I’ve got one of the early “fish gill” 556 rifles with fixed stock. Love the weapon but the furniture, not so much. What can I use to put it into a more “as issued” configuration without breaking the bank or making major alterations to the weapon itself? TIA

This message has been edited. Last edited by: Badhammer,

Your thread title doesn't have anything to do with your request. You might get more helpful input if you edit it to give people who have the answer a clue what's in the thread rather than skipping it over.

Assume you want to make it look more like a SiG 551? You can probably replace the fish gill handguard with the Swiss 551 handguard or the Sig USA copy of the same. For the stock, what’s on the back of the gun? Does it have a hinge on the side, or an AR type buffer tube?

It has the buffer tube.

Thanks Smudge!

Well, the Swiss Sig 55x series has a folding stock with a hinge at the rear of the lower. The buffer tube lowers of the early 556s had a different rear with a circular hole to thread in a buffer tube. It really can’t be changed to use the hinge. Best bet is try to find a later 556 lower with the hinge and then find a folding Sig stock.

Sig 551 plastic handguards can go for $230 or so. JDI/SAN swiss arms may be worth a call or waitlist.
https://swissarmsusa.com/produ...51-lower-hand-guard/
https://swissarmsusa.com/produ...51-upper-hand-guard/

sig 556 usa plastic handguards are very hard to find nowadays. they use to go for under $150.

sig lowers are not serialized, so easy to order i believe, but usually over $500 or so, then the stock is about $350? can add up if you don't want to go that way.
AGP arms makes a folding stock kit for the older AR style lowers. or trying a picatinny adapter and getting a newer folding stock that's 1913 compatible.. decisions...decisions. heh.
https://agparms.com/agp-arms-sig556-folding-stock/

Thanks to all for the replies. May just leave it as is.

quote:

Originally posted by Badhammer:
Thanks to all for the replies. May just leave it as is.

Here's a viable path that's not super expensive. Put a KNS adapter on the M4 lower, add a Sig collapsing/folding stock and then put a US or Swiss handguard (prices are similar these days). Here's one I set up thusly (though it's a 1913 adapter on a Swiss pattern lower; very close setup in the end):

When I bought my first, I hated the AR style collapsing stock. I put an A2 stock on it. Worked well. But I now have to look into the KNS adapter.

Vince