Swapping a Handguard

[SunsetIE]

I purchased this AR recently from a friend who built it, then was told by his wife to "get that evil thing out of the house" so I got a sweet deal on it!

The lower is in jail currently at Ammo Bros - I get it back in just over 5 days.

I dislike the free float knurled handguard currently on it, and would like to replace it with a Carbine length Magpul MOE. As this is my first AR, I do not know what all is required (extra parts/tools) to correctly install the desired handguard and I am seeking the knowledge of fellow Calgunners!

Here it is:
Franklin Armory lower
Palmetto State Armory LPK/ Buttstock Assembly
SOTA Arms railed upper

The make of the rest of the parts i do not have info on:
5.56 1:9 twist barrel
Knurled freefloat handguard - carbine length
railed gas block
BCG
Flash Hider


From what ive read, I will likely need a delta ring, but that is all I know - Help!

[crazyucbr]

You're for sure gonna need a table vise, torque wrench, ar tool, for basics.
You also need punch sets not marring hammer, if you're gonna change the gas block

[crazyucbr]

For parts you need barrel nut, delta ring assembly

[SunsetIE]

Thank you for the info, I have a vise aswell as TQ wrench. AR armorers tool is on the way - should be here later today!

The gas block will have to be removed to take the handguard off for sure, there is not enough space between the guard and the block to unscrew it and wiggle it over the block. I intend to use the same block if possible, as the front of the magpul handguard is open and looks like it has room to accommodate the block.

Any specific brand (quality) you would suggest for the nut and ring?

[crazyucbr]

Not sure where in the IE you're located. I live about 15 mins from ammo bros Ontario. I can let you borrow my AR wrench

[crazyucbr]

Thank you for the info, I have a vise aswell as TQ wrench. AR armorers tool is on the way - should be here later today!

The gas block will have to be removed to take the handguard off for sure, there is not enough space between the guard and the block to unscrew it and wiggle it over the block. I intend to use the same block if possible, as the front of the magpul handguard is open and looks like it has room to accommodate the block.

Any specific brand (quality) you would suggest for the nut and ring?

Ill stick with DPMS for this build. They're cheap and decent to good quality. I've used them more than one occasion and have had no issues whatsoever.

[SunsetIE]

Ok i will attempt to get those parts

I live in Upland, coincidentally also 15 minutes away. Offering me your wrench is quite generous, but unecessary as mine should be here in 4-5 hours via Fedex. On the other hand, I have zero experience working on an AR, and physical help would be far more appreciated!


I see you have found a new signature!

[CWDraco]

You will need a; Delta ring assy, which consist of a slip ring, weld spring and delta nut. The best tool for removing this are slip ring pliers. You will need a barrel nut, which requires a barrel nut wrench.

you will need a hand-guard cap plate, round is common for carbine and mid, while triangle is normally for full length ARs. It appears yours is a carbine since your barrel is M4 profile. This goes against the barrel shoulder and is held in place by the gas block.

You will need a new crush washer for the re-installation of your muzzle device. If that barrel is a real M4 then you will need a machine shop to remove it since its been welded on.

Place the BCG into the upper. Drop a cleaning rod down the barrel. Mark the exact spot even with the muzzle on the rod. Right at the edge. Remove the rod and measure it from the mark to the end that touched the BCG. 16 inches means its a 14.5 inch barrel and the device is welded on. 17 inches means the barrel itself is 16 inches and the device is screwed on. This is the only way a new guy like yourself will be able to tell. You lock that thing in a vise and start torquing on the muzzle to unscrew it and you will damage the upper if its welded on. Normally a good eye can spot the pin and weld. It will be at the 6 O"clock position. It will appear to be a small round discoloration in the bluing. That is a blind pin that was pounded in, welded over and sanded smooth.

I have no idea if your current barrel nut will require a special tool to remove it. Some of these free floated ones do. You may get by with a strap wrench or even a normal ar15 barrel wrench.

Good luck

PS- Warning - If the people that assembled that upper designed it specifically for that style gas block, there is a chance your gas port on the barrel is not at the mil-spec location. If they drilled the port, they would have lined up port to have the gas block sit flush against the barrel's shoulder, not accounting for a Hand-guard cap Plate. You will need to do some measuring to figure out if after you install the Hand-guard cap plate if the two ports will line up. You can not run a normal hand-guard system without a hand-guard cap plate.

[caoboy]

Do you know you'll be sacrificing a bit of accuracy by reverting back to a capped handguard that puts pressure on the barrel?

And damn if I were local and didn't sell my AR I would have swapped parts/uppers with you.

[SunsetIE]

Well damn, i thought this was going to be a somewhat easy process. Perhaps I will just take it to a gunsmith and let them sort it out.

[jewboy929]

I was in the same situation as you. You will spend more on tools than the cost to have a gunsmith do it. Riflegear charges $45 to swap a hand rail. Why buy tools to do just one build?

[SunsetIE]

I was in the same situation as you. You will spend more on tools than the cost to have a gunsmith do it. Riflegear charges $45 to swap a hand rail. Why buy tools to do just one build?

Thanks for the info but gas would cost me more than the gunsmithing!

[ar15barrels]

I have almost every barrel nut wrench that exists and a few I have had to custom make.
More importantly though is the experience of rebuilding thousands of uppers.
I charge $40 to tear down and rebuild an upper.
I do it while you wait so you only have to make one trip.
You get to see the job being done so you learn about what really goes into the job.
I also have barrel nuts, handguard caps and delta ring assemblies in stock.

[crazyucbr]

Ok i will attempt to get those parts

I live in Upland, coincidentally also 15 minutes away. Offering me your wrench is quite generous, but unecessary as mine should be here in 4-5 hours via Fedex. On the other hand, I have zero experience working on an AR, and physical help would be far more appreciated!


I see you have found a new signature!

Haha... Yeah I thought it was hilarious. I work in Pomona at night pm me your info and I can meet you to help.

[crazyucbr]

Well damn, i thought this was going to be a somewhat easy process. Perhaps I will just take it to a gunsmith and let them sort it out.

It sounds more complicated that it really is specially if its your first time doing it. But it really not that complicated. Just like fixing s car as long as you have the tools it makes everything easier... Well most things.