[nemohunter]

when i bought my upper i just knew i wanted a heavy under the handguards barrel. well i got it and liked it just fine but i have another 20" build under way so i would like it to be lighter. i want to turn the heavy down to a reasonable dimension under the rail. what do you guys have/recommend? what is a recon under the rail? what about an SPR? how far in front of the chamber should i start to turn? i have a couple of 5.56 barrels to judge from but i thought some of you guys with the lighter 6.8 barrels could chime in or point me to a chart somewhere.

thanks, nemo

 

[paulosantos]

The SPR contour is generally .840" under the handguard and .750" for the gas block and .750" forward until it drops down to app .730" near the end for the OPS inc SPR shelf.
The Reckon contour is similar except that it is around .740-.760" under the handguards. For a precision build, the Reckon is the lightest that I would go.

For a combat barrel, .700" is the lightest I would go under the handguards.

 

[nemohunter]

thank you Sir for the info. i'll try the SPR first and see if thats light enough. if not i'll turn it down some more.