How do I decide the COAL?

[Ross]

I have some Hornady 230 gr FMJ-RN .45 bullets I am loading tonight (cause the roads are to scary to venture out on).


The Hornady manual it reads a COAL of 1.230
The Sierra manual reads 1.260
The Lyman manual reads 1.275

And the PMC bullits my P90 love are 1.255

So how do I decide which to use? I am leaning towards the PMC size.

[rero360]

For pistol rounds, really so long as they are not super short and not so long as to prevent loading in your magazine or cylinder then you are generally good to go, pretty much just go in the ballpark of what the manuals state.

[joelogic]

Its a balance. Mag length and pressure. The deeper you seat the less powder you can use for the same pressure. Too deep and they wont chamber right.

[sequoia_nomad]

As long as the bullet weight and profile are the same, I'd go with what the gun likes.

[GeoffLinder]

Trial and error.

Load a dozen of several different length and try each batch. If a specific batch has function problems, don't use that length.

Staying in the middle of an identified range is never a bad idea to start. Heck, you may never wind up anywhere else once something works for ya'

[shinbone]

I set my OAL long enough such that the bullet is as close as possible to the lands of the barrel. I check for it by marking the bullet with a dry erase marker, and then seat it just a touch deeper so it barely contacts the lands. Then I goto the range and check to see if it feeds correctly. If it doesnt, then I seat .002" deeper at a time until it feeds reliably. The idea is to get the bullet as close as possible to the rifling of the barrel to reduce jump from chamber to barrel for max accuracy. Finally, adjust the charge accordingly, but this probably requires a chronograph.

[donger]

I set my OAL long enough such that the bullet is as close as possible to the lands of the barrel. I check for it by marking the bullet with a dry erase marker, and then seat it just a touch deeper so it barely contacts the lands. Then I goto the range and check to see if it feeds correctly. If it doesnt, then I seat .002" deeper at a time until it feeds reliably. The idea is to get the bullet as close as possible to the rifling of the barrel to reduce jump from chamber to barrel for max accuracy. Finally, adjust the charge accordingly, but this probably requires a chronograph.

The OP is asking about a handgun. What you're suggesting is more appropriate for a precision rifle.

[Ross]

The OP is asking about a handgun. What you're suggesting is more appropriate for a precision rifle.

thanks

[shinbone]

I do this with 9mm and 357 Sig. Again, its what I do, and I try to acheive the best accuracy. Doesnt matter if its pistol, or rifle. There's always a chamber jump. But, if youre just making plinking rounds, whatever feeds reliably.

[donger]

I do this with 9mm and 357 Sig. Again, its what I do, and I try to acheive the best accuracy. Doesnt matter if its pistol, or rifle. There's always a chamber jump. But, if youre just making plinking rounds, whatever feeds reliably.

Hmm, don't know if there would be a measurable difference in groupings between a couple of thousandths of an inch seating depth at realistic handgun distances. Seems to be a lot of work for nothing.

To the original question. Seat at the same COAL as your favorite factory load unless you work up something more accurate and more reliable.

[shinbone]

Youre right^^^. I should have taken into account what he maybe going after and what level of reloading he's in. Sorry to confuse, and thanks for rewording.

OP, pistols are rather forgiving. Factory rounds are set OAL to specs that work across the board. So go with that. Once youre further into reloading and perhaps you may want to fine tune, OAL has an ability to fine tune to your particular pistol, incase you want match grade accuracy.

[J-cat]

I like to start long, i.e 1.270", and work my way down. Try 1.270" first, work up a load, test it for accuracy and reliability, and then try a shorter length. Alot of people give up on loads too soon without trying shorter or longer OAL's. Don't make that mistake.

[xrMike]

And the PMC bullits my P90 love are 1.255

So how do I decide which to use? I am leaning towards the PMC size.

I totally agree with your logic here -- start with a COAL that you already know is good, and go from there.