Sig Cqb

[olek_Z_bc]

The previous 10 pages.....

Ooopsey... my bad.

 

[TSE JR]

FWIW -- I know some guys who had LMT bolts sheer on them during a firefight in Iraq -- poor QC happens (it sucks when it happens to you -- and it REALLY SUCKS s**t when rounds are going both ways.)

It almost seems to me like Sig did a B&T and sent faulty gear out (remember the B&T "Explodo" Cans... )

Of course the Mk18 bolts can be swapped a lot easier than a Sig system.

Kevin,

I spoke with SwissArms about this and they honestly ahd no idea until this was pointed out to them VERY recently.

I don't think it was a B&T style of operation here (yep, them cans explode REAL good.... who needs enemies when your suppliers can maime you more effectively).

JR

 

[KevinB]

JR good to hear.

BigRed -- you and Teddy need to get onto that issue.
Maybe Sig can wine and dine you guys

 

[Big_Red]

Another broken Sig on this site. Bolt carrier is split, some denting at the back of the gas piston, and the return spring rod is very loose and about to break.

I'll take some pics later today.

Only 2 more to go!

 

[redleg]

Another broken Sig on this site. Bolt carrier is split, some denting at the back of the gas piston, and the return spring rod is very loose and about to break.

I'll take some pics later today.

Only 2 more to go!

Not to labour the point but has anyone addressed this with Swiss Arms yet?

 

[Big_Red]

redleg, Not sure if this has been brought to Sig's attention. Doesn't seem like there is any interest in resolving the problem from our side...

 

[edward911]

redleg, Not sure if this has been brought to Sig's attention. Doesn't seem like there is any interest in resolving the problem from our side...

Big_Red,

How many rounds through the CQB and what brand/load of ammo are you guys using?

 

[Big_Red]

Big_Red,

How many rounds through the CQB and what brand/load of ammo are you guys using?

He was running 62 gr. Greentip new out of the box. Round count I would guess 1000- 2000 rounds.

 

[edward911]

He was running 62 gr. Greentip new out of the box. Round count I would guess 1000- 2000 rounds.

Winchester .223 62 gr. and some RUAG 63 gr. Operation, cycling, accuracy, and all functions have been fine and normal as expected.

 

[juliet lima]

redleg, Not sure if this has been brought to Sig's attention. Doesn't seem like there is any interest in resolving the problem from our side...

That's the type of budgetary/equipment concern I dream of...."Aww f*ck, it broke, hey Red, gimme one of those 33's"



FWIW, I have about 1200 rds through mine, mix of commercial and surplus 55/62gr, no prob's to date.

jl

 

[edward911]

Doesn't seem like there is any interest in resolving the problem from our side...

Big_Red,

What are the serial numbers sequence of the other other failed CQBs?

I would check the others as it may be a QA problem with a certain batch of CQBs that are failing.

good luck...

 

[redleg]

Guys,

Big Red does not run CQBs he has SG552s. They are different.

 

[juliet lima]

Guys,

Big Red does not run CQBs he has SG552s. They are different.

Guess that explains the additional positions for the selector

Seriously, I don't think anyone thought that they where the same, however, there are 'similar' parts aren't there? If it was a problem inherent to the design/short bbl. then I think it would be of concern though probably minimal as the stresses of full auto will never be realized by our 'sporting rifles' and we have JR and Redleg to take care of us

jl

 

[MPI]

Another broken Sig on this site. Bolt carrier is split, some denting at the back of the gas piston, and the return spring rod is very loose and about to break.

I'll take some pics later today.

Only 2 more to go!

Well I don't know if it's the return spring rod/guide failing that is causing the bolt/carrier to fail or the other way around but I would be surprised if they weren’t connected (no pun intended ).

This seems not to be a new problem as some Finnish Swiss Arms have had the same problem, which Bimex commented on back on post 76 and 78. He gave a Finnish site but I don’t speak Finnish…

Seems they have replaced the metal spring guides with polymer ones. The spring guides do seem to be a weak link on them with their screen door "hold open" stopper as a back plate.

So why the switch to polymer? Answers we need answers… I’m sure all CQB owners would gladly swap in a polymer guide as preventative medicine if required.

Here's Bimex's link to an N/S guide rod in Finland:
http://www.toiminta-ampujat.fi/phpBB/viewtopic.php?t=1356

Here Bimex’s old posts:

Post 76

The replacement recoil spring guide I received from the local Swiss Arms importer last autumn is made of polymer, and I haven't had problems since (~ 2.500-3000 rounds fired since). The original spring guide died well before 1000 rounds fired

Post 78

No other damage, just the broken rod (well as a result the recoil spring was naturally also bent). Been using misc cheap ammo (55gr Sellier&Bellot, AE, PMC, Magtech, Wolf etc), nothing very hot that is. It might make a difference that I've been using a suppressor from time to time (probably gives stronger blowback with a suppressor).

Some pics in a Finnish forum (these ones not mine).

 

[X-man]

I can't comment on the SG552 Commandos, although I'd love to own one, but I can say that I absolutely love my Swiss Arms CQB! It digests pretty much everything I've fed it, without a hitch! Only complaint I have it that it flings the brass about 30 feet in front of the rifle and off to the right. Hard on brass, but makes it easier to police them!

 

[MPI]

I don'tknow how people "use" their CQB but the stress imposed on the system between squeezing slowly behind a bench with 5 rd mags is very different from that firing tons of bursts at 800 rpm with 6X30 rounders at a time. The time I bust out 30 rounds with these tiny mags with the mag change in between (look I only have 6 mags), head back to reload and come back out, others can probably spew out 180 rounds already with regular caps.

I guess the steel rod is too stiff to flex so if the rod is not true to the bolt grou, the stress concentrates in a small section of the bolt group and the rod. When the system fires in burst, the rod has no chance to realign itself and the bolt group get hammered at the same spot and shears.

I thought this too until Bimax's comments. The Fin's Swiss Arms are not F/A so the stress is happening at a lot less then 800rds per minute. Semi at 6 rounds rapid shoot or 30 is not going to make a lot of difference, if it's misalining becasue of a weak spring guide (if that is even the problem) it could do it with one round (one full cycle). Anyway it's not a F/A problem that's for sure. I hope JR/Redleg are able to get some answers...

 

[redleg]

I thought this too until Bimax's comments. The Fin's Swiss Arms are not F/A so the stress is happening at a lot less then 800rds per minute. Semi at 6 rounds rapid shoot or 30 is not going to make a lot of difference, if it's misalining becasue of a weak spring guide (if that is even the problem) it could do it with one round (one full cycle). Anyway it's not a F/A problem that's for sure. I hope JR/Redleg are able to get some answers...

We have not had similar problems with any of the CQBs. I can't really provide answers for those with SG552s as I don't have access to the guns, and have no real idea of their histories, or use. All I can suggest is that they contact Swiss Arms and allow them to do some research on the problems. Both systems are now being shipped with plastic spring guides, so it is possible that this ws identified as the culprit in the SG552.

 

[OZZ]

We have not had similar problems with any of the CQBs. I can't really provide answers for those with SG552s as I don't have access to the guns, and have no real idea of their histories, or use. All I can suggest is that they contact Swiss Arms and allow them to do some research on the problems. Both systems are now being shipped with plastic spring guides, so it is possible that this ws identified as the culprit in the SG552.

Can we get these plastic spring guides for the CQB? Why chance it if they have an upgrade can we get this?

 

[edward911]

Can we get a plastic one off Swiss Arms?

If your CQB is from the latest batch purchased from TSE this past May, it should already come with a plastic/polymer guide rod.

Other areas to investigate are whether the recoil spring is strong enough to handle the FA recoil pressures of the 552 or the materials/casting process of the bolt carrier for the particular batch in question.

Nonetheless, nothing will get resolved if the users of the defective 552s do not notify Swiss Arms.

 

[Orvis]

Have there been any updates, explanations, or resolutions regarding the failures in the 552s and/or have there been any documented problems with the CQB?