That would be because most suppressors were not user serviceable and had to be returned to the manufacturer for cleaning.
I would not buy something I could not service myself.
Fortunately there are better options now, a bit pricey but in my opinion worth it.
I swore I would never own a suppressor if I had to jump thru all the government BS and would wait until they were deregulated, well that dog never hunted.
I finally broke down and ordered one from Silencer Central.
I ordered the newest in the line up, the Banish 46, it will or so they say work on anything .45 cal. on down.
I ordered all the extra goodies to make it work on practically every thing I have.
Things like a Nielson device and pistons.
This thing will probably be a bit bulky on pistols but I'm not going through the BS and wait twice or more times.
I could have done the Form 1 and built my own but it seems they are beginning to frown on that.
I'm sure a commercial unit will be better than what I could come up with anyway, as Dirty Harry said, "A man's got to know his limitations."
I do intend to shoot cast thru it, although they will be powder coated.
If I end up ruining $2000.00 worth of suppressor I will let you know so to save you the anguish.
At this point my suppressor is still in ATF jail.
In other words, I don't have a clue and I'm talking thru my rear at this point.
If I have only one hope it is to live long enough to have at least one range session with it.
At my age you never know, I have recently had a couple friends pass that were several year my junior.
I have been very fortunate so far.