So, I've already made it known that I'm not a fan of the Form 1 route for silencers, as I believe the trade-off between quality and monetary savings just isn't worth it. Well, my second trip to the range with my "homemade" .30-cal can on my 8.5" .300 BLK was every bit as frustrating as my first trip.

Can details:

• 8" SDTA Titanium "B" tube w/ direct 5/8"-24 thread mounts and titanium end caps
• 1 1/8" stainless freeze plug baffles
• Titanium space tube

My first trip to the range was on the New Year's Day group shoot. The bullets were impacting WAAAAAAAY low - so low that I thought my red dot was defective (I bore-sighted it before the trip). Member airmandan tried to help me out, but the bullets were impacting all over the place. I cased it up out of frustration and decided to come back to it later.

Well, this past Saturday was "later". I took it out again, and at 100 yards I had rounds impacting 2 feet up and to the left of the target, then the one right after it hit 12 feet low and to the right, and the one after that was dead on, and the one after that was 8 feet low and to the left. All over the place.

SM
Same ammo both times (S&B 200gr). My first thought was that I was getting baffle or end cap strikes. I took the can apart, and no evidence of that. To the naked eye, everything in the can appears to be mostly concentric to the bore, although the freeze plug baffle holes are obviously not perfectly round. I knew that when I was drilling them, so I made them a little wider to give some cushion and avoid strikes.

Anyway, the 8.5" .300 BLK upper shoots straight when the can is NOT on it, so I know it's not the barrel or the red dot - it's the can.

Anyone else experience this? Suggestions on how to remedy it (besides buying a commercially-made can)?

My first guess would be an endcap strike. It sounds like you’ve looked at that ... but I’d still keep it on the “maybe” list.

You said that the freeze plug holes are not ROUND. That’s concerning. Can you elaborate?

Wow... That's extreme.
Can you provide a few of the technical details? (Dimensions, torques, etc. ) How did you ensure that the passage through the can is "perfectly" concentric with the bore? Do you have a method for verifying concentricity?
I have to believe that with such extreme dispersion that there is contact, not just a harmonic distortion.

Caution * Not a suppressor expert *

ETA: If you meant INCHES instead of FEET, it would still seem extreme. I am confused as to how you could figure out that you were 12 and 8 feet low. What were you shooting at?

What size did you drill the holes?

If they are too tight it will interfere even without a full on baffle strike

As the saying goes, this thread is useless without pics, so I'm here to correct that.

The can:


The guts:


While I was out at the pit, I unscrewed the end cap to check for a strike, but I didn't see any evidence of one. Again, after taking it apart tonight and snapping a pic, I still don't see any marks:


And, to be honest, I couldn't get half of the guts out of the tube while I was in the field because they wouldn't come free, and I didn't have the proper tools. So when I say I checked, it was half-ass...I really couldn't do a full inspection. Now that I have them all out, I think there may be some projectile-baffle contact:




For comparison, here is a "good" baffle (I put that in quotes because you can see that the hole I drilled isn't perfectly round):


SDTA has a centering tool to drill pilot holes, which is what I used to get started before gradually opening it with larger bits until I hit 3/8":


I'm not sure if you can tell in the photo with all the guts removed, but about half the baffles are clearly struck and deformed. But here's the strange part: they were the ones in the middle; the couple at the muzzle end that I was able to remove in the field were intact (as is the end cap). So how the hell can the bullet strike in the middle of the can, but still exit straight?! That part has me scratching my head.

Also, the can still looks concentric on the barrel when I have the upper popped off and look through it, so I'm not sure why it's striking at all.

3/8” should be big enough

Did you use a drill press?


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I'm guessing based upon the impacts in the dirt and how far away they were from the target (steel plate at 100 yds on a dirt berm). Definitely feet, not inches!




I used a mill at first, but I noticed the vise was crushing the freeze plug walls so I switched to a drill press. I actually got better holes from the drill press, and I was holding them with my fingers (no vise)

Curtis, I had an issue with my freeze plug can where some of the freeze plugs got a bit angled on the inside; I think the pressure just slammed them around, and there wasn't enough flat-on-flat contact to keep everything in place. (The freeze plugs have a rounded edge, so it was too easy for them to tilt just a little.)

The result was that some of the freeze plugs are a little deformed.

I suspect you're seeing some of the same issue . . . ?

Yeah, I noticed when I installed them for the first time that they seemed to want to slide around and not stay seated. Definitely need some flat/square surfaces to keep them oriented properly. I didn't think it would be a big deal between the tight compression and the overbore allowance. I guess I was wrong!

Couple of observations...Disclaimer first...I am not a silencer expert, but I did say in a few Days Inns, once in a while...

First thing--good job on initial machining and assembly. The problem, though, is that you made a can that can be disassembled easily for a rifle.

You'll notice a couple of things that are common to the high-end rifle cans...first, they usually have a monobloc-type baffle stack. In other words, they are made from a single piece of metal. The diffusion baffles and the all-important blast baffle are all from ONE piece.

Next, the choice of metal. The metal you're using for the inner baffles are NOT meant to take the blast and heat of a metallic cartridge. Thus, you will experience plastic deformation of the baffles in short order--and the hotter the can gets, the more that deformation will be.

While you have assembled a workable can, I would suggest for your next project to use one of the combination machines--a mill/drill, at the least. I'd probably devise an easy way to ensure centering of the baffle stack/monocore if possible--such as making the ends of the can itself only .001 or less larger than the OD of the stack, to create a type of "sleeve" or pressed-bushing fit.

You can actually purchase Inconel bar stock, cut to length. It is difficult to machine--requiring special cutters and slow speed with lots of irrigation. However, if you can work your way past that, you can make yourself a superb suppressor that will almost last forever.

Ain't nobody got time for that! Even with better tools & materials, I'll still never come anywhere close to the quality and performance of a commercially-made can, which makes the argument for buying a can on a Form 4 a LOT more compelling. The only Form 1's in my future are SBRs.

I know it sucks to have to throw more money at it but now that you have it might as well get it working

Individual baffles shouldn't be a problem. My commercially made 9mm suppressor has removable inconel baffles and is rated for subsonic blackout. Rifle cans are welded together to withstand much higher pressures. Form 1 cans use a thicker tube to provide the strength. As long as your tube can take the pressure it shouldn't matter if the core is welded together or not

I'd ditch the freeze plugs and work on getting something closer to the baffles that come in commercial tubes. I searched for "inconel solvent cup" and a bunch of sites popped up

These two places sell cups but both are aluminum. Not sure how long they would last

https://www.aandlmachinearizona.com/product-page/copy-of-wix-aluminum-cups

https://www.preppersdiscount.com/store/c3/Maglite_Adapters_.html

This place has stainless:

https://solventtrapcups.com/#shop

This place has stainless and titanium:

https://totalityindustries.com/shop?olsPage=products

Honestly, I think I'm done with it. I'm not inclined to throw any more money at it, because the end result will still be a mediocre can with limited use. My money will be better spent on a SilencerCo Hybrid that I can then use for much more than just .300 BLK subsonic. Making (sort of) a can myself was a good learning experience; perhaps the most important lesson is to leave the precision machining to the experts.

Dude, that's what I'm saying! BE the expert!

It might be worth looking into a pro recore or some machined cones. You've already invested in the tube and stamp, get the Hybrid process started, and you'll have the Form 1 can to hold you over for the loooooonnnnnngggggg wait.
Look up "dual hybrid clip", it works. The fella that came up with it also does cores

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