I have a typical mini 14 which shoots about 4-6 inches at 100 yards. I have been doing much reading on other websites about the effects of muzzle brakes on these guns.
The consensus is that adding a brake generally cuts the diameter of the group size to around 2 inches.
The design of the brake having little effect on things, but the added weight apparently does something to the harmonics of the barrel when fired.
I have had better luck following advise of the folks on this board. So thought I'd post it here.
Is there any truth to all this muzzle brake mess? Anyone have any experience with this?
Years ago, I had a mini 14 that was a good shooter, it had a brake/suppressor attached to it. I don't know if this is coincidence or if they really help out. Unfortuanately I had to sell the rifle way back when because of a lack of funds in my budget.

2inch groups I can live with, the 6 inch that it currently produces.....well..... I reckon I'd be better off with one of those wrist rocket sling shots.

What is the difference between a flash suppressor and a muzzle brake?
They sell cheap Double Muzzle breaks at cheaper than dirt for around $20. They call it legal. I dont know the difference.

I too have heard that a muzzle brake improves the accuracy of a Mini-14. Whether or not there is an exact percentage it will cut your groups depends on the rifle. All will perform a little differently. You can read up on accuracy upgrades for the Mini-14 at www.perfectunion.com/forums.

The difference between a flash hider and a muzzle brake is the task they are designed to perform. A muzzlebrake is used to reduce muzzle climb and felt recoil, whereas a flash hider is intended to reduce the muzzle flash of a weapon. The terms are not interchangeable. One interesting thing about a Mini is that you can put a flash hider on them if they have a non-pistol grip stock or other features that would prohibit there use. That's why the M1A can have a flash hider (unless you are in CA).

I put a Smith Enterprises brake on my mini and it shoots 2-3" at 100 yards. Before that, I was only shooting at 50yrds, so I'm not sure what the difference at 100 was. BUT - I was getting the same size groups at 50 without the brake that I am getting at 100 with the brake.

hope that is helpful.

Tony