[m102404]

If it's brand new, the stock should come with a little picture of what you need to cut it to.

If it's not...here's how you figure it out.

On the end of the buffer tube that presses up to the receiver (the front end of the tube)...reach inside and feel around. You'll feel a section that is built up. It might be about an 1" deep, or maybe a bit longer. Try to get a good measurement of how deep that section is.
- you can take the washer that the stock screw holds on and drop it into the tube...then use a rod/stick/screw driver/whatever will fit to push into the front of the tube until you just touch the washer. Subtract about about 5mm from that length and write it down.

Then put all your sling plates, receiver plates, etc... on the receiver stud...make sure you've got whatever you'll want pinched between the stock tube and the receiver there.

Transfer the measurement that you wrote down to the remainder of the receiver stub. Obviously measure from the last plate that you mounted back towards the end of the stub!

Cut it there.

The stub should be just about 5mm shy of the washer that holds the stock tube on.

Cutting it 5mm short gives you (or the next person) the option of taking sling plate off without having to recut the receiver stub again.

Now...some receiver stubs have a "flat" bottom...that "flat" is to make enough room so that your wiring can just squeeze through between the bottom of the receiver stub and the inside of the stock pipe. It might be a really tight fit depending on your wiring and the thickness of it's shielding. You might need to file it a bit so the wiring clears. Use some scrap wiring for test fitting, so you're not chewing up the mechbox wiring as you test fit.

Some stock tubes have a little channel on the inside...that's for clearance for the wiring too. You might not need to do anything if the stock tube has a channel and the stub is flat. You've got to figure that space out yourself (or get someone to do it for you)

Some receiver stubs are round...there's no flat/channel for the wiring. You'll have to cut/file a channel in the bottom of the stub to fit the wiring. You might just need a shallow one if your stock tube has a channel...you might need a deeper one if your stock tube doesn't.

You can file the bottom of the stub flat...and you might get enough space to clear. You can also use a dremel cutting tool (a cylinder cutters meant to cut metal). A cutoff wheel is not the right thing to use. With a steady hand you can cut a slot pretty quick...but don't cut all the way through the stock tube. Just enough for the wiring, and leave as much metal as you can for strength.

Test fit, test fit, test fit....use scrap wiring until you think you've got it. The thickness of the wiring...and the thickness of shrink wrap is a nice touch.

NOTE: SINN's a champ with the clutch picture installation!