In this issue: "Cooking rounds" Prone performance Prone performance - question Rifle CG rebuttal Seminar with L. Bassham ************************************************************ Hello Michael, In the recent mailing list #14 I read the post by "Club Coach" about Cooking Chambered Rounds. I have another way of looking at this. I chamber my next round (without closing the bolt) as soon as I have ejected the last one. I then wait for my partner/s to shoot and fill out my score book. I believe that this means that all of my rounds are "cooked" to the same temperature, giving consistency. You can never be sure that you are going to get your shot away in a set time, every time. A gust of wind will make you stop and check conditions. All the time the temperature of the round is climbing while you are getting ready. I accept that if you are string shooting this may not be ideal but in the UK where we shoot 3 to a target this works fine as there is a 2 to 3 min. delay between your shots. Regards, David Crispin, Bovingdon, Hertfordshire, England, UK. Dorking & District Rifle Club. [Ed. note - this is out of my realm since it's highpower which I haven't shot yet, but I do reload and I think you should be as consistent in time in the chamber as possible. If you vary the chamber time by a minute or two, the temperature of the round will vary and make the pressure variable, thus killing accuracy. My coach says don't load until in position and ready to fire and, if you can't get the round off in time, eject it and start over with a new one.] ************************************************************* Prone Position Discussions By: Tom Kempley, M.Ed. - outdoors@pyramid.com High ten performance is required to competitive at the Olympic/National/NCAA level of competition. At the 4-H, Junior Olympic, Junior NRA, American Legion and JROTC levels any ten will do. High tens of the Olympic 50' .22 cal rifle standard on the A-36 Target are defined as centered groups of .23". The prone position is characterized by absolute repeatability. In order to shoot high tens perfect sight-alignment must be acheived from the prone position. Visual perception of sight-alignment is not reliable in prone position and must be discounted to the early positon adjustment of the preparation period. Perfect prone sight alignment hinges on at least six variables: left elbow placement, right elbow placement, sling tension, rifle butt placement, cheek placement and forward hand placement. The ability to absolutely repeat the location of these six constraints is elemental for high ten performance in prone position. [Ed. note - What do you mean by "Visual perception of sight-alignment is not reliable in prone position and must be discounted to the early positon adjustment of the preparation period." ? I disagree with your last paragraph also. Sight alignment has nothing to do with those except for cheek placement and butt placement perhaps. Those items you list effect the POI of the rifle (variable recoil), which is not the same thing unless you definition of sight alignment isn't the same as mine.] ************************************************************ I have a question now about prone since Ted brought it up. One of my shooters recently has been having problems with prone and I'd like your opinions. He was consistently shooting to the left a ring (A-36) even after adjusting his sights several times (which we did verify were working). At first I thought he didn't have proper sight alignment. Then I thought he was changing one of the variables disussed above. But I find it hard to believe he could change it so consistently so as to have nearly the same POI after incrementally adjusting the sights for 0.4-0.5 inches over. Any other things I should look for or suggest? Michael Ray ************************************************************ Hiyah Michael, Thanks for the postings. I feel a need to take issue with the following, please chuck it if I am out of order, I know how sensitive you colonials are. >(snip) > > The CG of the rifle is actually a secondary issue. The main issue is the > forces on the two contact points that support the rifle. These being the > non shooting hand and the shooting shoulder. The force on the non My first bible in shooting was Pullen and Hannenkrats book, and there was one theme throughout that has been good even some twenty years on. This theme states that there is only one "rule", in that, if something does not work try the opposite, or something else. To try to debate where the cg of a rifle should be is waste of good peoples time and money as far as coaching is concerned, it may be of interest to the academics amongst us, but then, only I suspect, when taken in relation to the body's cg, build of the shooter, length of arms, length of butt etc., etc.. > Now having said all this lets look at the positions and see haow they > work. First lets take the positions that use a sling. In these > positions the CG of the rifle is between the non shooting hand and the > butt of the rifle. The forces caused by the weight of the rifle is taken > up in both places. The non shooting hand carries most of the weight, but > some of the weight is carried by the butt, mainly by friction and the > horizontal force into the shooting shoulder. The closer the rifles CG is > to the non shooting hand the less the shoulder has to support through > friction, which means that the sling can be looser. It would be easier if we cloned shooters, wouldn't it? In the prone and kneeling positions the sling pulls the front of the rifle downwards, accomodating to taste, the effect of having the cg behind the supporting front hand. With the shoulder in place we now have three points of the rifle supported, one being transfered by the sling to the upper shooting arm. Shoulder contact is as much a matter of what works for the individual as anything else, with most top shooters having a preference for even how much area of shoulder contact the pressure is spread over. This obviously depends as well on clothing worn, shape/angle of buttplate etc., Why is a loose sling preferable, and to whom? > There are two other points of contact between the body and the rifle. > The cheek and the shooting hand. In the above discussion it is assumed > that there are no forces on there two points of contact. One way to a pain in the neck. I'm going to enjoy this digital dribble! (grin) > Now for the non-sling positions. Something needs to replace the force on > the shooting shoulder that was caused by the sling in the other > positions. Why? > The only thing that can create this force is the shooting > hand. To reduce effects on trigger control we would like to keep this > force to a minimum. This is done by keeping the CG of the rifle over the > non shooting hand. There is a greater stability, when standing, of the cg being slightly forward. This is due to the inertia of the barrel. >At the same time there must not be any vertical > component transfered to the rifle from the cheek. If the vertical components from cheek, trigger hand, and shoulder, balance and are consistant, whoopeee!!!! > When shooting with a > free rifle the CG of the rifle is placed forward of the non shooting hand > to insure that the hook of the butt plate is well placed in the arm pit > (this can also be done for kneeling). Hooks are useful as indicators for the security concious, they can give you warning of when things are not quite right, but woe betide those who may not listen to those warnings! > We have only looked at the CG of the rfle and its contact with the body. > In kneeling and standing we also need to look at the whole system (body > and rifle). A discussion for later. Why not in prone aswell? > carl > Cheers Carl, Love and cuddles, Peter. [Ed. note - several good points. I always try to keep it as simple as possible for my students.] ************************************************************ >I am sponsoring another coaches/shooters seminar with Lanny Bassham >the weekend of Feb 15-17, 1997 I will have a mailing out soon. >Good shooting, Neal nealjguns@databahn.net ************************************************************ End of UIT Mailing List #15 Michael Ray - Systems Engineer Rose-Hulman Inst. of Tech. Rifle Coach The Olympic Shooting Page - http://www.geocities.com/Colosseum/1190/