The small base die resizes to about the same size as factory ammo.
I thought that's what regular dies did. The manufacturer is aiming for the size that will put 95% of brass back to spec, which will already make some of your cases much smaller than maximum SAAMI case spec by necessity, and likely some of it smaller than minimum SAAMI case spec.
The real accuracy gained by the match barrel is usually the overall higher quality of materials and workmanship.
So I could buy one and have it professionally reamed out to maximum SAAMI chamber spec to have the best in accuracy and reliability? All while using mixed brass fired out of several different guns, to boot? Let's be honest. If you want to get the most out of any gun, including a gun with a tight chamber, one of the tried and true methods of increasing accuracy is by matching the size of your brass to the chamber of the gun. Most folks who will buy a match chamber for an AR are going to be particular about their brass for that gun, rather than make all their ammo smaller but retain the same amount of variation in size. Of course, there are exceptions. If you want to shoot your matches with factory ammo, then there's that. I didn't think most reloaders even gave a hoot about factory ammo, anymore.
For some of us, the real reason to buy a tight match chamber is that factory ammo is more accurate, for one. True. But also when you match your ammo to your chamber by partial sizing/bumping the shoulders, that ammo is more likely to be a tight fit to the chamber at the base when using a regular die. You're gonna HOPE that not all your brass fits... this indicates you have a good tight fit, and you'll sort and track your cases from there. And the bonus is your ammo will still be at least a little smaller than minimum chamber spec or even possibly still be smaller than maximum case spec, in case you need to shoot it out of a different gun.
If that sounds like a lot of work for an autoloader, it is probably why this combination is not that popular
for convenience-oriented reloaders.
-If I was starting out and can buy a die that works in 95% of rifles or one that works in 100% of rifles, I would go with the one that does 100% if they are the same cost.
For stockpiling years worth of plinking fodder where reliability is the most important thing, I completely agree. I said as such. But if you ever want to intentionally buy a semiauto gun with a match chamber, you may conversely want to experiment with a REGULAR die to reload for it, specifically. And you're talking about a measly 30-100 buck die over the course of 20 years of reloading 223. What you're suggesting only makes sense if you are worried you will accidentally come across a gun with a tight chamber, not care if it's particularly accurate, and will want all your previously made ammo to shoot in it... in which case reaming that gun to at least minimum chamber spec will also only cost $50.00.
You can also be 100% sure that even a small base die won't sufficiently size 100% of brass you may accidentally pickup. You can come across some that will be scores of mils too LONG after FLR, let alone too wide at the base. There's no way around it. It's a compromise. The manufacturers aim for the best compromise, and that's all it is, and that's why there are multiple sizes. And if the small base die were the best compromise, they would call the regular die the large base die.
A loose chamber, by your logic (which is correct) will not allow you to fire factory ammunition as accurately.
Yes, but we're not discussing buying a new gun. The OP already has guns, and as far as anyone knows at this point, his guns have average chambers. If his guns DID have loose chambers, that would be even more reason to not use a small base die. His brass and his reloading arm would be getting an extra workout for nothing.
