Need help with 9mm ar upper assembly

[titsonritz]

"The Chart" was the source of the beginning of what is now known as Butt Soreness if your rifle landed on the wrong side of The Chart.
IIRC, the Rock River guys were the biggest crybabies.

I trying to show some of the historical issues associated with and FSB. You got three items...
1. "F" Height Front Sight Base (FSB), plenty use to use the wrong size



2. Taper Pins at FSB. Some guy where using roll pin instead of the proper taper pins or worse using those stupid clamp-on units.

3. Finish Under FSB, the cheapskates would skip this extra step to pinch pennies and they would end up corroding, sometimes enlarging the gas port.

 

[oa98pistol512]

From what I've seen I wouldn't buy squat from those clowns. Issues I've seen...no dimple on the barrel and no loctite on LPGB screws, no Aeroshell 33MS on the barrel nut, barrel nut improperly torqued, Loctite on a YHM barrel nut which had to be cut off because it was destroyed even using the proper pin style armorer's tool.

That doesnt sound good but I have had great results and customer service from them. When I got my A2 very few companies made 9mm A2 and were super expensive. I was just suggesting getting their barrel because again few companies make them with fsb in 9mm anymore. That said my neighbor bought their new 1x14 twist and it also shoots exceptional. But to each their own and how much you want to spend.

 

[theduke]

welll...without pics.......its hard to be on point.

 

[arakboss]

Doh! Nevermind

 

[Member 53328]

I for one am a huge fan of the standard front sight post and quad rails.

 

[Hardcore_rucke]

I for one am a huge fan of the standard front sight post and quad rails.

Yah, I wanted it to be the 9mm brother to my FSB quad rail 556/223 carbine.

 

[DirectDrive]

Yah, I wanted it to be the 9mm brother to my FSB quad rail 556/223 carbine.

You'll want to make sure that your FSB bore will work with where you want to put it on the barrel.
It will be either .750" bore or .625" bore

There are some rail mount sights that emulate the look of the FSB.
As a Plan B

 

[titsonritz]

You'll want to make sure that your FSB bore will work with where you want to put it on the barrel.
It will be either .750" bore or .625" bore

There are some rail mount sights that emulate the look of the FSB.
As a Plan B

You also need to make sure the gas journal is long enough to accommodate an FSB, many barrels today are made for LPGB.

 

[Hardcore_rucke]

Thanks for all the info guys. Looks like I got a little too excited and bought parts before I did enough research. I'll be putting up some parts for sale to pay for a complete 9mm upper. Haha , should have done that first, oh well! On that note, if any one can reccomend a decent budget 9mm upper please let me know. Looking for 16" barrel and quad rail compatibility, preferably.

 

[DirectDrive]

Thanks for all the info guys. Looks like I got a little too excited and bought parts before I did enough research. I'll be putting up some parts for sale to pay for a complete 9mm upper. Haha , should have done that first, oh well! On that note, if any one can reccomend a decent budget 9mm upper please let me know. Looking for 16" barrel and quad rail compatibility, preferably.

Budget AR9 upper is probably going to be something from Foxtrot Mike or Palmetto State Armory.

 

[Ops]

is your barrel capable of a fsb? since they arent made for gas blocks , just blow back.

 

[DirectDrive]

is your barrel capable of a fsb? since they arent made for gas blocks , just blow back.

Good point, but I think the OP has sheet-canned his plan A and is now going with a complete upper.