Bad impacts on target

[Fuch]

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 .

 

[buckshotshorty]

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

 

[Ruger 13]

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

 

[Fuch]

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 !

 

[stansdds]

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.

 

[RWJ]

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

 

[Johnnu2]

Are your stock screws tight?

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

That's it for me !!

J

 

[Dave from Pa]

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.

 

[Fuch]

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.

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 !!

 

[BE Mike]

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

 

[CH4]

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.

 

[DWalt]

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.

 

[Llance]

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.

 

[Greyman50]

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.

 

[Fuch]

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

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

 

[cmj8591]

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.

 

[CB3]

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

 

[duman444]

scoped pie plate accuracy

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.

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.

 

[S&WIowegan]

Mini 14s

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.

 

[desi2358]

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.