Rear sight for non F-marked FSB

[pubb]

So I just picked up a 14.5" Colt SOCOM barrel and it is not marked with an F. The brown truck o happiness has not gotten here yet.

1) if it isn't marked, might it still be an F-height? How can I tell?

2) if mounted on a flat-top upper, what would be an appropriate BUIS choice?

3) Can I just replace the front sight post, or will it stick past the protective ears?

Thanks

[26 Inf]

So I just picked up a 14.5" Colt SOCOM barrel and it is not marked with an F. The brown truck o happiness has not gotten here yet.

1) if it isn't marked, might it still be an F-height? How can I tell?

2) if mounted on a flat-top upper, what would be an appropriate BUIS choice?

3) Can I just replace the front sight post, or will it stick past the protective ears?

Thanks


1) I don't know if they are all marked. The F marked sights are 0.04 taller. According to what I have seen the distance between the barrel to the flat surface between the ears of the FSB is 1.98 on the F marked and 1.94 on the standard.

2) I have a sample of one upper with a non-F marked sight. I have a fixed Troy Battle Sight on it - works fine.

3) If need be you could replace, several places have tall front sights: https://www.knsprecisioninc.com/product/square-072-front-sight-040-taller/ (pricey) https://shop.windhamweaponry.com/products/9349056-mod This one is .030 taller: http://www.jsesurplus.com/midwestindustriesinc-1-1-1-1-1.aspx (least expensive)

[scottryan]

Colt doesn’t mark them with an F anymore if this barrel is less than a year old and is factory assembled.

They are still the correct F height.

You still need to use a military dimension rear sight.

[26 Inf]

Colt doesn’t mark them with an F anymore if this barrel is less than a year old and is factory assembled.

Wonder why, wouldn't the F already be in the casting?

In that case it seems like work/expense to remove it.

[scottryan]

Wonder why, wouldn't the F already be in the casting?

In that case it seems like work/expense to remove it.


The F is stamped in the forging after the forging is made. The same forging was used for F and non F front sight bases. The machining is what separates the two.

Since colt no longer makes fixed handle rifles, they dropped the F stamping.

[26 Inf]

Thanks!

[HeruMew]

Just cranked down the barrel nut on my midlength BCA 5.56.

Has a front sight base marked as <B

Not sure what that means. Looks like non f marked to me. But not sure.

Out of curiosity, if it is a non marked, does that mean KACs or Matechs won't zero without moving the sight post too much?

[Iraqgunz]

Thanks for that information.


The F is stamped in the forging after the forging is made. The same forging was used for F and non F front sight bases. The machining is what separates the two.

Since colt no longer makes fixed handle rifles, they dropped the F stamping.

[HMsailor]

i wont be suprised if a 6920 just blows up in my face.

[TexasAggie2005]

i wont be suprised if a 6920 just blows up in my face.

52166

[pubb]

So as a public service, you can safely dispose of your 6920 with me for free. In the interest of your personal safety, I'll even pay shipping. Don't hesitate, your beautiful mug is too precious to risk with dangerous firearms.