What makes match ammo 'match'?

[HammerheadSSN663]

Found this on Yahoo regarding what makes a round match and thus so much more accurate that standard or military grade.

I am ignorant on the subject and suspect many more here are as well.

Can any of you seasoned firearm vets confirm the following?

ref: http://answers.yahoo.com/question/index?qid=20100122095424AAgmMrX

First off - match brass. The primer hole is normally 'punched' and this can leave one, two, three or no brass 'leafs'. These leafs will direct the primer's blast. In match brass these particles are removed using an inside primer hole reamer. Although is not such a big deal in pistol match ammo - it can mean the difference between night and day in rifle ammo!

Second - bullet conentricity. This is the relationship of the bullet to the brass. In pistol ammo a typical standard round can be .022" off center and you would never notice it by looking. In a standard box of ammo you will find bullets that range from .002" to as much as .038". In match ammunition - bullet concentricity is always kept to less than .004" using a much slower seating die in production. Because time is money - it does cost more to make match ammo.

Third - match pistol ammo is always subsonic. Not because of any special flight considerations of the projectile. If your bullet is traveling 1200fps and you are keeping the speed to 1% this is a potential difference of 12 fps. If you run the ammo at 990fps this difference between is now only 9.9fps - this is 25% more accurate just by using a different load.

These are the three main differences in pistol match ammo. In rifle match ammo there are actually 7 different things that make it work better for accuracy....... but they do not do anything for reliability. Hence the reason your military match ammo is always marked 'Not for Combat Use". Because it is always .010" longer than SAMMI standards.

 

[Millwright]

DoubleH,

First you gotta "separate the goats from the chickens". What makes "match quality" pistol ammo ain't the same for rifle rounds. Then there's the whole revolver/pistol thing, too.....

Not being a pistolero, I'll just briefly skim a few things for rifle rounds, (with the proviso that some carry over to pistol shooting, too).

"Match Ammo":

1. Consistent case weight, hence case volume within a small range.
2. Consistent case neck concentricity to case wall.
3. Consistent case neck thickness.
4. Consistent brass hardness.

If loaded ammo:

1. Consistent powder charge weight.
2. Consistent bullet seating/concentricity.
3. Consistent bullet crimp or "pull".

That's most of the "biggies", but myself, like other reloaders have a host of other "tricks" we use to wring the most out of our ammo in our rifles. Pistoleers are driven by the same manias no doubt. >MW

 

[wanderinwalker]

These are the three main differences in pistol match ammo. In rifle match ammo there are actually 7 different things that make it work better for accuracy....... but they do not do anything for reliability. Hence the reason your military match ammo is always marked 'Not for Combat Use". Because it is always .010" longer than SAMMI standards.

I was always under the impression the "Not for Combat Use" labeling on military rifle match ammo is due to the use of the dreaded HOLLOWPOINT bullet (excuse me, Open Tip Match configuration ).

For rifle match ammo, Millwright pretty much nailed the difference with one word: CONSISTENCY. The seating is more consistent, the better match bullets are considerably more consistent than hunting bullets or FMJs, cases can be better prepared, etc. Also, powder choice can make a big difference in rifle rounds.

As far as reliability, I doubt anything in match ammo makes it less reliable than ball ammunition would be. While not life-or-death like in combat, winning or losing matches can hinge on whether or not your ammunition functions properly every time.

 

[Cal-gun Fan]

Pretty much just consistency and precision-everything being the same for Rifle rounds, pretty much what Millwright said.

 

[ranger335v]

"Match ammo" is what ever a shooter uses at a match; however he does his loading and selection of components is up to him.

In application it's sorta like the definition of "reloading", in which the cartridges are typically cramed together almost by rote, and more meticulus "handloading" in which the loader puts more craftsmanship into his reloading. How anal we get about it depends on what we want it to do, how accurate our rig is, how much we know about accurate loading techiques, etc.