Carry Handle to Flat Top Help

[TimBoothe]

Hi folks,

I'm going to take a long barreled Bushmaster with a carry handle and change it over to a flat top so that I can mount an introductory level 1-4 scope, probably a Millett.

I have several questions that I'm hoping to get some help with.

Will my fixed front sight get interfere with the scope and if so, how to remedy the situation?

What tools are absolutely must haves to do this, I'm assuming an armorers wrench, what else?

Assuming that I can keep my front sight, all I'll need is a flat top upper, a flip up rear BUIS and a good mount for the scope. Am I missing anything?

As far as the mount, I'd like to do something that is a quick release. I'm more concerned about the mount failing than the scope. Is there anything out there besides Larue that you folks could recommend? I'll probably end up going with a Larue, but would just like to know if there is anything out there that is comparable for less money.

Thanks for the help folks.
Tim Boothe

[Heartbreaker]

1. No it won't interfere. You won't be able to see it on 4x, and at 1x it's there but not noticeable.
2. Armorer's wrench and an action block or barrel vice. You could use vice grips even but you are likely to put some gouges in the barrel. I think midway has action blocks for fairly cheap. Can't hurt to get go/no-go headspace gauges either.
3. Bobro and ADM also make nice mounts, all similarly priced.

[bkb0000]

you'll need a GOOD receiver block.. i recommend the DPMS "panther claw," and if you really want to do it right, get a good barrel wrench, rather than the generic and various armorers wrenches that circulate gun shows.

you might also consider upgrading to a free-floating handguard, depending on your accuracy needs. you said you want to do 1-4... it can make a pretty noticeable difference, depending on your needs. whats the weapon for?

as to the FSB- you'll notice some shadowing in the bottom of your optic, especially at lower powers. at 4x, it won't be nearly as noticeable... whether or not this is tolerable to you will just depend on you, and your optic (some ghost more than others, depends on the aperture size). if you can't stand it, you can replace your gas block with a folding block, like the ARMS folder or, better, the vltor model.. or if you end up going free-float, you can just chop down the FSB, run your handguard out over it, and install front folding buis. you pretty much have to have a free-floated guard to put your front sight on it, if you want your buis to hold anything resembling a zero.

as to mounts... ADM is a slightly less expensive alternative to Larue.. ARMS also has some less expensive models, but ARMS isn't an incredibly respected manfer for a number of reasons.. their mounts tend not to hold up nearly as well as ADM, Bobro, or Larue, and their company business practices are abhorrent.

sounds like you're still learning... these answers are pretty basic, and i recommend you keep reading for a while and get a little more comfortable with these different topics before you start disassembling, hacking, and spending.

[Eric D.]

I also recommend the DPMS panther claw. Rather than an armorer's wrench, I'd suggest the Precision Reflex barrel nut wrench, it has five points to grip the barrel nut. The only downside to this wrench is that it is made like a box-end wrench and you would have to remove your muzzle brake and FSB to slip it over the barrel. You could, however, cut a section out or the barrel nut wrench so it can be put over the barrel like an open-end wrench. I plan on doing this to mine. as said above, a free float is a nice upgrade as well.

[usmcvet]

As with most things the right quality tools really do help. I bought a cheap wrench for my castle nut and it sucked. Bought the hammerhead wrench next and it is awesome.

Brownells has some decent how to video clips on their website.

[Eurodriver]

If you are doing this for the knowledge, which is definitely a good enough reason, then go ahead.

But if you simply want a flat top, it'd probably be cheaper, and definitely easier, to buy a new upper.

[usmcvet]

I agree with Eurodriver. The tools will add up quick. BCM has been selling uppers for about $380. You could keep or sell your current upper and use the money to buy the upper you want. I wanted to build a lower and when I did the math a factory LMT or BCM lower was alot cheaper. A BCM blemished lower was even cheaper.