FSB ???

[TacDoc]

Hello folks,

Does any one manufacture an A2 Front Sight Base "F" Marked that uses clamp/screws instead of pins?

I have a Noveske bbl that don't want to cross drill (just in case I change my mind with the build).

If not, anyone have an idea/tutorial/link to modify a new one. Who have new FSB for sale? Does this FSB comes with or without the pin holes?

I'll appreciate being pointed in the right direction.

Thanks.

[C4IGrant]

Hello folks,

Does any one manufacture an A2 Front Sight Base "F" Marked that uses clamp/screws instead of pins?

I have a Noveske bbl that don't want to cross drill (just in case I change my mind with the build).

If not, anyone have an idea/tutorial/link to modify a new one. Who have new FSB for sale? Does this FSB comes with or without the pin holes?

I'll appreciate being pointed in the right direction.

Thanks.


Not sure I quite understand. Do you have a FSB installed now and want to change it to an Flattop rated FSB?


C4

[AR-15A3]

Bravo Company USA sells F type FSB with bayonet lug without pin holes.

You could have them tapped and four set screws installed and it would be better if you have your barrel machined with four flat surfaces common to the set screws.

Fulton Armory sells FSB with set screws installed but I'm not sure if they're the F type FSB or just the standard A2.

[TacDoc]

Bravo Company USA sells F type FSB with bayonet lug without pin holes.

You could have them tapped and four set screws installed and it would be better if you have your barrel machined with four flat surfaces common to the set screws.

Fulton Armory sells FSB with set screws installed but I'm not sure if they're the F type FSB or just the standard A2.

Thanks, just what I was looking for. What size set screws are prefered, 8-32 x 1/4 or 10-32 x 1/4?

[rob_s]

I have a Noveske bbl that don't want to cross drill (just in case I change my mind with the build).

What's on the Noveske now in the way of gas block or FSB?

[TacDoc]

What's on the Noveske now in the way of gas block or FSB?

This
http://i7.tinypic.com/4q6kuih.jpg

[AR-15A3]

Thanks, just what I was looking for. What size set screws are prefered, 8-32 x 1/4 or 10-32 x 1/4?

I'm not certain if there is a standard, if there is the CMP (DCM) match guys could have their own prefered size and the US Army's SDM-R rifle should also have a standard size, they could be different or even be the same size.

If you don't get a satisfactory answer here maybe ask ADCO, AR15Barrels.com and for sure Compass Lake Engineering would know because they specialize in CMP competition rifles.

http://www.compasslake.com/


I've seen a DIY thread at the other AR site which a member there used a 10-31 tap and he drilled it prior to # 21 size drill, he also made a taper in front of the set screw to a point and finally used red Loctite thread locker to prevent it from moving.

CMMG Inc. also sells A2 FSB with set screws, fourth up from the bottom of the page.


CMMG - Sights/ Gas Blocks/ Scope Mounts section (page 1) website link (http://cmmginc.secure-mall.com/shop/?shop=1&cart=691548&cat=5&noCookiePassThrough=Y&PHPSESSID=df5765cd2af99e0dd9e60f335c405c07)

[TacDoc]

Thanks AR-15A3!

After reading a lot about FSB's the general consensus is that a pinned FSB is the MOST RUGGED/SOLID way to go. So now I'm dealing with the idea of pin it myself.

I already placed an order for an undrilled F marked FSB and decided to use NON-taper pins (like LMT). I have a good drill press and drillbits.

What pin/drill bit size should I use? What size LMT uses?
Does someone here have any idea of how to support the FSB/bbl in place during the drilling process, besides using a jig?

Months ago I straightened this Romy AKM canted FSB with 1/8 SS pins (note the two shinny spots), but needed no jig for drilling the new holes as the bbl/FSB fit was very tight.
http://i8.tinypic.com/6649dap.jpg

Thanks for sharing your knowledge.