Stainless suppressor with rolled ring to hold blast baffle?

[daz59]

Hi,

MAE here in NZ make stainless suppressor, all of them have what looks like some sort of rolled ring that holds the first baffle in place. Does anyone know how things ring on the tube is formed?

Thanks
Darren

[daviscustom]

I would think it could be done with a pipe cutter.....you would just have to round over the edge on the cutter so it didn't cut the tube.

[SRM]

The tricky part is keeping everything strait.

[tmix]

With a ring roller.

Is it done on a lathe with a special tool?

[Enfield577]

Hi I believe it would be done in a lathe with a suitable rolling wheel form tool, similar to knurling

Cheers

[mg81]

If you look around on this site I remember seeing someone (in Finland?) using a large pipe cutter. The type you use to cut steel pipe with, not the little copper pipe cutters (but they look and work the same, just much bigger). They had taken the cutting wheel and rounded off the sharp cutting wheel so it was a radius. Then in a lathe would roll the groove. The lathe just made it easy to roll it, holding the cutter by hand as the lathe turned the pipe. I think you could do it by hand if you were careful, just holding the tube in a vice. It would just take much longer.

What makes the pipe cutter a good choice for this is the three points of contact. As the tube rolls it keeps things round, otherwise the pipe would likely try to collapse.

I made a replacement cutter for my pipe cutter to try and do this as well. It is harder than it looks. I think the radius and rate that you feed in the wheel is important. Also I think they had parts inside that supported the pipe on either side of the roll to keep it a nice, tight, narrow groove. My experience is it makes a tight groove, but without something inside the pipe it tends to also tighten the entire pipe for at least 1/2" to either side of the groove. So you can't push a baffle up against the groove, instead it would bind up before it got to the groove.

If I really wanted to make it work I would insert a tight fitting piece of bar stock on either side of the groove to support the pipe so I could get a nice groove then remove them once the groove was rolled.

Hope that all makes sense.

[daz59]

Thanks,

The blast baffle must have that same ring machined into it to allow that tube ring to be rolled into the blast baffle ring.
So once thats done the blast baffle is in there for good. I wonder how they keep the pipe straight?

I can see alot of pressure needed to roll a ring like that in 60 thou pipe.

[mg81]

My memory is the same as yours, a baffle or multiple baffles have a groove cut in them so when the groove is rolled into the tube the baffle supports the tube on either side of the rolled groove.

I don't know if you have ever used a pipe cutter like this for cutting plumbing pipe/gas steel pipe, which is at least 1/8" and more like 3/16" thick. It is no big deal to cut pipe this thick with a cutter like this. My experience is it is far to easy to roll a groove into a tube than you would like. The problem is that you will end up accidentally putting on to much pressure on the pipe and distorting it or cutting it.

In my mind it is a great way to hold things in place without fancy tooling or adding any extra weight. But it certainly requires some practice to get it right and it may not look as "polished" as some may like for a suppressor.

[daz59]

I have a lathe and milling machine so I could make up a tool like this Knurling tool, but have smooth rollers in it, you use the nut to bring the rollers in tighter so it doesnt put much stress on the lathe...

[Trex]

Here we go, I still haven't tried this yet, large pipe cutters here are £30-50 approx second hand and I have little free time.

Always good to see another Kiwi on-board. Was looking at a NZ Gunworx (sp?) yesterday, being used on a 6.8mm nice effective silencer, pleasant to listen to until the guy on next firing point let go with a muzzle braked .308.

viewtopic.php?t=35711

[mg81]

Trex, that is the post that was thinking of. That is the pipe cutter tool that I cloned to try rolling grooves with. Now that I see their baffles (with the groove machined into the edge) I get how they are getting such nice grooves. The tube is well supported by each baffle.

Thanks for reminding me about the caliber knurling tool. I keep meaning to make one of those. My lathe does not have the guts to do very bold knurling on hard steel (like 4140 HT). I think this tool is the ticket for that.

I will say though that I don't think this would work as well as a modified pipe cutter. A pipe cutter has three points of contact so it should do a much better job keeping things round.

[SilentMike]

The rolled in ring might be to simply locate the blast baffle (and by extension, the whole baffle stack) longitudinally in the tube like the 1921 Maxim/Parker Hale.

[vix1227]

There is a setup shown on a lathe about 2/3 of the way down on this post.

viewtopic.php?t=35711

[82nd airborne]

My setup looks alot like a mig welder.