Preferred 1911 Mag for 2700 Matches

What's your favorite (i.e. reliable) 1911 magazine?
I'm re-entering bullseye comp after nearly two decades and remember that the weakest link with the 1911 was the magazine.  Seems like every string (back then) had an alibi.
I still have my 1911 wad and ball guns which will be forever timeless, but a total smorgasbord of magazines laying around after all of these years.  What's the latest in technology, as well as your favorites?

Metalform magazines seem to be the ones in demand.  I have prancing horse colt ones and I don't have any function problems.

Metalform!

I like Wilson, Metal form and most Factory Mags,Colt, SA.

Tripp Research!

Dave

Thanks Guys!  I had good performance with factory mags and dabbled in Wilson (I think the only non-OEM back then).  May look into Metal Form and Tripp if I can't come up with matching sets around the house.

metalform, or wilson 7 round mags, you only need 3, two + a backup

Either I've been living right or just lucky, I've never had an issue with any of my mags in any of my 1911's including the compact 1911 I carry, with the sole exception of 2 used 8 rounders I acquired years back.  I replaced the 8 rd springs with 7 rd springs and they became as reliable as the others.

When you shoot 50 yard line you should use only ONE magazine. Magazine spring pushes rounds up against disconnector rail as well as releasing rounds different from magazines. As a result the pistol WILL shoot two different groups, one from each magazine. From Ransom Rest I've seen magazines shoot groups as much as 4" apart at 50. So I recommend using one magazine for the 50! One magazine will be consistent. Then again if you need a good excuse for the 50 yd line, now you have one

Good post Jon, and very correct.  10-12 years ago, I did extensive Ransom Resting with 30 shot groups out of each magazine at 50 yards when I was trying to eliminate variables.  2 of the 6 I tested did better than the others, those I engraved 'slow fire only' on and still use those 2 exclusively for the 50 yard slow fire portion. 

The other mags I use interchangeably for 50 ft and 25 yards.  It doesn't seem to make any noticeable difference at those ranges.

Al

Only comment I will make is stay away from 8 round magazines. Eight round magazines make some compromises in reliability to get the 8th round in.Browning designed the mag for 7 rounds.
 I use Colt and Metalform but I have had bad ones of each.

I completely agree with Jon that the magazine exerts force against the slide, but I don't believe the variables between magazines produced the different points of impact unless the lockup of the gun wasn't tight or the slide had lots of play.  Ransom rest testing is so touchy, I assert that some other factor could have been responsible.

In a gun with tight lockup, the only thing extra tension against the slide should change is lockup time if it creates enough drag to slow the slide down.

I only have 3 match magazines--all the same brand from the same lot.  My shots go where I call them with all 3 mags.  I just can't get the mechanics of it.  I could be wrong.

I don't have a ransom rest either.

I will add another comment from an Army armorer, B.J. Snow,( now making custom knives) from 25 years ago. He encouraged using one magazine for slow fire. His reason was that the different magazines caused different feeding angles of the bullet into the feed ramp. Thus there might be a different bullet distortion from magazine to magazine that caused a shift in bullet impact. I am sure his observance was from using a Ransom Rest.
 As Jon mentioned slide drag could shift point of impact due to a different lock up speed of the slide. Slide drag is a reason given for not using shock buffers. Once "pounded flat they interfere with the slide thus affecting slide speed and lock up.

As to using only one mag in slow fire, maybe you should only load one round at a time because if you don't the "slide drag" will be different with each shot as the magazine spring's compression force is different as each shot is fired.  But if it gives you that warm fuzzy feeling, go for it!  It has been proven many times that unless the damage to the nose of the bullet is severe there will be very little change in accuracy.  I seldom shoot beyond 50 yards so I have not seen this effect.


Good health and good shooting
Dave C.

I'm going to take this opportunity to ask a dumb question that has been rattling around in my head since I read this article:  1911 Magazine Analysis Part 2

Do the USGI/hybrid feedlips actually improve group size for ball rounds?

FTA:

A Magical Combo

My favorite discovery to come out of this whole experiment was the performance of USGI feed lips with ball ammo. The rounded profile of FMJ bullets works perfectly with the angles of the full-length feed lips to produce an unbelievably smooth feed. Chambering a round feels like you're dropping the slide on an empty chamber.

Even better, control over the cartridge is absolute. When taking photos, I discovered that it was impossible to push the slide forward slowly enough to misfeed the round. Momentum was never a part of feeding, so the entire process is controlled solely by geometry. To put it another way, the slide can be under-lubed, undersprung, or just plain dirty, but as long as it is physically capable of returning to battery, it will not jam. This is pretty much the Platonic ideal of controlled feed principles--which is only appropriate, seeing as how John Browning wrote the book on controlled feed in handguns.

Such well-controlled feeding produced one unanticipated side-effect: My groups shrank when using ball ammo in USGI mags. The cartridges were making it to the chamber with enough reproducibility in their motion that it knocked a healthy 25% off my group sizes. I refused to believe it until after I'd gone back and forth between magazines several times, but it was there.

Mec-Gar.          I used them in all my guns except for the Marvel unit.   If they made ones for the Marvel unit, I would at least try them.   



http://www.mec-gar.com/Magazines

I'll be the rebel.

I had Chip McCormick Power Mags supplied with three different custom M1911's from three different smiths of note.  That was good enough for me....I use them exclusively now.

I also use dedicated magazines for specific target M1911's.  Explanations aside; I can see the difference when I don't.

I've also have run across magazines that open groups up in a variety of guns; I simply dump and replace those.  Life is too short.

Jim

Ok, please explain how accuracy is effected by magazines.... once the round has been put in the chamber it has no contact with the mag, its job is over.  The round is in the chamber and in contact with only the bolt and the extractor.

Consistency is the key to getting a 1911 to shoot good. If magazines are not releasing cartridge into chamber the same way everytime the pistol will cycle irradically. Common problems with 1911 type pistol (especially older ones) is the magazine either releases cartridge too late and the extractor has to bend out to chamber cartridge into chamber. Extractor is designed for the cartridge to slide under the extractor at the breechface. If it releases too soon (can miss extractor and require extractor to bend to allow chambering), the cartridges can bobble into the chamber or hit the feed ramp/throat inconsistently. Again, one of the keys to accurate 1911's is consistency. Bob Marvel machined a groove into the disconnector rail on the slide to improve consistency because of the speed bump the disconnector causes during cycling. So back to magazine; You have 2 mags...One that releases early and one that releases late. TWO GROUPS @ 50! You have 2 mags...Weak spring and heavy spring. TWO GROUPS @ 50! Granted most shooters aren't masters and won't know the difference (sorry), but you won't typically see a master using 2 mags on the long line. I learned this using Ransom Rest and Federal Match 185gr WC ammo. My pistol was a consistent 1.5" pistol. Same mag, same group. Various mags and multiple groups. If you want to get technical, use physics. A magazine spring pushing a cartridge up into the disconnector rail with a force of 12# requires more effort than a spring with 9# force. It will cycle faster or slower depending on which spring is in magazine. Aside: If you use too light of a recoil spring your 1.5" pistol will shoot 3-4" groups because its coming out of battery too fast and not locking up long enough/correctly as well as cycling irratically. It can also cause cartridges to pop out of magazine partially (still feed) and chamber irratically. Jerry Keefer wrote an interesting post somewhere one time that even addressed the .22 pistols varying becausse of loading 5 rds vs. 10 rds. Hope this answers your question.

David,
I wish I knew why, it doesn't make any sense to me either and for the same reason.  If I hadn't done the Ransom test myself with 30 shot groups out of each magazine I'd be very skeptical. 

As this was many years ago, I don't exactly remember the process used, so I'm going to guess it was the same one I've always used.
1. Seat the 1911 into the grip adaptors and run at least 10-15 rounds through to seat it into the adaptors and check adaptor screws.
2. First round out of the magazine gets marked on the target.
3. 3 more shots.
4. Remove mag and refill the same magazine with 5 rounds.
5. Insert and shoot 5.
6. Remove mag and refill with 5 rounds until group round count is achieved.

I didn't try to figure out why, that's way above my pay grade and area of expertise, I just marked the best mags and went on. 

Perhaps the ammo used was more consistent.  All rounds were loaded with the same press (RCBS 4x4- I had before my Dillon) and the same Redding BR3 (with the small pistol micrometer insert) powder measure.

I've never tried to repeat the test with my new wad gun.  I did a 10 shot group test off the bags at 50 yards and it grouped better than my old wad gun with the same ammo, so I quit testing there.  I no longer try to squeeze every last 1/4" out of a group.  The group size is not responsible for those darn 7's.  I just need to work on the loose nut behind the trigger.

Al

I totally agree with David R on this one.  I don't understand how the mechanics of any part of the cycle of operations would have an impact on accuracy.  Like David R said--the role the magazine has played is over 100%.

Either the gun is locked up or it isn't.  The hammer falls, firing pin strikes the primer, gun goes boom, bullet leaves barrel BEFORE the gun goes out of lockup.  The shot should be in the same group no matter how different the magazine is.

I bet the change in group from one magazine to the next was a disturbance of the ransom rest or adapter during the mag change.

Rob Kovach wrote:I totally agree with David R on this one.  I don't understand how the mechanics of any part of the cycle of operations would have an impact on accuracy.  Like David R said--the role the magazine has played is over 100%.

It is fair to say that the magazine's job is over, but did it leave the pistol in a state where the successive shots will show variance in the group size?  Is it possible for one magazine to load a round leaving it more "consistent" position in the chamber than another?  And by that, I don't mean the act of loading the round, rather how the round ends up after the magazine has finished it's job.

I would hope that my barrels don't have multiple positions in the chamber for my rounds to go to after they come out of the magazine.

It should be a single positive insertion.  It should not be like a hot dog in a hallway.

Ah, but .001" does make a difference, no?

I've often heard of shooters putting the first round of a magazine into the backstop before shooting the rest because the first round was hand chambered.

Jon  is absolutely correct. The feeding cycle has a huge influence on the group. I like to say " that the gun should cycle so smoothly, that it appears to be empty."
Someone mentioned chambers... It is very difficult to get a true match chamber with some of the aftermarket barrels..Oversize, out of round, out of concentric chamber/bore walls, and lead angles are rather common place. A good bore scope  can be enlightening.   The extractor has or can have a large influence on the group.. Is the extractor exerting unnecessary side pressure on the cartridge base..? If  it is, it definitely is holding the cartridge to one side of the almost always over sized chamber. The reason I say that is, most reamers, are ground to SAMMI specs, which are generous. Custom ground reamers will reduce group size. Custom made barrels that allow single pointing the chamber, prior to reaming, have shot the very best barrel tester  groups.     Most extractors are too long, and push against the rim rebate angle.  Shims silver soldered into the extractor groove, and machining the groove to pull the extractor back away from the case is the only alternative in most every instance. Very few,  are the extractors that I don't have to weld..The Bob Marvel disconnector rail groove, which Jon mentioned, is a huge plus in preventing slide stall, and insure a consistent feed. Good for Bob, I am ashamed I didn't think of that..It's so obvious..  I often reduce the angle on the base of the disconnector where it contacts the spring to ease and  smooth up its function.   I use very weak magazine springs, and just enough extractor tension to reliably function..I want my extractors to rest "lightly" on the rim edge, and touch no where else on the cartridge.
 
Jerry