Originally Posted by buckbrush
I just picked up a new SPS and was wondering how to go about breaking in the barrel while developing a load, if it is possible.
I originally wanted to do this to save time and resources but now I recommend to do these separately. After cleaning your bore, any residue left behind may affect pressure and velocity of your bullets which wont give you the info that you need.
You certainly dont want to shoot groups with cleaning between each shot because your bullet will perform diferently in a clean bore vs a fouled bore and that's why most shooters shoot at least 1 fouling shot and usually more before shooting for groupd or hunting.
For break-in I will load cheap guilded jacketed bullets at a reduced load (to avoid over pressure) and clean between each shot. i also use a product to conditon the barrel during the process.
Once your break-in is done, start load development.