M4 Barrel Mount Sling Swivel and harmonics/accuracy

[CPT1911]

I was having some accuracy issues with my KAC standard rail system on my 6920so I replaced it with the free float DD Omega 7.0 which seems like a great product. This gun is obviously not for shooting prairie dogs at 300 meters, but since I have spent the money to free float the barrel, I am wondering if I ought to loose the standard M4 USGI sling swivel under the FSB. I would be happy to use a rail mounted swivel, but I'm sort of running out of real estate on the rail since I mount a surefire on the sling swivel side AND use the forearm to shoot--not a foregrip.

Anyway, I know sling PRESSURE will likely effect accuracy, but will having that thing just freewheeling on the barrel have any noticeable effect? Again, I know its a combat gun, but since I bought the rail...anyone noticed an accuracy improvement after getting rid of the standard sling swivel? Thanks.

[mattj]

Speaking from more bolt-gun experience here -- it likely does effect the barrel harmonics to some degree, but you can't really predict whether it will be a positive or negative effect for a particular ammunition. If you use handloads carefully 'tuned' to your gun with the gun how it is, or the ammunition that you do use happens to shoot like it's 'tuned', removing it could effectively "de-tune" the barrel to the ammunition, thus having a negative effect on your accuracy...

Though it's also possible that removing it could have a positive effect (new harmonic just happens to tune better to the ammo).


My guess would be that unless you are using 'match' grade ammo or carefully crafted hand-loads (and possibly not even then), that you won't be able to tell the difference one way or the other, so just do whatever is more convenient real-estate wise. You can always experiment.


For me, personally, having the option of sling-supported shooting without effecting POI would be reason enough to attach the sling swivel to the rail.

[Jay Cunningham]

I was having some accuracy issues with my KAC standard rail system on my 6920so I replaced it with the free float DD Omega 7.0 which seems like a great product. This gun is obviously not for shooting prairie dogs at 300 meters, but since I have spent the money to free float the barrel, I am wondering if I ought to loose the standard M4 USGI sling swivel under the FSB. I would be happy to use a rail mounted swivel, but I'm sort of running out of real estate on the rail since I mount a surefire on the sling swivel side AND use the forearm to shoot--not a foregrip.

Anyway, I know sling PRESSURE will likely effect accuracy, but will having that thing just freewheeling on the barrel have any noticeable effect? Again, I know its a combat gun, but since I bought the rail...anyone noticed an accuracy improvement after getting rid of the standard sling swivel? Thanks.

First off - do you realize that the Omega includes QD sling attachment points built into the rear of the rail?

[CPT1911]

First off - do you realize that the Omega includes QD sling attachment points built into the rear of the rail?

Yes, I just prefer having the front of the sling attached further forward. I use a vtac sling and if I need to cinch it tight against my body to get the weapon out of the way, having the sling mounted further forward works better than the location of the QD hole.

[mark5pt56]

I would attach that sling however you want and don't be concerned with what it does.

Unless you conducted experiments with tightly controlled conditions, you will never know and only speculate on the topic.

Unless you are doing some odd things, I seriously doubt that the weight of the mount and sling is doing anything you could measure with the shooting you would be doing with the carbine.

If you are concerned, either attach it via a mount on the HG or a Blue Force Gear wire loop.