16 vs 18 for 3gun

[nisils14]

I'm nitpicking between a mid contour 16" vs midcon 18" for a 3 gun upper. Both will be stainless with 1-8 twist. I will be shooting 55gr fmjs and eventually 69/77gr smk when I can warrant the use. Obviously a 18 is faster in velocity, softer shooting with a rifle length system. However would a 16" have an advantage in handling and small weight saving? Does someone have some first hand experience with this?

[asmo]

Bet you a dollar if I blindfolded you, that you wouldn't be able to tell the difference between the two.

[TheBelly]

Bet you a dollar if I blindfolded you, that you wouldn't be able to tell the difference between the two.

I can shoot my 16" gun into golf balls from a pretty long ways away.

[Hoser]

Get whichever one floats your boat.

Heck, get a 17 and be cutting edge.

[J]

I would be fine shooting either, but if you are building one specifically for three gun, I would just go with the 18" rifle length gas. The softer recoil is nice.

[MarkCO]

I shot a 5" group for 5 rounds at 400 yards with a CL 5.56 Chamber 16" mid gas 5.5 pound AR on Tuesday. My 18" 3Gun match rifle is about 3" with the same ammo. Built right and tuned correctly, nothing wrong with a 16" gun. But same ammo, I split the 18 faster and I transition faster with it as well. Enough that at the end of a 30 round rifle stage, it might amount to 0.42 seconds.

[moose76]

I have shot 3-Gun for 6-7 years now, most of it with a 18" barrel and a 2.5" comp hanging off the end. Not once have I said to myself, "Self, this stupid rifle is too long." More important then length is balance. (That's NOT what she said......[ROFL1]) Good balance translates to better handling more then shorter length.

I started with a 16", mid-length rifle. Then I switched to a 18", rifle length gas. My third newly completed rifle is another 18" barrel. Its a Nordic Components that I bought from Mark. Mark had the barrels made with a smaller gas port, which further cuts the recoil impulse without the need for an adjustable gas block.

The very few times a longer rifle will be a hinderance will be dwarfed by the constant benefit you will get from the smoother recoil of the rifle length gas system.

But my all means, if you plan to shoot Limited/Irons, get the 16". [Wink]

[cofi]

Why not do both 16" with rifle gas

[MarkCO]

Why not do both 16" with rifle gas

Not enough dwell time, so you need more gas and that defeats the benefits. 17" will work okay, but 18" is the sweet spot.

[moose76]

Not enough dwell time, so you need more gas and that defeats the benefits. 17" will work okay, but 18" is the sweet spot.

As Mark said, there isn't enough time after the bullet passes the gas port, but before it leaves the barrel to get enough gas into the system to work the action (dwell time).

Here is a link that does a pretty good job of explaining what happens, the good charts are at the bottom of the page: http://www.ar15barrels.com/prod/operation.shtml

[cofi]

Not enough dwell time, so you need more gas and that defeats the benefits. 17" will work okay, but 18" is the sweet spot.


As Mark said, there isn't enough time after the bullet passes the gas port, but before it leaves the barrel to get enough gas into the system to work the action (dwell time).

Here is a link that does a pretty good job of explaining what happens, the good charts are at the bottom of the page: http://www.ar15barrels.com/prod/operation.shtml
The couple I have built have thousands of rounds of cheap Russian steel case through them I'd have to disagree....... softest shooting rifles I have ever shot like shooting a .22

[MarkCO]

The couple I have built have thousands of rounds of cheap Russian steel case through them I'd have to disagree....... softest shooting rifles I have ever shot like shooting a .22

Lets not get silly basing this on crappy Russian ammo that uses fast powder. Sure a Dissapator set up is soft shooting, but not like a .22LR by any stretch. Shooting 69s and 77s are almost impossible to get tuned correct in them. Erroneous/niche feedback does not help the OP at all.

[cofi]

Have shot all kinds of ammo through them from 55gr Russian crap to very nice(and expensive) mk 262......feels like a .22 to me

16" dissy is where it's at :)