the evolution of my STC 10/22... if you are not familiar with the Chevy Truck Sportsman's Team Challenge, it was a three man team event over two days... one day required .22lr rifle, .22lr pistol, and center fire pistol the other shotgun....various combinations of rifle and pistol were shot... the long range targets were 10 steel falling plates at 90yd protected by various shape cut outs... circle, triangle, square, diamond, star, shot off hand... the star was the most difficult ... you were allowed two loaded magazines, 2 1/2 minute time limit, and had to reload magazine under time... the long range had about 45 targets IIRC... with a couple of 1" bonus targets at 75yd... another had vertical racks of 4" targets, that "unlocked" 2" targets out to 75yd
year 1... regular 10/22 with the addition of a Clark fluted match barrel, in factory custom stock, no barrel band... Leupold scope mount to receiver... Tasco AO 6-24x44 1/8 minute click, 1/8 minute cross hair dot....reduced the depth of the sear notch on the hammer, but otherwise pretty much stock... all 3 guns had loose mounts after the match (they had been loctited)
year 2... built a fixture so I could reduce the depth of the hammer notch by precision grinding of the hammer's bottom radius, another fixture to hold a square ceramic stone parallel in the hammer notch to incrementally change the angle of the trigger engagement ...adjustable with a fine thread cap screw...so the trigger would not "cock" the hammer ... (checked with a dial indicator)....relocated the trigger return plunger so that it pushed directly forward on the trigger and not diagonally across it... built a scope mount that cantilevered directly off the barrel...added a Fajen thumbhole stock...the trigger could be adjusted down to 10oz, but that was way too lite, so adjusted to give a 1 1/2# pull...had a informative talk with Ken Tapp and David Tubb at the match
year 3... Ken Tapp suggested full length bedding of the barrel, and adding a second mounting bolt and not try to support the barrel with the aluminum receiver as if it were full floated... David Tubb suggested reducing the head space of the bolt... I did both...made a cheek cut out to allow the rifle to be held more vertically... got better with higher magnification of the scope in practice
year 4... added a harmonic tuner for the barrel... my SW M41 liked WinSuper X high velocity ammo (you had to knock down the steel plates so we opted for the supposedly less accurate high velocity ammo)... this really helped as you could tune the barrel vibration harmonic to the ammo, rather than searching for the lot of ammo that worked the best... a piece of 1 1/4 inch round aluminum stock about 4" long was center bored for the .930 barrel... a lengthwise saw cut, and two cross pinch bolts was added... you shot a group at 100yd, and moved the harmonic tuner... you could watch the groups open and close with the slight change of location... on a wind less day off a rest it would consistently put 10 shots on an IPSC paster at 100yd
year 5... the added accuracy from the tuner showed up a first shot flyer when dropping the bolt by hand...scratched my head, but in looking at the bolt noticed that the firing pin had considerable up/down motion...we had played with some of the high end match ammo, that had the dimple in the middle to evenly distribute the priming compound around the rim, so it occurred that the ignition might be at fault... ground a "v" to a hardened cap screw, and tapped it into the firing pin slot to limit vertical movement... a friend then TIG welded it in place, and faced it down... no more first round flyers...built a cartridge rim thickness check gauge to separate "match" ammo, but spent most of the time working with the pistol and a couple of scopes...at the time I could still see pretty well, and shot it better with open sights, which I used... this was the last year (1998) the match was held in south Florida... it was one of the most fun matches I have competed in
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