300 win mag COAL issues

[Johan]

Components:
Winchester brass
Sierra 190G HPBT

I read what Randall posted on his page about the different lengths of the free bore and why its done, but here is my question...So when I was using the OAL gauge i was consistently getting an average of 2.914 (using the bullet comparator) I pushed the bullets in .040 from the rifiling to start off. So when I measured the COAL it was 3.450 and all my books say that the max COAL is 3.340

I made some dummy rounds to chamber and check how it cycled through the gun and it worked fine. I'm pretty sure it should be fine, just want to see what others think.

On another note, when I go to make hunting rounds (150g) there's no way I'm going to be able to seat the bullet close to the rifling

[buffybuster]

If this is a factory barrel, most factory barrels have a long throat/freebore to keep pressures down (and liability lawyers happy). Usually it is not possible to seat the bullet into the lands of a factory barrel and still feed through the magazine/stay within published COAL. Usually the bullets are going to have to jump to some degree and they usually still shoot reasonably well.

I've got an FN with a throat so long that I'm jumping the bullets over 0.200". Still shoots sub-moa, but it's not a 1/2moa rifle.

[Johan]

So it is ok then to have the COAL longer than what the book says or should I seat it deaper to what the book says for max?

[buffybuster]

So it is ok then to have the COAL longer than what the book says or should I seat it deaper to what the book says for max?

Longer is OK (as long as it fits, feeds and chambers). Shorter will increase pressures, since you are decreasing the available case volume.

[swerv512]

COAL is not what i'd consider a limiting factor. so long as your brass is trimmed to under the max length, then COAL is a matter of preference. if you're loading from a magazine- you probably will seat the bullet further from the lands to facilitate smooth cycling of your firearm. if you find that your rifle shoots best when the bullet is seated say 0.010 from the lands (one long cartridge!) then you compromise the ability to feed multiple shots from a blind or detachable magazine- but you may gain accuracy. one exception would be when the factory throat is sooo long that your bullet wont sit far enough in the case for a tight fit...

[Johan]

Thanks everyone for the info.