Home Forums Hunting & Shooting AR and Tactical Rifles So, whatever happened to SI Defense?

Tonight I acquired an AR in .260 Remington, built on what appears to be a matched SI Defense upper and lower set. They fit together nice and snug. I knew the man who put this gun together and unfortunately he's no longer around. I had thought he built the gun on Aero Precision receivers, but I obviously misremembered.

So what about SI Defense? I can't recall the last time I ever read or heard the name.

A .260 AR would be sweet! Not much that it wouldn't be good for here in TX. How much does it weigh bare?

A bit heavy at 8-3/4 pounds. I'm exploring handguards as I don't care for what's on it, but not because of weight...I may change the buttstock as well.

It's gonna be my daytime piggy killer. I figure it'll reach out as far as I can see so it'll wear a conventional optic.

Those Falkor Defense AR rifles are stupid heavy. The 6.5CM is 10.25 lbs! Add a scope base, scope, full 10 rd mag, sling and you're lugging around a 12lb. log.

That's the main reason I've never owned a large framed AR before. I want to take a little weight off IF I can do it economically. It has a composite PRI handguard on it now and I don't like it even if it weighed half an ounce. Not sure I'll keep the buttstock as well. The barrel is a Lilja and I know it shoots, so it stays, weight be damned. It's probably gonna weigh ten pounds or better all ready to rock no matter what I do, so I'll just have to get used to it.

You might look at the fore end and Mission First Tactical minimalist stock that POF use.

Yep. But that was the answer to the Op's question.

SI --> Falcor

Yes it is, thank you. Any other relevant info or discussion is welcome too.

I don't have any other info, but do remember the name SI from back in the day. A snug fit lower and upper means they put some work into it.
You're in a better position to let the forum know how it shoots.

It should be ready for its first handloads soon. Here it is in its [almost] final form. I shaved a little weight off with the new Odin Works handguard and the Magpul fixed stock and am down to 8.4 pounds bare-assed naked. Soon a Geissele SSA-E trigger will arrive to replace the Rock River NM 2-stage currently installed. The barrel is a Lilja 1:8 of about 19-1/2 inches and I fully expect MOA performance or better even though I won't need that for slaughtering Central Texas piggies. I think I'll scope it with a Super Slam 3-15x50 duplex with illuminated dot...that should be perfect for an all-around dawn-to-dusk hunting rifle. I've selected 120-grain Ballistic Tips and will be loading my first trial loads in the next few days...I'm sure they'll work out fine.

For full darkness I have a couple of less powerful alternatives equipped with thermal scopes. I'm fully covered now, for sure!

Nice rifle. The Lilja won't disappoint...nice grouping ahead!

Took it out this morning and it did not go well.

The rifle was built by my neighbor about ten years ago. The guy was generally pretty good with his hands but I think he took advice from the wrong people more often than he realized. I remember there were issues with the rifle after it was built, and I guess the whole thing just slid to the back burner and never was addressed. I didn't realize that there were still problems with it.

I had feeding issues all morning. I had to chamber the first round of each magazine manually, then insert the mag. I was using the P-Mags that my neighbor always favored and did not have the single ASC mag with me...I think the P-Mags may be part of the issue. Also, a bit of the feedramp profile of the barrel extension is a bit proud and may be catching the nose of the bullets. Overgassing seems to be an issue...ejected brass flies to about the 2 o'clock position. All the while I was wondering why the bolt catch would not work, and a while ago I discovered that the gun has the wrong buffer in it. It is not only probably too light at 2.95 ounces, but it is too long (3-1/4") and won't allow the bolt full travel in the buffer tube. I have an Odin Works adjustable .308 Carbine buffer on the way. Maybe, just MAYBE that will cure the feeding problems...but for the doubt I also ordered a couple more mags. I've never been a P-Mag fan.

The trial handloads I fired were not so good...everything was looking too hot (and some undoubtedly WAS too hot), and the feeding difficulties were very distracting. There was actually a few positive signs, but I wasn't really in the game this morning. After analysis of my velocities I've made some adjustments and will try again in a week or three.

I'll get this thing ironed out, one bug at a time. I expect it to shoot bugholes.

Is the RRA trigger for sale? I'm always looking for deals on more of them at reasonable prices. They are pretty dang good triggers. Have won quite a few matches with them.

Sure. Send me a PM. Or I'll send you one.

Check the gas block alignment while you're at it.

Good looking rig and I’m sure when you get the bugs worked out it will be a great piggy killer.

Consider installing one of the new Arkin LW 4-16 scopes. I just ordered one for my RRA that’s a bit on the heavy side too. I’m ok with the weight for that one.