Newb gas block question

[Xstang77]

first time tinkering on an upper, installing a free float on my spikes m4 le style upper which the fsb pins were so tight I broke my starter pins until my air hammer got them moving easily, my deal is im installing a low pro Troy gas block in its place/screw on from what I've read you should dimple the barrel for the screws, however I noticed the screws will go where the notches are cut for the a2 fsp, so do I just loctite and run the screws into those notches using them as my dimples? Also if I wanted to revert back to the a2 at some point won't the gas block screws mess up the notches?
Thanks in advance.

[tehpwnag3]

If it were me, I'd save a little money (return the Troy) and keep the stock FSB. Then cut it down, check for clearance, cold blue it, and it will be hidden under the rail. Pretty much bombproof.

[Xstang77]

I was thinking about doing that originally but wanted to
Save the parts and option to easily go back to an m4 carbine look if I wanted, am I opening myself up to possible reliability issues by doing this on a barrel that originally had an a2 fsp?

[tehpwnag3]

If there was a chance you'll go back to stock, don't muck up the pin slots. Maybe try a clamp style gas block instead of set screws. Still though, if this is going to be a fighting gun, I'd strongly suggest that it be pinned OR do what I prefer and keep the FSB intact. Simple, strong, reliable.

[Xstang77]

Guess I'm at a cross roads then, wonder what most guys do in this case aside from grinding the a2,seems to be a very common thing to replace it with a set screw low profile

[MistWolf]

I would cut down the original FSB and reinstall with the taper pins. Trying to use the set screws where the pin holes ate is going to do nothing but cause you heart ache. If the metal is thin enough, it will collapse as the set screw tightens down.

Clamp on gas blocks are larger and may give you fitment problems with you free float tube. They also place strain on the clamping screws which can lead to the screws failing

[Xstang77]

Ok so then in my situation since there was notches from an a2 grinding one down is the best way, next question, from what ive read no 2 fsb pin locations are the same? So I can't just buy a spare one to grind down and reinstall in the original notches and keep the old on intact?

[tehpwnag3]

Nope. They are unique and IMO would be cost prohibitive to retrofit a new one. Up to you though.

[MistWolf]

If you think you really are going to restore the barrel to the original configuration after grinding down the FSB, buy a replacement barrel

[556BlackRifle]

There's a pretty high likelihood that you'll never go back to using the FSB on that barrel. There are a lot of guys on M4C that have cut them down and are very happy with the results. Personally I've just replaced the FSB with a low pro block - but I've never gone back to using the FSB again. (I have several FSB sitting in my parts bin.) Bottom line, next time I'll cut and grind.