Hornady 75 Gr A Max .223 - Seating

rkaine

rkaine

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Hamilton, Ontario
What do you use as a OAL for this cartridge? Lyman gives 2.39, I seated mine there and am fairly happy, want to play with them a bit in my Savage 12FVSS, I've been told by two people at the club, they seat them as far out as 2.45.

Cheers

Ron
 
You probably want to set them about 0.020" short of the rifling. This means you have to measure what the overall length which puts this bullet touching the rifling in your rifle. There's several different ways to measure this distance, including some special tools you can buy.
 
OAL is an almost useless measurement. It only affects whether or not the round will fit in the magazine. Within the chamber, you're mor concerned about the ogive - rifling distance. Basically, a long ballistic tip bullet can make for a much longer OAL (but still not engage the rifling), than say, a lead RN bullet.
 
prosper,

That is only partly true, since it is actually quite difficult to measure the length from the base of the cartridge to the point where the diameter of the bullet would engage the rifling. This is of course the critical dimension. I think most of us make the assumption that this point on the bullet is a consistent length from the tip and therefore we use the OAL of the cartridge measurement - since it's easy to do with readiliy available measuring tools. Of course this point on the bullet is not always a consistent distance from the tip, therefore in my opinion it is better to stay back from the rifling by about 0.020". This way you may have a 'jump' that varies from 0.015 to 0.025" but this is less detrimental to accuracy than having some bullets pressed against the rifling and others having a short jump.

The other complicating factor is that most seating dies press on the bullet at some piont inbetween the tip and where the ogive will touch the rifling.

These are my current therories and opinions only of course.
 
There are a lot of variables. Pressure (amount of powder and how far you sit your bullets) and max length in the magazine to name a few.

Any time you go off the loading manual spec, do it a bit at a time and watch your pressure signs. Play safe.....:)

Danny
 
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