Badger Arms
Member
Looking at the book, Ruger and his Guns, I found that the twist rate of the Mini-14 started out at 1-in-10" in 1975. It then changed to 1-in-7" in 1989 and then finally to the current 1-in-9" starting in mid-1994. I'm wondering if this might result in the reports of poor accuracy we get often on this board. If you're shooting Military Ball ammo of the 55gr fodder out of the 1-in-7" barrel, you're not likely to get good results even in an AR.
The serial numbers are approximately:
1989: 185-56000 or for the Ranch Rifle: 187-84000
1994: 186-35000 or for the Ranch Rifle: 188-75000
These are rough numbers and I don't know if any better numbers exist. Any guns made before these is likely to be 1-in-10" and after these is likely to be 1-in-9" Twist. Inbetween you'll have 1-in-7" twist. Understand that for accuracy, none of these twist rates does an admiral job on the most common type of ammo available, the 55gr FMJBT.
So what does all this mean? If you have accuracy problems with your Mini-14, don't ditch it. Find out what your twist rate. If you're close, perhaps you should do the cleaning-rod/jag trick. Wrap a piece of tape around a cleaning rod and mark a line along the bore axis in . put a tight-fitting patch on a jag and run it down the bore. Count one turn and measure how for it's gone. This can get you pretty close, close enough to tell if the serial numbers above get you too close.
Now, if you have a 1-in-7 twist barrel, only buy 62gr or heavier bullets for it. In fact, I'd suggest 69 or 70gr bullets as that's about what your twist rate is optimized for. All other things being equal, you should see an increase in accuracy. If you have the slower twist rates, I'd still stick with a 62gr bullet and don't go down below 55 if you want it to be accurate. Just a suggestion, it might save you from ditching a good gun because you fed it wrong.
BTW, my current Mini's are 1976 and 1996 years of manufacture. My inventory Mini's are both 1-in-9" twist guns. I'll have to switch to the 62gr bullets and see if I can improve. Has to wait till summer, though.
The serial numbers are approximately:
1989: 185-56000 or for the Ranch Rifle: 187-84000
1994: 186-35000 or for the Ranch Rifle: 188-75000
These are rough numbers and I don't know if any better numbers exist. Any guns made before these is likely to be 1-in-10" and after these is likely to be 1-in-9" Twist. Inbetween you'll have 1-in-7" twist. Understand that for accuracy, none of these twist rates does an admiral job on the most common type of ammo available, the 55gr FMJBT.
So what does all this mean? If you have accuracy problems with your Mini-14, don't ditch it. Find out what your twist rate. If you're close, perhaps you should do the cleaning-rod/jag trick. Wrap a piece of tape around a cleaning rod and mark a line along the bore axis in . put a tight-fitting patch on a jag and run it down the bore. Count one turn and measure how for it's gone. This can get you pretty close, close enough to tell if the serial numbers above get you too close.
Now, if you have a 1-in-7 twist barrel, only buy 62gr or heavier bullets for it. In fact, I'd suggest 69 or 70gr bullets as that's about what your twist rate is optimized for. All other things being equal, you should see an increase in accuracy. If you have the slower twist rates, I'd still stick with a 62gr bullet and don't go down below 55 if you want it to be accurate. Just a suggestion, it might save you from ditching a good gun because you fed it wrong.
BTW, my current Mini's are 1976 and 1996 years of manufacture. My inventory Mini's are both 1-in-9" twist guns. I'll have to switch to the 62gr bullets and see if I can improve. Has to wait till summer, though.
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