My flip up front sight did not come with a roll pin for the gas tube.  It is a new build, so I don't have the standard FSB.  I also can't seem to find a small enough roll pin to fit in there (3/32 is too big).  Will the rifle operate without it?  I appears that the gas tube is sealed before the hole for the roll pin, therefore it wouldn't affect the operation.  Any thoughts?

TIA,

Brian

One of the causes of Short Stroking is a missing gas pin. (check it out in Chapter 3 of the -23&P).

I certainly wouldn't run my rifles w/o it.

do you happen to know what size this pin is?

If there's no pin, what's to keep the gas tube from pulling out of the gas block?

Quoted: do you happen to know what size this pin is?

0.312" long X 0.081" diameter

Quoted: If there's no pin, what's to keep the gas tube from pulling out of the gas block?

Conversely, what would be pulling the gas tube back....?

It would probably work for a little while, but I wouldn't do it.  At least put a paperclip in there or something.  

Oh well, guess I am not going shooting this weeked.

Thanks for the info guys

*ahem* finishing nail *ahem*

worked for me

I can't tell you for sure, but I think that if you shoot a few rounds from it without securing  the gas tube at the front end, that tube will rotate a bit and at least partially cover the gas port and give you some malfunctions due to restricted gas flow.  I am pretty sure it won't due any permanent damage, but why don't you just wait until you get the correct roll pin?

If you go shooting and the gas tube moves and your rifle stops working in the middle of your session, was it worth the trip?
Seems like a wasted day to me.

You may want to contact the company that made the gas block to find out what size pin they recommend.

HTH

Home Depot

Quoted: Quoted: do you happen to know what size this pin is? 0.312" long X 0.081" diameter

Translated = 5/16" long and 5/64" in diameter. Any hardware store should have something close.
If longer, whip out the dremel and cut till you can do better if you want to shoot right away.

Danny

ETA:
   ----------------------                                                              LENGTH--------------    DIAMETER
                                                                                                             
A1 sight drum roll pin---                     1/4" - 0.250------------ 1/16” - 0.062

F/A pawl roll pin--------                     1/4" - 0.250------------ 1/16” - 0.062

Charge handle latch roll pin---- 1/4" - 0.250------------ 1/16” - 0.062

A2 windage drum roll pin-                      3/8” - 0.375------------ 1/16” - 0.062

Bolt ejector roll pin----                      7/16” - 0.437---------- 1/16” - 0.062

Gas tube roll pin----                      5/16”- 0.312----------- 5/64” – 0.081

Bolt catch roll pin-                                  7/16” - 0.437----------- 3/32” – 0.093

Elevation housing roll pin-                      5/8” – 0.625----------- 3/32” – 0.093

F/A retaining roll pin-                      5/8” – 0.625----------- 3/32” – 0.093

Trigger guard roll pin-                      5/8” – 0.625----------- 3/32” – 0.093

Local gun store had one!!!!!!  Wooooooooooohooooooooooo!

Got it installed and headed to the range tomorrow!

I was about to say HOW could you lose something like that but then I saw that it was a flip up sight you bought...

Good luck!

Quoted: Quoted: If there's no pin, what's to keep the gas tube from pulling out of the gas block? Conversely, what would be pulling the gas tube back....? It would probably work for a little while, but I wouldn't do it.  At least put a paperclip in there or something.

Ahhh shit dude, were you peeking in my window when I put that Oly FIRSH back on my rifle and noticed that the gas tube pin was missing?

Fires great with the paperclip while I wait for the friggin roll pin to get here with some other stuff.

Quoted: *ahem* finishing nail *ahem* worked for me

                                                                                                                                                                        ......they like to "take off" before i can get em started....this is my fix too....tight fit.....2 snips with the cutter......all set......or a "heavy" piece of wire.....same same

Quoted: Quoted: *ahem* finishing nail *ahem* worked for me                                                                                                                                                                         ......they like to "take off" before i can get em started....this is my fix too....tight fit.....2 snips with the cutter......all set......or a "heavy" piece of wire.....same same

Just make sure you dial back the seating depth on the nail gun!