Has anyone had experience with the bolt on GG&G / PRI Front sights?

[ROUGH]

The reason I am posting this question is because, I have an LMT 16" M4
Carbine Barrel that has a slightly canted front sight and the front sight
channel is slightly milled off center to the left. Compounding the windage
more than just the very slight cant. Causing my BUIS to have 15 clicks to the left
to zero @ 50 yards. The barrel is not over torque as I checked it and the final torque is at 48 ft-lb’s.
It is installed in a CMT Upper and the indexing pin allows no twisting movement in the upper.
I thought about sending to LMT, but I have already refinished under the FSB
with Norrels and don't think they would accept it for a repair or replacement.

LMT barrel markings

http://i19.photobucket.com/albums/b190/roguear/1.jpg

This is to show the front sight post is not directly above the hole for the
gastube. the gastube is centered directly over the centerline of the barrel.

http://i19.photobucket.com/albums/b190/roguear/lineup.jpg


I am interested in the bolt on flip up front sights and want to know the

GOOD, BAD, UGLY, of these two systems.


Direct description and picture from GG&G

RETAIL PRICE $173.50

The New GG&G Bolt On Flip Up Front Sight Gas Block is a top of the line flip up
front sight gas block system that is easy to install. The Flip Up Front Sight Gas
Block is secured in place by a Tri-Point clamping mechanism
guaranteeing consistent accuracy and trouble free operation. The
sculpted finger groove design is not only ergonomic but allows for quick
deployment. Manufactured from 4140 chrome moly billet steel with hardened
wear points and finished by a mil spec manganese phosphate process,
this unit is ready for rugged use. As a method of standardization the M16A2
square front post is used, which is fully adjustable for elevation zero.
Protective ears are provided for the sight with additional gripping serrations to
aid in raising and lowering the sight assembly. The GG&G Bolt On Flip Up Front
Sight Gas Block is equipped with a spring-loaded, positive wedge lock detent
system that keeps the front sight in the up position preventing accidental
lowering of the unit while maintaining on target repeatability. The locking
system is designed to be operated with one hand so that the fire control hand
does not need to be removed from the weapons fire control system to deploy
or lower the sight. Further, the sight comes equipped with a standard 1"-
inch, ambidextrous sling swivel that bolts to the gas block at a low position.
Additionally, there is a provision for the easy attachment of an optional MIL-
STD-1913, ambidextrous 1"-inch long dovetail for mounting flashlights, LAMs
and other small accessories onto the gas block base.


GG&G Front Sight

http://i19.photobucket.com/albums/b190/roguear/pg4_top.jpg



Direct description and picture from PRI

RETAIL PRICE $179.00

PRI Flip Up Front Sight w/ .750" Crossbolt Design FUFS-B Fits Barrels .750" dia.
M16 M4 and AR15 Eliminates the shadow cast on optical sights mounted on the
M16 Flattop receiver Lightweight aluminum top post Low reflection matte black
corrosion resistant coatings The sight post locks in the up and the down
position Solid 4140 cast steel base with
provision for the gas tube an integral part of the unit Accepts any standard
retrofit M16 front sight post.

PRI Front sight

http://i19.photobucket.com/albums/b190/roguear/05-0025.jpg

Thanks everybody have a good one ROUGH :)

[DPB]

I've got the PRI on one of my rifles. It was bought to try to fix a gas problem that turned out to be an improperly drilled gas port in the barrel, so it was $175 I didn't really need to spend.

Having said that, I like it a lot, and it will probably be the flip front I use in the future. It is extremely solid.

I wouldn't get caught up in the "cast base" thing. One, it's not a moving part, nothing should be impacting it, and two, I believe castings dissipate heat better than forgings, which would be a good thing in a gas block. I've also been told that's why engine blocks are cast, so the heat dissipates over the whole of the block.

I haven't seen the GG&G, but I can't imagine you being disappointed with the PRI.

doug

[Boom]

It looks like your tower is off by 2 or 3 thousands. Take a rubber mallet and give it a real hard smack on the non ejection side or the left side if you are looking at the tower from the back. This should correct your problem.

But to answer your question the GG&G tower is the better tower of the two models shown. You do have to send it to GG&G to have it installed. There is almost no play in the GG&G tower ver the PRI which has lots of forward play of the swing up arm/sight. The PRI you can install yourself if so inclined.

Of the two I have found the GG&G to be a much better sight. Its all steel and provides very smooth operation.

Edit: I just saw that you can install that model of the GG&G sight. I have no opinion of that model. Sorry for the misunderstanding on my part.

[Steel_Weasel]

I have used the GG&G modular folding front sight for years; the dedicated model not the screw on version, but I exzpect both are similiar in form and function. My big gripe about them, of which I informed GG&G and they disregarded is the fact that the 'wings' around the front sight are too thin and easily bent.