New Army (rifle) marksmanship manual
 

https://rdl.train.army.mil/catalog-w.../TCx3-22.9.pdf

Very robust and light years beyond the previous manual.
It only takes several decades to adopt tried-n-true techniques from competitive disciplines.
If you've shot PRS, 2 gun, 3 gun, high power, long range, tactical,USASOC matches, etc. nothing new there, but I am glad to see big army catching on. Let's see how the pistol manual looks like and if it's up to TS standard! ;)


Still, no mag on the ground :rolleyes:

Check page 6-24, the NOTE on the bottom of the page says you can place the magazine on the ground when prone unsupported.

Very, very bad idea.

A barrel is like a tuning fork and makes the same vibrations every time it's fired. And like a tuning fork if it struck while touching something else it does not have the same tune (vibration).

Besides that if you're placing pressure on the mag while firing you're asking for a jammed weapon.

But what do I know..... ;)

thank you for the correction :o

Barrel harmonics are not affected by placing the magazine on the ground. I know it's an old rule of thumb about mags on the ground but the facts are that placing the magazine on the ground doesn't induce malfunctions...but that still doesn't keep some people from repeating that old wives tale. ;) This I know. :)

Barrel harmonics aside (don't know enough to comment), I recently had the displeasure of watching young Marines trying to zero with iron sights at 25y. Shooting unsupported prone, none of them could shoot a group tight enough to even begin to know what adjustments to make.

Had they placed the mag on the ground, their groups would have tightened up enough to at least enough to make adjustments with some degree of accuracy.

(Better support from the mag on the ground would have greatly outweighed any issues with barrel harmonics.)

Maybe,, maybe not.. Some of that old wives tail has has do with lazy GI's not seating their mag completely and/or using poor aiming & mounting..

When my platoon was on the firebase (not to often :( ), We would have mad minutes. We would fire into the wood line using as many mags a possible.. Afterwards, I can remember partial mags laying around because they were "misfits" and "bent"..

Not really, the kids would half/a$$ insert the mag,, get a jam,, and move on to the next one.. They also would be shooting from inside bunkers,, using the window sills (usually a stack of rock hard sand bags) as a steady point,, being to lazy to use a proper shoulder mount.. They were counseled,, but kids??

AND this was with the old 20rd mags..

Had one kid, who would insist on using an AK-47, with 50rd mags. I wouldn't let him take outside the wire. He was always cursing and screaming, because the commie mags were bad,, it was his poor handling. I think he still has a SIZE problem?? I see his name in the paper every so often.. :D

By the By,, outside the wire, without window frames,, no problemo..

This was discussed before, science and all. But we can go back to placing butter on burns too.

Riddle me this, why oh why do we have "heavy barrels?"

http://www.stocks-rifle.com/harmonics.htm Just one of many harmonics/vibration discussions.

I'm guessing you both are SF snipers and 18B's? :D

I must have missed something somewhere. I don't understand why we are discussing barrel harmonics when the topic is placing the magazine of an M4 on the ground when firing prone unsupported. Did I miss a post or something here?

I think my point was missed. Even IF placing the magazine on the ground effects barrel harmonics (I'll let you guys argue that), the benefits of a stable position that comes from the mag on the ground will far outweigh the negatives of any harmonics issue (if there are any.)

I personally think the 'mags on ground induces failures' is not true, based on my personal experience and the opinion of others that I trust. I don't doubt it was once based on some truth, but I don't know what happened in Vietnam, and none of my mags are from that era. I inspect them religiously and consider them expendable. (I also crush them when the lips start to spread or crack. You can write "bad" or draw a big X on them and throw them away, but some dumbass will fish them out of the trash and put them back in rotation).

No, your point is not missed and you are correct in your statement. The unit I am in conducted an extensive assessment of this and actually at one point in time did MTTs to conventional units, teaching this as part of the course. I too grew up with the urban myth that it induced malfunctions but after seeing it proven wrong so extensively over time and circumstances, have changed my opinion on it and now am a strong advocate of it. It works, it doesn't cause issues and it increases the shooters performance/groups at the target. The bullet doesn't lie.

Where's Longrange1947 when you need him!
 

An M-4 mag catch assembly was not designed to hold the weight of a firing M-4. It's an already flimsy catch that barely holds in the magazine. With a 20 rd mag holding the weight of the M-4 might not be bad a 30rd mag will rock back and forth and as was pointed out might start to bend/crack parts that were never intended to hold weight. I'd sure like to examine the mag catches on those that have been firing with mag touching the ground and view the wear. Especially compared to those that have not used the mag as a firing platform.

Also, as a sniper, I cringe at the idea of using the mag as a firing platform and then attempting to double tap, or acquire the sight with speed as my weapon jumps off the hard ground from the first round.

I fairly certain we already had this discussion concerning harmonics ie the weapon touching something hard like a rock, or a mag resting on a rock and then fired as opposed to firing with a hand in between the stock (or mag) and the rock.

There's a reason we have "free floating" barrels and heavy barrels. And while I know the M-4 is not a free floating barrel the whole idea is not to touch anything hard that might affect barrel harmonics.

Now if you want to sling lead downrange then have at it. Hell I saw a video of a police shooting the other day where the police officer was employing the "gangster hold" on his pistol.

And while I appreciate your unit conducting testing, I'd rather see an weapons engineer from say "Colt" conduct those same "tests" and see what they have to say. ;)

Another thing: In the event of a case head failure, the design of the M4/M16/AR family of rifles funnels the force of the explosion down the mag well and out the bottom of the magazine. This blows the floor plate of the magazine off and spews the contents of the magazine all over the place. If the the magazine is being used as a mono-pod, that practically turns the magazine into a grenade...

This happened to me about 15 years ago. Twisted the bolt carrier in the upper receiver, bulged the sides of the upper and lower receivers, split the bottom of the bolt carrier, and vented all of those hot gasses down and out the bottom of the magazine. Magazine body was bulged out almost like a soda can, and blew the floorplate, spring, follower, and remaining rounds out the bottom of the magazine. I got a scrape and bruise on the inside of my support forearm as magazine contents made their exit, but that was the worst of it.

Tried mortaring the gun to clear it, and ripped off the end of the charging handle for my efforts. Actually had to remove the barrel nut to get the gun apart. Upper and guts were toast, but aside from bulged magwell, lower was fine. Squeezed the sides back together in a vice, slapped a fresh upper on it, and the gun ran fine. I probably have pics, if not that old trashed bolt carrier, still around here somewhere.

I just got done with an MTT mission. Had a pvt who couldn't group worth a damn. Shot 17/40 paper qual for the warm-up qual. I changed his position, got his L hand off the heat guard & sand bag and placed it at the mag well for both supported and non-supported. Likewise, I showed him a kneeling technique where you put the mag on your knee (2:22 https://www.youtube.com/watch?v=gOH7NrZNvdM) He shot 30/40. The MTT unit I'm with did a test with sandbag vs. sling vs. hand. Using guys who know how to shoot (they shoot ragged group at 25 w issue M4/M16) and same point of aim, we got different point of impact with each position. Conclusion: that non free-floated system is crappy enough that having a sand bag vs no sandbag is enough to cause zero shift at 25m! So effect of position/hold/rifle-surface contact on barrel harmonics is definitely there. Mag on the ground and holding at the mag well create a consistent, improvised "free float." It does require a degree of flexibility though.

FWIW, I have experienced malfunction (double feed) with resting mag on the ground. Marked that magazine, tossed it away, and I never experienced another malfunction using "well maintained and inspected" mags.


Not only I rest mag on the ground, with that rocking motion, I jam the mag to the ground then pull it to my R shoulder with both L hand (on the mag well) and R hand creating a solid platform that moves as a single unit with each recoil. It's like opposite of loading the bipod. That rack grade A2 with issue ammo gets an "upgrade" in accuracy with that technique ( visual example at 0:33, also various weapon systems with mag on the ground and no malfunction https://www.youtube.com/watch?v=3rXykqvVHmkO ) . I made a believer of folks at various units after they see the groups at 25, 100, and 200. Still, that "flimsy catch" worth merit to investigate. I admit I never shot thousands of round ( only < 300 in a single session) with that technique and observe wear and tear. Let me ask my contact at Colt and the head armorer at Barrett

In the meantime, some empirical testing (having anti-tilt follower helps)
https://www.youtube.com/watch?v=IcBGtoH_uSc

We need Longrange1947 and Gene Econ to chime in :D

Jeff, the moment one starts thinking there is nothing new to learn and stops looking at a subject with an open mind is the moment one becomes outdated. If you doubt what has been said here, then go out on the interwebs and google this topic. I can save you some time though and tell you that resting the magazine of the M4 on the ground doesn't have a detrimental effect. As has been mentioned here, the anti tilt followers in todays magazines is probably the biggest reason but even if you have an older one without the anti tilt, chances are you won't experience a malfunction.

This practice has even sparked industry to produce what is called mag-pods. These are placed on the bottom of magazines to help make a more stable platform for using this technique. And as you can see, it's also in the manual now. Not saying that it's right just because its in the manual, as we've all seen wrong things in manuals before. Remember when 6400 mils was in the sniper manual and that higher humidity meant the air was thicker? Both used to be repeated ad nasuem and even taught when I went through SOTIC. Today, no up to date instructor will repeat any of that dogma, as it has been proven to be incorrect. However, even in this "new" manual, they still managed to fuck it up and use 6400 mils in Fig 3-2 when discussing MOA and MILs in chapter 3. So I can see how even now, you might be skeptical of placing a magazine on the ground despite what others have said.

The point being is that you don't have to believe me, the manual or anyone else in the shooting industry. But if you are dead set on not believing what has been presented, then go out and try it for yourself and see how it turns out. In fact, I encourage you to go out and do it and prove the rest of the world wrong. I know what the outcome will be....but what do I know. :)