Swiss Arms SG 553 R (7.62x39)

[Bret]

After over a two year wait, I finally have my San Swiss Arms 553RP. Here it is below my Sig 556 SBR.


Field stripped.


Here's the barreled action of the 553RP versus the 556 SBR. Note that the gas system of the 553RP is slightly shorter.


As a result, the gas piston of the 553RP is slightly shorter.


The trigger groups from each rifle appear to be virtually identical. I'm hoping that they'll interchange which would give me three easy 922r parts. The pin diameters are the same.

[Bret]

I took it to the range today along with 110rds of Wolf 123gr FMJ Copper Jacket that was made in a Ukrainian factory that the Russians destroyed. I loaded the ammunition in (2) Magpul Gen3 30rd mags, a Hungarian 20rd mag and an Eastern Block 30rd metal magazine of unknown origin. I've used the Hungarian and Eastern Block magazines previously with no issues. The Magpul Gen3 mags were a bear to get locked in place. Once locked in place, it was difficult to retract the carrier to the rear. However, once I did that, they did cycle just fine. They were also a bear to unlock. The Hungarian and Eastern Block mags inserted easily, the carrier retracted easily with them in place and they were easy to unlock.

Now for the sort of bad news. I had (7) failures to fire. Looking at the primers, it appears that they were hit hard enough, but just didn't ignite. Now I might be worried about this, but I've been down this route before with my Windham Weaponry 7.62x39 AR-15. It would fail to ignite the primers of this same ammo occasionally too, but they would always fire on the second strike. I didn't retry when this happened in the 553RP. The Windham would run 100% with Lapua 123gr FMJ and IMI 123gr FMJ. After I installed a Wolff extra power AR-15 hammer spring in the Windham, it runs 100% when running this Wolf 123gr FMJ Copper Jacket. So, lesson learned. These primers are kind of hard to ignite.

Now for the thing that concerns me. I had two failures to feed when using the Eastern block magazine. Both times the bullet ended up hitting above the chamber which made the cartridge stop at about a 45deg angle.

When I got home I grabbed an assortment of AK magazines. All would lock and unlock easily except the Magpul Gen3's and Bulgarian waffles. Interestingly, the Magpul Gen1 that came with the pistol locked in and unlocked just fine. Perhaps I was overthinking it going with the Gen3 version because they have the metal insert at the top. I took a file to the underside of the mag catch of the two Gen3's. It took a while, but they now lock in pretty easily. They still take a little force to unlock, but I didn't want to push my luck.

My plan when I go to the range tomorrow is to see if I get light primer strikes with other ammo. I also need to see if I have any feeing issues when just using the Gen3 Magpuls. I'm taking some Golden Tiger 123gr FMJ bimetal to try out initially. If it works fine, then I'll know that the Wolf ammo I tried just has hard primers. If I still get failures to ignite, then I'll give it a go with some Lapua 123gr FMJ.

[Bret]

I had better results at the range today. I fired 85rds of Golden Tiger 123gr FMJ bimetal using the two Gen3 Magpul magazines. All fired and cycled successfully. I'm going to purchase some new Wolf Polyformance 125gr FMJ copper jacket to see how it performs. Brass cased 7.62x39 is very expensive, but I'd rather not shoot the bimetal jacketed ammo through the 553RP.

[Bret]

Today I fired 120rds of the aforementioned Wolf Polyformance 125gr FMJ copper jacket through the 553RP. Function was 100%. I ran the 1st through with the gas regulator set to 14. It was tossing brass about ten yards. For the 2nd, 3rd and 4th magazines, I set the gas regulator to 13. Most cases went about five yards on average. I didn't try setting it to 12 because I figured that would be pushing my luck too far. Now to fill out that Form 1.

[Bret]

I took the 553RP out to the range again today. I'd purchased some Tula 122gr FMJ copper jacketed ammo from SGAmmo.com and wanted to see if it would run like the Wolf Polyformance 125gr FMJ. It fired and cycled 40rds through the 553RP just fine. It's hard to say if it's as accurate as the Wolf due to the lack of a buttstock. I also fired another 40rds of the Wolf Polyformance 125gr FMJ copper jacket which fired and cycled just fine too. I actually changed the gas valve over to the 12 setting and it was ejecting spent cases with plenty of distance. Perhaps it was tossing spent cases further today at the 12 setting due to it being a bit warmer. The magazine I used was a 30rd Arsenal waffle for all but the first 10rds which were fired through a couple of 5rd Arsenal waffles. Oddly enough, the 5rd mags had difficulty locking in while the 30rd mag was not problem. This is odd since they appear identical up top with the 30rd mag just being longer.

[ramairthree]

Cool.

I have the 556, SBR. Not factory. Pistol upper with the stocked lower. I do have issues with light primer strikes with some varities of steel cases ammo with it.

I recently got a used 556R Carbine. The 3rd gen magpuls are my tightest mags. I have not had light primers strikes or any malfunctions with it. I have used first gen and later magpuls, tapco it came with, some Chinese smooth backs, some 40 rounds smoothbacks, and some assorted European metal ribbed. It likes 124 grain TULA HPs best group wise. I no longer have any of my Norinco ammo stash.

Other than length, what is the essential difference besides length and this being real SIG vs USA compared to the 55R?

I regard my 556 as a less ergonomic AR with a folding stock.
I regard my 556R as a more ergonomic AK.

Neither of which matters as both are dead platforms.

[Bret]

I can't speak for the 556R because I don't have one. However, comparing my 556 SBR to this 553RP, I'd say that the difference has to do with the quality of manufacturing. This difference is especially evident when you look at the bolt carrier and bolt. The Swiss bolt carrier and bolt just look perfectly manufactured. That said, my 556 SBR is a great rifle. The only thing I find lacking is that it is over gassed, but I'm working on a fix for that. I know there were some reliability issues with the US 556 rifles, but I have been fortunate enough not to have had any problems. I could buy a 5.56 chambered Swiss manufactured 553, but the 556 SBR is doing everything that I want it to do, so I don't feel the urge. Plus, I actually like the fact that it takes AR15 magazines. I have a Swiss manufactured 551 on order from JDI and wish that it would also take AR15 magazines. I know that's blasphemy to some and I do like AK type rock and lock magazines, but I just find that the proprietary Swiss 5.56 magazines don't offer an improvement over AR15 magazines. Plus, the AR15 magazines are less expensive and give you three easy sec922(r) compliance parts.

[ramairthree]

Thank you.

I suspected something along those lines, but do not have one to compare.

[Bret]

I got the stamp back to make my 553R an SBR. I'm now working on the stupid sec922(r) compliance. The US magazine counts for thee parts and the trigger group counts for three parts. I need one more assuming the flash hider is removable. Based on the finish, the flash hider looks to be a separate part from the barrel. Before I start cranking on it, does anyone know if it's somehow permanently attached? If not, is it right hand or left hand twist?

[PNorris]

Standard 30 cal flash hider threading