I think Sam Pikula is a firearms historian and writer, he may have written the AR-10 Saga
I just came across that photo in a search.
... and we now return to our regularly scheduled program ...
So I talked to some mechanics and they say venting the two chambers may be more effective at sound reduction citing various muffler designs.
At the same time, my concearn is that venting would drop too much pressure causing short strokes. Too much and it could cause the aluminum to fail, unless I use steel and I don't have a supplier for that.
If you haven’t seen this it’s a pretty cool video. Obviously there’s quite a bit more going on inside using a rifle cartridge versus a 9mm.
How do you not have access to steal tubing? ... there’s plenty of places online you can order DOM.
If I’m not mistaken the entire construction, except for the threaded piece that attaches to the barrel, on the HK SD suppressor is aluminum - although I’ve never had one apart.
The cutaway SD suppressor you posted I believe is an early design, note the wall thickness in the first chamber.
The one below is later. If someone knows different please correct me if I’m wrong.
HK SD suppressor (Credit: TPM Outfitters)
Below is the aftermath of not cleaning a suppressor.
In the second pic you can see the layers of carbon as it built up.
I’m not an engineer or suppressor designer but there seem to be a couple of things I would take a look at.
You have exposed barrel threads in chamber 1. These threads are going to fill up with carbon.
Chamber 1 does not fully extend to the end of the barrel. The carbon coming out of the muzzle is going to build up on the outside of the barrel. I’m not seeing any wiggle room right at the area you have marked with the letter D.
If you look at the above picture, barrels on the SD are prone to a lot of carboning.
Both of these could pose a problem removing the suppressor.
Anyway, just my opinion and observation.
I'm sitting in the departure lounge at BIAP to come back to the states after my first rotation with Triple Canopy in 2011 and there's a couple pieces of baggage next to where I platzed. I notice the name "Pikula" stenciled on them, and I'm thinking, "Why is that name familiar?" (it takes a second or two, context, right?) and I think, "Maybe he's got a son over here". I'm so used to being the old guy on a team, right? Most of the guys are 15 years younger than me, or more. A couple minutes later Sam comes back from the can and I ask, "Are you Sam Pikula?" He goes, "It depends, does he owe you money?" LOL. It is of course him, and I say "I read your book!" Channeling George C. Scott playing Patton of course. Bought my copy back in 1999 from him direct by mail when I was living up in Canada, where there happen to be a lot of Dutch Armalite AR-10's, which I am totally into for years.
So we talk a bit while waiting for the flight to be called. Turns out we are both working for TC on the same contract. I mean this guy is like a ****ing rock star in my world, right? I've know who he is for like 15 years already at that point. NEVER expected to meet him, Interweb jabber had him living in Finland or something. So when I get home I got through all my stuff in storage and pull out that copy of his book, take it back with me to have it signed. He does so, and then when I rotate back out the next time a few months later, I put it in my footlocker and mail the whole thing. Of course it never shows up. Was I pissed. The Iraqi's **** us around on our visa's, so I wind up being out for like 4-5 months. The visa thing clears up, I'm still pissed, I give a rat's ass about all the gear in there, I can get more of that. A few days before I'm to head back, the wife goes, "Well, what if they tried to deliver it but couldn't, where would it be?" So I have to figure out what Postal Substation our carrier works out of. I head over there, and make inquiries. The guy goes and finds it, "Oh that's you? That thing's been back there for months, we were supposed to ship it off to unclaimed whatever after 30 days (or something) it shouldn't even have been here". Awesome. I was sure that thing was gone forever.
Last edited by Lamont; 03-11-2019 at 01:29 AM.
"We do bad things to bad people".
Very cool Lamont! It’s one of those times where it’s not always bad to meet your hero ;)
@21HK yes I saw that video a couple of times, pretty cool.
I'll change the threading distance but I doubt it would matter as there is a rubber gasket that varies the depth at how much the suppressor screws in depending on the rubber compression. That's why I didn't want to thread short.
I'll consider modifying the barrel but to cover the tip od the barrel
Yes I know the notorious fact if the MP5 SD being a difficult thing to clean.
OK so your aware of the gasket, I didn’t see it pictured or that it was compensated for in your illustration.
There’s no need to consider changing anything, ... as mentioned it was just some observations.