how loud is an unsuppressed 308 with subs?

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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 08 Apr 2012, 18:04

flyingirish04 wrote:none. Or at least not enough that you can hear the difference. You have shot a 45 before right???
I will dis-agree with you there. Shoot a standard velocity 22 and a high velocity 22 side by side. Not only is there a notable difference in noise at the muzzle, but downrange, one bullet will be subsonic, the other will be supersonic. It will be the same as a 308 at 3-400 yards like the OP stated. Quieter at the muzzle (i'd still wear hearing protection though) and much quieter at 3-400 yards.

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flyingirish04
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Re: how loud is an unsuppressed 308 with subs?

Post by flyingirish04 » 08 Apr 2012, 18:11

Not significant enough for anyone to notice. Not with that charge of powder in that size of weapon.

22, yeah. 308 no.
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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 08 Apr 2012, 18:53

There is no way there will not be a difference. Not only will Trailboss burn completely well withing that 20" barrel, but the bullet will also be traveling 1400FPS slower. I'm not sure you are familiar with Trailboss powder.

Op here is a thread I just found on the same question
http://www.msgunowners.com/t21507-subso ... suppressor" onclick="window.open(this.href);return false;
My .308 150's sound like a potato chip bag being poppped without a suppressor and with it sounds similar to a primer being fired out of the barrel. Have no vids, sorry.

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Rapier1772
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Re: how loud is an unsuppressed 308 with subs?

Post by Rapier1772 » 08 Apr 2012, 19:15

Question, (I don't really want to make a new thread for this) but doesn't a subsonic .308 defeat the purpose of a .308? Its made to reach out & touch someone but making it subsonic would be cutting the velocity in half, thereby limiting the range.

I understand using a suppressor on a normal .308 round, minimize muzzle flash & make it harder to locate source, but what is the range drop to for a sub .308?
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Re: how loud is an unsuppressed 308 with subs?

Post by f3rr37 » 08 Apr 2012, 19:43

Rapier1772 wrote:Question, (I don't really want to make a new thread for this) but doesn't a subsonic .308 defeat the purpose of a .308? Its made to reach out & touch someone but making it subsonic would be cutting the velocity in half, thereby limiting the range.

I understand using a suppressor on a normal .308 round, minimize muzzle flash & make it harder to locate source, but what is the range drop to for a sub .308?
Using a 200GR SMK... drop is in inches.
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi" onclick="window.open(this.href);return false;
200 -30.2
300 -94.6
400 -195.4
500 -334.7
600 -514.9
700 -738.2
800 -1007.0
900 -1324.0
1000 -1691.7

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flyingirish04
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Re: how loud is an unsuppressed 308 with subs?

Post by flyingirish04 » 08 Apr 2012, 19:59

A suppressor is largely used on a rifle for those reasons rapier. I know the ones we had were used with regular match grade ammo. The use was purely to mask muzzle flash and directional noise, like you said.

Subsonic rounds were never used in that round for any type of at range shooting. Purely CQB weapons.

And SRT, I see what you are saying. I still think it will be loud enough to not want to shoot with ears. All the subsonics that I have shot, have been still loud enough to cause hearing damage.
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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 08 Apr 2012, 20:08

subsonic 308 serves the same role as 300blk subsonic. short range hunting and cqb.

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flyingirish04
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Re: how loud is an unsuppressed 308 with subs?

Post by flyingirish04 » 08 Apr 2012, 20:09

Yes, 300 blk and whisper is a bit more efficient of a round though.
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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 08 Apr 2012, 20:22

how is it more efficent? it is a .308 caliber bullet traveling at subsonic velocities.

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flyingirish04
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Re: how loud is an unsuppressed 308 with subs?

Post by flyingirish04 » 09 Apr 2012, 10:28

Still use less powder and powder burn is more efficient in shorter, thinner, less shouldered case.

I am mainly speaking for the other reason both were designed: achieve 7.62x39 type supersonic capabilities. The 300 W, and blk do that much more efficiently than the 308.
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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 09 Apr 2012, 12:32

so im assuming you know nothing about trailboss powder.

how is one .308 [email protected] better than aanother .308 [email protected]?

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Re: how loud is an unsuppressed 308 with subs?

Post by romer522 » 09 Apr 2012, 13:25

srt-4_jon wrote:so im assuming you know nothing about trailboss powder.

how is one .308 [email protected] better than aanother .308 [email protected]?
These might not be efficiency related, but...

1. 99.9% of 308 rifles are not rifled for 200-220gr bullets at 1080FPS, 99.9% of 300BLK rifles are.
2. Subsonic 300BLK 220gr will cycle semi-autos in that cartridge, subsonic 308 will not.
3. Safe powder choices for sub 308 are very very few, many more for 300BLK. Subsonic 308 is just more picky/dangerous all the way around.
4. Ammunition weight, mag capacity, reloading costs etc are all better with 300BLK.

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flyingirish04
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Re: how loud is an unsuppressed 308 with subs?

Post by flyingirish04 » 09 Apr 2012, 14:34

Accuracy. Trail boss is crap for accuracy in a 308. You have other loads that work in the Whisper and Blackout that won't work with the 308. The 308 win is a terrible subsonic round.
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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 09 Apr 2012, 18:45

http://www.snipershide.com/forum/ubbthr ... er=2316224" onclick="window.open(this.href);return false;
12.2 gr. with the AMAX and 14.2 gr. with the RN put me just above 1030 fps out of my 22" barrel. Groups were sub-MOA with no first round drop out
http://www.snipershide.com/forum/ubbthr ... er=2811277" onclick="window.open(this.href);return false;
9.8 gr. Trailboss
175 SMK
2.780" coal
16" 10 Twist barrel w/ AAC Cyclone suppressor

1020 fps and <1 MOA accuracy.

http://www.snipershide.com/forum/ubbthr ... 230&page=1" onclick="window.open(this.href);return false;
16" Krieger 1/10

220 Hornady RNSP
10.7 gr of Trail boss
1040 fps
mag primers, win cases
3/4-1" groups at 100
not temp sensitive or powder position sensitive
slightly louder than loads with Green dot or other pistol powders, but more reliable. Add water and it's super quiet
2. Remington M700, 16" 1/10", War Tech Tensioned Barrel System w/ST Black Star 8" installed, H&S 5R stock and bottom metal, Leupold MK4 1-piece base, Leupold MK4 1" Medium alloy rings, Bushnell 3200 10x40:
Case: Federal Gold Medal
Primer: CCI 200 Large Rifle
Powder: IMR Trail Boss
Bullet: Sierra 170gr (30-30) bullet .308 dia. #2010
Starting Load: 9.0gr (980 fps average)
Work Up: loaded to 9.8 (1017 fps average)
Accuracy Load: so far most producing Sub-MOA
Rem 700 PSS (FACTORY) .308
Threaded 5/8 X 24 w/ VORTEX Hider
Stock: BELL/CARLSON "Tactical Adj"
.
.
.
When i say ACCURATE as long as I held the mils it WOULD ONE HOLE the group. VERY clean hole no tumbling or unstableness shown AT ALL

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flyingirish04
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Re: how loud is an unsuppressed 308 with subs?

Post by flyingirish04 » 09 Apr 2012, 19:30

Sub MOA at 100. 3 MOA at 200.

Tell you what, try in and post your targets. I have shot 308 subsonic loads, and they are terrible past 100. I have shot 300 Whisper with identical projectiles and it held tighter groups further. Still not really useful past 300 yards in my experience.

It is easy to post stats from message boards, but from a person that just spend a year fine tuning my 6AI loads, I can tell you it is another thing getting results in the real world, especially with factory equipment. I own 3 custom rifles and they took a while to shoot CONSISTENTLY in the 3s and 4s and hold that at range. So I am going to have some issue with someone that claims they can get all world performance with TB and a 308 cartridge on a stock setup. It is possible to get it at 100, but where does it go from there?

There are every once in a while factory rifles that shoot very well, but to take the net's word, everyone owns one, and that just isn't true.

But for subsonic work, go for it. Chances are that the 300 Wh and Blk will perform better at range though.

But go right ahead and try. I still bet you wear ears either way.
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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 10 Apr 2012, 07:22

I have actually already said I would shoot it with hearing protection. It was back in one of my first posts in this thread. I am posting many others' good experiences and showing references and you are just talking about your limited time trying it.

Back to the OP
Yes subsonic 308 will be quieter than supersonic 308 to the shooter and especially downrange.

Image

That graph alone tells it all about the flight noise.

Here is a first hand experience
http://www.silencertalk.com/forum/viewt ... =2&t=86948" onclick="window.open(this.href);return false;
When running targets in the pits at the 600yd line, I can very distinctly hear the bullets 'crack' as they fly overhead. You'd swear they are pulling the trigger directly in front of you. Not so. At that distance you can not really hear any of the muzzle report, all you're getting is the supersonic crack as the bullets pass over the pit. Loud enough to require plugs.

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flyingirish04
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Re: how loud is an unsuppressed 308 with subs?

Post by flyingirish04 » 10 Apr 2012, 07:51

Fair enough. I don't think it would matter at 600 yards though, you likely aren't going to hit the target with a subsonic load. Possible, but not likely.
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srt-4_jon
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Re: how loud is an unsuppressed 308 with subs?

Post by srt-4_jon » 10 Apr 2012, 08:24

i agree with that. the drop would be horrible. that said, there will still be notible differences at closer ranges.

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