Experienced long range marksman... I need clarification

[robcoe]

Is there any true to something I was told while at the range?

Someone said that if you rest the weight of your rifle on the magazine while shooting prone, that your zero will be altered. I was wondering if this is true or if the person that told me that may have been mistaken. For 3 gun we often shoot prone out to long distances and everyone uses their mag as a monopod when shooting prone, so I don't see this being a big deal, but I was wondering if there was any truth to this statement.

I can't see it having an effect on the zero point, most I could see would be the magazine wobbling and throwing you off(they don't have a real tight fit) or it somehow causing a misfeed with the next round. To throw off the zero it would have to change the relationship between the upper receiver, the barrel and the optic, none of which would be changed by the magazine being on the ground.

That of course assumes it's an AR type, other guns might be different.

[CK_32]

The idea of what you were told is partly correct, but majority is not.

As far as your zero being altered that is incorrect.

Where it holds some water is that the mag being rested on the ground, due to it having wobble and play, will be an inconsistent base platform for your rifle to rest on. The movement of the mag while trying to hold true will alter your consistency and POA.

Also it will have some small effect at longer distances due to your barrel harmonics again going back to the uneven pressures and movement your mag will allow during the vibration period of the rifle during each shot.

But that's all minute compared again to the mount of inconsistencies you will see from the bad foundation. The wobble of the mag will be making your POA move around a lot and be difficult to hold steady while the mag try's to support the weight of the rifle, flopping to one side of the mag and the other.


Also mag pressure sometimes leads to feeding malfunctions when pushing the mag up into the rifle, to support the weight of the rifle. But in short, no your zero will not be effected.

Hope this helps.

[Untamed1972]

I think this is like bedding a stock. Yes, I know AR's aren't bedded like bolt guns but different stress on the barrel/action depending on how it is held or braced could make a difference with any gun. Probably not enough to matter but it could. Best thing is to try it and see.

That's what I was thinking. Theoretically yes, pressure on the mag, transferred to the action and even the upper receiver where your optic is attached could have an effect, but such effect in practicality is so minute that most people would never notice it.

[MrSam]

That makes no sense whatsoever. The only reason that using a mag as a monopod would alter your shot, is if the mag isn't steady or balanced enough to keep your gun on target.

[tonyxcom]

That's what I was thinking. Theoretically yes, pressure on the mag, transferred to the action and even the upper receiver where your optic is attached could have an effect, but such effect in practicality is so minute that most people would never notice it.

The upper is all one piece though. Do you really think that resting the gun on the mag will stress the receiver enough to change your POI? The uppers already flop around on the lowers with no effect in accuracy.

This type of wives tale might have some merit on a different platform but it certainly doesn't on an AR.

[russ69]

OK guys listen up. You do not want to rest any part of the rife on a hard surface. Not the barrel, the handguard, or the magazine. If you rest the rifle on a hard surface your shots will not go where they normally go.
The best place to rest a rifle is usually in front of the mag well (not on the mag well) as near to the receiver as you can get. On a free floating forend, any place is good but you should always try to use the same spot. A sandbag or some other softer surface is the best.
For field expedient positions it's best to hold the rifle the same way every time and rest it on your hand (on the handguard) or soft surface as you would normally shoot. The bottom line is that ANY change in hold will affect where your shots go.

[TheChief]

There are a couple of similar posts out there...

http://www.ar15.com/forums/t_3_118/421681_n00b_question__ok_to_rest_rifle_on_magazine_while_shooting_.html

http://www.thehighroad.org/archive/index.php/t-342798.html

I would not have thought of that but when I was in green we were told not to rest on the mag as it could induce feeding issues. From what I am reading, that advice has changed as well.

The only thing I could think of is it may change the pressure points, though on a free floating barrel that shouldn't affect the barrel....However, I don't shoot past 300 yards so wouldn't really know

[jaymz]

That's as crazy as saying you need to re-zero if you remove the stock from a bolt action.

[ja308]

In my marksmanship training USMC, we were taught never to rest the magazine on the floor when shooting in the prone position. The correct form and posture when shooting prone wouldn't allow for the magazine to rest on the floor. Plus I remember the PMI's stressing the point the the old aluminum 30 rounders tend wobble. Thus affecting your ability to correctly sight in due to shooters countering the wobble by muscling in the rifle in the prone.

Semper Fidelis Sir
I recall my USMC training to build a steady platform by attaching a loop sling, keeping my support elbow under the rifle and have my breathing to control elevation after obtaining a natural point of aim,in that the shot gets fired when all the air is released . Yup I fired expert with the M14

I'm kinda thinking the USMC that has taught marksmanship prior to the constitution could learn a few tricks from some expert marksman here on Calgunns . What say you ?

[russ69]

...Yup I fired expert with the M14 ...I'm kinda thinking the USMC that has taught marksmanship prior to the constitution could learn a few tricks from some expert marksman here on Calgunns . What say you ?

I'll assume that is sarcasm. The few hours of training a military solder gets shooting a government issued gun and ammunition, does not make the solder an expert on small arms nor marksmanship. We have the national matches to decide who is the top shooter in the country. That was set-up so military personnel and civilians could compete together and share their experience. In the last few decades it's been rare that a military shooter had a chance to win the national matches. You will find quite a few Calgunners that are top level marksman and you can learn a lot from them.

[eviioiive]

his reasoning is wrong but any change to anything will have an impact to some degree.

[ja308]

I'll assume that is sarcasm. The few hours of training a military solder gets shooting a government issued gun and ammunition, does not make the solder an expert on small arms nor marksmanship. We have the national matches to decide who is the top shooter in the country. That was set-up so military personnel and civilians could compete together and share their experience. In the last few decades it's been rare that a military shooter had a chance to win the national matches. You will find quite a few Calgunners that are top level marksman and you can learn a lot from them.

The top level marksman who are Calgunners are not teaching using the magazine for support in the prone position . I've seen a few shooters use the mag with loop or hasty sling in the standing position but never in prone .


IIRC the USMC rifle training was every day for weeks not hours. Never was using a mag for stability taught . NRA doesn't teach it either .

I suppose a novice shooter could occasionally make a better shot by using the mag for support . But the success would be more luck than any repeatable, proven method for good marksmanship as taught by USMC, Army, NRA, Appleseed or any other institution that prides itself on rifle marksmanship .

Rarely do I see anyone at public ranges practicing the art of rifle shooting . Its likely those who favor using a mag for support always use a concrete bench when available, many even place the rifle in some sort of cradle or vise type device.

I suggest the OP attend a class that teaches basic proven marksmanship techniques and then spend many free hours every day doing dry fire drills .
There is no gimmick that transforms a poor shot into a winning competitor, it's always hard work, proper training and dedication that wins matches .
Of course some are born with more natural ability than others.

[PyroFox79]

I'll assume that is sarcasm. The few hours of training a military solder gets shooting a government issued gun and ammunition, does not make the solder an expert on small arms nor marksmanship. We have the national matches to decide who is the top shooter in the country. That was set-up so military personnel and civilians could compete together and share their experience. In the last few decades it's been rare that a military shooter had a chance to win the national matches. You will find quite a few Calgunners that are top level marksman and you can learn a lot from them.

I definitely remember spending an entire week learning theory and snapping in day and night. Then a whole other week with practical application with live rounds. I know my Primary Marksmanship Instructor shot and won 1000yard matches with service rifles with iron sights. This was just in boot camp. In the fleet. We would spend the week before the range snapping in and doing refresher training. Basically it was more than a few hours. And let's face it national matches are all about the same people for the last few decades. Top level marksmen in the military are usually out applying skills in some far off place and don't have the time not do they feel the need to prove themselves.

[russ69]

...Then a whole other week with practical application with live rounds...

No doubt that the Marines get good fundamental training but it's not the years and years of shooting most competitors have. Military personnel are trained to do their job. It's just the starter training. Top level marksmanship takes a lot more work than what the military has the time to train. If you are curious about measuring your skills against top shooters, try a highpower match. It can be humbling for new shooters but it will give you a accurate measurement of your skill level.
Back to the original point, yes there are some good shooters here and people should hear what they have to say.

[PyroFox79]

No doubt that the Marines get good fundamental training but it's not the years and years of shooting most competitors have. Military personnel are trained to do their job. It's just the starter training. Top level marksmanship takes a lot more work than what the military has the time to train. If you are curious about measuring your skills against top shooters, try a highpower match. It can be humbling for new shooters but it will give you a accurate measurement of your skill level.
Back to the original point, yes there are some good shooters here and people should hear what they have to say.

the point was that it was more than your so called "few hours"