Just finished a 14.5" midlength build with a Daniel Defense CHF stripped barrel, and fear theres a problem with the fsb taper pins. The pins come loosely attached to the fsb from the factory for assembly to upper.
I used a Brownells FSB block and large flat punch to reassemble, but the DD pins seem too small for fsb. They measure .78", while my BCM pins measure .85".
The pins went in easily (too easily) and would not go completely through the fsb. The fsb feels secure, but I really dont want this thing loosening up on me. The pins also seem “soft” or mar easily compared to other brands of uppers I’ve assembled/disassembled.
Also noticed the barrel was completely parked, but the FSB wasnt parked in the barrel area? I cant remember checking the underside (barrel area) of other FSB’s to see if theyre parked or not.
Please let me know if anyone else has had issues, or if I’ve made an error.
Pics: 
I am slightly confused. Who makes the FSB? Was the barrel already drilled for the FSB to be put in place?
Did you put the pins in the correct way? If you look closely they are tapered.
I wouldnt worry about them being a tad short. From the photos, they look like theyd be flush to the FSB surface at final press fit.
As for them going in too easily, did you mean at initial tap in or do they not press fit at all? Taper pins will tend to fit easy initially due to the tapering then come to an initial stop. Once there, it will need a final press fit punch, to which your pin will be driven about 1/16" further in.
The entire barrel assembly is from Daniel defense. The fsb came attached and pinned, was the $269 special from AIMsurplus. Pretty sure the whole barrel assembly is factory, same park on fsb and barrel.
I assumed the barrel was drilled for fsb and pins were press fit at factory, but they came not flush and slipped out with one small tap of a punch and jewelers hammer.
I’ve only removed fsb pins from factory complete barrels, and never used press to re-install pins.
Please let me know what Im doing wrong here, dont think DD uses junk parts.
The last barrel assembly I used was a DD and the pins, once set, were pretty close to flush on both sides. They just don’t use pins as long as others like BCM. You put the pins in the right direction, so there is no problem there.
Drilled at factory yes, press fit no. This is intentionally done to ease the end user’s assembly process. They took into consideration the fact that you still have to slip in a barrel nut of your choice.
As for them not being currently flush, they will fit flush upon final press fit. As stated in my first post, once you put the pins in, you will need to hammer ithem in for a final press fit. By doing so, it will in turn drive your pins in about 1/16" further. It is only then that you will see them flush on both sides.
Should I use a special type of punch or press to finish installing the pins? The large flat punch is marring the pins, even with electrical tape on the head.
if the pins are tight, i wouldnt worry about it. you can go get 2/0 taper pins at the hardware store, install them, and chop off the excess with a dremel, if you no likey.
WHat flat punch are you using? Try using a brass one. That should be kinder on your pins.