Silencer on a gas delayed blowback pistol?

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Historian
Silent But Deadly
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Joined: Mon Mar 29, 2010 11:37 pm

Re: Silencer on a gas delayed blowback pistol?

Post by Historian » Mon Mar 09, 2020 12:10 pm

Addendum:

My personal cure when things
run off the rails is to hear about someone
who has had life toss them knuckle balls
and are given No-Respect!. This worked
yesterday:

<< https://www.youtube.com/watch?v=LGvnHvba_b0 >>

Play a set of Rodney Dangerfield and after you have
picked yourself off the floor howling you sides from
laughter all looks brighter.
Last edited by Historian on Tue Mar 10, 2020 9:05 am, edited 1 time in total.

#40Fan
Silent But Deadly
Posts: 204
Joined: Tue Nov 20, 2018 6:41 pm

Re: Silencer on a gas delayed blowback pistol?

Post by #40Fan » Mon Mar 09, 2020 7:29 pm

That sucks to hear. What happened? Neither of them are salvageable? Pics?

User avatar
Capt. Link.
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Posts: 2561
Joined: Wed Oct 17, 2007 10:05 pm
Location: USA.

Re: Silencer on a gas delayed blowback pistol?

Post by Capt. Link. » Mon Mar 09, 2020 8:20 pm

Gas delay has been used on one of the best suppressed pistol ever. The H&K P9S plus the P-7,P-13 and the mighty desert eagle use gas delay.
I wish more major caliber pistols used frame mounts as barrels are easy to build and no Nielsen device is needed.
If you are having problems getting a barrel made drop me a line.
-CL
The only reason after 243 years the government now wants to disarm you is they intend to do something you would shoot them for!

strantor
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Posts: 14
Joined: Sat Feb 22, 2020 6:57 pm

Re: Silencer on a gas delayed blowback pistol?

Post by strantor » Fri Mar 13, 2020 8:20 am

Historian wrote:
Mon Mar 09, 2020 11:39 am
strantor wrote:
Sun Mar 08, 2020 7:09 pm
I ruined both my barrel blanks. I'm furious. I don't have any spare cash to buy more.
Nothing has gone my way in a long time. It will be a while before I try again.
We in this small 'elite' band of brothers have total empathy!

We all have been there and by
the grace of the Universe are still standing,
joyously dreaming of the next pile of
metal to butcher on that lathe of our dreams.

Yes brother!! We have all experienced ( just yesterday in fact)
eFFing up a part.

"What! I cut off more than .002 I had dialed in.
Third time! *$^#*@#** . Wasted that expensive rod.
What an arrogant dick thinking
you can emulate the Good Captain, T-Rex, Fishman, Monog0,etc."

"Kick-in-the-Nuts is that Heavenly Coffee!' becomes the background
theme.
Now all the unique descriptive bombastic words learned so long ago
in that machine shop from Dorchester Irish grumpy 'James Joyce' machinists come out in
a firehose stream.Downer.

Our combined 'arm around-the-shoulder' to you!
As the Bible says "...and this too shall pass". Guaranteed.
In the near future you shall overcome and make swarf ...
from the best teacher in the universe: the ice-cold-enema
of living as a human.

All the above blather is to say we all have so often been there, done
that, and fully recovered. Take heart, Sir!

Best!!
Thank you :D that made me laugh!

strantor
Member
Posts: 14
Joined: Sat Feb 22, 2020 6:57 pm

Re: Silencer on a gas delayed blowback pistol?

Post by strantor » Fri Mar 13, 2020 8:50 am

#40Fan wrote:
Mon Mar 09, 2020 7:29 pm
That sucks to hear. What happened? Neither of them are salvageable? Pics?
I will post pics this weekend. I made the same error on both, for different reasons. I turned the OD of the barrel too small to be press fit into the gas block.
On the first blank, I was turning that critical OD, about to take that final skim pass, final .0005" to get it a perfect match for the original, and I ran my tool too hard into a shoulder at the other end (hadn't turned that end of the barrel yet), which must have grabbed the tool and pulled the tool post imperceptibly in toward the work, and instead of removing a half thou I removed 3 thou. I couldn't think of any clever fix for that. Perhaps I could continue turning it down to the OD of the other end of the barrel (so the whole barrel is a uniform OD) and then make a sleeve that takes up the difference between the press fit OD and the gas block ID, but that seems a little too kludgey. The pin groove that keeps the barrel in the gas block is very shallow. I didn't measure it but intuition told me it would probably only successfully pin the sleeve to the gas block and the barrel would be free to creep inside the sleeve.

On the second blank, eager to succeed where I had just failed, prove to myself that I'm not an idiot, I changed up the order of operations so that turning that critical OD was one of the first steps. I started with that 1.5" blank, turning it down by eye as I usually do, to be followed with digital caliper checks to within 10 thou, to be followed by micrometer checks to the final dimension. I never even made it to caliper checks. My eyes lied. Something about the OD I was turning, contrasted against the virgin 1.5" OD, it looked very different from what it was. I cruised right past the proper dimension by at least 10 thou.

strantor
Member
Posts: 14
Joined: Sat Feb 22, 2020 6:57 pm

Re: Silencer on a gas delayed blowback pistol?

Post by strantor » Fri Mar 13, 2020 9:11 am

Capt. Link. wrote:
Mon Mar 09, 2020 8:20 pm
Gas delay has been used on one of the best suppressed pistol ever. The H&K P9S plus the P-7,P-13 and the mighty desert eagle use gas delay.
Best suppressed? Why is that? And what are the criteria?
My theory is that, being delayed on opening until the gas pressure is low, will keep the highest pressure gasses (and resultant noise) going down the barrel to be arrested in the suppressor, rather than escaping from the open ejection port.
Is that true? Is that why the P9S, P-7, et. al. are in the "best suppressed" club?
Capt. Link. wrote:
Mon Mar 09, 2020 8:20 pm
I wish more major caliber pistols used frame mounts as barrels are easy to build and no Nielsen device is needed.
Agreed. I had never looked specifically for them before. I was surprised to find the slim pickings. I really wanted to do this with a .45ACP. The only fixed barrel offerings I found in that caliber were the Hi-Point at the extreme low end and Korth at the extreme high end, and virtually nothing in between.
Capt. Link. wrote:
Mon Mar 09, 2020 8:20 pm
If you are having problems getting a barrel made drop me a line.
-CL
I appreciate the offer. If you had caught me before I got started I might have taken you up on it. But my spirit animal is the mule, and now that I've failed I won't be able to let this go until I succeed.

HD Bee
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Joined: Sun Sep 11, 2011 6:12 am

Re: Silencer on a gas delayed blowback pistol?

Post by HD Bee » Fri Mar 13, 2020 11:24 pm

To error is human! We all do it, Weather you are an old-timer or a newbie.
So lets turn this into a teaching moment.
1. 90% of machining is set up. Old machines have backlash, tolerances stack due to wear. Check and recheck before cutting
2. SWAG doesn’t work in finish machining! SWAG= Scientific wild-ass guess.
3. You measure twice and cut once.
4,. If you are unsure about a finish machining operation make a few practice runs on a piece of scrap.
5. This is the biggest one! DON’T GET IN A HURRY!!!!. This is a hobby for fun. You don’t have management standing over you to get production. Take your time. If you are tired or buzzed stop and come back to it later.
6. If you have children that are interested get them involved. Sometimes a second set of eyes will catch something no matter how inexperienced they are.

So my question to you is do you have a carriage stop for your lathe?

Also bores might not be concentric to the outside of the barrel.
I always run barrels between centers with a face plate and a dog when I turn or thread them.
If you use a 4 or 6 jaw with a spider on the back you need to run a rod down the bore to indicate on both ends.
If you don’t have a rod. You can use a couple of gage pins. You can get them cheap from McMaster-Carr.

Bottom line is don’t get discouraged. Try again when time and money permits!
Last edited by HD Bee on Tue Mar 17, 2020 9:58 pm, edited 1 time in total.

HD Bee
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Posts: 11
Joined: Sun Sep 11, 2011 6:12 am

Re: Silencer on a gas delayed blowback pistol?

Post by HD Bee » Sat Mar 14, 2020 9:50 am

Capt. Link. wrote:
Mon Mar 09, 2020 8:20 pm
Gas delay has been used on one of the best suppressed pistol ever. The H&K P9S plus the P-7,P-13 and the mighty desert eagle use gas delay.
I wish more major caliber pistols used frame mounts as barrels are easy to build and no Nielsen device is needed.
If you are having problems getting a barrel made drop me a line.
-CL
The Desert Eagle works like a M1 Garand, M14 or AK 47/74. It uses a gas piston and the breach is locked by a rotating bolt.
The delay is caused by the cam in the bolt carrier or the op-rod on the Garand and M14 not by the gas.

The HK P9s is a roller locker. A mechanical delayed blowback like the HK G3, 91, 33, and MP5. No gas piston involved!

The P7 and 13 are gas delayed blowback pistols.

SILENCERSTUDENT
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Posts: 13
Joined: Mon Sep 16, 2019 2:46 pm

Re: Silencer on a gas delayed blowback pistol?

Post by SILENCERSTUDENT » Sun May 03, 2020 12:02 am

Happy to have stumbled upon this as ive thought i was the only one who wanted to build a suppressed ccp.

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