So I have my new 580 series tactical mini-14, and I am thinking about
what 'improvements', if any I should consider. This is my first Mini I
about 10 years, and am hoping the reports of improved accuracy are
accurate. I only want a 2 MOA gun - not expecting a tack driver.
The ones I've shot have been about 2 MOA.
Based on what I am hearing, I am considering the following mods:
Heavier recoil spring. Wolff recoil spring since I am told by many the
gun is undersprung and really batters the action.
Recoil spring buffer: see above
As with almost any semi-auto, the recoil spring is not designed to cushion the action so much as to store up energy. It doesn't need to be any stronger than necessary to chamber the next round. While an excessively weak spring may contribute to premature wear, the stop surfaces are intended to sustain repeated impact, so worries about battering the action are kind of like worrying about battering your sledgehammer by breaking concrete. Recoil buffers may also degrade reliability by shortening the length of the stroke.
A more important consideration is that springs work both ways. Given that the Mini uses a floating firing pin, you probably don't want to be slamming the cartridge into the chamber with any more force than is strictly necessary.
Smaller port bushing. I don't need brass thrown into the next county
but I want 100 percent reliability, so not sure about this one.
This is a good modification. Mini-14s aren't so much undersprung as overgassed. The direct impingement gas system plus generous bushing apertures allow it to remain reliable given severe neglect. Provided you clean it at all, you will not notice a reliability decrease from a smaller bushing.
My 16" Tactical model loves to chuck brass, much more so than my father's 18" Ranch Rifle. Even after dramatically reducing the bushing diameter using bushings purchased from Walkenbear on the perfectunion.com forums, it still throws brass about 30 feet and dents it some. This is fine by me, as it's defensive gun and therefore reliability takes precedence; just be prepared to experiment a bit with bushing sizes, and know that getting the gas block off the first time is going to be a hair-raising experience. (Those staked bolts really don't want to come off.)
As for the line between reliability and gentleness, my rule of thumb has always been that with a fixed-ejecter system like the Mini-14 uses, cases ejecting forward is a sign of insufficient ejection power relative to the extractor strength.
Stone sear. I considered the Accuracy Systems adjustable trigger, but
don't know if it's worth it for a field gun.
Your call. My Mini came with a horribly creepy trigger, so I sent it to Bill Springfield to have the break cleaned up but weight retained.
Ultimak rail: Possible. Depends on if I put an optic or not. Also not
sure how it will effect accuracy.
I got one and like it a lot, especially when paired with a red dot type optic. You can technically co-witness through a tube sight, but the sights are so low that this occurs right at the very bottom of the sight.
Here's a photo of my setup (click for larger):
I've noticed no accuracy difference with the Ultimak rail, but then I haven't tested the gun for accuracy since installing it.
Finger adjustable rear sight. Does anyone make one for the 58x series?
Looks like the Accuracy Systems only fits 180x series ranch rifles.
I don't think anyone makes one of these. One option could be finding thumbscrew style round screws that fit the threading on the sight, which will at least allow you to adjust it without using an allen wrench. Supposedly the earlier models had some warranty-voiding modifications that could be done to install an M1 Carbine rear sight, but that has the additional disadvantage of being tuned for .30 Carbine ballistics and therefore being something of a hack. For ad-hoc shooting, you might be better served with an M4-style battle zero that takes advantage of .223's flat trajectory to allow hits at the widest variety of ranges. Pair that with an optic and you've pretty much eliminated the need for adjustable rear sights.
Any other thoughts? I don't want to turn this into a $1500 rifle. Just
looking for low cost, high payoff add-ons/fixes.
If the length of pull provided by the factory plastic stock seems a little short for you, a Hogue stock will make the rifle feel a little fuller and will space it out a bit more for a bladed stance. FYI, the LOP and trigger location for the factory stock with rubber buttplate is almost identical to that found on an M14.
As mentioned above, I'd eschew alteration of recoil springs or addition of buffers, as those aren't going to gain you much and could introduce costs you don't want. Gas bushing changes are the right way to go about reducing recoil and ejection distance, provided you don't mind modifying your gun.
If you put optics on your Mini, don't cheap out. A ring-mounted scope on the receiver will have to contend with fairly violent recoil, which many of the cheaper models can't handle. The aluminum Ultimak rail will act like a heatsink on the barrel; theoretically, this should minimize POI shifts and add stiffness to the barrel, but one practical side effect is that any optic attached to the rail get really hot during long strings of fire. Inexpensive optics often can't take the heat.
As for the trigger, as long as it breaks cleanly, I'd leave it as-is. Trigger quality enhances the component of accuracy provided by the shooter, but if the Mini is used as a field rifle, the inaccuracy introduced by field positions and the mechanical limitations of the rifle is going to diminish the value of trigger work.
The only other advice that I'd offer is to shoot it a bunch before jumping into any alterations, then only change the parts that get in the way of your enjoyment. Too many people jump into modification for modification's sake; n.b. the number of 1911 threads where people who have just bought a "GI" style 1911 ask, "what should I change on it?" If you're not sure what to alter, shoot it until areas for improvement jump out at you. That way you spend less and know that the money you spend produces a positive result, and on top of that you end up with something customized to your exact intended use, with no extraneous features to get in the way.
