On another list, we've been having this debate.  So a couple of us did some testing.


I did mine today - good thing too, for when I was in the basement doing it, my water main started leaking all over my supplies!   Nut just got loose I guess.   Who would guess a test would turn into a crisis?


I had intended to set the mag bottom on a scale, and push down on the gun to get a reading - but my scale wouldn't handle that.



So, I have:

1 DPMS
1 Professional Ordnance carbon 15
1 Rock River Arms
3 Bushmasters

6 mags, 20 round, fully loaded
13 mags, 30 round, fully loaded

All bolts were closed on all weapons.  I selected one gun at a time, and inserted each mag and pushed on the bottom until it seated.  I removed the mag, tried the next, repeated until I finished the stack.

No mags had to be slammed or hit to seat.  All were just pushed.

ALL MAGAZINES SEATED IN ALL 6 WEAPONS

The RRA was a bit tougher, as was one of my Bushmasters.   But we are talking degrees here.   There was some variability between mags, and if the top bullet wasn't seated correctly that had an effect also.


End Results were exactly what I expected - ALL MAGAZINES SEATED IN ALL 6 WEAPONS

So that's 6 guns x 19 magazines = 114 combinations/insertions


- Paul

How old were the mags?  How many times had the mags been loaded & cycled before the test?  I'd need to know the make of the mags, follower types, weather conditions, wind speeds etc before a determination can be reached in regards to the validity of your testing...  


I used to down load em to 28, now I just use 30 cause I hate math & loose rounds floating around.

Sly

Try different slings and mag floor plates!

Shooting or just hand-cycling?  

Some of the 28/30 round problems can go away with MagPul followers and newer chromium silicon springs.

Didn't now this was still an issue.  I never download AR or pistol mags and no problems yet.

Magazine made for 30 rounds, mine get loaded to 30 rounds.

Quoted: Try different slings and mag floor plates!

I agree and do it87 more times!

Quoted: Quoted: Try different slings and mag floor plates! I agree and do it87 more times!

I put 29.5 in my 30 rounders.

Danny

Quoted: Quoted: Quoted: Try different slings and mag floor plates! I agree and do it87 more times! I put 29.5 in my 30 rounders. Danny

Dude... STFU right there......

That shit is SO tactical... you CAN'T be sharing it on the internet like this.

We told you not to tell anyone...  

Quoted: How old were the mags?  How many times had the mags been loaded & cycled before the test?  I'd need to know the make of the mags, follower types, weather conditions, wind speeds etc before a determination can be reached in regards to the validity of your testing...   I used to down load em to 28, now I just use 30 cause I hate math & loose rounds floating around. Sly

1 to 30 years old.   Cycles?  1 to hundreds.   Current loads - between 1 month and 2 years.

Wind speed - none - it's my basement.

I always load 30 rounds in a 30 round magazine, even the Colt Magazines  with the Red Power Springs from SAW get 30 rounds

Better only load 10 rounds in that mag to be safe.

I did something simular.

New Labelle mags w/ green follower 30 rnds
New Labelle mags w/ Magpull Ranger Plates and Magpull followers 30 rnds.

Test 1. seating mag on closed bolt.   No issue with either
Test 2. Tac reload on closed bolt. No issue
Test 3. seated mag on closed bolt and loaded round. No issue
Test 4. BCG locked back, loaded mag and released bolt catch. FTL on both setups.

My solution: load 30 rnds. Load rifle by use of charging handle every time.

Are you the bald guy who wears the beret?
JR

Quoted: On another list, we've been having this debate.  So a couple of us did some testing. I did mine today - good thing too, for when I was in the basement doing it, my water main started leaking all over my supplies!   Nut just got loose I guess.   Who would guess a test would turn into a crisis? I had intended to set the mag bottom on a scale, and push down on the gun to get a reading - but my scale wouldn't handle that. i10.photobucket.com/albums/a150/fight4yourrights/Weapons/Magtest001Medium.jpg So, I have: 1 DPMS 1 Professional Ordnance carbon 15 1 Rock River Arms 3 Bushmasters 6 mags, 20 round, fully loaded 13 mags, 30 round, fully loaded All bolts were closed on all weapons.  I selected one gun at a time, and inserted each mag and pushed on the bottom until it seated.  I removed the mag, tried the next, repeated until I finished the stack. No mags had to be slammed or hit to seat.  All were just pushed. ALL MAGAZINES SEATED IN ALL 6 WEAPONS The RRA was a bit tougher, as was one of my Bushmasters.   But we are talking degrees here.   There was some variability between mags, and if the top bullet wasn't seated correctly that had an effect also. End Results were exactly what I expected - ALL MAGAZINES SEATED IN ALL 6 WEAPONS So that's 6 guns x 19 magazines = 114 combinations/insertions - Paul

+87

I don't get the point.. so you were able to insert mags in with a closed bolt in a stress free environment with out any stress or being under the clock.

The whole point of downloading is to make it EASIER to insert a fresh mag and having it lock up easier and minimize the chance of the top round puhing off from the closed bolt . Spring cycles has nothing to do with it.

It's a technique, some use it some don't, I'watched enough shooters pop a mag in their carbine rel quic and watch it hit the deck a few moments later (Myself included). That's why I use this technique. Slaming it or "Not being a pussy" has nothing to do. it'a technique (like push/pull) to minimize the chance of that happening.

I think that's what most shooters don't get. it's not about "it holds 30 so I load 30) Techniques are used to eliminate Murphy

An "Amen" to Harv.

Yup, it's one time where I endorse pulling on it .

Bomber

Another +1 to what Harv said!

Quoted: I don't get the point.. so you were able to insert mags in with a closed bolt in a stress free environment with out any stress or being under the clock.y

The "MYTH" that has arose is that you HAVE to download mags or they won't seat.

The truth is that they will.


Now if you want to download to make them easier to seat, more power to you  - but chuck did a test and it took 11 lbs of force to seat a 30 round loaded mag, or a 28 round loaded mag - NO DIFFERENCE






.......and I've done the same and had a loaded mag fall out too.  

Quoted: tried it in the prone? that's the only time it's been a problem for me

No, but I don't see where that would make a difference - again, I just pressed the mag into the well for my testing.

Quoted: Try it with two magazine in your hand and get back to us.

And sprint 25 yds first, then drop to one knee - that'll compress the ole diaphragm a bit.

Feelin' the love, yet?

Quoted: And remember, in a tac reload, you will have the loaded mag and the partial empty in you hand at the same time while doing this.  Try it with two magazine in your hand and get back to us.

As I mentioned, Chuck took a scale and measured the insertion force - 11lbs for a 30rd mag, 11lbs for a 28rd mag = SAME



I've done plenty of tac loads in courses I've taken, and during private training - WITH fully loaded mags - no problem.

Quoted: As I mentioned, Chuck took a scale and measured the insertion force - 11lbs for a 30rd mag, 11lbs for a 28rd mag = SAME

I don't see where you mentioned that.  Said something about your scale not handling that...

Anyway...

Seriously?  The force lb'age was the same for 28 vs 30?

I can't measure it with a device, but I'll guarantee it's different on mine.

originally from Fightfor yourRights

The "MYTH" that has arose is that you HAVE to download mags or they won't seat. The truth is that they will.

See....When you start bring Math and Science into it, it just kills all the fun out of it for me......

I think what it is and that the "technique" that is used was mis understood by the masses (Like a lot of Things) and the two camps formed on either side of the fence.

You don't HAVE to download any more then you don't  HAVE to have a BUIS or HAVE to have any formal training.
Or HAVE to have a light on your carbine or Have to have a sling....etc.

I can drive my truck pretty good  one handed as a technique, but when the road conditions are bad, using two hands is a better technique.

The force may be the same  read on a scale, but the empty space at the bottom of a mag is going to be empty by 2 rds allowing for the other 28 to compress down against the Bolt making it more likely that you will more easily engage the mag catch with the cutout in the mag under the stress and duress that normally attributes to the  mag dropping on the deck. And the funny thing, the few times I did drop a mag, was under the clock when I was in a hurry, never during a casual range day.......hmmm.

Again, its not a deal breaker and I would never force my views and opinions on what works. if a guys ask's me .. I tell him.  If it contributes to the defeat of Murphy just one time in my whole shooting career...then to me, it's a technique worth using.....

Quoted: Quoted: As I mentioned, Chuck took a scale and measured the insertion force - 11lbs for a 30rd mag, 11lbs for a 28rd mag = SAME I don't see where you mentioned that.  Said something about your scale not handling that... Anyway... Seriously?  The force lb'age was the same for 28 vs 30? I can't measure it with a device, but I'll guarantee it's different on mine.

Well, we've got a thread on a discussion forum, and it was posted there


Yes, someone took a trigger scale and measured the insertion force, and got 11 lb for a fully loaded or downloaded mag
Both of my black teflon 30rd DPMS mags would readily accept a 31st round.  With 31 loaded, they would NOT seat in a gun with the bolt closed.  (I only tested 1 gun, but I believe it to be accurate)

None of my other mags would take an extra round

Here's a question for you downloaders - WHY DOWNLOAD 2 ROUNDS, WHY NOT 1?   (19 & 29)

Don't get me wrong, man.  I believe your findings.

Didn't mean for it to appear otherwise.

fight4yourrights

Here's a question for you downloaders - WHY DOWNLOAD 2 ROUNDS, WHY NOT 1? (19 & 29)

I don't have a good scietific answer. other then 2 seems to be optimal for performance while not lowering your rd count to a level where it defeats having a 30 rd mag. Mostly this has been passed on by Soldiers who experienced some problems with full magazines not wanting to seat easily.

Like I said, it's a technique, I might get by loading 30 my whole life and never have a problem, but if it makes things a little easier to load under the clock or under stress and minimizes Murphy poppin his head in at the wrong time.
I've done it for well over 20 years and it seems to work, so I have confidence in it as a viable technique and that's what makes me continue to use it. For me, somethings are just not that complex and I don't put that much thought into them, lifes to short....

But tac reloads are not done under the clock so to speak.  

A tactical reload by definition is a reload where there is no shooting or targets and you are topping off your weapon for the next engagement. If there are targets in front of you you fight to bolt lock back and speed reload behind whatever cover you can find.

You do tac reloads when there is no shooting going on and you are behind cover.  The extra time to slap on it and pull it to make sure it is seated takes about 1 second.  If you are doing a three gun competition for sport where it is timed I can see the point.  I can not see the point in downloading when time is NOT an issue such as with a tac reload.  Spend the extra second or two making sure you have the 30 round mag loaded propperly and get the full capacity of your magazine.  It was designed specifically to close with 30 rounds on a closed bolt. There is NO EXCUSE for a mag hitting the deck.  None.  You violated the rule of ensuring your mag was seated if that happened.  It CAN NOT happen if you ensure the magazine is seated before you begin firing.

There is of course a trade off.  You are spending an extra second during a non shooting time with no hostiles in view to get those extra 2 rounds.  Of course it seems the trade off is when you are engaged with an enemy that is shooting back at you that running out 2 rounds early is the alternative.  So which is better?  An extra second of shooting time while you are shooting at an enemy who is shooting at you or an extra second saved when there is no enemy shooting at you, no shooting going on at all and you are behind cover?  Seems pretty obvious Id rather take my extra second to ensure I have 2 more rounds under a non shooting situatiuon than to run out 2 rounds earlier in a shoot to bolt lock back situation.  Others would prefer to run out 2 rounds early in an active shooting sitation so that they can save a second in that relatively "safe" sitation because someone might pop out a second too early during a tac reload.  Magazines hitting the deck are a non issue.  Again if that happens you didnt tug on your mag to be sure its seated.

In one situation you are risking a second of time when the probability is low that a target will present itself.  In the other (shoot to lock back life or death sitation) you are guaranteed to run out early because you have 2 less rounds.  I will take the extra second during a non shooting position behind cover to ensure I wont run out earlier when I may be exposed or have someone threatening my life at close range.

Downloading 2 for competition means you can skip the tug on the mag to snsure its seated part because its just a game determined by the fastest time.  The fastest person wins the game and if you have a mag fall out you dont die.  In real life you should ALWAYS pull on the mag to ensure it is seated.

Somehow the download 2 people still disagree with me and cant give a logical explanation to their view other than "<insert guru> told me to download and he knows better than you," arguement.

Quoted: Mostly this has been passed on by Soldiers who experienced some problems with full magazines not wanting to seat easily.

I haven't heard of any soldiers saying this since Vietnam, though.  Maybe I'm talking to the wrong hundreds of soldiers or something, but I think this "soldiers' advice" is a bit outdated.

Quoted: Quoted: Mostly this has been passed on by Soldiers who experienced some problems with full magazines not wanting to seat easily. I haven't heard of any soldiers saying this since Vietnam, though.  Maybe I'm talking to the wrong hundreds of soldiers or something, but I think this "soldiers' advice" is a bit outdated.

The person who started this on an email list is a Vietnam vet, a LRPP (real one) even.   He said there's no reason to download, and set about to show why.  I continued it.

Do you download your strippers as well?  

I'll have to type it out, but there's a Pat Rogers quote in the Jan 2006 SWAT.

EDIT:

Written by Patrick A. Rogers: A cautionary note here:  While the capacity of a thirty-round magazine is in fact thirty rounds, load only twenty-eight in them.  The reason is simple: some magazines, when fully loaded, will not lock into the mag well if the bolt is forward.  By downloading two rounds you can be sure that you can lock in any mag (remember - Push Pull!) whether the bolt is forward or not.  At any given carbine class I will see thirty to fifty instances of a shooter failing to lock the mag in the well.  The mag then falls out of the carbine.  The shooter gets vapor lock, spends a great amoung of time trying to force something that won't happen and fails to transitiion to his pistol.  Even if he does correctly transition to his pistol, the entire line must wair while the errant shooter (hopefully) gets himself squared away. SWAT Magazine, January 2006, Beta Company Reloaders, Patrick A. Rogers, pg 86.

I only own one AR, but I loaded 5 different magazines with 30 rounds, then inserted them into the mag well - bolt FWD.

I then took those exact 5 magazines and downloaded them to 28 rounds and inserted them into the same weapon's mag well - bolt FWD.  All 5 magazines displayed less resistance - it was not a mind staggering difference, but one nonetheless.  That's about as unscientific as it gets.

What I'm most curious about is fight's findings.

The problem I have with 30rd mags is that if I load 30 rounds sometimes the top round won't strip from the magazine.  That's why people do the 28rds.  Not because they are hard to seat-- the bolt is open when the magazine is seated anyway.

I don't need a scale or anything else to tell me that I want to load 28 rounds in a 30 rounder.  I organize an action rifle match once a month and see the proof every month that loading 30 rounds and seating a mag with a closed bolt are not a good combination.  Several times at every match in the year we've been doing them, a shooter starts a COF only to have the mag fall out of the bottom of the gun.

This is one reason I participate in shoots like this, to see what works and what doesn't.

ETA:
Regarding the bolt always being back when reloading....
One of the other things I see at our matches is the various types of malfunctions that occur.  One of these is the gun going "click" when the bolt is forward.  The shooter generally makes the assumption that the mag has gone dry and does a reload.  Sometimes they are correct and for whatever reason the follower didn't catch on the bolt-stop, other times it's a dud round, or a round failed to strip out of the magazine.  Either way the end result is the same, they are trying to stuff a magazine with 30 rounds in it into a rifle with the bolt forward.  Far too often the shooter winds up dropping this mag on the deck after they work the bolt.

Same here:  after seating a 30 round mag with bolt fwd, then working charging handle, having a round not feed.  Can't remember the last time I tried this, though.

For the most part - almost without exception - when I load an AR, I lock the bolt back, seat the mag, hit the bolt release.  Rarely, if ever, will you see me operate the CH to chamber a round.

Regarding Mr Rogers' quote that I posted above:  I highly value his opinion.  

But I trust my life to NO ONE until I evaluate their recommendations.

Quoted: The problem I have with 30rd mags is that if I load 30 rounds sometimes the top round won't strip from the magazine.  That's why people do the 28rds.  Not because they are hard to seat-- the bolt is open when the magazine is seated anyway.

SO why not do 29 rounds?  


easier to visually see you've down loaded, since the round will be on the 'wrong' side

Another "gamer" who switched from 30 to 28 after a difficult match.  In the end dropped mag's cost me the match.  2nd felt pretty hollow that day.

I clamp two mag's for matches (and for HD).

I tug down, but when not seated properly, a hard tug results in the weight of the pair coming down hard and it is possible under stress to drop them.  I continue to work technique in dry-fire and will continue to as long as I draw breath.

28 in each improves the % of me beating Murphy.  Whether in a game or in real life, Murphy can be a fearsome adversary.

Why not 29?  No authoritative reference, but it was suggested to me by someone who should be in the know that it has something to do with the follower setup.  That it's useful to load from the "same side".  That's why 28 not 29 as explained to me.

YMMV.  Do what works for you...

Safe shooting,

CZ52'

One thing that I noticed during this thread that I found very true.  The tactical reload is done to maximize the ammount of rounds loaded in the magazine currently inserted in the weapon (taking a partially spent mag, inserting full mag) so that you have an advantage.  This is THE ONLY TIME (other than if you keep your AR with mag inserted, but no round chambered) you are inserting on a closed bolt (or at least should be).  If you shoot to lock, then inserting a 30 round mag vs. a mag downloaded by 2 is going to feel the same, since the resistance is not there.  I don't do 3 gun, and I've never had a mag fall out because I didn't slap the bottom hard enough (I have always pulled on it after inserting and smacking).  I just don't see this being such a big deal when your not presented with a situation where a "tactical reload" is going to happen often enough to worry about repeat performances.  

Plus, if your in the field, and your mag drops because you didn't pull on it, you should go to your pistol (because if you are so pressed for time that you can't stay behind cover and pull another mag and insert it, you are at pistol ranges.  Perform the transistion, IMHO.

Otherwise, I feel that this was a good test, if you look at it for what it is, a test in a controlled environment.  You guys read too much into this stuff.  

All he found was that it took the same pressure to insert the mag at 30/28 rounds, not that it "felt" different.

Quoted: The problem I have with 30rd mags is that if I load 30 rounds sometimes the top round won't strip from the magazine.  That's why people do the 28rds.  Not because they are hard to seat-- the bolt is open when the magazine is seated anyway.

DING! DING! DING!

Give the man a prize...

According to Peter Kokalis (more military firearms experience than I will EVER have) the reason for 28 rounds is that is the agreed upon round count to aleviate any failure of the bolt to cycle FORWARD after using Charging Handle to load weapon. The quick release of the bolt catch during a RELOAD usually strips the round off smoothly... It is our sometimes weak release of the charging handle that slows the bolt enough to stop while stripping a round...

I have had that happen to me several times at the range when I forget to let the charging handle snap back home on a full 30-rd magazine. It is HUMAN error... and is not uncommon. In COMBAT that human error can cost a life...

Rmpl

Is there a difference (reliability, etc) using a full 20 round mag with 20 rounds, as compared to loading a 20 round mag with 18 rounds?

I can't even remember the last time I used a 20 rounder...

EDIT:  gonna leave the grammar error...I'm freaking tired...I'm gone...

Quoted: This is THE ONLY TIME (other than if you keep your AR with mag inserted, but no round chambered) you are inserting on a closed bolt (or at least should be).

Re-read my post.

I don't do 3 gun, and I've never had a mag fall out because I didn't slap the bottom hard enough (I have always pulled on it after inserting and smacking).

If you're anywhere near Lake City or Ft. Lauderdale you need to come out for FDCC or SFDCC shoots and give it a shot.

"SO why not do 29 rounds?"

Because I'm not sure but I think 31 rounds sometimes fit into some 30rd magazines, this means if I strip one I'm still at 30.  If I load them full and strip two I'm guaranteed not to be at 30 which seems to be a not working combination.

I don't count-- I just fill the mag and strip two rounds off the top.





The following is completely from lack of experience mixed with a very tiny amount of experience.
I have little experience with 20 round magazines but I think 20rds might actually feed reliably from them-- or at least from the horribly old range mag 20rounders that I have.  That still doesn't mean I would want a 20rd mag-- the extra eight rounds are nice to have and I like the size and shape of the 30rd magazine-- no good reason but time spent with the 30rd magazine there.   I do admire the quality of the 20 rd mag with steel front insert and aluminum follower though.

With the below rifle, a 20-round mag is the IDEAL... as a 30-rd mag would make prone A PITA.

20 round mags have their place...

To seat a 30, all you have to do is take extra time, right?  Plenty of extra time at the gun range. All of us shoot on a gun range and NOT in combat, so why worry about it, right?  Lets be realistic, 99.9 % of us are really just civilians with no chance of ever getting in a firefight, let alone one that lasts more than 30 rounds. Be honest, what are YOUR chances of ever seeing combat? Can we return to reality now?

I'll try and find the exact data, but I read on HKPro that downloading a USP mag by 1round relieves about 20% of the stress placed on the feeding lips of the mag.  I would presume the same to be true for AR mags.

I have been reading John Plaster's recent non-fiction book about SOG in Vietnam and he mentioned loading 20 round magazines with only 19 rounds.  It sounded like he thought it was bad for the magazines to be loaded to 20 rounds.  

He also mentioned a personally purchased [through guns and ammo magazine] 30rd magazine saving his life by giving him two additional bursts when he needed them.  It sounds like he was deffinitely an advocate of the 30rd mags.