SIG550 (StG90)

About: K'NEX gun builder here at Instructables. More or less retired from the community, but I still pop in now and again.

Small Arms: Visual Encyclopedia by Martin J. Dougherty states this of the SIG550 (StG90): "Adopted by the Swiss Army as the StG90, the SIG 550 is in many ways a traditional design, but much careful thought wen into is 'usability.' It has spawned a family a variants including short-barreled carbine versions." I would say that is is pretty fair to say, as even the K'NEX version of this gun is highly "usable."

It is, on the whole, a handsome gun. With it's epic stock, nice mag length, and perfect handle degree,  I would say that it is a great gun. The sights are great, and the gun is very sturdy. At least one other attempt, to my knowledge, was made at this gun, and I would say that dr. richtofen did a fairly good job at modeling it. Mine is just one inch over the actually length, mine being 40 in., and the original being 39".

My reason for building this was simple...I could not decide what else to build. I was not in the mood to build another sniper rifle, as I just posted my M14/M21. I did not want to make another one of my trademark firearms, as I thought you guys might be getting bored of those. So, seeing this in my Small Arms: Visual Encyclopedia book, I built it.

Now, to the more interesting fact, it's range. This gun, shooting from a muzzle loaded round, pointing (almost) straight forwards, fired 52 ft. Pointing it 45 degrees into the air made it shoot 86 ft. I was quite happy, as you might imagine, to find this out. Now, it must be admitted that I was not firing a bullet from the mag, but I was out side, and since this gun shoots dark grey connecters with a green rod attached to it, I did not want to lose the round.

-Great range: (52 - 86 ft.)
-Great looks (IMO)
-Nice stock (credit to Blue Mullet 2's SIG552)
-Nice sights
-Kinda piece consuming
-Almost the same length

Well, there you have it, my SIG550 (StG90). What do you guys think?

-The Red Book of Westmarch

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    45 Discussions


    6 years ago on Introduction

    Aww man that's really cool :) An updated version of one of my favorite guns, back from my MoH2 days :) Awesome, looks good, nice work. Keep it coming man!

    1 reply

    It would be awesome =D well I'm trying to update my mp5k and I know you mentioned something about the top row of connectors being to wide. I tried to make that area thinner but its not working so I'll be going back to the normal for that part. I'm going to be making the mag use green rod ammo to get a more realistic size and see if I can make the sights better,still trying to make it use a folding stock(nearly impossible with the pin)