Swiss SIG 553 pistols have hit the US market

[SPARTAN HOPLITE ARMS]

Finally! Oh, and my wallet hates you. LOL.

I'm intrigued at being able to put a 550 together for $2600 since all original imports seem to go for double that. Assuming the upper includes the bolt of course. A 553 can be put together for $2k, as can either length 551.

Swiss stocks for $200....now all we need is handguards. I paid $700 for my used set of green furniture...

The problem is you'll need a donor receiver to do the conversion work and a gunsmith with the know how to remove and re-install the barrels. The upper on the 550 series is the firearm and therefore not easy to bring in as a separate piece. As a pistol, yes, but not as a stripped receiver, otherwise ATF will assume someone is trying to build banned models with parts kits. It's the reason the stripped receivers were stopped years ago.

[PGT]

Right. I asked that Q and I guess JDI is trying to import complete uppers based on their email response to me. "ready to bolt on to your swiss lower"

[SPARTAN HOPLITE ARMS]

Right. I asked that Q and I guess JDI is trying to import complete uppers based on their email response to me. "ready to bolt on to your

That'll work and you can add a lower later on. Not a bad option though I'm waiting on the SAPR at this point.

[PGT]

I'd love a SAPR and a 550. I'd also like a proper 551 SB upper but probably not enough to get in addition (two 553', a 550, a SAPR and a US 551-A1 will satiate for a bit LOL)

[JoshNC]

I just tried a 5.45x39 Bulgarian and East German. Neither fit in my steel lower. Didn't try the alloy lower. The mags were too wide to insert. Thought I had some Bulgarian 5.56 mags; however, I think I sent all I had to my son.

553R lower will have different magwell and mag release dimensions from the 5.56mm 55x. Also I don't believe the ak74 mags are dimensionally the same as 7.62x39 mags, so a 5.45 mag will not fit a lower machined to accept a 7.62x39 AK mag without altering the lower and mag release. Not sure if the aluminum lowers can be modified to accept a 5.45 mag.

[Bret]

I don't believe the ak74 mags are dimensionally the same as 7.62x39 mags

I can confirm that they're definitely not. Since 5.56x45 Galil magazines lock in to most 7.62x39 AK magazine wells, there's decent odds that the Galil magazines will lock in to the 553R lower. Serbian M85/M90/M95 magazines are also a possibility.

[PGT]

24 hours, a liberal amount of Kroil and heat broke loose the thread locker on my B&T rail. Too bad I don't have a 7mm open-ended wrench small enough to install it.

I did a quick testfit w/ a spare Vortex Sparc and its too tall to cowitness (not unexpected). The same optic does work however on my railed 553. I had bought an Aimpoint H1 for the Diopter gun but looks like it will find another home and I'll just run irons.

[sigswiss]

24 hours, a liberal amount of Kroil and heat broke loose the thread locker on my B&T rail. Too bad I don't have a 7mm open-ended wrench small enough to install.

I'll bet that was a relief. Drilling into an otherwise good B&T rail would be disheartening. I was about to let you know that it was "normal" right hand thread, but sounds like your rail is happy again!

[PGT]

I have some extractors, but, yeah. What's interesting is this rail was off a cut up receiver but the rail was removed prior to the gun being scrapped. Not sure how that happened but its not an issue now.

[sigswiss]

On the 553, I believe it is actually a good thing that the 5.56 AK-74 mags are wider.
Notice the horizontal ridge along the SAN mag where it meets the mag well? It prevents the mag from going any farther in, unlike an AK mag which locks the rear "protrusion" of the mag between the mag release and an internal fixed metal part.
So, by removing only enough of the plastic needed in order for the mag to enter the mag well, the needed ridge was provided.
Too bad though, after cutting off the rear "protrusion" and screwing on a replacement similar to the SAN mag, I realized that I had been sold a 5.45x39 rather than a 5.56x45 -after a 2 hour drive..

It's a "work in progress" project though, but I'm determined to have a U.S. mag.
I ordered some cheap 5.56 AK mags (by mail this time), so we'll give it another go after Christmas.