O.K. A little background first. The company I work for issues Bushmaster M-4gerys. These rifles are fitted with Trijicon Reflex II sights on a goosneck mount and a Blackhawk 3 point sling. Recently, the powers that be have decided to mount Surefire M500 lights on each rifle. We have been looking at new slings as the current ones won't fit with the Surefires in place.

A suggestion was made to go to the QD GG&G sling things which mount on the front sight tower. This would have the added benefit of making the slings ambidextrous. When the next guy comes on shift, he could just pop the sling off, flip the rifle over, and pop the sling back in.

One of the LT's contacted the NRA and was told that if we mount our slings on the front site assembly we can expect a bend in the barrels. They have had up to a 10 degree bend!

Now, I don't see how a 3 point sling could put enough pressure on an M-4 profile barrel to cause a 10 degree bend. I realize that a shooter with a 1903 sling can put enough pressure on a barrel to cause a change in the POI, but to bend it?

What do you guys think?

...How would the NRA know?

I greatly doubt a permanent deflection of 10 degrees is possible with human-generated forces. A temp deflection seems like a stretch, even. Maybe a bullet path effect.

I trust the NRA for lobbying, and even then, I'm a little suspect.

sounds like he's full of schit.

If you put a LOT of sling tension on you CAN experience a POI shift.

However, I can only imagine maybe a few MOA at the very most.  That might be acceptable for a 'service' rifle, but for a match or maybe a Designated Marksman (i.e. precision shooting), that's a LOT.

Competition service rifles usually have an internal float tube, so shooters can use full sling tension without experiencing POA shifts.

EDITED TO ADD:

I find 10 MOA hard to believe, but then again, I've seen some pretty amazing things.

Someone better notify the IDF, pronto!!!

Quoted: I honestly don't know the answer but that sounds unlikely. I would not pick the NRA as a resource for this type of information, but I really don't have any ability to back that up with concrete facts

Don't take my word for it.  If you ever go to a big match, count how many floated and non-floated service class AR rifles you see.  You'll probably see a ratio of 4:1 if not higher.

Then ask the high-master class shooters from the USAMU to give up their float tubes and listen to what they say.

EDITED TO ADD:
Keep in mind it takes a lot of sling tension to cause a POI shift, but 15+ pounds is routine for match shooters.  I probably use at least that.

DOH!

I just reread the note.  Are you sure the guy advising your LT said 10 degrees?  I thought you ment 10 MOA!

Furthermore, I would also like to add that for this application any possible shifts would be insignificant.

Quoted: DOH! I just reread the note.  Are you sure the guy advising your LT said 10 degrees?  I thought you wrote 10 MOA!

Yes. 10 degrees.

Quoted: Quoted: DOH! I just reread the note.  Are you sure the guy advising your LT said 10 degrees?  I thought you wrote 10 MOA! Yes. 10 degrees.

OK, I get it now.  I'm in line with the others then.  Barring some catastrophic part failure there's no way you're going to see a 10 degree shift.

I think an AR, or any gun for that matter, would KABOOM if its barrel was warped by 10 degrees.

Tidbit: For the math challenged, 10 degrees is 600 MOA.

PS. You can trust me. I have a trigonometry joke under my name.

zombievt,

Does your organization run around waiting for the day they can yell safehaven?  Just curious as to who it is, not a big deal.

I work for a private security company at a power plant.


WTH is safehaven?

Disregard then, I figured you would know the term.

If You don't know the term, you don't need to know the term. And yes Stickman I do know the term.
Ex 81170/81172.

Quoted: I greatly doubt a permanent deflection of 10 degrees is possible with human-generated forces.

+1

I agree with you completely.

I have been able to cause a POI shift with a M16A1 20" barrel while using a sling, and have caused a smaller POI shift with a M16A2 barrel and sling. No way have I have ever caused a 10 degree deflection, though. I have tried the same with my CMMG M4 barrel, and did not notice any POI shift at 100 or 200 meters. Of course I am significantly older and weaker now so that might not be a valid comparison I don't think I have ever seen a photo of an IDF trooper using their sling to steady the weapon while firing. I just figured the ranges were close, and they used the sling to carry the weapon, period. Are they trained to use a hasty sling?

XM17SBullpup,

I'm with Zombievt, WTF is the meaning of safehaven in that context?  Sounds like a mall ninja term.

XM17SBullpup and myself were just thinking of older days when we used to do something different.

Back to the original question, it wouldn't cause a problem.

Quoted: Sounds like a mall ninja term.

I was thinking airsoft myself, but with a little investigtion I figured out what the hell they're talking about.

I figured you would, probably just a little different angle.

The only time there is any tension on the barrel is if the sling is mounted to the FSB and than it would only be while the rifle is slung. If you got it up in a shooting position the sling won't have any tension on it. And they really ain't ment to be used to stady the rifle during shooting either.

My call is total BS.

Ok first things first

1) There is not much defelction difference mounting the sling to the front sight vs mounting it to the sling swivel.  If you'll not the sling swivel is PART of the front sight assembly.

2) The NRA knows jack shit about tactical deployment of slings - they only know high-power which is another ball game altogether.

3) 3 point slings are not used to steady the rifle - they are mearly a means to hold the rifle in place when your hands are busy doing something else.  When you go to shoot there should be no tension on the 'tactical sling' so it won't interfer with the shot.

This is true if you are using a 3 point, 1 point, or IDF/CAR type sling setup (were its just a long strap attached to the front sight tower & top of stock.

If you are properly using a GI Carry Strap (the so-called 'Silent Sling) it will NOT be tensioned and will not effect accuracy.  NEVER use the so-called 'Hasty Sling' as it CAN deflect the barrel and provides no to 'nearly no' help in accuracy.  You should never be 'slinging up' for any 'tactical' type of shot.  Tactical slings are only to hold the rifle when your hands are busy (consider them a holster for the rifle).

The only time you'd have to worry about barrel deflection is if you are using a proper competiton sling - which provides a 3rd point of stabilityfor the rifle (upper arm).   This is not type of sling you use for 'tactical' use.