Ammunition & Hand Loading > Cartridge and Shotshell reloading
On reloading...
Neeco:
--- Quote from: bkoenig on February 04, 2013, 02:26:16 PM ---COAL doesn't determine headspacing, just the distance the bullet has to jump to the lands. Ideally you want that as short of a jump as possible, which means seating the bullet farther out. Too long and you can jam the bullet into.the rifling which can cause a dangerous pressure spike. In most mag fed guns you will end up too long to fit into the mag before you reach that point.
A rimless case like .223 headspaces off the case shoulder. Tighter headspace (within reason) will generally lead to better accuracy. If the shoulder is bumped back too far it can cause excessive headspace. I saw that once with a member here. He was having primers back out on a rifle he just bought. Since it was factory ammo we thought his gun had excessive headspace, but after measuring the unfired cases he found the shoulder was way too.far back. Once.he reloaded them with good dies the problem went away.
--- End quote ---
Maybe I need to learn my terms better. I thought headspacing was the distance from the shoulder to the chamber and the distance from the bullet to the rifling. I now see that its only the shoulder to chamber.
So maybe my question is about bullet seating more than headspacing.
Is there a test you can preform to find out exactly how far to seat the bullet? Or does it not need to be that specific. Especially on a training/plinking round where accuracy is not the upmost importance.
unfy:
If you're really concerned about bullet jump to rifling grooves...
Take a piece of unprimed empty brass that's been sized (even just neck sized is fine if that's what you're working off of). Put a bullet in it by hand... make it stick out long. You want the bullet to not just fall in the brass, but also to not have an "impossible" to move it kind of resistance.
Carefully and slowly chamber the round by hand so that it's in full battery (admittedly easier with a bolt action gun).
Carefully and slowly eject the round by hand (don't let it go flying off).
What should have happened: when chambered into full battery, the bullet should have been pushed against the barrel / rifling / chamber throat ... and then further pushed down into the case. You might even just barely see the rifling grooves marks on the bullet itself.
The cartridge you just cycled will be your absolute max length to seat THESE PARTICULAR bullets at IN THIS PARTICULAR GUN. As mentioned above, you'll actually wanna back that off by a couple thousands of an inch (ie: seat a little deeper) to avoid pressure spikes. If you switch bullets or gun, re-run the test if you're going for as little 'jump/run' as possible.
Too much 'run to the rifling grooves' will affect accuracy, resting on the rifling grooves and you'll have pressure problems most likely.
With the above said... the general rule of thumb is that seating deeper causes higher pressure, seating further out decreases pressure. This isn't always the case, but it's a good rule of thumb. You'll note there are several of these 'general' rules of thumbs that aren't absolutes :).
Keep an eye out on your primers, how the gun behaves, and what the brass looks like afterwards.
Be safe (your gun, yourself, and the spent brass will let you know).... and if in doubt, back things off a bit.
unfy:
PS!!!
Congrats on your first hand loads of 223! :)
One of us....
One of us....
One of us....
One of us....
One of us....
One of us....
One of us....
Neeco:
--- Quote from: unfy on February 04, 2013, 02:53:23 PM ---If you're really concerned about bullet jump to rifling grooves...
Take a piece of unprimed empty brass that's been sized (even just neck sized is fine if that's what you're working off of). Put a bullet in it by hand... make it stick out long. You want the bullet to not just fall in the brass, but also to not have an "impossible" to move it kind of resistance.
Carefully and slowly chamber the round by hand so that it's in full battery (admittedly easier with a bolt action gun).
Carefully and slowly eject the round by hand (don't let it go flying off).
What should have happened: when chambered into full battery, the bullet should have been pushed against the barrel / rifling / chamber throat ... and then further pushed down into the case. You might even just barely see the rifling grooves marks on the bullet itself.
The cartridge you just cycled will be your absolute max length to seat THESE PARTICULAR bullets at. As mentioned above, you'll actually wanna back that off by a couple thousands of an inch (ie: seat a little deeper) to avoid pressure spikes. If you switch bullets, re-run the test if you're going for as little 'jump/run' as possible.
Too much 'run to the rifling grooves' will affect accuracy, resting on the rifling grooves and you'll have pressure problems most likely.
With the above said... the general rule of thumb is that seating deeper causes higher pressure, seating further out decreases pressure. This isn't always the case, but it's a good rule of thumb. You'll note there are several of these 'general' rules of thumbs that aren't absolutes :).
Keep an eye out on your primers, how the gun behaves, and what the brass looks like afterwards.
Be safe (your gun, yourself, and the spent brass will let you know).... and if in doubt, back things off a bit.
--- End quote ---
Perfect. I will give that a shot.
Now what about COAL. Is there a way to test headspacing? A measuring guide? Or another one of those "unless you're trying to shoot a bees wing at a mile" stick within this certain range....
A-FIXER:
--- Quote from: Neeco on February 04, 2013, 02:30:25 PM ---
I use standard PMAGS and had zero issue with feeding or cycling. Should I increase the COAL up to max? Or is a consistent COAL what you are after? The primers are seated deep enough and the case will sit completely flat on a flat surface (as I think UNFY mentioned in another thread). The primer strikes look no different than those of factory rounds. Nice and consistent.
I am certainly not trying to be a "mad scientist", I am only trying to enjoy the joys of saving a bit of money and reloading. I DO NOT wish to blow off a booger picker or worse. Hence the reason I am asking.
You maybe happily suprised and the normal book set length as and longer that the mag allows you will have issues .. plz don't take offense to the mad scientist remark lets leave that to unfly ;)
Thanks for your input!
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