I know this has been asked before,I just couldn't find the answer,so I will ask it again.I was wondering what the optimum barrel length is for the 223/5.56?Does it depend on the load used?

The reason I ask is I was thinking of getting a varmit/target rig up and was wondering what barrel length to get.Is there a point of diminishing returns?

Thanks,Frank

Depends on the use. The point of diminishing returns from what I've read seems to be around 20 inches. After that, you end up with minimal gains. Alot of varminters use 24" barrels though. Personally, i couldnt decide so I split the difference. 22". Touch more oomph and fireworks then the 20 incher, little less weight and bit more handy then the 24 incher.

Personally, I think the 20" will do everything you'll ever want to do with your AR.

18" might be the optimum all around length in terms of size, muzzle velocity and general utility.  No one offers an off the shelf 18" barrel though. so go 16 if your emphasis is on portability, or 20 if muzzle velocity is your primary concern.

I look at this kinda stuff like golf clubs..

Each shot can be made by any club in the bag...but a better shot may be taken with the appropriate club

Of course if you are a lousy golfer (no native ability) or (have't practiced much) or both in the first place it probably won't matter too much..:)

imo

For a varmint rig I suppose you want all the velocity you can get for the flat trajectory. Mine is a 24" Krieger. Yes there is optimum barrel lengths but then that is load dependant and you start splitting hairs. I reload and use Sierra's info for their  bullets.  They say that their testing was done in a 20" AR.  I get 200-275 more fps than their listing with my 24" barrel. My rig is built primarily for varmints and some F class competition.  If I was building another AR for T/R class and it was going to stay a 223 then it would have a 26" barrel because it needs EVERY bit of steam to stay supersonic at 1000 yards.

Then you have to consider the practicallity of the build. My gun with a 24" barrel and A2 buttstock is LONG! It is hard to maneuver around in a truck or even carry. When I load up to go shoot crows, transportation is a pill.  If you are going to shoot varmints in the 300 and under, a 20 would be fine and easier to transport.  If you want to really reach out there with max handloads then you want the length.

20in

overall, i prefer the 18in but a 16in wouold suite me too