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.