hello all
yesterday during my shooting session with my Ruger mini 14 223 rem, I noticed that several impacts arrived askew in the target, this did not happen with each shot but around 6x out of 25 shots, (see attached photos ) could you tell me what would be the possible causes of this? I would point out that I had some problems with the 30-shot magazine the edges guiding the cartridges were a little distorted and the rearming was sometimes failed, I do not know if this could be one of the causes of the problem, but I solved that .

Attached Files

impact travers1.pdf (1.07 MB, 316 views)

Wow! I have never seen anything like that before. Those bullets are severely tumbling???

How old is the mini 14? Perhaps the muzzle is worn?

Hello
it is a series 182, year 1981, it is true that it is not very young, but I have already fired a few cartridges with it and it is the first time that I have this problem !! it is a weapon that I bought in 2nd hand, I do not know its past but my gunsmith where I bought it is competent and trustworthy, I sent him the photos of the target, I am waiting for his answer !

You definitely have poorly stabilized bullets and they are tumbling. This can be caused be a very worn barrel or a barrel that has an oversized bore. In the same vein, undersized bullets will also tumble. Another possibility is that the bullets are not being properly stabilized due to the rifling twist rate being too slow. A poorly designed or poorly attached muzzle device could also induce the occasional tumbling bullet if that device makes contact with the bullet as it exits the muzzle.

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VCDL, GOA, NRA

Is it possible that you have ammunition mixed, with different weight bullets? I have seen similar occurrences when firing 62gr. M855/SS109 out of older AR-15/M16 barrels with a slower twist.


IIRC, DSS utilized the Ruger AC556K as one of their early long guns (phased out in the '90s), and it was specified to use 55gr. FMJ ammunition only; the M16A2s were using the 62gr. bullet as the duty round, until the M4 came around.


I believe the twist rate for those earlier guns was 1:10, but I can't find my notes right now.



FWIW


RWJ

Are your stock screws tight?

Are you using .224" bullets and not the old .223"...?

That's it for me !!

J

Too slow of a twist or too heavy of a bullet will cause the round to key hole.Low velocity will also do this.An improperly installed muzzle device could also be a cause.

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SWCA#2288
SWHF#407

during these shots I actually used reloaded ammunition and also other manufactures but I cannot define which cartridges caused these weird impacts, I carefully cleaned the flash hider and the barrel with Hoppe's copper solvent the next time I will shoot with manufactured ammunition 55gr and I will see the result let's wait and pray !!

This is classic "keyholing". You probably were shooting bullets that aren't compatible with the twist of the rifling in your barrel.

What's the twist rate of your rifle v. the bullet weight you're using? Have you used this combination before? Your rifle definitely isn't stabilizing the bullets.

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213th FBINA

Actually, bullets in flight do not tumble (i.e., end over end), but they can yaw severely if they are not spinning rapidly enough to become gyroscopically stabilized. Heavier and longer bullets require a faster rifling twist rate to stabilize them. If there is "keyholing" evident on the target, it will most likely be the result of a rifling twist rate which is too slow for that bullet length and weight. It can also occur if the bullet itself is grossly unbalanced, but that is unlikely. Another posibility is that there is some device on the gun's muzzle, such as a flash suppressor, that the bullet can graze as it exits. I remember reading something about early M14 rifles having that problem with their flash suppressors.

Regarding firing the M855 5.56 round (green tip) in one of the original slow twist (1:12) M16 barrels designed for use with the early M193 round having a 55 grain bullet, bullet instability is a problem with the 62 grain bullets, especially in very cold temperatures where the air is denser. However, even so, bullet yaw is not too severe out to around 100 yards. That's why the later M16s switched to using a 1:7 rifling twist, to adequately stabilize the 62 grain bullet under all conditions.

older rifles had a twist rate of 1/12 whereas newer rifles have a twist rate between 1/6 to 1/9 in order to stabilize the heavier bullets.

The older mini14's have a twist rate of 1/12 and should only be shot with 55gr bullets for proper stabilizing. Unless you don't care and want to do the most damage to the AH who is barging into your house.

All I’ll say is had an early mini-14, would only shoot “ barn door” MOA, hard to believe but traded it straight for a M-1 Garand which I gave to my son.

55 g fmj i used since a long time with any problems before yesterday !! i don't understand i hope as the barrel is not too much old

Either a bullet too heavy to be stabilized by the rifling twist or ammo that is not driving the bullet fast enough to be stabilized or a combination of those two factors gets my vote for this problem. If you fire the factory 55 grain bullets and get the same result, then the gun has a problem.

The key-holed bullets look more like 62 grain bullets rather than the shorter 55 grain.

OP does not mention what distance he was shooting and whether the gun was scoped, but my early Mini 14 shot groups like that with a scope (no keyholing, though). Did not matter what bullet weight was used, tried 55 to 72 and could not get better than pie plate at 100 yds.

This was before AR's came down in price and became more popular. As soon as I shot a scoped AR, the Mini14 went on the market and out the door.

I have a Ruger Mini-14 I bought in the early 1990s. It was never very accurate and I learned from others that Mini-14s were known for this. Ruger supposedly changed the barrels in newer guns. My gun is in the back of my safe and hasn't been shot in over 20 years. Mini-14s were really "spray and pray" guns originally.

One possibility is your barrel may be severely fouled and needs expert cleaning attention.

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Bob.
SWCA 1821

My old Colt SP-1 with the 1 in 12 twist would do this with 62 gr bullets. Stable enough to get to the target but cut sideways holes when they did. The older barrels weren't rifled to properly stabilize the heavier bullets, one of the main reasons for the faster twists used on modern AR platforms. Suspect they were yawing bad enough to go sideways the instant they touched paper. It was strange because some would cut normal holes while others gave me those bullet profile shaped ones. I stuck to the 55gr bullets from then on and since the gun has migrated to my sons house it's his problem to make sure it gets fed the right ammo now lol.

It's not the bullet's weight so much as it's the bullet's length which requires a tighter rifling twist to stabilize it. I won't get into the details, but once I was evaluating .223 frangible bullets which were jacketed around a copper/polymer composite core. They weighed around 45 grains and were fairly long, longer than the 62 grain M855. I was using a 1:12 twist rifle, and I experienced many keyholed bullet holes at 100 yards - and grouping was poor. They performed much better in an M16A2 with a 1:7 twist barrel, no keyholes. Also worked fine in an M249, same twist as the M16 as I remember.

I was Army 1965-67 and never got my hands on an M16 because they went straight to Nam. One buddy went through OCS and artillery school with M14s. When he got to Nam he was handed an M16 and one mag full to qualify. The early M16s did not stabilize the bullets. The Army said that was OK because the bullet made bigger holes. That works if the guy is close enough be get hit. Secretary McNamara may have been in error, but never in doubt.

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Bob.
SWCA 1821

The earliest M16s had 1-14" twist barrels. While those worked OK to stabilize the 55 grain bullet of the M193 round, in cold weather, it would not stabilize the companion M196 tracer round bullet, which was somewhat longer. So the M16's rifling twist was speeded up to 1-12". Later, when the M249 was adopted, which was intended to use the M855 round (green tip with heavier 62 grain and longer bullet) and had a 1-7" barrel, for the sake of ammunition commonality, the M16 was changed to use the same 1-7" rifling twist of the M249. Actually, the M855 round is not that terrible when used in a 1-12" barrel, it produces good enough grouping to do an effective job on a human-sized target at 100 yards but you won't win any matches with it. It is incorrect that the early M16s would not stabilize the M193's 55 grain bullet.

Fuch,
As mentioned in previous posts, the classic keyhole profile on paper tells the tale. Also you have a couple other oval holes that testify to the bullet starting to yaw and destabilize.
223’s with the slower rate twists will not stabilize the longer/heavier bullets, which is why there was a move to 1/7 & 1.8 twist barrels.
As I understand your post # , you are shooting 55 grain bullets.
Those certainly should be stable in your Ruger. I would try shooting another 55 grain bullet, and or have your gunsmith scope that barrel and see of you have issues internally.

I come back from the shooting range and I believe I have found the source of the problem of bad impacts in the target: it is the magazine which is in question, during the transfer of the bullet from the magazine to the chamber the edge of the magazine deforms the cartridge , I took pictures of the deformed cartridges that I removed manually after chambering, I then made about twenty shots per shot by loading the mini 14 manually without a magazine and no more bad impacts, I am reassured because the barrel is intact, now I just have to buy new chargers !! [B][SIZE="5"]

Attached Images

balles mini 14 déformées 2.jpg (47.5 KB, 62 views)

Wow! I am surprised the round would even chamber and allow the bolt to go into battery with the round in that condition. I have been shooting Mini 14’s since the 80’s and the only magazines I have found to function reliably are the Ruger factory magazines. They cost more than the after market mag’s, but function well.
Don”t know if those are available at your location.
Glad you found out what the issue was.

thank you for your answer yes your remark is relevant, I am also amazed that the cartridge can enter the chamber in this state may be the force of the breech spring straightens the bullet a little, that leaves me in doubt, but in any case this does not come from the ammunition or the barrel because as I specified I fired by reloading manually shot by shot and the problem disappeared

That was my first thought - how could those rounds even chamber? But beyond that, I can't imagine how than much case bending even happened. I've not seen anything like that before.

My early one was the same way. Gone and replaced with a much more accurate AR.

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S&W Accumulator

that's for sure yesterday at the shooting range I took my mini14 and my AR15 ruger, the AR is much more precise, but despite that I still adore my mini14 which is superb !!

My first experience with Keyholing was when I owned two Bisley model Rugers.

One a Blackhawk chambered in .45 Colt, the other a Super Blackhawk .44 Mag.

I was shooting 240 grain cast .44's at 25 yds and noticed some holes that just didn't look right. Before I even looked at the revolver, I knew exactly what I had done. Luckily the .45 Colt didn't so much as hiccup from the undersized rounds.

Youthful haste lead to carelessness.


I've seen keyholing few times since, but not because I picked up the wrong ammo or firearm!

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GOA
USA Shooting Supporter

OK, we used early Minis in industrial quantities. While not varmint guns, they generally shot acceptably* and were extremely reliable. The twist rate in the early (180-18? series) guns was 1-10 which would stabilize up to and including the 69 gr SMK. I have no idea what the OAL of the 62 gr slug is, but if longer, could possibly cause issues.

Ruger refused to sell 20 and 30 round magazines to the general public for quite some time. This resulted in a lot of companies getting into the magazine business and the quality ranged from decent to awful. It would appear you got one of the awful quality. Pick up some Ruger magazines if you can find them. John Masen also makes some very good magazines.

*Due to what I think is the design of the gas system, if you rest the forend on something hard or mount a bipod there, strange things happen to your point of impact. Usually by hitting really, really low. It may or may not affect groups.