quote:

Originally posted by PGT:
8.9" barrel and short gas? Looks like it.

I believe it is more like 10" in the 551 micro. Mg34_Dan can you confirm the barrel length?

quote:

Originally posted by JoshNC:

quote:

Originally posted by PGT:
8.9" barrel and short gas? Looks like it.

I believe it is more like 10" in the 551 micro. Mg34_Dan can you confirm the barrel length?

Since the original pictures were taken, the front sight base assembly has been attached. I just measured everything and it looks like the barrel length, tip to a$$ is exactly 11". Ain't that interesting?





Oh, even though it appears that the flash hider is a separate assembly, it is not. As with the 500 and 551, it is machined on the barrel. I have no idea why the barrel immediately behind the flash hider is shiny. That's the way I got it. I didn't touch or play with it.

I sold my WCA 551 and picked up a 551-2. Brought it home today. Very happy to finally have one after many, many years of pining for one.

quote:

Originally posted by PGT:
I sold my WCA 551 and picked up a 551-2. Brought it home today. Very happy to finally have one after many, many years of pining for one.

48240! That's nine higher than mine:

pretty cool! is your barrel extension black? Looks like it from the pic whereas mine's still stainless

Is there at source for the flash hider extender?

Michaels Machines made them for the surplus LE guns they sold so as to make them non-NFA.

quote:

Originally posted by tomday:
Is there at source for the flash hider extender?

I had a machinist buddy make it and then have it refinished.

Here is what a machinist needs to manufacture a barrel extension:

quote:

Originally posted by PGT:
I sold my WCA 551 and picked up a 551-2. Brought it home today. Very happy to finally have one after many, many years of pining for one

Where did you find the real 551 at? Looks minty in that foam box. It looks like one of the ones which Mike Ott was selling?

quote:

Originally posted by PGT:
Michaels Machines made them for the surplus LE guns they sold so as to make them non-NFA.

Yep, the barrel extension is a small 2-4" tube which initially screws onto threads of the real 551. After that's done, a small connector bracket is spot welded to solidify everything. It changes a 14" barrel to a 16", thereby making them non NFA weapons.

As an aside; look at my picture above of the disassembled 551. Do you see the groove machined around the barrel at the front of the chamber area? That is a visual indication that the barrel's chamber and throat are manufactured to US specifications for a .223 Remington cartridge.

quote:

Originally posted by MG34_Dan:
As an aside; look at my picture above of the disassembled 551. Do you see the groove machined around the barrel at the front of the chamber area? That is a visual indication that the barrel's chamber and throat are manufactured to US specifications for a .223 Remington cartridge.

Is it not just a marking to differentiate between Twist length? Switzerland/Europe/CIP does not differenciate between .223 Rem, 5.6mm Swiss, 5.56x45 etc. The difference between Commercial civilian ammo and Service type ammo is the ball and the chamber pressure, but neither exeeds the max recommended CIP chamber pressure.

quote:

Originally posted by OTD:

quote:

Originally posted by MG34_Dan:
As an aside; look at my picture above of the disassembled 551. Do you see the groove machined around the barrel at the front of the chamber area? That is a visual indication that the barrel's chamber and throat are manufactured to US specifications for a .223 Remington cartridge.

Is it not just a marking to differentiate between Twist length? Switzerland/Europe/CIP does not differenciate between .223 Rem, 5.6mm Swiss, 5.56x45 etc. The difference between Commercial civilian ammo and Service type ammo is the ball and the chamber pressure, but neither exeeds the max recommended CIP chamber pressure.

Daniel;

None of my other 550s or 551s have this machined groove. Only the Law Enforcement 551-2 marked ".223 Rem." on the receiver has it. I was told that the only difference among them is that the lead on the .223 Rem. barrel is slightly different than the 5.56/5.6 barrels. What this difference actually is, I do not know.

On another somewhat related issue, I have a pair of Colt AR-15 9mm carbines. Both are model 6540s. One is "Law Enforcement" marked while the other is not. The barrel on the "Law Enforcement" 6540 is marked "9mm NATO" while the unmarked 6540 is simply marked "9mm". Isn't that interesting?

I assume it´s probalby marked only for the purpose to differentiate between the 5.54 and the 9mm. Swiss Service firearms on the other hand dont have any Information on caliber and chamber dimensions at all.

quote:

Originally posted by OTD:
I assume it´s probalby marked only for the purpose to differentiate between the 5.54 and the 9mm. Swiss Service firearms on the other hand dont have any Information on caliber and chamber dimensions at all.

Let's add some additional fuel to the fire:





Those boys at Neuhausen certainly do make life interesting.

Weill, you,took a Picture of an export gun, not a Swiss Service rifle. We only use Stgw 90,04 ans 07, no 551s.

quote:

Originally posted by OTD:
Weill, you,took a Picture of an export gun, not a Swiss Service rifle. We only use Stgw 90,04 ans 07, no 551s.

I also have an early '80s 551-2 that SIG imported into the US. It does not have any .223 markings anywhere. My thoughts are that for US law enforcement sales, the unique markings were specified in their contract(s). Hence the .223 and 9mm NATO markings.

The above 551-2s came from the Sate of Louisiana Department of Fish and Game. I know the State of Pennsylvania also has/had 551s that were issued to their State Police Troupers for use when on patrol duty. I haven't seen any of them hitting the used market, yet.

my 551-2 SP came with a sight rail on it (included by the previous owner). Now, I know why. The piston that locks it in place in the rear diopter base was rounded over. I have a B&T example for my 553 so I measured that one as 7mm and tried to mic this one as well. It seemed to be the same. Ordered a small, thin 7mm wrench from Amazon.

It arrived today and works great on the B&T but not the one on the 551-2. I got out the Dremel and a milling bit to put new wrench flats in. No luck..it rotated a half turn with a lot of effort and then nothing. I'm guessing the previous LEO's who had this loctited it in addition to the set screw.

So...I took more drastic measures and got out a small air saw. No more piston....

In case you ever wish you had the rail, MidWest Distributors has lightly used BT Rails for $89 I bought my LEO 552-1 from them, but whoever installed it didn't use Loc-Tite

This is before I got my stamp ...

I got one from Gatewood Supply awhile back and just put it on my diopter 553.