SKU: 539000218
UPC: 011516703385
MPN: 7990338
This Lyman Rifle Case Length/Headspace Gauge is built for handloaders working the 350 Legend straight-wall cartridge. It gives you a fast, repeatable way to confirm 350 legend case dimensions without breaking out the calipers for every piece of brass. Drop a sized case into the gauge and the stepped ends tell you whether the case falls within minimum and maximum trim length, and whether headspace sits in spec. For anyone running 350 Legend through an AR or a bolt gun for deer season, it's a simple go/no-go check that keeps your brass within SAAMI tolerances and your chambering consistent.
The gauge works on the principle of a precision-machined block with cut steps that correspond to minimum and maximum case length for the 350 Legend. Slide a resized, deprimed case in base-first and compare the case mouth against the high and low steps milled into the gauge body. A case that sits below the low step is too short; one that protrudes past the high step needs trimming. The same fixture also checks headspace by referencing the case head against the gauge face, flagging cases sized too far or not enough. Pair it with a 350 Legend modified case and a 350 Legend expander die for a complete case-prep workflow on this cartridge.
Reach for this gauge during your sizing and trimming step, before you flare and seat bullets. Verifying length and headspace on processed brass cuts down on failures to chamber and uneven crimps, which matters most when you're loading 350 Legend in volume for practice or hunting. It's a low-cost insurance policy that lives in the same drawer as your trimmer and shellholders. When you're setting up your bench for this round, look at our 350 Legend factory crimp die and our broader selection of measuring tools and calipers to round out your case-prep station.
It checks two things: case length and headspace. The stepped ends of the gauge show whether a sized case falls between minimum and maximum trim length, while the gauge face references the case head to confirm headspace is within SAAMI spec for the 350 Legend cartridge.
Use it after sizing and trimming, before flaring the case mouth and seating bullets. Checking length and headspace on processed brass at that stage catches problems early, so you avoid failures to chamber and inconsistent crimps once the rounds are finished.
Drop a resized, deprimed case into the gauge base-first and compare the case mouth to the high and low steps. If the mouth sits below the low step the case is too short; if it protrudes past the high step, it needs trimming to bring it back into spec.
Yes. The 350 Legend is a straight-wall cartridge popular in both AR-15 and bolt-action rifles, and this gauge references the same case length and headspace standards regardless of platform. Consistent case dimensions help reliable feeding and chambering in semi-auto rifles.
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