Couple M4 questions

[BigBuckeye]

Guys,

 

i just installed my FFT mag tube and 922r parts and I have a few questions:

 

1) Is the spring retainer clip supposed to just sit in the tube and use tension to keep it in place or does it "snap" into place somewhere?

 

2) Do I need a different spring for the lengthened tube or can I use the same spring that came with the stock setup?

[calviroman]

Welcome.

 

1. The magazine spring retainer ring sits in the tube under tension and does not "lock" or "snap" in. Because of this, it is not suggested to remove the thread on magazine end cap when the magazine is loaded as the magazine spring retainer can launch with a good amount of force (ask me how I know)

 

2. Sorry don't know. Back in 2010 when I put my seven shell tube on to replace the factory five shell tube I can't recall if Kip included a new / longer mag spring or not.

[StrangerDanger]

1. The spring retainer is simply tension fit. Listen to caviroman about removing the barrel with the magazine tube full.

 

2. The OEM spring should work. If it isn't strong enough, the failure will metastasize during the last round in the magazine tube loading. That is when the spring will exert the least amount of force on the shell. Carriercomp and FFT sell a replacement spring that are nice. They're from Wolff so they're a good product. The OEM spring tends to take a set rather quickly in my experience.

[NoTycoon]

You will need a longer mag tube spring when you add an extension. Most extensions come with a longer spring. If you are only adding 1-2 shells, you may be able to get away with the stock spring.

[BigBuckeye]

Thanks all

[Toaster]

@1. Couldn't a slot be cut to retain the ring with a T-slot cutter, or for the home DIY, a Dremel and a cut off wheel? Into the titanium ID Doesn't need to be deep at all.

 

Seems like an oversight in manufacturing.