If you don't use optics, the factory sights are a little crude for accurate shooting beyond 50 to 75 yards. The standard Mini rear sight only offers 1-MOA adjustments and the front sight is too wide for a good sight picture out at 100 yards and beyond. I don't use optics on mine and prefer the Williams Foolproof Target rear sight as shown below. As for the front sight, I reduce it's width to .070" by milling the upper half of the blade on both sides, also shown in the photo below. This creates a very precise sight picture. The sights alone will not make your rifle more mechanically accurate, but will let you shoot it more accurately. If you don't have access to a milling machine or the skills to use one, you can do this with a file, if done slow and carefully. You can also have the front sight done by your gunsmith (extra cost).
FLASH SUPPRESSORS AND MUZZLE BRAKES:
The older Mini-14s with thin barrels have problems with barrel harmonics. Just by adding the weight of a brake or flash suppressor has been shown, in most cases, to signifficantly reduce group sizes. Sometimes this is all that is needed to reduce group sizes by 1/2. It will not however help with vertical shot stringing when the barrel heats up. This will be addressed later.
There are several flash suppressors on the market for the Mini, including a M-14 look a like with an integral rabbit ear front sight, which requires the removal of the standard front sight. Most of the flash suppressors are of the pin on type.
The true muzzle brakes on the market for the Mini are of the threaded type.They work very well in reducing muzzle rise and felt recoil, which allows you to shoot more accurately in rapid fire. The only drawback is that they require the barrel to be threaded by a gunsmith (extra cost).
Be sure to check your local or State laws regarding flash supressors and threaded barrels. Some States don't allow them...........
The photos below show the only true pin on type muzzle brake/comp available for the Mini-14. Even with Nato ammo, there is zero muzzle rise and less felt recoil with this brake. It is also Cali legal. I can be contacted via PM for more info and availability of this brake.