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What is that made out of, ABS?

I wouldn’t be surprised if they do a version three eventually, not sure what his name is (the STO guy), but he strikes me as a tinkerer that will never stop based on reading through some of his blogs. 😉
1 - No, they are aluminum. At least mine (the short version) is.
2 - They aren't "that" quite ! Better than nothing, but...

Mike
 
I received my GK-1 (.22) from Kelly last week. Great service and very responsive to questions after delivery.
I purchased the Brevita .30 cal from STO mostly because of size. It works very well for its size. It does take the bark out but not quite as quiet as some others. It is a very convenient size.
I have tried about half a dozen moderators including Huma 30, Tanto, Tatsu, STO Falx, Impulse Air 1350 (.25) and some 3d printed ones.
Subjectively, the one that absolutely works best for me, is the Impulse Air 1200 (.22). Whisper quiet. This was confirmed by several shooters at the range, standing at various distances. Once again this was subjective and not objective (no meter).
With Kelly's moderator adapter I had no clipping and no change in POI with the Impulse 1200. Be advised it does block the front sight, so I am using a Holosun Dot sight.

Damn that's nice to know - had no idea ImpulseAir's were that good - Donny internals are trash though, they only quiet due to the volume -

The Ronin is the quietest probably only because it's got 19.63 cu inches of volume vs 5.31 cu in. in the Impulse 1200.

I'd like to see the Ronin compared to STO Sarissa - they have about the same volume

STO Falx and DFL FatBoy have about the same volume as well, I'm pretty sure the latter is the loser.
 
My buddy designed a 1911 grip for the gk1

56CFE369-4A8D-4536-9242-07656721196C.jpeg
 
I'm going to be testing some mini moderators on my GK-1 after the storm moves through, but here's a preview of what will be tested:

IMG_3157.jpg


These range from between 4" and 1 ½" in length and 25mm to 31mm in diameter.

1. Standard 4 baffle: 3" Long 25mm diameter
2. Standard 4 baffle with holes drilled in the end: Same dimensions as #1
3. Standard 3 baffle 2 ½" long, 25mm diameter
4. A compensator I found on Thingiverse. No baffles but it is ported on the top to reduce muzzle jump: 1 ½" long 25mm diameter
5. My friends design, 4” long, but only 2 baffles: 4" long 1 inch diameter
6. The STO experimental one I bought a couple years ago: 2 ½" long 321mm diameter
7. One section of the Huma MOD30: 2 ¼" long 30mm diameter

I have a cheap Amazon db meter I'll be using to record the peak sound level from each. #6 and #7 render the iron sights useless due to the diameter blocking the front sight. All the rest retain the use of the iron sights.
 
and the results are in...

Bare Barrel: 117.7db
1. 110.2db
2. 110.8db
3. 111.1db (Matched #6, the STO Brevitas)
4. 115.2db
5. 111.5db
6. 111.1db
7. 114.0db
8. 108.2db - this is the MOD30 with 3 sections!

The small 3D printed LDC is only 2db louder the the 3 section MOD30, and only a ¼ the size! Who says big things can’t come in small packages?

Here they are in rank order, quietest to loudest!:

1. 3D Print 4 baffle design
2. 3D Print 4 baffle design with 8 holes drilled in the end
3. 3D Print 3 baffle design
3. STO Brevitas (tied for 3rd place)
4. My buddy’s 4” long 2 baffle design
5. Huma MOD30 - 1 section
6. The 3d print compensator

I’m no sound engineer and can’t say I really understand the mechanics of sound, but I will tell you the difference between a bare barrel blast of 117.7db and 110.2db from the 3D Printer 4 baffle LDC is huge! Hard to imagine 7db makes that big of a difference! Or, maybe it’s just the cheap Amazon db meter I’m using!
 
and the results are in...

Bare Barrel: 117.7db
1. 110.2db
2. 110.8db
3. 111.1db (Matched #6, the STO Brevitas)
4. 115.2db
5. 111.5db
6. 111.1db
7. 114.0db
8. 108.2db - this is the MOD30 with 3 sections!

The small 3D printed LDC is only 2db louder the the 3 section MOD30, and only a ¼ the size! Who says big things can’t come in small packages?

Here they are in rank order, quietest to loudest!:

1. 3D Print 4 baffle design
2. 3D Print 4 baffle design with 8 holes drilled in the end
3. 3D Print 3 baffle design
3. STO Brevitas (tied for 3rd place)
4. My buddy’s 4” long 2 baffle design
5. Huma MOD30 - 1 section
6. The 3d print compensator

I’m no sound engineer and can’t say I really understand the mechanics of sound, but I will tell you the difference between a bare barrel blast of 117.7db and 110.2db from the 3D Printer 4 baffle LDC is huge! Hard to imagine 7db makes that big of a difference! Or, maybe it’s just the cheap Amazon db meter I’m using!
Were this dry fires or with pellets? I find pitch plays a lot to the perceive loudness. I'm not an acoustics engineer ether, but I experiment with different cavity volume to cancel out the tones.
 
I limit my PCPs to 20fpe based on some of the targets I have on my 60 yard range. Because of this I’m focused on .177. I have a HW44, Crosman 1720 and BRK Atomic in .177 among other pistols. I pre-ordered a Huben GK1 in .177 but learned when the first orders came in that Huben hadn’t completed the development of the .177 and the retailer wasn’t sure if they would be available this year. So, I canceled my order. But I still continued to follow this thread. After reading the accuracy some folks were seeing with the Predator GTOs and the general opinion that the GK1 was the best thing since sliced bread, I decided to order a GK1 in .22. I talked with Kelly (Kraz Cool) and had him configure the GK1 with a ~1lb trigger pull, moderator adapter and spare mag release arm based on thread comments.

I received the GK1 about 2 weeks ago and I can verify it is (almost) the greatest thing since sliced bread! I set it up to shoot the 11.75gr GTOs at ~ 690 fps (14.2fpe). I am impressed with the trigger, smooth shot cycle and initial accuracy at 10yds with this setup. Not impressed with how loud it is without a moderator.

My initial accuracy at 10yds with a bi-pod, adjustable butt rest and Optisan CP 3-12x32P scope was really good. Will be moving to 30yds in the next few days. After I get a good idea of its accuracy, I will remove the scope and go with open sights or red dot.

Target at 10 yards. 38 shots. Started at 290 BAR and finished at 200 BAR,
Hi 710fps
Low 680fps
Avg 693fps
ES 30fps
SD 8.5fps

GK1 10yds.JPG


GK1.JPG
 
I limit my PCPs to 20fpe based on some of the targets I have on my 60 yard range. Because of this I’m focused on .177. I have a HW44, Crosman 1720 and BRK Atomic in .177 among other pistols. I pre-ordered a Huben GK1 in .177 but learned when the first orders came in that Huben hadn’t completed the development of the .177 and the retailer wasn’t sure if they would be available this year. So, I canceled my order. But I still continued to follow this thread. After reading the accuracy some folks were seeing with the Predator GTOs and the general opinion that the GK1 was the best thing since sliced bread, I decided to order a GK1 in .22. I talked with Kelly (Kraz Cool) and had him configure the GK1 with a ~1lb trigger pull, moderator adapter and spare mag release arm based on thread comments.
I received the GK1 about 2 weeks ago and I can verify it is (almost) the greatest thing since sliced bread! I set it up to shoot the 11.75gr GTOs at ~ 690 fps (14.2fpe). I am impressed with the trigger, smooth shot cycle and initial accuracy at 10yds with this setup. Not impressed with how loud it is without a moderator.

My initial accuracy at 10yds with a bi-pod, adjustable butt rest and Optisan CP 3-12x32P scope was really good. Will be moving to 30yds in the next few days. After I get a good idea of its accuracy, I will remove the scope and go with open sights or red dot.

Target at 10 yards. 38 shots. Started at 290 BAR and finished at 200 BAR,
Hi 710fps
Low 680fps
Avg 693fps
ES 30fps
SD 8.5fps

View attachment 388379

View attachment 388380
I limit my PCPs to 20fpe based on some of the targets I have on my 60 yard range. Because of this I’m focused on .177. I have a HW44, Crosman 1720 and BRK Atomic in .177 among other pistols. I pre-ordered a Huben GK1 in .177 but learned when the first orders came in that Huben hadn’t completed the development of the .177 and the retailer wasn’t sure if they would be available this year. So, I canceled my order. But I still continued to follow this thread. After reading the accuracy some folks were seeing with the Predator GTOs and the general opinion that the GK1 was the best thing since sliced bread, I decided to order a GK1 in .22. I talked with Kelly (Kraz Cool) and had him configure the GK1 with a ~1lb trigger pull, moderator adapter and spare mag release arm based on thread comments.

I received the GK1 about 2 weeks ago and I can verify it is (almost) the greatest thing since sliced bread! I set it up to shoot the 11.75gr GTOs at ~ 690 fps (14.2fpe). I am impressed with the trigger, smooth shot cycle and initial accuracy at 10yds with this setup. Not impressed with how loud it is without a moderator.

My initial accuracy at 10yds with a bi-pod, adjustable butt rest and Optisan CP 3-12x32P scope was really good. Will be moving to 30yds in the next few days. After I get a good idea of its accuracy, I will remove the scope and go with open sights or red dot.

Target at 10 yards. 38 shots. Started at 290 BAR and finished at 200 BAR,
Hi 710fps
Low 680fps
Avg 693fps
ES 30fps
SD 8.5fps

View attachment 388379

View attachment 388380
Hi fderry,

Congrats on your GK1. I’m the person on here who was touting the GTOs and I am glad to hear that they are working well for someone else. I switched briefly to the use of JTS 18.1s, mostly because the GTOs are expensive. But…. After a weekend of shooting, I am back on the GTOs because they are so much more accurate. I urge others to try them. I’ve been through dozens of different pellets and slugs and all I can say is that there is some alignment of the stars between the GTOs and Huben barrel, at least for the 22. I am shooting them at 890 for ~20fpe and the groups at 40y are consistently 3x smaller than anything else I’ve tried. I’m happy to suck up the cost given the accuracy.

Edit: excuse the messed up reply format - I got caught up with replying to another post…
 
Thanks for the image, and for making and testing the muffler, M0ist0ne.

It seems I managed to match Gregor's 26 mm OD coaxial muffler in terms of sight clearance. Usable, but perhaps not ideal. Your feedback about that would be appreciated.

My intent with this design was to make it "strong enough", as there is no aluminum or CF outer tube. Also; to make the Huben pistol hearing safe, rather than backyard friendly. there may be room for thinning out walls and adding baffles, to reduce dB, but that would need to be approached cautiously. The 8.5" long version of this 1.5" OD offset muffler would no doubt be noticeably quieter. And where does the 6.5" long oval muffler fit in...
 
Thanks for the image, and for making and testing the muffler, M0ist0ne.

It seems I managed to match Gregor's 26 mm OD coaxial muffler in terms of sight clearance. Usable, but perhaps not ideal. Your feedback about that would be appreciated.

My intent with this design was to make it "strong enough", as there is no aluminum or CF outer tube. Also; to make the Huben pistol hearing safe, rather than backyard friendly. there may be room for thinning out walls and adding baffles, to reduce dB, but that would need to be approached cautiously. The 8.5" long version of this 1.5" OD offset muffler would no doubt be noticeably quieter. And where does the 6.5" long oval muffler fit in...
I couldn't wait for the weekend to do some sort of testing, I'll post up a video in a little bit.

Your mod, the FX by donny and the impulse ia1350.

Yours is right on par with the FX by donny--so hearing safe = ✅ !! The impulse was slightly quieter than both (5 baffles tho and $$$)

80.6/80.7 yours
80.8/80.1 FX by donny
78.7/79.3 impulse ia1350

Meter was 45 degrees from my 12 o clock at about 3 ft away.
 
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I couldn't wait for the weekend to do some sort of testing, I'll post up a video in a little bit.

Your mod, the FX by donny and the impulse ia1350.

Yours is right on par with the FX by donny--so hearing safe = ✅ !! The impulse was slightly quieter than both (5 baffles tho and $$$)

80.6/80.7 yours
80.8/80.1 FX by donny
78.7/79.3 impulse ia1350

Meter was 45 degrees from my 12 o clock at about 3 ft away.
May I ask what decibel reading without the mod? I appreciate you taking the time to testing!
 
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Thanks for the image, and for making and testing the muffler, M0ist0ne.

It seems I managed to match Gregor's 26 mm OD coaxial muffler in terms of sight clearance. Usable, but perhaps not ideal. Your feedback about that would be appreciated.

My intent with this design was to make it "strong enough", as there is no aluminum or CF outer tube. Also; to make the Huben pistol hearing safe, rather than backyard friendly. there may be room for thinning out walls and adding baffles, to reduce dB, but that would need to be approached cautiously. The 8.5" long version of this 1.5" OD offset muffler would no doubt be noticeably quieter. And where does the 6.5" long oval muffler fit in...
Very much appreciate the excellent posts and progress by yourself, TeslaTTM and others in the design of these mods. I’m curious to know if you are printing them such that they can be press fitted or glued into a piece of carbon tube with a certain ID? It’s pretty easy to get those and cut them to size.
 
Quick video is up - totally subjective purposes only.

Meter was about 3 ft away, 45 degrees from my 12 o'clock. IMO @subscriber 's design has a really nice sound/tone to it.


Edit: added title pic so you can see size comparison a little more clearly

View attachment 388474
What is the setting? Shooting from indoors or out in the open?