What would be the ideal way to lose some weight on a 20" AR10T upper? Re-contour the entire barrel down to .740 (gas block at .750)? Or re-contour just the gas block and forward, and flute the factory diameter barrel under the handguard? Flute the whole thing, and keep the .875 gas block?
- Thread starter sanman28
- Start date
Hit the gym...skip the other nonsense and leave your barrel well enough alone! 
Look...the AR-10T upper isn't a heavy pig by a long shot, but the 20" SS T barrels can be a bit unwieldy depending on how you are running the rifle as they come in at ~3.5lbs. Once you start re-contouring, fluting, shortening, etc. any barrel, you run at least the potential risk of taking a sub-MOA capable tube and turning it into a tomato stake. The Armalite tubes can usually be worked on in my experience without causing any such issues, but the risk is nevertheless there and you have to weigh the pros/cons to determine if its worth it to you or not for what you'll pay a quality smith to do the work combined with what you'll have when you are done versus just snagging a new barrel for the upper and offsetting the cost by selling you current barrel. Fluting will buy you the least in total weight savings unless you just get crazy with both the depth and number of total flutes. If you do both behind and in front of the journal...you may save up to 3/4lb (guesstimate). A complete reprofile to more of a medium/hybrid weight barrel (0.750" behind the journal, 0.750" out to the muzzle/threads...leaving the 0.875" journal intact), could save you well over a full lb of weight (again...best guess...YMMV).
If you want lighter, then it is easier/safer to just get a new barrel that is shorter overall or a lighter contour or fluted or all of the above, depending on your end goals/needs for the rifle.
Look...the AR-10T upper isn't a heavy pig by a long shot, but the 20" SS T barrels can be a bit unwieldy depending on how you are running the rifle as they come in at ~3.5lbs. Once you start re-contouring, fluting, shortening, etc. any barrel, you run at least the potential risk of taking a sub-MOA capable tube and turning it into a tomato stake. The Armalite tubes can usually be worked on in my experience without causing any such issues, but the risk is nevertheless there and you have to weigh the pros/cons to determine if its worth it to you or not for what you'll pay a quality smith to do the work combined with what you'll have when you are done versus just snagging a new barrel for the upper and offsetting the cost by selling you current barrel. Fluting will buy you the least in total weight savings unless you just get crazy with both the depth and number of total flutes. If you do both behind and in front of the journal...you may save up to 3/4lb (guesstimate). A complete reprofile to more of a medium/hybrid weight barrel (0.750" behind the journal, 0.750" out to the muzzle/threads...leaving the 0.875" journal intact), could save you well over a full lb of weight (again...best guess...YMMV).
If you want lighter, then it is easier/safer to just get a new barrel that is shorter overall or a lighter contour or fluted or all of the above, depending on your end goals/needs for the rifle.
I don't know how much weight fluting will remove. I have a dpms LR308L that comes from the factory with a HB turned down to 750 at the gas block for weight savings and a carbon fiber handgard. A friend of mine has the same length barrel only full heavy, with a standard DPMS quad rail, and holding the 2 guns I cant tell a difference even though mine is the "lite" version. Maybe half a pound between rifles?? We'd need to put them on a scale to be precise but when the guns are 13lbs with a mag, .5lb isn't much. Especially when you look at the expense and trouble you'll go through to get it. Drop down to a 18" quality barrel with a lighter contour. A whole new Barrel would be cheaper and an upgrade as opposed to putting your factory barrel on a lath.
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