I thought this might make an interesting thread. If you have owned many guns, there are bound to be times you were disappointed in a particular gun.
My biggest disappointment was in a Ruger Mini-14 Ranch Rifle I bought in 2006. My idea was to use it as a coyote rifle. It was a lot cheaper than other .223 Remington semi-auto rifles. And I am a big fan of Ruger firearms in general. But the Mini-14 I got was a disaster as far as accuracy was concerned. I mounted an older Redfield scope I had from when I replaced the optics on a deer rifle. The scope rings provided by Ruger seemed secure and fit like a glove. So off I went to the range with 3 different brands of ammo.
The gun would not sight in worth a damn. I assumed it was the scope or scope mounting, or my inability to hit at 100 yards. I went home and bore sighted the gun again. Then I took a small gun vise I had with me to the gun range. I clamped the rifle into the vise, and put a 6'x8' piece of cardboard up at 100 yards. I figured that way I could see exactly where it was hitting and adjust the scope accordingly. My first 5 shot group had a spread on 9 inches. 9 inches! WTF? I put an additional sandbag on the clamp and got the same thing.
I tried a few more times but never got it anywhere near decent accuracy. The rifle was fun to shoot, and I never had any feeding issues. But a rifle that isn't accurate isn't of any use to me.
A coyote at 100 yards would still be killed.
A 9 inch spread for 5 rounds means one or two shots might kill a coyote. I expect much better accuracy, especially from a .223 or 5.56mm. My next attempt to build a coyote rifle was with a Bushmaster AR. It had a 24" bbl. I could put 3 shots on target at 100 yards. I shot numerous 1 inch groups, and few that were less than that.
That Bushy should shoot dime size at 100, fine rifles!!! Got the wife a "spike tactical" AR, she loves it.
I have a Howa (basically a mauser) 223, threaded, suppressed, Boyds stock, MKAr Leopould (made for 223) Oh my what a shooter. Twist is right for 50Gr hornady balistic tips. Twist very important with 223's and what weight is best bullet.
My Howa is my varmint gun, do my part and see it it's exploded.
I would never hunt anything that wasn't with the best it could be. May be varmints but they are souls and deserve quick, painless.