500 metres is not that far. Therefore I would base your choice on two things:
1. Ammunition cost
2. The type of target you are shooting at and what is around the target, in the event that you miss
The 223 would be a good choice, however it is a small intermediate energy bullet. In adverse conditions. you will not see bullet impacts. For example, on a dry day you will easily see .22lr impacts in sand at 500 metres. On a wet day, you may fail to spot .308 impacts into grass at the same distance. If you are shooting paper or electronic targets, don't worry about it as you will either have a marker or it will show up on the screen.
The calibers I would recommend based on good availability of a good choice of match ammunition are:
223
6.5 Creedmoor
308
I would not recommend 243 as it is primarily a hunting cartridge and quality factory match ammunition is limited.
EDIT: just saw you bought a 308. Good choice.
in2anity wrote:bladeracer wrote:Agreed, get a price on a thousand rounds of .308Win match ammo and decide how seriously you want to shoot factory ammo.
Sickening to think what that would now cost. In a 2021 Queens, a SH shooter decided he was gonna run the Tikka TAC-A1 thingy in 6.5cm... with factory Hornady Match ammo. The quality required to be competative in such an event.
The bloke paid $75/20 box multiplied by eleven boxes - so
$825 worth of ammo required just to compete (let alone the cost of practice leading up to the event). Then the entry fee on top was $175 or similar. So it effectively cost him $1000 to shoot that queens. The poor bastard had the event win slip through his fingers on the VERY last stage of day three, due to a couple of inner-4s from nerves. Very expensive mistake considering there was considerable prize money on the line.
He now handloads after that little escapade.
Be smart people.
I use factory ammo, including the 6.5 ELDM you mention. There is no disadvantage, other than cost, for all but extreme ranges. At extreme range, you will get lower SD on your muzzle velocity with home loads which will mean you get less vertical dispersion on your impacts. You can get single digit SD on home loads vs low 10s fps on factory match ammo. However other than extreme range, this doesn't really matter. It definitely doesn't matter at 500 metres. You also mention that nerves cost the match... would home loads have made any difference? Weren't there also people in that event who used homeload ammo who were nowhere near the top?
Most people who home load do so for cost reasons. There aren't many people who can homeload, do load testing and do their own quality control to the degree where they have an accuracy advantage over match factory ammo. When I go to the range with people with homeloads, there is always someone who cannot hit anything. There is also the time cost of home loading. Not just the time doing the home loading itself, but the time and cost of ladder testing and doing load development. Or someone will home load but then turn up with a knock-off Harris bipod and some random rear bag or even no rear bag. Or they will use a dope sheet rather than calculate for atmospherics and their powder temperature - any possible advantage of homeloading goes straight out the window.
>> Only a few Military type rounds have their projectiles Doppler radar tested to gain real flight BC data .
These days almost every match bullet has good doppler radar data to and beyond transonic ranges. Hornady do their own testing and you Brian Litz of Applied Ballistics has measured BC data for just about everything.
FWIW I had a first round impact at 1-mile using factory ammo, quality bipod, quality rear bag and entering everything into the ballistic solver. I've also had a lot of %^&*-ups, but there is minimal non-cost disadvantages of factory ammo if you don't %^&* it up yourself.