Determining Chamber Length--AR 15

[gilream]

Is it possible to use the Sinclair Chamber Length Gauge in an AR-15? Or should I just trim them all to 1.750" and move on? Sinclair's instructions state that the tool is for use in bolt guns only but I thought that you guys might have some thoughts.
Mike

 

[mac86951]

Trim to 1.750" and move on.

Semi-Auto you'll want any extra space for reliable feeding and extracting.

If you want to determine distance to the lands for single-loading and bullet jump
there are better tools to do so.

Just my opinion.
-Mac

 

[gilream]

I have the Stoney Point (Hornady L&L) tool with the modified case and am comfortable determining the distance to lands in the event that I should ever want to single load the heavier bullets in my 1:7 twist chambers. No problem .

I am asking about chamber length and how to determine it in a NATO chamber. Would you have to cast the chamber if the Sinclair gauge is not the answer? I plan to crimp my handloads to be magazine fed so I suppose the exact chamber length does not really matter. Still... inquiring minds want to know.

 

[jsn]

You can give it a try, but I think you would have to remove the extractor so that it isn't exerting pressure on the piece of brass, creating space between the bolt face and the brass. Make sure to use some case lube on the plug, that the plug is tight in the brass (your caliper will move it if it's loose), and that you've drilled out the primer pocket so that you can drive it out. Take several careful measurements to prove results/consistancy.

 

[bigedp51]

I'm loading for three different AR15 rifles, I trim to 1.750 and don't worry about it. If your shooting a single National Match AR in competition then maybe a competitor could say something if there is an advantage of having a longer than specified length case neck.

I just bought the WFT for trimming my cases in all three rifles and I don't worry about it.

 

[gilream]

Thank you all. I'll trim to 1.750 and not worry about it.