Just for fun, Google zirconium silicate and click on images, then go read the IBS rule pertaining to bag fill material. I think that it is kind of amusing. It seems to me that this is of no practical consequence, but I doubt that very many shooters who shoot IBS sanctioned matches, and use some kind of heavy sand in their bag(s) that are actually using the stuff that is specified in the rules...if they are buying their material from one of the vendors that serves the shooting community. Perhaps someone should revisit the wording of that rule.
A while back, I looked up the IBS, and NBRSA rules for bags and fill for both long and short range. They are not identical by sanctioning body, or distance.
Recently, I have looked over the new NBRSA long range rule book, paying particular attention to the part that deals with sand bag fill materials.
" A sandbag is defined as a bag with or without a pedestal, with a
leather or cloth cover, that is capable of
being easily flexed by the
fingers, and contains a dry finely divided nonmetallic substance
such as, but not limited to, sand, gravel, or grain, without additive
and packed loosely enough that the bag can be easily deformed
by pressure of the fingers. The
cover of the sandbag must not be
bound in such a manner to prohibit free movement of the
contents.
Velcro cloth may be used on sandbags ONLY in Long
-
Range BR Shooting Competitions.
Lubricants such as talcum
powder, Vaseline, mica or friction reducing tap
e of no more than
.011" total thickness may be used on the bag for lubrication."
Within this rule there are a couple of things that short range shooters may find interesting, first that the allowed fill material list is longer and more liberal, secondly that there is a short range rule contained in the long range rules, specifically pertaining to the use of Velcro on bags. I mention this because It is my understanding that at least one successful short range shooter currently uses Velcro on his bags, something that may not have been previously been addressed, and which he may not have thought to look in the long range rules for for guidance.
Perhaps someone could enlighten us as to why the NBRSA long range and short range rules differ as to allowed bag fill. If the long range rule is a survivor from an earlier time, and was previously the rule for both, perhaps consideration of making it cover both distances might be considered, if that had been the case in the past. On the other hand, if the rules came from different sources, tha t would be another matter.