The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Daryll wrote:For a .22 calibre rifle it probably will be 1/2 inch... 20tpi for european and 28tpi if its an American rifle..

Full-bore ARs are normally ½UNEF (28tpi) and the rim-fire versions are generally no exception.

Ovenpaa wrote:

Alpha1 wrote:Davids scrap bin contents are a joy to behold in my opinion and I am all ways keen to grab some when they are available. I can see what they were intended to be in most cases. A lot of them I can not fathom why they are not up to snuff and why they were scrapped. But what is more important to me is a hands on bit of kit that I can examine and see how its been done.

Call it distant learning. You can take over when I retire.

I wish. I don't think I have enough years left to be able to ever achieve your skill level.
I will be whizzing some more of your off cuts around to morrow I set it up to day.

I spent this morning gardening and the afternoon in the Shed.
After Listening to peoples advice and after spending a couple of hours turning and threading I am of the opinion that the threads are more likely to be 1/2x20tpi unf at the muzzle and may be 1/2x28tpi unef on the moderator.
So i have made an adaptor that has a female 1/2x20 thread and a male 1/2x28 thread. I have left the outside diameter larger because I don't know the diameter of the barrel until I can measure it
I also made some male and female gauges to check.
Still lots of interesting stuff in the scrap bin. I will have to think of another project to use it up.
The pieces are not finished yet so they still have some sharp edges etc.
I have an issue though and could do with some advice. After threading I undercut but I can not get the pieces to screw right up to the shoulder do I need to take a deeper cut or am I doing some thing wrong. If you look at the second picture you will see what I mean.

I think I need to make a 1/2×28 female to a 1/2×20 male adapter to cover all the bases. Maybe to morrow depends whats going on work wise when I log on in the morning.

Sorted the screwing up to the shoulder issue. I did a google search followed by a couple of you tube videos. As you do. And all is revealed.
Job done.
hmm so whats next.
Well nothing really. Just marking out and getting prices for my new shed.

I got to measure the thread today. It turns out the male thread on the barrel is actually the same thread as the female on the silencer. The issue is the thread on the barrel is longer than the one in the moderator/silencer. So currently the silencer wont screw up to the shoulder on the barrel.

Often the issue is the sound moderator has been shot on a previous rifle with a shorter thread which leads to carbon build up on the inside of the female thread. Run a tap down to remove the carbon and you are good to go.

Ovenpaa wrote:Often the issue is the sound moderator has been shot on a previous rifle with a shorter thread which leads to carbon build up on the inside of the female thread. Run a tap down to remove the carbon and you are good to go.

You were right. Job done.

The only problem with running a tap through is you can take out more than just the carbon leading to a less precise fit, plus carbon is abrasive. I use good quality ground taps and have undersized taps in a couple of common sizes for the carbon reason. It is worth getting to know the different classes of thread taps.

A final tip, if you buy a new set of taps for a fiver on eBay you should not expect perfect results. Having said that, do not be put off by used sets, especially the more obscure as they are likely to be both good English names and sometimes only used for one job. I recently picked up a set of L.A.L. Taps (Lehmann-Archer & Lane) for a fiver delivered and they look to be unused and tap flawlessly. For the more common sizes I only use Volkel.

Distant learning :)

The thread turned out to be 5/8x20tpi.