I found some posts on this topic and recognize that my new Mini-14 (580-series) isn't going to be a tack driver. However, what weight ammo is most likely to group best?
- 40 gr
- 50 gr
- 55 gr
- 62 gr
- 69 gr
- 77 gr

Want to use it for coyotes. AR-15 not an option in my State.

Hunter308

Bullet weight selection is dependent upon barrel/bore twist to a large degree. I believe your Mini 14 would have a 9 twist which would work fine with the 55gr upward to the 69gr range. It may well shoot OK with heavier, 77gr, bullets. Some earlier Mini's had a 12 twist and accuracy suffered when attempting to use the heavier range of bullets. I would try the 69gr Sierra MK's for seeing just how accurate the rifle/load performs. You should also do well with the various 55's out there.
I understand the newer Mini's are more accurate than the older ones, but as you say, not going to be match level accuracy, but plenty good enough for varmints, plinking, etc.

I have an early 90's Ranch rifle Mini-14, shoot mostly 55 grain bullets and some 60 Nosler Partitions. It seems to like these weights. Doesn't do quite as well with the 50 grainers. I am getting 1.5"-2" groups with cheap ammo after a couple of mods.
I pinned a gas deflector/flash hider on it and a recoil buffer and I retorqued the four front screws.

My mini 14 shoots those 55gr bullets best, The 69gr bullets not to fast.

I don't own a Ruger Mini-14 (or any Ruger long guns for that matter) but a friend has one that actually shoots fairly good.....he uses only 55 grain bullets in it.

55 grain Winchester 5.56 white box.

What about using the Winchester 64 gr Power point .I use looaded a bunch to see how they fly.

There are the semi-point bullets which are short for weight and have longer bearing surfaces. They might make a difference in accuracy.

I have found that the Ruger Mini can be picky about bullet design as well. In all the different mini's I have delt with the flat based bullets work much better. When starting out with load develpment I would start with a 55gr flat base.

I have had good luck shooting 68 gr. hollow points. I have gotten 1.5" groups with these and two whitetails. This is an older Mini 14 also. My Mini 30 is completely opposite. I get 4-5" groups with it.

I shoot 55 gr bullets is my mini's. Seems to work the best. They are 1.5 to 2 in rifles. I have shot some sub 1 inch groups with some of them but not very often. With mil spec ball all one can expect is around 2 inchs. But that is the same for most AR's.

Feed a AR better ammo I belive it is easier to get them to shoot better then a mini. I have had no trouble killing things out to 200 yards with my ranch rifles.