Is there a way to determine MIN COAL

motoman202 · February 26, 2013, 08:03 PM

I have seen a lot of load data that will give MAX COAL and i have seen some load data that will give MIN and Max. My question is can you calculate the min coal somehow for any given load?

Brian Pfleuger · February 26, 2013, 08:17 PM

There really isn't a minimum except under specific circumstances.

Practically speaking, you would eventually seat a bullet so short that the case mouth would be past the ogive (full diameter section of the bullet) and the mouth would start catching on the feed ramp or other things, possibly even just fall into the case, for bottleneck cartridges. You also will begin to increase pressures, as the bullet begins to take up space that the powder wants.

For handguns especially, having short rounds can cause significant pressure problems but even then a knowledgeable loader could reduce the charge appropriately and seat the bullet as short as he'd like, until the case started catching on things again, I suppose.

In any case, particularly with rifles, you'll GENERALLY find that LONGER is more accurate. Most folks load rounds close to the maximum length that will fit in their magazines or just a couple/few thousandths short of the rifling.

rlc323 · February 26, 2013, 10:44 PM

That's good advice. I like to find a factory cartridge that has a similar bullet weight and shape to what I am loading and go from there. Keeping in mind case volume so as not to compress powder in handgun loads like .380.

I found some old Remington Kleen Bore 9mm 124 grain the other day that measured out at a rather long 1.160. The price was handwritten on the box. $6.20.

February 26, 2013, 08:03 PM	#1
motoman202 Junior Member Join Date: February 12, 2013 Posts: 11	Is there a way to determine MIN COAL I have seen a lot of load data that will give MAX COAL and i have seen some load data that will give MIN and Max. My question is can you calculate the min coal somehow for any given load?

February 26, 2013, 08:17 PM	#2
Brian Pfleuger Moderator Emeritus Join Date: June 25, 2008 Location: Austin, CO Posts: 19,578	There really isn't a minimum except under specific circumstances. Practically speaking, you would eventually seat a bullet so short that the case mouth would be past the ogive (full diameter section of the bullet) and the mouth would start catching on the feed ramp or other things, possibly even just fall into the case, for bottleneck cartridges. You also will begin to increase pressures, as the bullet begins to take up space that the powder wants. For handguns especially, having short rounds can cause significant pressure problems but even then a knowledgeable loader could reduce the charge appropriately and seat the bullet as short as he'd like, until the case started catching on things again, I suppose. In any case, particularly with rifles, you'll GENERALLY find that LONGER is more accurate. Most folks load rounds close to the maximum length that will fit in their magazines or just a couple/few thousandths short of the rifling. __________________ Nobody plans to screw up their lives... ...they just don't plan not to. -Andy Stanley

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

February 26, 2013, 10:44 PM	#3
rlc323 Senior Member Join Date: January 23, 2013 Location: Forgottonia, Il Posts: 217	That's good advice. I like to find a factory cartridge that has a similar bullet weight and shape to what I am loading and go from there. Keeping in mind case volume so as not to compress powder in handgun loads like .380. I found some old Remington Kleen Bore 9mm 124 grain the other day that measured out at a rather long 1.160. The price was handwritten on the box. $6.20.