Random Lock Weirdness

[I Eat Gins]

Hello

I didn't know which section to post this in, though I'm not a beginner and have 4 or 5 years experience with high security locks.

I bought a Lockwood Twin which are known for their very high tolerances. I've had it less than a week and have been picking it over and over amongst other locks.

It has three standard pins and three spools, as well as a few sidepins.

For the first few days, I'd pick the standard pins and drop into a false set straight away, every single time.
From last night onward, the lock has been acting differently for no obvious reason. Now when I lift the last standard pin needed before a false set, I won't drop into a false set. The pin isn't binding as tightly as it was before.

The key works, I've checked all the pins and nothing is wrong.

To get a false set I need to lift that last pin, counter rotate manually just a fraction (not even noticeably if you were watching), then tap that pin. I've tried this many times now and it's the only way to get my false set.

Using heavy tension doesn't change it.

The other two standard pins bind tightly and give a clear, loud snap when I set them. This pin feels spongy and it only just started to happen last night.

The narrow sections of each spool bind at the shear line.

If this pin drops while setting a spool, same thing happens. Lift, counter rotate, tap the pin to get false set back.

The only thing I can think of is that this one pin isn't dropping back down all the way into the plug for some reason, which doesn't make sense because the spring above it is strong, the lock is high precision, and it started happening out of nowhere.

I've tested the lock with only this pin in it and same thing happens.

Does anyone here know what could have caused this? I've picked dozens of locks over the years and never experienced this.

[GWiens2001]

It may have started having one of the security pins catching in the counter-milling in the pin channel.

Gordon

[I Eat Gins]

It may have started having one of the security pins catching in the counter-milling in the pin channel.

Gordon

There is no milling. It's a Lockwood Twin, not an Assa.

I tried heavier springs, same issue. A different pin, same issue.

The problem is with the pin chamber and I have no idea why this could suddenly happen with a brand new lock.

[GWiens2001]

Because picking can damage locks. Just ask anyone who has worked a lock-pocking workshop somewhere.

Gordon

[I Eat Gins]

Because picking can damage locks. Just ask anyone who has worked a lock-pocking workshop somewhere.

Gordon

I know that. I've never damaged a lock before though and this has only been used for less than a week.
I have dozens of locks and have picked them many times.
Bad luck i guess. A shame too because this lock is rare now.

[GWiens2001]

Since the key works, you can disassemble the lock and look in the pin channel in question for any damage.

Gordon

[I Eat Gins]

Since the key works, you can disassemble the lock and look in the pin channel in question for any damage.

Gordon

It's too far in to be able to see. I checked the plug and saw nothing obvious.
Though the smallest change/damage can cause something like this to happen, even if not visible to the eye.
It is what it is. Thank you anyway.

[demux]

If you can take the lock apart, get a piece of smooth rod just slightly smaller than the diameter of the pin chamber and stick it down in there at a very slight angle. The idea is to use it to feel the camber sidewall all the way around. If there is a defect, you may be able to find it this way. You may or may not be able to do anything about it, but at least you'll have an answer as to what's going on. A drill bit would work as well, but use the shank end, not the cutting end, and make sure there is no damage from the chuck. You don't want to make the problem worse...