Wow, I am late joining this one, but your results definitely are not what I would consider normal for a Form 1 can. I have not checked out Factory CAN pricing lately, but back when I built mine a few years ago the $ difference was extreme st the least. I had $400 total including stamp into my 1st can (9mm 8" long). The cheapest factory cans were $700+ at the time then additional $200 stamp and over 12mos wait via form 4. My Form1 stamp was back to me in 90days.

Now I do not claim they all shoot sub MOA, I have noticed an opening in group with my form 1's, but I have heard the same said for factory cans. My 2nd can I just used last nov to take a Coues Deer @ 430yrds+ My hit was off a bit but given it was my 1st game animal shot(major nerves/shakes) at a steep downward angle and at 4500ft elevation (all my shooting been sea level) I call it a success as those other factors had more to do with the shot than the can did.

I am not saying it is your shooting, obviously you had some baffle strikes, any deformity to the baffle shape or hole will tweak bullet flight. Like others, I would say get yourself a set of K cups and find a buddy/machinst you are close with that has a lathe. Have him show you how to chuck up, then center bore some round stock. Then once you know how to do that you can chuck the baffles up so you can properly center bore them yourself off the baffle's OD. Provided you do that and that the ID of your can and the endcaps are concentric then you should be good to go. You already have the tube and engraving, dropping another little bit into good bafflers is worth it I think.

I still think it's worth salvaging

With the proper baffles it will suppress just as well as a commercially produced can. The only downside is that it will be heavier

Go do what you want though, run free, get some other cans. Spread your wild oats. Maybe sometime down the road you'll circle back and find a use for this one

Well, 4 months have gone by, and I've given this problem some more thought - specifically, having a professional re-core performed by a SOT dealer/manufacturer. I've called around and been given all kinds of quotes, ranging from $150 to $400. But what never occurred to me until today was to call the company I bought the solvent trap from - SDTA - to see if they do re-cores. Turns out they don't advertise it, but they will perform the service. I spoke to Amy this morning, who is very friendly, helpful, and patient with my myriad questions. She gave me the option of stainless ($175) or titanium ($250) monocore; I'm going with titanium to keep the weight down. I'll ship it out today and hopefully have it back in 2-3 weeks. I'm looking forward to getting this thing back in action!

Interesting. I'd love to see pics of what they send you, and let us know your thoughts!

I have heard of a few people doing the recores. I also will be very interested to see what results you find on performance.

The recore idea sounds great.
I’m interested in doing a 9mm can now.

That is awesome to hear it will be working again. Looking forward to the forthcoming update!

So, why are the stainless freeze plugs no good, are they to "mild", not heat treated to the right hardness?

Stainless freeze plugs are just fine for a 300 Blk, even at the blast baffle, at least as far as the material is concerned. Some people take that stuff way too far because of inexperience; you don't need inconel baffles in a semi-auto 300 Blk or even a 308. Freeze plugs are heavy and inefficient, but that's a different problem.

OP:
It was pretty clear from the description in the OP that baffle or end cap strikes are the problem, nothing else causes that kind of POI change when a suppressor is attached. With that much of a problem, I'd be concerned that the can itself is not threaded straight to the bore, regardless of the core. That can be checked by shooting it without any baffles inside; a small POI change is to be expected but if it's a large change and/or accuracy goes bad, you'll want to get that rear end cap trued up and maybe have the barrel threads checked too.

There are a lot of little details that go into making a suppressor work right, and unfortunately the general shooting population does not know what those are or how to check them (although plenty are willing to give advice). That's part of why I really dislike these "solvent trap" suppressor F1 assemblies; if a guy doesn't know what he's doing, he should expect a heavy and expensive piece of junk that doesn't work very well, if at all. Even with a recore, I would not expect it to sound as good as a decent commercial suppressor, and it will still be a lot heavier even if you go with the Ti baffles.

The plugs themselves are not made/designed to be perfectly concentric (in machinist/machining realm) so you are starting off at a disadvantage. Yes they are round and to a certain OD, but they are mad to a min dimension and do not have to be round as their job is to press in and deform to fit the hole in an engine block.

That said I think a large factor is the forming and the machining involved when people make a Form 1 can. Most folks building these will use a drill press to drill them out. You will not get them exactly in the middle or uniform doing it this way, sorry folks it's just the way that sort of setup works and the drift in a drill press. That is why many of the threads and data out there have the hole size to drill so much bigger than the gun/bore size. For safety you er on the larg size so if you are not perfectly concentric you have margin of error. Best/only way to get them truly uniform and concentric to the outside of the freeze plug is in a lathe, I work at a machine shop and that is what I did. In doing so I, knowing I would be perfectly centered, I also went with a smaller bore size on my plugs. That may be why mine sounds like it does. When compared with a commercial suppressor (side by side, same gun, same ammo) it was not any louder and had just a slightly different tone to it.

The other huge "problem" with freeze plugs is the forming as well. Most people are using some sort of "dies" or kit form any number of places and pressing them in a bench vice. The pressure exerted will be different each time, combined with variations in each plug from factory, etc and you get baffles that are not uniform to each other. That also messes with sound and accuracy.

All that said. As Yonderling mentions, the sort of shift the OP was seeing are out of the norm, even for a Form1 garage build can. I do not expect my $200 DIY build to be shooting sub MOA, but I can tell you right now it is not shooting like the OP's and while I have not measured yet I would say it hurt accuracy by no more than 2 MOA based on the shooting I have done with it. Heck I shot out over 400yrds and was not as far off as the OP was @ 100.

I would HIGHLY recommend taking Yonderlings recommendation and verifying that the endcap and barrel threading are concentric to the bore. It is not unheard of for barrel threading and/or shoulder to be off. If it is off then you are going to waste that fancy new core on the 1st shot.

My SD Tactical titanium "B" tube .30-cal re-core came in yesterday, and it looks really good! I'll need to have the end cerakoted to match the rest of the can, but that's easy enough.









Range day will be Saturday. I'll put some S&B 200gr subs through it to check the sound reduction and the POI shift. With the can mocked up on the upper (8.5" .300 BLK), it looks concentric to the naked eye (if it wasn't it would likely be obvious), so I don't think there are any issues with the threaded mount end being off. I asked SD Tactical to check that as well, and it looks like they fired at least one round through it before sending it back, so I trust they are OK with how it performed. But I will probably put at least 100 rds through it on Saturday afternoon to make sure!

My buddy has a Form 1 silencer and it does the same thing. Makes me believe it is concentricity issue ie. alignment from the direct thread through the baffles and all the way down to the muzzle. If you could use a dowel or rod which fits snug from the first baffle all the way to the muzzle this should keep your baffle stack aligned with the muzzle when you assemble. Second issue is--is getting the bore of the barrel aligned with the baffle stack but at least you should have a consistency.

Thunder Beast Arms silencers are touted as the go to in accuracy and they wire EDM cut the baffle stack and end cap at the same time to keep concentricity.

No, it isn't obvious; the level of concentricity needed is more than just eyeball accurate. You can have baffle strikes with a can that "looks" concentric.

You'll need to use a straight range rod that closely fits the bore to check suppressor concentricity. The reason you started this thread indicates things are not as straight as they may look.

Actually, the naked eye is very good at picking up on non-concentricity, provided you have good eyesight and know how to line up everything. That isn't to say it's all that is needed to verify; I'm simply saying you can usually tell just by looking. And the reason I started this thread is primarily because the baffle stack shifted inside the can, not necessarily because my holes weren't concentric. But neither of those matter because it's now a monocore and the concentricity is guaranteed by SD Tactical.

Damn dude that monocore looks great! Looking forward to the range report.

Yeah that's awesome. How heavy is that thing?