A-tec CTM-4 suppressor. Report and effect of shooting with 1 2 3 or 4 baffles.
This is a compact "telescopic" (overbarrel) modular suppressor made by A-tec in Norway.
I bought this through Stager Sport and it was fitted by Dean Maisey.
My goal was to reduce the ear damage factor from single shots while out hunting. I use muffs on the range and try to get earplugs in if I know I'm going to be firing a few shots at animals but over the years a few shots every now an then adds up. Also, as someone recently observed, "if you have a suppressor, you have freinds". Freinds who can still hear, anyway. So, I don't need compete "silencing", just an increase in safety margin for some of my shooting and was looking for something very light weight and compact even if noise suppression wasn't top of the line.
It comes in a beautiful box with a silky soft touch finish, providing a legacy storage and display facility, surpassing even what Apple send their iPads and iPhones out in. With carbon credits, retailer markup, GST and what not it would have added quite a bit to the price that I would have been quite happy to do without. The thin fold up cardboard box and roll of corrugated cardboard my scope came in were just fine. For the same cost they could have supplied a solid plastic box like reloading dies come in or even a moisture permeable wooden one.
http://i812.photobucket.com/albums/z...at/Atecbox.jpg
The front end of the suppressor is a bit recessed, which I suppose could direct blast forward.
http://i812.photobucket.com/albums/z...tecmuzlend.jpg
The back end has a plastic bushing which needs to be turned on the inside to fit over the barrel, with 0.1 mm clearance. It is held in place by a circlip, but not tightly. It isn't a tight fit in the suppressor so moves and rattles a bit. I'm a shooter not a gunsmith but I suspect this allows it to float a bit so there won't be any torque on the barrel.
http://i812.photobucket.com/albums/z...tecbarlend.jpg
There are 4 modules with a baffle in each. This is what they look like inside:
http://i812.photobucket.com/albums/z.../Atecbafls.jpg
The barrel screws into a steel fitting which was coated with the yellow zinc type plating. The thread size (M14x1) is shown on it.
http://i812.photobucket.com/albums/z...Atecinside.jpg
Here it is on the gun, with two baffle modules removed.
http://i812.photobucket.com/albums/z...5wAtecCTM4.jpg
I tried it out at full size with 4 baffle modules, then removed them one by one. I thought perhaps a change in weight on the end of the barrel could affect harmonics and point of impact and was looking for a number where the gun shot the same with and without suppressor. No luck there.
These are 3 shot groups at 100m from a bench with bipod. Load is 7mm08, 140 gr BT and 43.0gr AR2208 and it's a standard weight barrel about 22". Because it had been taken apart, the gun took a dozen shots to settle down before I started this test. Top left is without suppressor, the with 4 and 3, the the bottom row is 2 and 1 baffle then back to no suppressor at bottom right on the black target. I didn't adjust the sights at all, between groups. I wasn't comparing accuracy, just MPI, so they are only 3 shot groups. I fired each group of 3 and then let the barrel cool while I shot a couple of groups through my air rifle. After 3 shots the suppressor was warm to touch but not too hot to hold so it was working well under the 100C recommended in the instructions.
http://i812.photobucket.com/albums/z...aflnumtest.jpg
I was aiming at the bottom circle on each target, so sighting in was spot on with bare barrel but shots grouped about 3-4 cm high and 3-4 cm right, with no definite change in impact. Accuracy didn't seem to be adversely affected by using different numbers of modules, either. I will set the sights for use with the suppressor but for the time being am leaving it as is.
Balance is definitely different depending on the number of modules in place and noise reduction and recoil also changed noticeably with each baffle. With 4 in place it made the typical "Scroosht" suppressor sound while with one it was quite a "Bang !" but not the "HBOOOM" of an unsuppressed 7 mil 08.
This gives me confidence that I can try whatever number I feel like at the time, perhaps more at the range and fewer if out in the bush, and work out what's a good compromise between length, balance and suppression.
