FN Herstal Firearms banner

Concussion Question

14K views 90 replies 38 participants last post by  ranger56528 
#1 ·
Hello - I'm new to the forum and a new owner of a SCAR 17s and PS90. I did a search on previous topics with what I thought were relevant keywords but didn't come up with anything so thought I'd post a new thread in hopes of getting feedback on my experience. I recently took the SCAR 17s out and shot it for the first time. Pretty impressive rifle but my take-away was I felt like I was getting punched in the face every time I pulled the trigger. The punch in the face I'm referring to was from the muzzle blast that seemed re-directed to the rear of the rifle and the concussion was so great it was like an invisible punch. Again, I'm not sure if this has been covered before or not so thought I'd throw it out here and go from there.
 
#3 · (Edited)
Welcome to the forum! :) Congrats on your new FN acquisitions! :?

Yes, as mentioned above the PWS is a very unfriendly albeit effective muzzle device, since you think you're getting punched in the face imagine what those to either side of you feel? :evil: Even on my 16s the PWS is a frikkin' loud, obnoxious beeaatch which is why it is coming off to be replaced by a much friendlier albeit just as effective if not more Surefire WARCOMP... :?
 
#8 ·
Good point - Definitely under a covered firing line on each occasion. I haven't tried it out in the open yet but ultimately sounds like I need to get some kind of solution for the muzzle brake since both of the long range shooting places I go to are going to be under cover. So far I've done 500 meters and 1000 yards and I'm really happy with the shooting. Thanks for your reply!

-RJ
 
#73 ·
Yup!

Learn to love the concussion! It's the feeling of freedom! Heheh.......
Learn to embrace the blast! Right on.

I used to get angry at the guys with loud guns because it would mess up some of my shots. Now I'm "that guy.​" :shock:
I'm that guy too, I just don't care. Some panty waist started complaining about the noise on Saturday when I was shooting my SCAR 17 a lot. Something like, "That thing is really loud...like a 300 win mag." (with his face all screwed up like he was going to cry). I said, "Yeah huh." He could have asked to move, but instead he packed up his stuff and left. Tears....

Look, we all end up shooting close to loud weapons sometimes, you can always put on more hearing protection.

OP: I have 2 SCAR 17s that still have the PWS brake. I had some problem when I started with the way the SCAR 17 sounded, but after awhile I learned how to deal with it and now I don't notice it after the first couple rounds. I frequently shoot at a range that actually has 6 foot wide walls coming almost back to the shooter and a roof over the whole thing. You get used to it.
 
#9 ·
Interesting - I guess I hadn't really noticed the recoil being less comparing to my Sig 716 or others. Truthfully - aside from where I was hitting on the targets; my mind was fully on the discomfort. I appreciate your reply and will search through the other threads and see if there's anything that quantifies the trade-off between muzzle brakes and felt recoil. Any recommendations are immensely appreciated. We all know there's the initial cost of the weapon and then the added costs to customize it to our liking.
 
#11 ·
Thank you Sir! You've got a point and I definitely wouldn't trade places with anything down range of this rifle... I'll check out the Surefire WARCOMP and appreciate you pointing me in that direction. I'll probably hold-off until I can read some more but if you happen to get it replaced and can comment on any trade-off (e.g. felt recoil, etc.) that would be great.

Separate question - are you prior Navy?
 
#27 ·
That's where that suppressor comes in I suppose - I'll have to look-up that one too. Seems like it would be nice to have a complete list of brake options and a write-up but I'm guessing nothing like this exists. If I may ask, what prompted your choice of the Good Iron over other options?
 
#18 ·
Learn to love the concussion! It's the feeling of freedom! Heheh...... Seriously though open your mouth a little to unlock your jaws and separate your top and bottom teeth from making contact with each other. It sounds like BS but it really works if you do that and relax your facial muscles. Personally I love that concussive blast wave....makes you feel alive and gets the heart pumping! Oh crap! Where are my manures welcome to the forum brother!
Oh and the others are dead on about the PWS break causing the issues. Two ways to solve it. New flash hider or suppressor. Surefire muzzle breaks are great for recoil but if you shoot at a range next to people it ticks some people off. I'm a Surefire guy so I would recommend the new SF-Pro Comp. Best of both worlds, reduces recoil and blast is directed forward and a little bit upwards reducing muzzle rise.
 
#21 ·
the military scar17 do not use a pws. the pws brake is actually spelled pos brake in my opinion.

ive since switched mine out a long time ago. the increase in recoil really isnt much at all. that honking big bolt carrier and gas system is really whats soaking the majority of recoil. if you think of the scar17 as a featherbed, a muzzle break is like tossing on just one thin blanket to increase softness.
 
#26 ·
Thank you for this and good to know - I'm tempted to take mine off and sh-- can it despite its gnarly weird cool factor. Maybe I'll have the gunsmith remove it tomorrow and do some before and after comparison. Love the blanket analogy and I tend to agree...
 
#25 · (Edited)
Been there and I try not to - I'm certainly not a new to shooting but have *never* experienced anything like this. 2 outings and the gun sits until I can get a solution here. I actually had a couple of other guys try it since they were poking fun and the look on their face after one round said it all. The first guy said - "well it still looks cool..." I'm taking it to the gunsmith tomorrow to get another opinion as well.
 
#29 · (Edited)
I'm not too "jumpy" and muzzle blast usually doesn't bother me, even my Scar 17 doesn't bother me in the least. But I had the misfortune of being in the lane next to a 16" Vepr in an indoor range recently. Each of his shots was like a gut punch that knocked the wind out of my lungs, it was awesome! I had to cease fire while he did his thing though, it interfered with my concentration that much, a first for me not counting the .50 Barretts that occasionally are rented and shot where I shoot. But Barrett shooters tend to shoot 5 or 10 rounds and they are done. 7.62x54R is cheap so the dude ran quite a bit of it that day. On the one hand it made me want a Vepr like his for its pure awesomeness and the respect it commands. But on the other hand I can see the practical disadvantage that setup yields as every living creature within a 20 mile radius will hear and feel it roar and that is not such a good thing in a tactical or hunting situation. But if they start making Veprs here in the US as I have heard rumors to that effect, I would be interested in a .308 version if the price is right.

I have AAC SDN-6 suppressors and tax stamps applied for and awaiting processing, the sure-cure for these kind of Scar 17 complaints.

But I would be afraid of the 16" Vepr in 7.52x54R shortening the life of a can because of all of that incredible muzzle blast. Perhaps a 20" barrel might lessen the effects I witnessed with the 16" barrel?
 
#24 ·
Been there and I try not to - I'm certainly not a new to shooting but have *never* experienced anything like this. 2 outings and the gun sits until I can get a solution here. I actually had a couple of other guys try it since they were poking fun and the look on their face after one round said it all. The first guy said - "well it still looks cool..."
 
#35 ·
Or an M1 Abrams for that matter... Even worse!!! Ultimately - there's a lot of different factors but mine was simply the muzzle blast directing back toward the shooter. Incredibly noticeable and I don't want to knock FN but WTH were they thinking??? There does seem to be some consensus about the blast coming back at the shooter but some don't seem bothered by it so I wonder if there's some difference in the brake on my rifle compared to others. IDK The gunsmith said they were probably going for looks because it's "wicked" - I laughed... Ultimately I know without the brake it's on or above par with what I'd expect in a rifle that caliber and that level.
 
#31 ·
Here's an update from my trip to the gunsmith's... I put a couple of rounds through on their outdoor / uncovered range. I could still feel the blast and the gunsmith standing alongside slightly rear also could feel the blast. He looked at the muzzle brake and explained the design and why it's directing so much back toward the shooter. He proceeded to remove the brake and I shot without it - voila problem completely gone. I'm not sure how to quantify it but it didn't feel like there was much or any increased muzzle climb. Ultimately the brake was definitely the culprit as many eluded to from the onset so this confirms it in my mind. Thank you all for the input on this and any additional thoughts on replacement brakes would be appreciated.
 
#52 ·
right now im using a bcm 7.62 hider/comp does a decent job. the surefire fire brakes dont have the backblast issue. i run one on my mossberg 7.62 mvp patrol 16" barrel. it seems to redirect the blast further to the sides leaving the shooter in a blast free zone. you still need hearing protection but i dont get that concussion in the face like the pws does. if you really want to be back blast free get a midwest industries 762 bladt diverter it redirects everything towards the front. i use one on my 300blk pistol.
 
#32 ·
I initially sighted the rifle at 100 meters and then progressively went out to 500 meters shooting steel. My first several shots at 1000 yards were lower than expected so when I finally figured out the aiming point I was able to consistently get on paper. The wind was a little gusty at times but didn't seem to have much effect. I'll take a picture of the target I used and post it. My take away from the experience was significant drop due to the barrel length - that conversation also came up with my gunsmith yesterday and occupied a good portion of time. I had also purchased a Kel-Tec RFB and shot it the same day under the exact same conditions but it had even more drop than the SCAR 17 - despite both have close to the exact same barrel length. I'd almost compare the 17 to my Sig Sauer 716 but I do have some variance in optics and general setup between the two.

This is probably another thread entirely but as it relates to the muzzle brake - I asked if I added a suppressor or something to extend the barrel length if that would affect the drop. I don't remember the exact answer but it seemed that it could indeed affect this. I'm wondering if I took the length up to 20" or longer if that would affect it. Does anyone else have any experience with this?
 
#38 ·
You would if you shoot it in a typical indoor range booth. Any enclosed area will direct the pressure to the front and back.
 
#40 · (Edited)
My first foray into 7.62 aside from 7.62x39 was my .300 Blackout. .300 Blackout (7.62x45) is the ultimate subsonic suppressed round that hits accurately out past 300 yards with roughly the power of a .45 ACP (~200 grain projectile going just under 1080 fps). You can't beat the .300 Blk for its combination of accuracy, quietness and punching power. I'm not rich enough to buy a dedicated suppressor for every rifle I own, but I can afford to put an adapter on every rifle I own and share one or two suppressors among all of my rifles.

With that said, I want the best suppressor for my .300 Blk that will also work on my other rifles, including .308 and .223. A suppressor designed to work on multiple calibers tends to work best on the one caliber it was primarily designed for and is more of a compromise on other calibers. So let my .300 Blk be as quiet as possible and let my .308 and .223 not be as quiet as they could be because they are SUPERSONIC and therefore will NEVER be as quiet as a .300 Blk running subsonic loads. A properly suppressed .300 Blk running subsonics runs at about the same noise level as an air rifle BB gun.

Since AAC is the company that developed the .300 Blk and got it SAAMI certified, I am biased towards their brand for my purposes. And the AAC adapters have a flash suppressor so they look good and have some functionality without an AAC can attached.

That makes the AAC SDN-6 can my choice since it was developed by AAC as part of their .300 Blk program and the SDN-6 will do an adequate job on my .308 and .223 rifles as well. And the SDN-6 comes already ceracoated in black rather than bare silver metal like some other cans so I don't have to have it ceracoated to match my rifles.

There are many other fine suppressor choices, some better at suppressing the Scar 17 than the SDN-6 can. But they are not the best selections for my personal needs.

If and when Desert Tech releases the MDR in .308 and I am able to get my grubby hands on one that I can acquire, I will be looking to get an OSS baffle-less turbine type suppressor for it since the MDR is being designed around the OSS. The OSS looks like a great setup for a .308, but seems like it would fail to make a .300 Blk as quiet as an air rifle. The benefit of the OSS, depending on which version you get, is it's compactness because it surrounds and covers the last several inches of the barrel, moving the suppressor rearward rather than projecting it forward and adding length to the rifle. For an ~8 pound .308 bullpup that is just pure freaking magic.

Here is a link to the AAC adapter I will put on my Scar 17, .300 Blk and .223 rifles:
Flash Hiders | Muzzle Brakes | Adapters
 
#49 ·
Awesome - Thanks for taking the time to explain in detail. I've never purchased anything in 300 blackout and was on the fence for a long time (still am...). I finally broke down and got a couple AR57 uppers now that I have a PS90. I hate having lots of calibers but I think the 300 blackout would be worthwhile based on ballistics and sub-sonic loads you mentioned. Having the rifle sound like an airgun would be amazing...
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top