When you’re handloading ammunition, there has never really been a good way to check that all of the dimensions are correct. Sure you can grab your calipers and check every dimension of every finished round, but that’s time consuming and inefficient. Especially when you’re slicing up existing 5.56 brass into 300 BLK brass, you want to be doubly sure that your handloads will fit perfectly in the chamber without any issues. That’s where something like this slot gauge comes in handy, from Sheridan Engineering . . .
The concept is simple: the gauge mimics a 300 BLK chamber and lets you double check that all of the dimensions are correct. The barrel end of the gauge is calibrated to ensure the proper COL of a loaded bullet. The breech end has markings that let you check that the shoulder is in the right position. And the open design allows you to visually inspect whether your hand-rolled round has any imperfections that might cause an issue.
I know what you’re thinking. “Hey Foghorn, it’s just a die! How long could the review possibly be?!” And while I may have just covered the basics of the die’s functionality, I wanted to take a second and talk about the quality of this thing, too.
Sheridan Engineering might not be a big name in the die making industry, but they put a ton of time and effort into this thing. Everything about it is well thought out, from the way the headspace gauge is designed right into the base to the serrations on the side that let you grip it even when your hands are covered in lube. It’s a well-polished piece of equipment and for those who load their own 300 BLK ammo I highly recommend spending the money to pick one up. It’ll save you having to bust out the calipers each time, and make your workflow much simpler.
Sheridan Engineering Slot Gauge
Overall Rating: * * * * *
I really wish that I had one of these for each caliber I load. Having a visual reference to make sure that my rounds are in-spec is worth the $60 to me.