Jwise and other smart on the AR guys...

[M-11]

Vertical grip question:

I do not run a Vertical grip on my M-4, I just grab the Mag well (Button for my light is on the right side of the mag well)

I was talking to one of my Combat arms trainers and he mentioned that you should only put a vertical grip on a rifle with a Floating front end. He states a study demonstrated that a shooter under stress can clench up and actually flex the rifle when firing under stress, slowly loosening the barrel and throwing the rifle out of whack.

Is this truly a factor?

Ever heard of such?

M-11

[jwise]

That's correct. If you attach a VFG to the barrel, and gripped it very tightly while shooting, it would throw off your point of impact.

Don't worry about it actually messing up the barrel, but it will affect the harmonics of the barrel.

This is just one more benefit of having a free-floated forend.

[Nightshift va]

I have a forward grip on my personal M4 Bushmaster but not my duty M&P. And like most, i revert back to my training when I shoot my rifles and i have to actually "think" about even using the thing because my natural grip is my off hand wedged pressing on the crook between the top of the mag well and the O" ring heat shield wrapping my free fingers around the O ring in a circle. I have short arms and it works for me. The first time I shot the Black Rifle was near 2nd Battalion at the rifle range on Paris Island in 1987 and not much has changed except im older and fatter and have a harder time "snapping" into the various positions.
The big advantage for me with the forend grip is probably bringing it up faster for close up shots. But anything at a distance I go back to what I know.

[beavo451]

Highly doubtful that you will loosen your barrel with a VFG. If this happens, the barrel nut was probably installed improperly.

[Blackdog F4i]

If we are talking about precision 500 yard shots, then it's a concern.

If we are talking about 500 yard body hits IT IS NOT.

I run a VFG on the standard M4 handguards. I had no problem running the Army qualification course to 300M with my Aimpoint. I used a VFG hold and the magazine as a mono-pod. Many so-called experts will tell you not to do this because it will cause the weapon to jam. It may if you have not tested your weapon AND ALL MAGAZINES for it.

The person giving you this advice has probably never witnessed how tight a match sling on a M16A2 is when shooting a 500 yard qualification. I used to sling up my rifle tight enough that I would loose blood flow in my arm. The mechanics of the position puts way more stress on the gas block than a vertical grip could ever hope to.

Now as to unscrewing the barrel: On a properly assembled AR/M4/M16 etc, this is impossible. The gas tube prevents the barrel nut from turning. Besides the pressure you are placing on the VFG should be to the rear, NOT to the side. If you are torquing to the side, you are going to whip some shots where you don't want them to go.

Lastly, a magazine hold should be a last resort. It is less efficient for driving the gun than a VFG and in the case of a detonation it's going to injure your support hand. I do run a mag hold for the first shot after an emergency reload if a followup is required. If an immediate shot it not required then I return to a VFG hold. The grip you can use with a VFG is a bit different than what you can get with a magwell. On my VFG I run a "thumbs forward" grip almost duplicating the grip I would use with my support hand on my pistol.

[jwise]

Blackdog- regarding the sling position, was your point of impact the same, whether you shot off a bag or "slung up?" My understanding was that using that sling position was fine, but you had a different point of impact.

What was your experience?

[Blackdog F4i]

I am sure there would be a small POI change, however we ALWAYS shot slung up. I never shot the rifle on the qual course over a bag on the same day. However I don't recall ever having to re-zero from qual to field shooting (not slung).

Remember that the M16A2 is not a precision rifle. Nor are most of the M4's we are talking about. I am confident that unless you are shooting a pencil barrel AR, the deflection caused by a sling or VFG are a non-issue for LE Engagements.

[Mstangfk]

i have a Mil-issue Knights Rail System and use the supplied grip, it takes some rounds to find the optimal placement, but not more than a mag..


as the others have said if its a good rail system, not only will it not loosen a barrel it should make NO differance on POI under 500 yds IMO

using the MAG WELL as a foregrip is ok, but i have personally experienced fail to feed when resting GI mags on the ground as a monopod, or when pulling back slightly on the magazine itself.


S&W M&P-15-ORC

Eotech 511

KRS rail system

YHM front and rear BUIS

Spec Ops Mamba sling

[Maverick1701]

Vertical grip question:

I do not run a Vertical grip on my M-4, I just grab the Mag well (Button for my light is on the right side of the mag well)

I was talking to one of my Combat arms trainers and he mentioned that you should only put a vertical grip on a rifle with a Floating front end. He states a study demonstrated that a shooter under stress can clench up and actually flex the rifle when firing under stress, slowly loosening the barrel and throwing the rifle out of whack.

Is this truly a factor?

Ever heard of such?

M-11

I have heard from some of my marine buddies that a few of our boys over in Iraq would torque down on those vert grips (twisting it under stress like you described) and would crimp off/mess up their gas tubes

[Blackdog F4i]

I have never heard of that happening. Not saying it can't, but I have just never heard of it.

Now you have piqued my curiosity on how much force that would take.

[M-11]

Cool, who's gun are we breaking?

M-11

[Blackdog F4i]

If I had a spare M4 I would crank it in a minute.

Unfortunately my only VFG equipped AR is my duty rifle.

[Sleuth]

Don't confuse your fighting rifle with a target rifle.

[11b101abn]

Rate of fire need to be high enough to heat the bbl to flex it like that.

[Surf]

Is this truly a factor?
Yes and no. In theory yes. Can it be made to happen. Yes, but not under any kind of normal operating conditions, even under severe battle conditions where the user is pulling or gripping the weapon to the point where the POA / POI is affected under conditions that the carbine is meant for.

Again you can make it happen. Place a standard non-float rifle on a sand bag rest at the fore grip area and shoot it. Then using the same rest and position of the rifle, place your non-shooting hand on the top of the upper receiver (flat top, or carry handle) and press down heavily with the barrel and foregrip still on the rest. Fire the weapon and see the results. You can make anything happen.

Ever heard of such?

Sure, I have heard it often. This is one of those "Moby Dick / White Whale" stories that is often flung around at carbine type classes. You know, the old, this study says, or a "Marine buddy of mine said" type of thing. I heard of this "giant white whale but have never actually seen it. As a matter of fact I ran a rifle with a stock M4 handguard and VFG for a few years of heavy use, as well as several other guys on our teams. Never ever had this issue rear its ugly head.

M-11

He states a study demonstrated that a shooter under stress can clench up and actually flex the rifle when firing under stress, slowly loosening the barrel and throwing the rifle out of whack.
M-11

As for loosening the barrel nut? 99.9% not likely, on a properly torqued barrel nut is not going to do this. Properly torqued (torque to spec, loosen, torque to spec, loosen, torque to 30ftlbs and then proceed to tighten to the next gas tube notch) of upwards of 80ftlbs is not going to come loose from gripping and re-gripping a VFG, even under any copious amounts of stress induced gripping.

I have heard from some of my marine buddies that a few of our boys over in Iraq would torque down on those vert grips (twisting it under stress like you described) and would crimp off/mess up their gas tubes

Again can a barrel nut turn and crimp a gas tube? Yes, however see above about properly torqued barrel nuts. This even goes for those brands of AR/M4's that are not higher quality. I will refrain from naming brands in order to not hurt any feelings.


I have even seen a couple (one in particular) infamous pictures of such effects. One of the problems being is that this weapon platform is seeing huge amounts of use, and many soldiers are placing different fore ends on their rifles. There is no guarantee that whomever is doing the work is actually certified much less really knows exactly what they are doing. Also I have seen from a few manufacturers, where this phenomenon happens, however this is definitely blamed on a lack of QC and the barrel nut not actually being torqued to spec properly. This was the case with one of our 75 Colt M4A1's. So given the sheer numbers under heavy use, problems can arise. However this can almost always (never seen otherwise) be attributed to improper work.