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BCB
03-04-2018, 03:22 PM
I noticed a few targets that my wife shot at were “wild” to say the least. She shoots better than the targets indicated. Both with factory ammo and reloads…

So, I went to my bench and loaded the short magazine with reloads and fired them at 10 yards using good rest—all over the board so to speak. Vertical stringing of around 6”…

Loaded the extended magazine and fired the same reloads—all into a 2” group. (Good for me and open sights)

I did the same with the Sig factory rounds and it did the exact same thing…

I read someplace that Ken Waters mentioned this also. Has anyone ever noticed this type of accuracy differences using two different magazines?...

Thanks…BCB

dverna
03-04-2018, 03:32 PM
Never checked off a rest, but unless the bullet is affected as it exits the magazine and hits the feed ramp and/or barrel I cannot envision the magazine having an affect. I would extract each round without firing and start measuring where the difference in the rounds are.

Mica_Hiebert
03-04-2018, 03:35 PM
I would say it is relevant to grip or balance and not a mechanical change.

country gent
03-04-2018, 03:58 PM
I and a lot of others have noticed several Magazine related issues with NRA high power rifles. 1) is first round isn't in the group due to difference in chambering by hand to semi operation. 2) Mags not shooting to the same Point of impact of each other. A lot tested m14 and at mags pairing them together when 2 were found that shot together. A lot also found that certain mags exhibited less 1 shot differences and designated these 2 round or the first magazine. I have tuned a few 10-22s and one place to fine tune is the magazines follower tension it can make a difference. I see no reason the same wont hold true with hand gun magazines. Follower tension, shape, feed lips, and other little things can all combine to make a mag different, and may be hard to see or notice

35remington
03-04-2018, 07:33 PM
It is a grip issue. The extended magazine probably lets you get more fingers on the gun and less vertical stringing. If it was horizontal and vertical dispersion it would be something else most likely.

The vertical only dispersion seems determinative. With my 40 Shield if I do not HANG ON the vertical dispersion is noticeable. The extended magazine lessens the effect compared to the shorty magazine I cannot get my pinkie on.

BCB
03-04-2018, 08:10 PM
A couple more quick pics…

The paper target shows 5 Sig factory rounds fired from the short magazine (no grip extension)…

The bottom group on the steel target shows the same factory ammo fired from the magazine with the grip extension…

I used factory to eliminate error with the reloads—brass length, crimp, etc. Although the reloads are good as I was pretty particular with them…

The short magazine shot 5 holes that spread about 5”…

The extension magazine shot a group about 2” in diameter…

I am uncertain as to how any accuracy could be obtained with the short magazine. Is it possible it could be defective? Both factory magazines came with the Micro 9...

Thanks…BCB

Dusty Bannister
03-04-2018, 08:48 PM
The magazines are noticeably different and the short one is missing a cut similar to the 1911 magazine. I have to wonder if the springs and followers are the same or perhaps the magazines got mixed up at the factory. Maybe another owner of the Sig micro 9 has seen something similar with his pistol? If they are not following the thread, there is nothing to alert them of the question. Maybe a new thread with a clear subject line would get some owners to respond?

Panman213
03-04-2018, 08:52 PM
I would tend to agree with Mica and 35rem about it being a grip issue. I have a LC9s pro and found different groupings with the finger extension than without it. Doesn't much matter to me. Im not shooting for scores with that gun. It will still print minute of bad guy.

str8wal
03-04-2018, 09:18 PM
My Ruger American Compact came with a 12 round as well as a 17 round mag with a piece to fill the grip gap. I shoot to the same POI with either mag. No FTF's with either, either.

35remington
03-05-2018, 12:12 AM
I too am wondering how the short magazine stays in with no cutout for the magazine retention/release bar. It looks like they are oriented such that it should be visible. I am puzzled that I cannot see one after taking a look at the picture.’

Dan Cash
03-05-2018, 08:04 AM
I too am wondering how the short magazine stays in with no cutout for the magazine retention/release bar. It looks like they are oriented such that it should be visible. I am puzzled that I cannot see one after taking a look at the picture.’

What puzzles me is that the long magazine has the magazine release notch on the wrong side.

I am inclined to think the accuracy differences are grip related.

6bg6ga
03-05-2018, 08:14 AM
When you have a finger dangling in mid air it affects accuracy. Its grip related. Install a longer magazine and your accuracy will improve. In my opinion its a shame people have to purchase these little micro guns so they can hide them better and the result is generally they can't hit the broad side of a barn.

winelover
03-05-2018, 08:42 AM
With either the Beretta Nano or the Kahr CM-9, I find no accuracy difference between the short magazine or the extended, at social distances. I do prefer the short magazine on the Kahr..........I find that the short exposed gap between base plate and mag well, typical on Kahr magazines, is uncomfortable, during recoil, for me. I recently added the Pearce extension on the 6 round Kahr mags and it seems to be a viable option.....it's on the Kahr now in my Mika pocket holster, as I'm typing.


Winelover

BCB
03-05-2018, 08:54 AM
When you have a finger dangling in mid air it affects accuracy. Its grip related. Install a longer magazine and your accuracy will improve. In my opinion its a shame people have to purchase these little micro guns so they can hide them better and the result is generally they can't hit the broad side of a barn.

Actually this little Micro 9 is fairly accurate at resonable distances. Post #6 sort of shows this. The bottom cluster was shot with the extended magazine. The paper target with the short magazine...

I am happy with the accuracy using the extended magazine, but maybe 30 feet is not a real indicator of accuracy? That's the limit for my eyes and open sights...

Good-luck...BCB

dverna
03-05-2018, 09:02 AM
The OP says he fired off a “good” rest. Hard to believe grip caused the accuracy issue. Dusty B made an astute observation. Start there.

I am not familiar with the gun....how is the magazine retained?

BCB
03-05-2018, 09:21 AM
The OP says he fired off a “good” rest. Hard to believe grip caused the accuracy issue. Dusty B made an astute observation. Start there.

I am not familiar with the gun....how is the magazine retained?

Yep, a real good rest. Both magazines where fired using the same rest...

I just looked at the magazines and the extended magazine has notches (excuse my ignorance of terminology of semi-handguns) on both sides, the short magazine only has a notch on the right side...

Maybe this doesn't matter?...

Thanks...BCB

Dusty Bannister
03-05-2018, 10:02 AM
When you shoot the short magazine, and the group is horizontal, do the bullet impacts "walk" or is it just random left or right?

dverna
03-05-2018, 10:32 AM
Look at the difference shown in your photo as to how the round is positioned in the lips of the magazine. The geometry is different, and that may affect how the round is chambered.

To convince yourself. Do not feed rounds from the magazine. Single load every shot with both magazines in the gun. I suspect your groups will be the same. It is an easy test

Dan Cash
03-05-2018, 11:00 AM
Look at the difference shown in your photo as to how the round is positioned in the lips of the magazine. The geometry is different, and that may affect how the round is chambered.

To convince yourself. Do not feed rounds from the magazine. Single load every shot with both magazines in the gun. I suspect your groups will be the same. It is an easy test


I am not sure what type extractor the SIG has but if it is the Colt tyype, I would not single load rounds directly into the chamber as you will damage the extractor. If the extractor is a spring loaded, pivoting type, no problem.

lefty o
03-05-2018, 11:26 AM
magazines can have an affect on accuracy. depending on its spring tension and how high it allows round up into the feed lips. typically more noticed on rifles such as the M14, but even on a pistol a mag with a weak spring can have a different POI than one with a stiff spring as it changes the amount of force exerted on the slide from below. notice the slop between the frame and slide in many auto pistols, now imagine a mag with a stiff spring pushing up on the slide from below. things move!

Biggin
03-05-2018, 01:09 PM
Might not be related but what position are you resting your pistol on the rest? Putting pressure on the mag from the bottom can cause feeding problems. That might affect accuracy.

rfd
03-05-2018, 02:42 PM
if all rounds are built exactly the same, and all rounds can be verified to chamber exactly the same, the magazine is out of the consistency equation.

9.3X62AL
03-05-2018, 03:33 PM
Walther PP x 32 ACP ALWAYS shoots better for me with its finger-hook magazine than with its flat-bottom mag. Grip consistency and dynamics exert A LOT of influence over shot placement--resting the pistol might help some, but differences still occur downrange.

BCB
03-07-2018, 08:39 AM
Called Kimber the other day and they are sending me a new magazine—the one that is flush with the base of the grip…

The guy I talked to said the single notch in the side of the short magazine is the way they are to be. The double notch is what the extended magazine is to have…

It appears the short magazine must be made by some other company other than Kimber as there is absolutely no name or marks on it at all unless they are on the inside…

Well, guess I will give it a try and see what happens. Who knows? If it shoots the same as the other one, then it must be the way the handgun is griped with the shorter magazine. If that is the case, reckon I will purchase the extended magazine…

Thanks…BCB

6bg6ga
03-07-2018, 08:55 AM
Walther PP x 32 ACP ALWAYS shoots better for me with its finger-hook magazine than with its flat-bottom mag. Grip consistency and dynamics exert A LOT of influence over shot placement--resting the pistol might help some, but differences still occur downrange.

Like he said

sac
03-07-2018, 01:14 PM
The magazine is doing nothing but holding the rounds. The may you are holding the firearm is different with the extended magazine.

35remington
03-07-2018, 02:02 PM
Kimber does not make magazines. Other vendors make them and stamp the Kimber name on them.

lefty o
03-07-2018, 03:49 PM
most firearms manufacturers do not make their own magazines.

BCB
03-08-2018, 12:06 PM
I got a PM from a follower of this thread and he indicated some more clarification might be helpful. So here goes…

The handgun is a Kimber Micro 9 in the 9mm cartridge…

The factory ammo was Sig Sauer 115 grainers…

The target that shows the string of impact points is deceptive. The target is oriented the wrong way in the pic. The impact points ARE VERTICLE and not horizontal as the target shows. The writing on the target was at the top when the “group” was fired…

The first round was the highest impact. The other 4 just hit at random during the shooting process. Yet, they remained in a fairly straight line…

It would be difficult to know who made the magazines. The spokesman from Kimber indicated they were made by other than Kimber. So, maybe they are all made by the same company? Yet the long one has 2 notches and the short one has 1 notch. Maybe lowest bidder at any particular time...

Kimber is sending me another short magazine. They had no problems doing this when I explained to the person what was going on with the different magazines. Maybe they have heard of this from others? So, I will be able to do a comparison when it arrives. Maybe compare both short ones? Or the new short one with the proven extended one? Or maybe do both comparisons…

I realize that the hold difference with both magazines could be the problem. I certainly have noticed this with all the wheel guns I shoot. BUT, I would think that if the handgun, when used with the short magazine, was held to one position on the sandbags that the hits might be different than with the extended magazine, but they should group the same, but a different location…

And, as the guy who PM’ed me thought that maybe if I could remove the extension and put in on the short magazine and give that a try. I might, but I really hate to try to remove it as I KNOW I WILL NEVER GET IT BACK ON THE CORRECT WAY—this type of deficiency I have had to live with my entire life!!!!...

Thanks…BCB

Dusty Bannister
03-08-2018, 06:46 PM
The first shot high and the rest at random does tend to weaken my thought that magazine spring tension could be a factor. If the first shot was low, and the rest moved up on the target, that would make one suspect that less tension on the bottom of the barrel would allow it to not be pressed firmly to lock up with the slide. Meaning the barrel could be tilted down a little bit in the rear and result in high hits on the paper.

Does the gun fill your hand or does it seem a little small for the size of your hand? Dusty

6bg6ga
03-08-2018, 08:03 PM
The magazine is doing nothing but holding the rounds. The may you are holding the firearm is different with the extended magazine.

Amen

The spring pressure in the magazine has absolutely NO effect on the lock up and thus no effect on shot placement. The very simple fact is the gun doesn't fit right in your hand with the small magazine.

Groo
03-08-2018, 10:25 PM
Groo here
The function of the mag is to hold and feed the cartridge.
It will have NO effect on the bullet when fired.[ the bullet is out of the barrel before the slide unlocks]
The finger extension WILL effect the grip the hand has on the gun!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Few people understand how the little finger controls the climb of the gun when firing..
To test, put your little finger Under the extension and shoot .
It will not be the "same " as the flat mag but will show a difference against holding the finger rest mag normal.

BCB
03-11-2018, 09:42 AM
Well, there are two groups one fired with the extension magazine and the other with the NEW MAGAZINE sent to me by Kimber…

The new magazine has 2 notches as does the extension magazine. It is identical with the exception of the length. Even down to the name etched on it. (The old one was completely nameless—not a marking on it at all)

Both groups were fired at 30 feet from a good sandbag rest. As could be expected, even from past experience with wheel guns, P.O.I. was different, but groups were very similar…

I realize I only did one test run with the new one, but it is obvious to me, the group is “the same” (around 2”) as the group produced by the extended magazine, just a different location…

The groups likely would have been better had I used the laser rather than the open sights…

I guess all reading this can decide what the problem actually was/is…

Thanks…BCB

rfd
03-11-2018, 09:45 AM
did the cartridges feed ok? did they chamber ok?

if so, i would love to know just how a magazine, all by itself, can change POI.

BCB
03-11-2018, 10:02 AM
did the cartridges feed ok? did they chamber ok?

if so, i would love to know just how a magazine, all by itself, can change POI.

Everything worked fine...

One thing I did notice was the cartridges were much easier to put in the new magazine than the old one...

Who knows? Maybe just a freak group that can't be repeated?...

BCB

rfd
03-11-2018, 10:05 AM
Everything worked fine...

One thing I did notice was the cartridges were much easier to put in the new magazine than the old one...

Who knows? Maybe just a freak group that can't be repeated?...

BCB

as described, it literally makes no sense at all. once the round clears the mag and properly enters and seats in the chamber, there is no mag involved in ignition or firing.

Dusty Bannister
03-11-2018, 10:05 AM
did the cartridges feed ok? did they chamber ok?

if so, i would love to know just how a magazine, all by itself, can change POI.

A good example of how the POI could change based upon grip. The short magazine does not offer support to/by the little finger.

See post #23

rfd
03-11-2018, 10:07 AM
grip is EVERYTHING. i would have assumed a lock down rest was used for this testing. physically holding the gun in any manner will totally skew the results.

BCB
03-11-2018, 10:18 AM
Well, it is what it is...

I make no claims as to why this group was better than all the other shootings with the short magazine. Even shooting off-hand the hits were always closer with the extended magazine...

All groups were fired from sandbags that were at the same location on the bench and the grip was the same and never changed except to remove and insert a new magazine. Solid as the "rock of Gibraltar" so to speak...

Oh well, at least the new magazine has 2 notches and the same etching as the extended--sort of a Matched Pair!...

Maybe just one of the mysteries of Nature!!!...

All's well that ends well, I reckon...

Thanks...BCB

rfd
03-11-2018, 10:21 AM
....
All groups were fired from sandbags that were at the same location on the bench and the grip was the same and never changed except to remove and insert a new magazine. Solid as the "rock of Gibraltar" so to speak...

then the test is flawed and why there are different POI's for each mag.

BCB
03-11-2018, 10:56 AM
then the test is flawed and why there are different POI's for each mag.

Reckon so…

Well, in all honesty, I’m not overly concerned about it, but I was just curious about it when I started the thread. I had no great expectation of benchrest accuracy from this little semi-handgun, but the difference in groups, both from a good rest and off-hand were highly noticeable…

Maybe the spring is so stiff in the first short magazine that it slowed the slide down when chambering the round and the round did not completely chamber the same each time?...

I don’t know as I don’t completely know the exact mechanisms of function of this handgun…

Guess the bottom line is I now have 3 magazines for this handgun…

Is what it is…

Thanks…BCB

lefty o
03-11-2018, 05:10 PM
grab the slide on your auto pistols, if you can move the slide up and down on the frame by hand, a magazine below it can do the same thing, and that is how they can affect accuracy. this is not a new phenominon.

BCB
03-18-2018, 04:20 PM
Finally had a half-decent day, weather wise, so I went to my range and fired another group using the new short magazine that Kimber sent me to replace the “no name” one that came with the Micro 9…

I used sandbags to lay my entire forearm on and two sandbags to support my shooting hand and the handgun…

Group was shot at 30 feet as where the others…

This group impacted a different location than the one in Post #23, but this was due to fact of a different hold. This I never debated as to P.O.I. I know it will change depending on grip…

The issue with the NEW MAGAZINE is groups have become more consistent in sizes, no matter what the grip/hold differences are. The impact points may change, but 5 shots stay close together. This was not true with the magazine that came with the handgun…

I know there are some who say a magazine doesn’t affect accuracy and others who say it does. I believe I am convinced it just might affect accuracy as I have seen in a good many cases since I got this replacement magazine from Kimber…

I also shot 10 rounds, at a steel target 45 feet away. All 10 stayed in a group the size of a baseball. This was with a good sandbag rest and I consider that “very good” for me as the sights and target basically become a blur as I continue to shoot rounds. The original short magazine never would have place 10 rounds this close together—it wouldn’t allow that even at 30 feet…

So, I’m convinced the old magazine, with one notch, was the problem with accuracy…

And, if rfd is correct and my test is flawed, I am happy that it has remained consistently flawed!!!...

Good-luck…BCB