I have a Sig 1911 TacOps, and want to make it suppressor capable, so I purchased the Sig TacOps threaded barrel. It states "may need fitment".
Are there any tests or measurements that would help me determine if fitment by a 'smith is needed? I don't mind paying to have it done right, but if it is not required, I'd prefer to save the energy and time of going to the shop, etc. Thanks in advance!

You may be over-thinking this. I would just try to install the new barrel and see how far you get. If it requires fitting, it will become apparent as you reassemble and test cycle.

Well, here's an update:
I took some measurement of the two barrels; original and new-threaded; hood width, barrel diameter under bushing; and they were spot on the same.
So I went ahead and installed the new barrel. It seemed to behave normally, would go into battery w/o a cartridge, so I tried a couple of metal snap-caps; made from nickel ammo with FMJ bullets and rubber "primers". Here's where things got interesting. With one snap cap, it worked fine, went into battery and allowed the hammer to drop. With the next snap cap, however, the slide would not go fully into battery. It appeared to be 3-4 mm pulled back from the full battery position. Made some measurements on the snap caps, couldn't see anything different enough to explain the behavior. Note: both snap caps behave normally with the original barrel installed.
Any thoughts?

Thoughts?

There is a slight difference in the chambers of the two barrels, but almost certainly both are within specifications. That coupled with a slight difference in the homemade snap caps causes the failure to go into battery of the one. One question I’d ask is did you fully resize the cases?

Even if you did, a small difference in the case thickness coupled with possibly some variation in bullet diameter might also be the cause. The first thing to check is how the “caps” chamber when the barrels are removed from the gun. That would rule out any other issues.

The same thing can be done with factory loaded ammunition, especially premium quality stuff.

Homemade snap cap issue aside, I think you are ready to take it to the range for testing. Load one round in a magazine and see if it feeds. fires, extracts, and ejects. Then try two rounds. Nothing bad will happen.

I was wondering if this could be the case. I just didn't want to try chambering a bunch of live rounds in my house.
These snap caps were bought on-line, Ebay. I guess someone takes empty cases and inserts a rubber cap and FMJ bullet. What disturbed me was that they both worked with the original barrel, but not the new barrel. But as you point out, the problem may be with the snap cap geometry, and the older, broken in barrel is just more forgiving. Thank you!

quote:

Originally posted by sigfreund:
Thoughts?

There is a slight difference in the chambers of the two barrels, but almost certainly both are within specifications. That coupled with a slight difference in the homemade snap caps causes the failure to go into battery of the one. One question I’d ask is did you fully resize the cases?

Even if you did, a small difference in the case thickness coupled with possibly some variation in bullet diameter might also be the cause. The first thing to check is how the “caps” chamber when the barrels are removed from the gun. That would rule out any other issues.

The same thing can be done with factory loaded ammunition, especially premium quality stuff.

Seems like a good plan. If anything doesn't look right, I won't drop the hammer. Thanks!

quote:

Originally posted by GaryBF:
Homemade snap cap issue aside, I think you are ready to take it to the range for testing. Load one round in a magazine and see if it feeds. fires, extracts, and ejects. Then try two rounds. Nothing bad will happen.