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Discussion Starter #1 (Edited)
I know a few have done some testing with these bad boys, but I wanted to do a little more in depth review.

I have ordered this gizmo nearly a year ago, and have not had enough time to mess around with this accessory.
this is the site that I purchased this device
Muzzle Brake Jet SRVV 5,45 mm. (.222)

I wanted to test these 4 aspects
-accuracy (as the manufacturer claims that it is 30-40% more accurate)
-decibel level
-velocity (as some claimed it increases velocity_
-recoil

1) Accuracy was done nearly 5 months ago, but since I did not have a chronograph available at the time, I wanted to hold off the write up until complete
using standard 7N6 at the distance of 100 meters I fired a few groups to determine whether I will have a POI change compared to a standard AK74 muzzle break




the POI did change indeed, you can see that the group shifted up and to the right compared to what was already fielded on the rifle






you can see that the group did indeed shrink, so the manufacturer was telling the truth



Now I wanted to see how it will behave under rapid fire

I switched to 200 meters and fired off around 20 rounds rapid to see the consistency of the accuracy




ended up shooting the chains off the all but 1 targets. excellent results.

2)Recoil and decibel level (noise)

from the shooters perspective AND both behind and laterally the Jet exhibited a bit more nuisance. It was more loud compared to the standard 74 brake. However, the felt recoil was reduced as well as muzzle climb- at the cost of being a little louder.

3)velocity.

this is where things got interesting. We set up a chronograph directly in front of the muzzle and fired a few rounds. Since the accuracy test was completed, I did not want to use 7N6 (for those who know and use this ammo; cleaning is a bit extensive for just firing a few rounds) and ended up using an old black box of Wolf 60gr HP.



when my friend was recording data he was under impression that I was using my AKM, as the velocity was lingering around 2400 f/s.

2400 f/s???? I stopped and went WTF? No dude this is 5,45x39...
here is the list of spread of black box Wolf HP


Jet Standard 74 break

2404 2471
2447 2413
2430 2435
2401 2431


this was interesting indeed. The standard velocity for a 53 grain 7N6 out of a 16 inch barrel is around 3000 f/s. Wolf was 600 f/s less. That's about 20% decreased velocity! I understand that 7n6 is 7 grains lighter, but it would not create a 20 per cent difference. US manufactured Hornady, which is also 60 grains travels at 2850 f/s at the muzzle. Wolf is 2400.

at first I thought there was something wrong with the chronograph, so I switched back to 7N6

Jet Standard 74 Break

2991 3012
2989 2983
2998 3016
2990 2985




That's better! back 3000 range as it should be. I am now wondering about ALL and ANY commercial ammo...and just how much do they down load the powder charge to save on some $$$$$$$$$$
I will go out and chrono the rest of my 5,45 (silver bear, Golden tiger, other wolf) and see the difference.


the final test was to remove muzzle breaks all together and compare velocities (still using 7n6)

2995
2979
3024
3001


well there you have it


there is no significant change in the increase rate of velocity. All (3) variations were within 5% of each other.


Conclusion: chrono you ammo...looks like some companies like to save a few shackles by reducing the powder charge...

as far as the Jet 5,45 goes:
-Accuracy was increased from 2.2 to 1.5 inches
-recoil was reduced as well as muzzle climb
-velocity was not increased compared to a standard 74 break and no break at all
-noise level was increased to 360 degrees of the shooter.


Overall I am very pleased with this product. I wish I could have a select fire 74 to test this break with. When I did rapid fire out to 200 meter I felt significant reduce in muzzle climb, meaning I was staying on target more and more consistently. I bet this gizmo would really shine on a select-fire AK.
 
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Excellent review, voron, and thank you for the chronograph research. I see these are available in the US as well. Might grab one to try out on some long range shots. Well Done....:thumbsup:

Welcome to Circle 10 AK
 

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Nice review indeed, I also picked one up a while ago. The only negative I can honestly think of is that since it's not chrome lined, shooting surplus through it will require cleaning, since it won't take much for it to start turning orange.

One thing on my to-do list for it is to take it out and observe it's flash-hiding characteristics. I'm sure it probably doesn't have any, but I haven't found any info anywhere about it in that regard.

ETA: Also to add, as you saw with the Wolf, that's one of the reasons I stick to 7N6.
 

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Discussion Starter #4
this break has ZERO flash-hiding characteristics. In fact, we did compare them in low light, and they were about the same. I do agree that it would have been nice if they chrome-lined this bad boy.....but chrome or not chrome...you still need to clean it. I have seen Russian breaks that were chrome-lined exhibiting pitting. this was simply due to NO cleaning what so ever. All chromium does is increase the time to where corrosion starts. It does not prevent from it.
 

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Since voron's OP, I have two SRVV Jet Brakes installed on Vepr 7.62x54r rifles. I discussed these with Luke at Circle 10 AK and he felt the 3 port brake would be best. The 54r cartridge was knocking
the stock screws loose and limiting my range time, not to mention felt-recoil was tough on the shoulder after 50 rounds.

After installing the SRVV Jet, all of the stock screws stay snug and I can easily shoot over 100 rounds of mil-surp 54r without the least bit of shoulder discomfort. Accuracy is great, groups are tight and
cleaning the Jet brake is no hassle at all after a lengthy range session. The bluing is very durable and both brakes still appear new after many outings.

Thanks to voron for the review and bringing the SRVV Jet brakes to my attention.
 

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Thinks for this write up howevrr I'd like to see 5-shot groups for an accuracy report. 2-shot groups does not an accuracy report make.

I have a 20" 54r Vepr coming and I do need to start thinking about a muzzle device.
 
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