The difference is mainly in the bullets. Short range guns shoot flat back bullets, that stabilize quickly. The long range guns mostly shoot boat tailed bullets that don't fully stabilize until they are out 100 to 200 yards. My long range gun (Savage 110 Shilen 1 in 8 twist barrel chambered in 6x47 lapua shooting 108 Berger boat tails) shoots just about as good as my short range gun. (in the .3's)
Something else very few short range bench rest guns shoot .1 or.0 groups, (In the .0 area it is called a screamer and you get a patch for it.) there is some freak groups that are shoot from time to time, but this is not the norm. Go to Kelby's super shoot and look at the wailing wall most groups are in the .5 area. Only a small percent are smaller, I would say a competitive gun shoots groups in the .2 area. Being consistent is the key to winning. As the saying goes "You don't have to shoot small groups to win, just don't shoot no big ones." Don't get me wrong Tony boyer usually shoots some .1 area groups, and may other have as well, but every time they go to the line there is a good possibility they will shoot a larger group.
Other difference between a short range (SR) and a long range (LR) gun besides weight. A SR gun they use a slow twist barrel so that the rifle doesn't torque in the rest, and stays on target. They use the slowest twist they can to just barley stabilize the bullet. In a 6PPC they shoot mostly 14 twist. In my area you will not see many 15 twist do to the cold weather, and the bullets will not stabilize in the cold, but they will in the hot weather. SR guns have short barrels because of the weight. (It is hard to make weight) You will mostly see fixed power scopes, fiberglass stocks, and guns chambered in a 220 Russian variant. (6ppc, waldog, ((even modified 6br)) Tall dog, small dog, and 30br.) All because this is what works. The main thing is for the gun to move as little as possible, and when it does move for it to go back to the aim spot quickly. Light 2oz (or less) triggers are used so that they do not disturb the gun. Depending on the conditions may state the way you shoot. On a calm day many will take their time shooting. On a day with fast switching winds many will shoot off there rounds quickly, trying to keep the same condition. In SR competition there is tons of flags used, depending on the size of competition and the range there could be a few hundred flags out. Funny thing is many people shoot light gun in heavy gun (under 13 lbs) class because a heavy gun shoots different. Look at the records the light guns usually have better and/or smaller groups.
In a LR gun, they need fast twist barrels to use heavier bullets to go the distance. The use longer barrels, to gain velocity and to help make weight. 17 lbs is a heavy gun. You will see a lot of laminate stocks used, variable power scopes. To get the weight up many people fill the stocks with lead. A heavier trigger (4 to 12 oz) can work because the gun is heavier, and harder to disturb. In LR good shooters shoot fast, and there are very few flags out. Shooters use trees, grass and other things to judge conditions. The guns are heavy so a heavy recoiling round doesn't move the gun as much, and it help the shooter by not beating them to death with recoil.
There is no magic in building a SR or LR gun, the same principles are there. Many LR shooters use the exact same custom actions that the SR guy use. (Bat, Panda, ETC) some use the bigger versions to accommodate the longer cases and bigger caliber.
I hope this answers all your questions.
Bookmarks