For anyone following this thread, I spoke to Nick at Straight Jacket Armory (bought my replacement barrel there). He is going to make a video showing how to do this procedure. For those starting from scratch, here are a few helpful tips / tools I have found so far:
TOOLS
There are many options here. These are merely suggestions if you don't know where to start. If you are a pro, feel free to skip.
- Barrel nut wrench ($34, here)
- 1-1/16-Inch Crowfoot Flare wrench ($24, here)
- Bench vise ($190, here), barrel vise jaws ($30, here), paper drywall tape to protect the barrel ($4, here). There are plenty of alternatives:
- High-end: Short Action Customs, Modular Barrel Vice ($425, here)
- Mid-level: Barrel Removal Tool - requires a bench vise ($175, here). As of 3/9/2023, I have not found anyone else carrying an "action wrench" for the Cross. See this other thread as well.
- Entry-level: Wheeler Barrel Vise ($84, here)
- Git 'er done: go to home depot, buy a block of oak, drill hole, saw in half through hole diameter, clamp it with what you have.
- "GO" and "NO-GO" gauges ($90, here).
- You can save money by buying only a "GO" gauge and making it "NO-GO" by putting painters tape on the base to create the proper dimension.
- Miscellaneous - torque wrench, grease, thread lock, Fix-It sticks, etc.
DISASSEMBLY (draft):
There are instructions in the Cross Rifle Operators Manual (click
here), but it assumes you have a barrel removal tool shown on page 95. Unfortunately, the barrel removal tool is not readily available for purchase. Both SIG and the one vendor in the "TOOLS" section above are out of stock. This and the next section are for the mere mortals who have tools that can be easily purchased...
Caution:
- Another Sniper's Hide member said he broke the dowel pin in his barrel extension by not first loosening the castle nut and then loosening the barrel nut (thread here).
- Your's truly made the same mistake and broke a piece off the dowel pin guide in the aluminum receiver.
REASSEMBLY (draft)
Numbers in this section are from the Cross Rifle Operators Manual where available. Otherwise, I will note source information.
Torque specs:
- Castle / jam nut: ?? (same question different thread here, here. 3/13/2023 SIG cust svc said this is armorer-level spec, need to ask armorer)
- Barrel nut torque: 40 ft-lbs
- Handguard screws: 17.5 in-lbs
- Receiver top rail: 35 in-lbs
- Stock assembly: 50 in-lb.
The lack of clear instructions on how to do a SIG Cross pre-fit barrel swap (including the elusive "just reuse the factory extension") has been really frustrating, so I am doing my best to share what I have learned.