I have been an automobile mechanic for over 51 years , and when I was a kid I was always curious as to what made mechanical objects work , so yes , I was and I still am a "TINKERER" , especially with my firearms .
When I get a "new" gun , whether it is new in box , or used ( New to me ) , I always dis-assemble it to verify that all appears to be safe and in a workable condition .
I will bed the action and recoil lug , check the bolt and receiver for fit and smooth operation , check the safety and trigger and try to adjust the trigger to a smooth pull of reasonable weight , and thoroughly clean the barrel . Sometimes , I will replace the trigger assembly with a quality , adjustable after-market trigger .
I will then install my choice of base and rings , and scope , and then bore-sight the scope using a Bushnell collimator-style optical bore-sighter .
I very rarely will shoot factory ammo , preferring to reload my own , so I will begin load workup , and tinker until I get close to achieving my goals of velocity and accuracy .
If I choose to buy a rifle that shoots magnum cartridges ( example - 7mm Rem. Magnum ) , then I try to work up loads that perform in the magnum velocity range that are accurate .
I have a Remington Sendero 7mm Magnum , that I bought used , that after tinkering , will consistently shoot 162 grain A-MAX bullets at less than .75 MOA .
However , when I had my first trip to the shooting range with this rifle , it would scatter the shots all over the paper , the empty cases were very hard to extract from the chamber due to the side of the chamber having a ridge , just above the belt area of the case that after firing the case would be held in the chamber until I tapped back on the bolt knob to extract the case which would have a scar on it's side . Also , the bore was so coarse that I could not get it cleaned .
A trip to my gunsmith corrected the problem in the chamber when he removed the barrel , spun it in his lathe , and using emery cloth , removed the bad spot in the chamber . Looking through his bore scope , he said that the barrel was so coarse that I should replace it , but , having limited funds to spend , I thought that I would try some of the bore-lapping bullets that might help smooth the bore .
Using the fire-lapping bullets ( 130 grain ) , loaded to a low velocity reduced starting load , I would shoot 1 shot and clean , and repeat for a total of 10 shots of coarse grit coated bullets . 10 shots into about 2" .
Clean again , then using the fine grit finishing bullets , 5 shots and clean ( this time the group was approximately 1" , and the cleaning patches were much easier to push through the bore ).
Clean again and shoot 5 more of the fine grit coated bullets , but this time all 5 bullets were clustered together overlapping each other , and the group size measured slightly less than .25" . The bore cleaned easily , feeling almost slick . That final group I ran through a chronograph and the velocity was 2400 FPS - SLOW.
So , yes , this rifle can shoot bugholes at slow velocities , but it defeats the purpose of the magnum case . Why load a 7mm Rem.Mag. down to less performance than a .30-30 ?
Accuracy does not always trump velocity .