs, although not common, did pop up with much more regularity.
::I have heard that it is getting harder to win in this game. The data seems to support that statement. Although small, the trend is for the difference between the winning aggregate and the median to get smaller...albeit slowly.
::IMHO, the 6PPC is the single greatest contributor to the shrinking aggregate. The "standard" system of a stiff, straight action glued into a synthetic stock with a shortish stainless steel match barrel came into being in the early 70's, but it wasn't until the late 70's and early 80's that the real shrinking of the aggregates really started to happen. As in most things in this sport, this statement is open for debate.
::One more observation: Many of the aggs shot from, say 1982 on, have been pretty darn good. Nevertheless, if you look at the plot of the IBS Champions' multi-gun aggs you will see a lower plateau under .250" starting in the early 90's.
::I will leave it up to the rest of you to argue the relative merits of the shooter's ability to tune and the myriad of incremental improvements in barrels, bullets, stocks, actions, et. al. Maybe enough fodder to fill up the winter that is around the corner."
I have also reposted the two accompanying .xls files. In the 2005 thread, I think it was Jerry Sharrett, mentioned the more universal use of windflags became popular in the late 70s. That was a very important advance.
Oh, I miss the days of a couple of range-owned wind socks providing the condition input.... Guess that is why it doesn't bother me when the the third flag in the line is 1.4 inches too high and .64 inches left of the vector measured by a 278 degree azimuth from the left shoulder of a right-handed shooter. For a left-handed shooter the numbers are reversed, except in the southern hemishphere...LOL."
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