COAL of Factory Ammo

[Ramjet]

Well I was reloading some 6.5 Creedmoor ammo Friday for the first time and my Lee Dies show a max COAL of 2.825" . Just as a comparison I measured the 2 boxes of Federal Factory Loads (140 gr bullets ) I have on hand and they averaged 2.680" . I have noticed this before and I guess their standard is so that their ammo will fit any chamber.

I have noticed this in other calibers I load for as well. At 2.825" my ammo will just fit the magazine of my Ruger American. I went with 2.70" because the Federal shoots very well in my gun and there is no clearance issues with my magazine.

My Savage 16 , in 708 has a very short chamber and with some bullets set at the max COAL the bullet is jammed into the lands. I know this because while testing them they have stuck in the barrel when I extracted the cartridge throwing powder everywhere.

Just some thoughts

 

[K22]

While I haven't shot factory ammo since the late 60's (except for rim fire) I have several buddies who shoot factory ammo (rifle bottle neck cartridges)

All the factory ammo I've seen have COAL's considerably less than the maximum SAMMI specs. presumably so they will fit any chamber. I've seen some amazing groups shot at the range with Federal Premium factory ammo. Kind makes we wonder about all this fuss about distance from the lands.

 

[Bill Norris]

While I haven't shot factory ammo since the late 60's (except for rim fire) I have several buddies who shoot factory ammo (rifle bottle neck cartridges)

All the factory ammo I've seen have COAL's considerably less than the maximum SAMMI specs. presumably so they will fit any chamber. I've seen some amazing groups shot at the range with Federal Premium factory ammo. Kind makes we wonder about all this fuss about distance from the lands.

While some rifles will shoot factory ammo at those shorter seating depths many will not. Totally depends on the throat & barrel and what it likes.

 

[D-4297]

Many rifles will tolerate a large "Jump" , and still shoot a better than reasonable group . I've loaded some Sierra #2156 Palma bullets that had a extremely long Jump of .165 and they gave me a 189 - 7x at 600 yards in my Kelby TR rifle . The long jump was predicated on my chamber having a 180 FB , and getting enough bullet into the case , to hold it in place properly . These were loaded with my normal loading practices for competition Match ammo . However ; when you compare the average over - the - counter , to Match-grade , hand loads . The OTC rounds can not , and will not compare on the target . Kind of like the load that shoots all rounds touching in one good hole at 100 , to being 5 or 6 MOA at 600 yards . All of the "fuss" about seating depth is based on precision . One half MOA can be the difference between 1st place , and 5th place . In one shot . One half MOA of Deer is still meat in the freezer .

 

[divingin]

The factory COAL has more to do with fitting in magazines rather than fitting chambers.

One of the many benefits of reloading is that you can set the cartridge for your rifle, rather than everyone else's.