Straight or bent OAL gauge for AR15?

[zanemoseley]

I've never used a OAL gauge but need to get one to improve my reloading. I'm particularly wanting to test a new 6mm Fat Rat AR I'm building. Do you guys use a straight or bent OAL gauge for your AR? Seems like you might be able to take the upper off and use the straight gauge but I've seen someone using the bent one before.

 

[alb]

I'd guess that you'll actually hit the magazine length limit before you hit the lands. The gauge that comes with the RCBS Precision Mic works, so long as you're patient and try it a few times.

 

[Economist]

I have the bent one so that's what I use. It's a lot less work to just go through the ejection port.

 

[zanemoseley]

On this 6mm Fat Rat I'll have both a single feed load and a mag length load. Basically it will act like a bolt action part of the time and a semi auto the other time.

 

[Unclenick]

I would decide based on what other guns you own. The purpose of the bent version is to work in guns you cannot access from the rear, such as a Garand or M14 or BAR or other semi-auto in which the back end of the receiver is a dead end. With the AR, you can just take out the carrier and bolt and go straight in. If you own only other bolt rifles or rifles like lever actions from which the bolt may be removed, you don't need the bend. I own both, but find the bend a little less easy to get a delicate feel with, and I feel like the set screw fixes the straight one's ram position slightly more exactly. But that's really just personal preference in the end, as most bullets are not so precisely identical that plus or minus a thousandth or two makes any useful difference to your finished loads.