Cartridge checkers

[plant_one]

generally speaking - cartridge checkers are a good yes/no gauge and not much else.

in fact there's usually nothing you can learn from them that you probably cant find out with a pair of calipers

but they're damn sure quicker than taking a bunch of measurements and having a chart handy to compare to, which is why i have them for like... 7 calibers now

[Bmt85]

I recently bought one made by Lyman. This really cuts down on the number of cases that I have to resize. If my empty cases don't fit in the checker I then use a modified shell holder (Thanks Hoot) to take out minute bulge left in cases closer to the head that were fired in AR or Bolt Action platforms. I have used the checker on my reloaded rounds but the bullets are set too far out so rounds don't fit into it. It is a handy tool to have on your bench, especially if you have both a single shot CVA Scout and a Ruger bolt action like I do.

So, the Lyman gauge just showed up. (My reloading room is about to become a guest room for 2 weeks, so one quick playtime then closed for business until after Tax Day... Good thing I love my daughter and her wedding is not a burden, and good thing I love my mother-in-law). Anyway, all the .223/5.56 cases I had resized drop right into it just by gravity. No pushing necessary. the. Base is inside the top step at the back and slightly above the bottom step (I think that’s what Lyman wants- between the steps). I trimmed them and they’re all at, or slightly inside, the other end of the gauge.

This is all according to Hoyle, right? If the case drops in the gauge and is right at, both ends, I can load them and they should cycle through our AR’s just fine (clearly some range time is required before making that hypotheses a fact). After I get some bullets stuffed, I’ll do it again. You’re saying that they might not chamber in the gauge, but will still work in the rifle?

As hoot explained, chambers can be very different, even from the same manufacturer. Which helps explain what I was saying before, as to why I don’t use them anymore for bottleneck cartridges. If you set your sizing dies to what the instructions say, you should get cases sized to within saami, usually on the small side. Which should fit in a case gauge. However, if you use a headspace comparator and check a few once fired cases, to the cases that fit in a case gauge, you will probably find that sized cases are a lot shorter (over .005) than want the chamber is cut to. For plinking ammo and cases you don’t care about, it’s usually ok. Problem is, in extreme circumstances, you can have an oversized chamber and undersized brass, and an issue where the extractor doesn’t pop over the rim, leading to a no fire. In normal circumstances, they should work and go bang, but you will end up overworking the brass, and brass life takes a big hit. This is why I don’t use them anymore on bottlenecks.

For the 450b it probably won’t be an issue, but at the same time, not really needed. Maybe to check factory ammo.