Need help with FSB (irons only build)

[turnburglar]

Hey fellow shootist

I have half the spare parts to put together a carbine just sitting in my safe. For this particular build I want to do an A1 carry handle receiver with a front sight base. This will be kinda a retro/irons only build. I even want to do a CAR stock and A1 pistol grip.

The barrel that will be going in this carbine is a Faxon 14.5 Mid gunner. This barrel has been a spare since it came off my 2 gun rifle. My only concern using this barrel for this build, is how do I get a FSB on the .625 gas block journal? And is there any FSB that will work with the A1 rear sight better? I think F marked front sights only apply to a .750 gas block?

Also who makes the skinniest mid length hand guards?

[utahjeepr]

.625 std. height fsb is not uncommon. Check retro rifles for a selection.

No idea on the hg's

[markm]

I'd get a factory FSB'd barrel. There's a few challenges with FSBing a gas block barrel.

[turnburglar]

Thanks for the heads up on retro rifles. They have most of the parts I need for this build and they are fairly priced given the times. It seems that I need a .625 NON F. F marked are for flat top pic receivers.

@Mark - Since its a 14.5 it needs a pin and weld anyways. Is it a ton more work to drill for a FSB?

I also have access to a BCM 14.5 mid gov contour. That ALSO had a gas block on it though. I thought the Faxon might be better for this build because it has the lighter contour.

[Curlew]

I’d say that drilling and reaming an FSB for taper pins is more work than a flash-hider pin/weld job, but if you’re set up for it and do it regularly, I wouldn’t say a ton more....

As for middy handguards, if you’re going for something along the lines of an old CAR or an A2, there are two options that I’d call “skinny” : Armalite and Rock River. I prefer the Rock River, but it’s far from perfect. Cav Arms has some nicely made pseudo-A2’s but they’re noticeably taller than the others.

[utahjeepr]

The block and reamer will run you about the same as having a smith do it. If you feel comfortable betting your parts money on your skillset go for it. Like Will often said, "this ain't rocket surgery".

[GH41]

I'd get a factory FSB'd barrel. There's a few challenges with FSBing a gas block barrel.

Many people looking to save coin shoot themselves in the ass while trying to succeed at it but rarely do.

[Circle_10]

Just be aware that Retro Rifles was known for having some CS and communication issues last I knew, but you should be able to find a .625 NON-F height FSB on other sites too such as Fulton Armory or JT Distributing.

[Leonidas24]

I'd get a factory FSB'd barrel. There's a few challenges with FSBing a gas block barrel.

I've gone looking for a .625 barrel with FSB and they're not common anymore. Spike's was about the only ready to ship barrel out there in the 14.5" mid variety.

[bikemike555]

I've assembled two free floated rifles with fixed front sight gas blocks, one a Ballistic Advantage, one an FN marked chf chrome lined barrel. Both were a bit challenging to disassemble for a hobbyist like myself. Removing the taper pins of the BA barrel wasn't so bad, https://uploads.tapatalk-cdn.com/20210321/bfc31bfe5d53a13166ad5f23532a872c.jpgbut I bought a new 3lb hammer and a few new punches just for the job of displacing the taper pins in the FN barrel and gas block front sight so I could replace the barrel nut and install a different handguard.

https://uploads.tapatalk-cdn.com/20210321/5f17bd77c72f24e8af0b1b8ae5883e33.jpg

I believe it would be substantially more challenging to align the gas block front sight perfectly and drill the holes for the taper pins through the front sight and through the barrel. https://uploads.tapatalk-cdn.com/20210321/a2fb831f84f5be32f54ab4ffd707f777.jpgFront sight gas blocks come without the holes pre-drilled.

I have purchased a pre-assembled barrel from a less than reputable vendor (lesson learned) and found that the front sight gas block was misaligned, to the point where using it for sighting duties was not an option. I also couldn't remove the gas block, so I'm planning on cutting it down to a low profile gas block and sliding a handguard over it which is compatible with a standard barrel nut ( a Centurion, Samson or a Troy).

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[jbjh]

Since it needs pin and weld, why not send it to ADCO and let them do both?


Sent from 80ms in the future

[Sparky5019]

I'd get a factory FSB'd barrel. There's a few challenges with FSBing a gas block barrel.

I concur. I’ve done several and even with the proper tools and alignment jogs, it’s a pain in the balls. Lol

[bikemike555]

Exactly, these last two comments are spot on.

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