Conventional rifling..... Once a rifle has been given a name/NSN/model number and you change one thing then it has to be re named and the build procedures get re written or modified and all this takes an act of congress. That's why they are up to the (M40A594564534121XYZ-Charlie) or something crazy now. That's why they are still using the conventional rifling. Nothing wrong with conventional rifling. 5P Barrels requires less work, reduces vibration, chamber psi, fowling, less pressure on the bullet due to odd number lands and grooves compared to the USMC 6 land and groove conventional barrel having a land directly across from each other, you will see an increase in velocity due to these factors. With an increase in velocity the scopes elevation turret won't match the trajectory of the issue sniper ammunition. This would not be cost effective in the long run. Sounds crazy but its true. If they would change to Gary's 5P they will never go back to conventional rifling. This will stir the pot a little with the ones that need to do barrel break ins. With the 5P I have never had to shoot X amount of ammo, stop, wait, clean, repeat steps 1, 2, 3 drink some coffee etc. etc. We didn't do that mess with Conventional barrels either. We just shot 50 rounds thru them and cleaned them good the next day. If a 175 gr bullet at 2600 FPS shot thru the barrel over and over again year after year wont ruin a barrel then a plastic coated rod and bore brush traveling at 2 feet per second wont either. Buy a 5P and save the ammo from (Barrel Break In) for shooting targets/ deer/ coyotes and such. Sorry about the long answer, I chased a rabbit there for a minute. P is for polygon so the lands don't have any 90 degree shoulders.
