i bought a very nice barrel for cheap because the previous owner damaged the threads (1/2-28)
i can get a birdcage on if i force it, but i don't want to do that for obvious reasons


i'm having a heck of a time getting my 1/2-28 die on to clean the threads


any suggestions short of cutting new threads?

Find a Smith or machinist who is competent enough to "pick up" the threads. Set the barrel up in a lathe for threading and use the threading tool to chase the threads.
I have saved many a thread that appeared damaged beyond repair.
That's the best way.
You can also get a "thread restoring" file that may clean them up acceptably.
If worse comes to worse you can also use a new three corner needle file and individually clean up each thread, time consuming and not as accurate but if all you plan on running is a flash hider it will suffice.
If you have any intention of suppressing the rifle bite the bullet and have the threads picked up or lop the barrel off, re crown and thread.

Check with your local ACE and see if they have a thread file.  That way you can work on the dinged section by itself. They come in all different threads, like this:



http://www.amazon.com/Allstar-Performance-ALL11039-Metric-Thread/dp/B003BZLK6O

if you have never chased threads with a die look at both sides. one side has a taper to it.
that is the side to start. my 1/2-28 die is also adjustable for cut depth. i start by loosening the screw, then if needed
tighten the screw some more on a second pass.

the die CAN be a hassle doing it by hand. buy generally isnt.
keep trying.

OR

get a jeweler file/ diamond file and clean the threads up by hand.
there are also thread files you can buy. then just use the #28 side and clean it up that way.

^^^^this^^^^^
although not metric
http://www.amazon.com/Allstar-Performance-ALL11038-Standard-Thread/dp/B003BZR1OO/ref=pd_bxgy_263_text_z

Chasing threads with a die is technically not "chasing threads", you're recutting them and the result is NOT necessarily true/straight; it wouldn't be much different than just threading your barrel with a die. This can be a problem, you more than likely will only make it worse.

The proper way is to use a thread chaser. This is a multi-piece die held together by a spring. You pull the piece apart, expanding them out so they slide on without even touching the thread, and you place them back where the thread is good. This way you have good threads as a guide. You then slide the wrench on the chaser and back it off, it will deform the thread back into place and may cut a little off as well.



There are other styles of thread chaser as well... they all have their pluses and minuses...

ive seen a lot of tooling. never saw that one.
nice

interesting.

i did a brief google search and couldn't find one of those

recommendations where to find it?



 

Made by several companies: although google results seem to be mostly dominated by the murray set I linked below, I know I've seen an Irwin-Hanson set before and I'm confident they aren't the only maker. You want to search for "split die thread chaser"

Murray Set... a bit pricey for a full set and I don't think it includes UNEF thread patterns

A more in-depth explanation of their use and benefit Note: this article insinuates that this maker has developed something radically new; it's not a new concept, only the hinged design is new.

As long as you use an adjustable die you can chase threads.
Open it all the way so it spins down with no real cutting.
Tighten and repeat.
It just takes a lot more time.

There are 1 inch dies that are adjustable.
They are NOT the cheap ones.

The original purpose was to allow cutting of different thread classes.

Does anyone offer the “split die thread chaser” in 1 /2-28?

If an adjustable die can open enough to start over your damaged threads that should do it, otherwise have a properly skilled gunsmith or machinist “pick up” the threads and single point / lathe cut the threads (its not that difficult of an operation, a guy that knows what he is doing can handle the job)

A thread file of the correct pitch should do the job.
Just work VERY lightly and slowly.

http://www.amazon.com/Drill-America-High-Speed-Adjustable-Threading/dp/B00CTS5WC2/ref=sr_1_2?ie=UTF8&qid=1439737306&sr=8-2&keywords=1%2F2+28+die

Unless yo live near a LARGE manufacturing area,'odd' dies have been a mail order thing for many many years.
We used to balance the cost against actually making a die.
Above about 2 inches making often won.