Krebs Custom Guns Sig 556R Enhanced Safety Lever

Got this new safety lever made by Krebs Custom Guns and it is great!

The original Sig 556 safety lever is short and has sharp edges on it. It's very awkward to engage and disengage.

The Krebs safety lever fixes this short fall perfectly.

You can quickly snap off the safety when bringing the rifle to bear and be ready for action where before it was very difficult to do.

Flicking the safety on is just as easy as the tip of the lever is right at your thumb.


If you would like to improve the factory safety lever on a Sig 556 rifle this is your chance. Marc Krebs said he only did a run of a 100 of these safety levers so you better call in and get it!

Sig 556R Back From Sig Sauer Custom Shop Services

I got my Sig 556R that was manufactured February, 2011 back from Sig Sauer Custom Shop services.

They had the rifle two days.

Pretty quick turn around. Fedex took the bulk of the time require 7 days to get there and 7 days to get back to me.

 According to the gunsmith comments the work performed was:

- Inspected rifle

- Upgraded sear and sear spring

 - Upgraded the mag support plate

- Upgraded the torsion assist. I cannot begin to guess what this means but could the the ejection port increase.

- Upgraded the extractor and extractor and extractor spring.


There is no mention from the gunsmith that he widened the ejection port by removing material.

Gunsmith report.

Ejection port before sending in.

Ejection port after. Job looks sloppy.

Comparing the ejection port modification or "upgraded torsion assist" with a photo of someone elses modification from Sig Sauer Custom Shop Services my job looks pretty rushed and sloppy. The gunsmith, "M. Burlingame" must had an off day. There doesn't seem to be a quality control step that inspects the out going work to make sure it's at least consistent with some sort of standard.

Sig Sauer 556R Factory Fix of FTF/FTE - Increase Ejection Port Size (Top old, Bottom new)

Above photo shows another persons "upgraded torsion assist" workmanship. Looks good to me.

Mag Support Plate added.

I haven't taken the rifle out to the range yet to test fire it and verify the fix.


 Update: June 05 2012

Well, I have test fired the 556R now and it's got an interesting new problem.

It looks like the charging handle is going all the way back and smashing into the rear of the upper receiver and denting in the metal.

Below is a photo of the damaged upper receiver.

Damaged upper receiver caused by reciprocating charging handle

It's clearly noticeable in the above photo that the charging handle hit the back of the receiver.

Inside view of damage.

I also can see the rubber is coming lose from the rivet.

Charging handle lined up.

Charging handle contacting the receiver causing damage.

Sig Sauer 556R Factory Upgrades For Premature Mag Shelf Wear and Ejection Port Widening

I did some research regarding my new acquisition of a Sig Sauer 556R having read that some people were having problems with their rifles.

I wanted to have all the latest greatest upgrades and improvements to the rifle so it can run its best.

Some things I noticed is that the Sig Sauer 556R exhibits premature mag shelf wear on the receiver if you use steel AK magazines.

This was pointed out early on when the 556R originally came out in 2011 by other intrepid internet posters and Sig Sauer worked on a fix for this.

This could be a problem if, over a period of years, the receiver wears down to the point where the magazine is no longer held nice and firm or, worse yet, the magazine fails to be retained properly.

It turns out I bought a rifle manufactured in February 2011 and it didn't have the magazine shelf steel insert upgrade.

I thought it did have the latest upgrades because I went to the 2012 SHOT Show to look at the latest Sig Sauer 556R on display at their booth with the serial number 28B001638 (mine is a 28A0019XX serial number) and it looked identical to the one I bought.

Turns out Sig Sauer is still producing the 556R without the magazine shelf strengthening steel insert to prevent premature receiver wear.

Here are a series of pictures outlining the differences:

2012 SHOT Show 556R New Production Rifle (SN28B001638) - Old Mag Shelf

2012 SHOT Show 556R New Production Rifle(SN28B001638) - Old Mag Shelf

February 2011 Production 556R Production Rifle(SN28A0019XX) - Old Mag Shelf

Sig Sauer 556R Factory Fix For Mag Shelf Wear (May/2011) Steel insert

Sig Sauer 556R Factory Fix For Mag Shelf Wear (May/2011)

Sig Sauer 556R Factory Fix For Mag Shelf Wear (May/2011)

In addition to the magazine shelf insert to prevent premature wear there were issues reported regarding failure to eject and failure to fire.

To fix the failure to eject problem Sig Sauer opened up the ejection port quite a bit as shown in the following photo:

Ejection port portion that is removed.

Sig Sauer 556R Factory Fix of FTF/FTE - Increase Ejection Port Size (Top old, Bottom new)

The failure to fire issues were remedied by increasing the hammer spring strength to make sure the harder primers found on Russian ammo would be ignited.

Other miscellaneous parts were upgraded during the improvement process.


Bottom line is if you are an informed consumer and do  your research you can get the upgrades done buy Sig Sauer by phoning customer service.

I phoned them and within half an hour I received a prepaid shipping label. I'll be sending in my rifle for the work.

Hopefully, the turnaround time won't be too long. I'm expecting 4 weeks.