Thank you! I get it now (at least the tip of the iceberg of it)
North Country Gal wrote:Anything that attaches to a barrel will affect barrel harmonics - how the barrel vibrates during the shot. That, in turn, can have a pronounced effect on how consistently the barrel vibrates, shot after shot. That consistency is what makes for accuracy. Notice how bench rest rifle barrels tend to be very thick and relatively short. This makes for very consistent barrel harmonics.Mags wrote:.
Please explain the bit about the pressure sensitive point. Why is that?North Country Gal wrote:... I usually rest the gun just forward of the trigger guard to minimize contact with the forearm, since the forearm is a sensitive pressure point on many gun designs.
Anything that touches the barrel, then, will have an effect on barrel harmonics. It's why there are numerous ways a rifle action and barrel are bedded in a stock. Free floated barrels in bolt action rifle stocks where the barrel doesn't touch the forearm is one method, but it is certainly not the only method. In fact, some bedding designs deliberately have the stock touching the barrel at a given point and removing it, via a do-it-yourself free floating job, can destroy accuracy.
Rifle designs where parts are directly attached to the barrel tend to be the most sensitive to a rest because the upward pressure exerted by the rest is directly transferred to the barrel through these parts. A good example is my Contender and Encore rifles/pistols where the forearms are screwed directly onto the barrel. Even have to be careful when changing barrels to torque those forearm screws the same. Too tight or too loose can affect accuracy. That's why I rest my Contender and Encores well back towards the receiver when shooting from a rest.
Lever guns are another gun design that can be touchy about forearm pressure, especially forearms that use a barrel band. More than one shooter has discovered that over tightening a barrel band can wreck accuracy. Rifle style lever gun forearms with a cap are generally a better design, but, remember, there's a lot of stuff dangling underneath a lever gun barrel like a tubular magazine and so forth. Even a loose tubular magazine bouncing around during a shot can affect accuracy.
In the end, it's always, always, always consistency that counts if you're after accuracy. Pretty tough to get that consistency if you keep changing any of these pressure points on the gun from one shot to the next. If you are going to rest that lever gun way out on the forearm, you must be careful to place it in exactly the same place for every shot. Resting the gun under the action greatly reduces this variable, though, because it's a less sensitive pressure point than that forearm.
Whew! Hope I haven't lost anyone with all this stuff, but I've really only touched the tip of this vary large iceberg. Go to a benchrest competition, sometime, where these folks actually build their own rifles if you want to see how complicated and detailed these discussions can get.
