Front Sight removal

[SIGSHR]

In endeavoring to remove and replace a broken front sight from my 1978 vintage Remington M870 barrel with rifle sights, I find the front sight is so
securely wedged in that even using a 2lb mallet isn't budging. Sprayed some
penetrating oil on it, meanwhile, is there a tool-somewhat like those made to
adjusted fixed rear sights on semi-auto pistols-available?

 

[Dfariswheel]

The Williams sight pusher tool is one of the best:

http://www.brownells.com/aspx/NS/store/productdetail.aspx?p=16152&s=

The Remington front sight ramp is brazed on the barrel, but if you pound on it hard enough, you can knock it off, or even distort the barrel itself.

 

[SIGSHR]

That looks like what I am looking for, I am trying to remove the sight blade,
not the entire ramp.

 

[Picher]

If you're not willing to buy a Williams tool, or just don't want to wait for one, you can still remove the front sight by using a vise.

Just stick a couple of 1/8" thick pieces of brass on one jaw face, spaced to straddle the sight dovetail. Stick a piece of steel on the opposite jaw that's narrower than the top of the dovetail. Double-stick tape should work to hold the pieces of metal on the vise jaws.

Carefully place the ramp upside-down in the vise and tighten the vice to push out the sight blade enough so it can be knocked out with a hammer and pin punch.

Picher