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I built a 12.5 pistol setup using a BA Hanson barrel firing through a Deadair Sandman S. Its just barely hearing safe with the Hornady 123s. I added a Superlative Arms adjustable gas block to help vent some of the gas. Still just barely hearing safe. Im considering building a 18 or 20 setup if I can make it quieter. Im trying to build a rig that can be used with a hunting partner, wife, right next to me without too much noise. The can does a good job on my 16 300 BLK.
Any advice
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I'm betting most of your noise is from the chamber, some from the can, especially the supersonic crack that you will not be able to muffle.
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My Tranquillo works great on both my 12.7 and 18”. Hearing safe on both, or at least no worries about shooting next to someone.
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Its more than the supersonic crack. I guess there is no way to change the pressure in the chamber other than the forward venting SA gas block I have is there?
Newish to ARs. Learning as I go!
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I do notice a little gas release, but not bad. The crack is by far the loudest (seemingly) portion of the event for my weapons.
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AR-Hunter,
I am looking at three different muzzle pressures (Quickload) for typical supersonic ammunition that your suppressor is going to cool/slow/contain.
13,000lbs for the 12.5" Grendel.
7,500lbs for the 20" Grendel.
4,500lbs for the 16" Blackout.
Your 30cal suppressor will have about .02" clearance between the exiting bullet and the baffles in the Blackout. Using a 30cal on a 6.5mm increases the clearance gap to about .032". I have not tried this myself however have read that having more clearance decreases the back-pressure in a semi-auto which means that less gas is being contained by the suppressor and more is permitted to escape out to the front. More pressure out the front means more sound so it's a compromise idea.
Looking at the muzzle pressures and clearance it is fair to say that your Blackout is going to be the quietest of all three scenarios and your 12.5 is going to be the loudest. I take it your suppressor is rated for the higher pressure of the short barrel? Regardless, it is going to take more punishment and wear-out faster.
One last thought...using suppressors with supersonic rifle ammunition is not hearing safe. You are going from about 170+ decibels down to 140db. I know we would like to think it is hearing safe given the cost and effort but that is just the reality of physics. Around 30db of reduction is the most you can expect with current designs. We used these things at work all the time and always wore hearing protection as part of compulsory PPE. Hearing loss is a cumulative thing so a few shots here and there when hunting may not be noticed in the scheme of growing old but probably not wise to not wear them just to make a point.
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Klem,
Thanks for the educated response. I did not think about the clearance difference of the 6.5 and 30 cal. So simple, yet far from my mind. I did in fact contact and speak with the owner at Deadair to confirm that the Sandman S is capable to handle the pressure of the 6.5 in a 12 barrel. He was the one who suggested the Superlative Arms gas block.
Looks like the 20 would be a way to help drop the noise. Add in the fact that is significantly increases the effective distance the Grendel can be used as a deer rifle makes me highly consider building a 20 setup. My main issue is that overall length for handling
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why not drop to a 18" then? you'll still get some of the gains from the longer barrel, however won't be too long in the length category. Plus you will only lose about 150 fps from the 20" barrel
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Closer to 40fps in 2 inches. Under 18 then you start dropping fps like mad.
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What would I see the boxed Hornady 123 amax in the 18 barrel with 1:8?
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AR_Hunter-Reloader Wrote:What would I see the boxed Hornady 123 amax in the 18” barrel with 1:8?
I have had groups as small as 3/4" at 100yds out of my Alexander Arms, and that is with myself and 2 others on the gun. Velocity wise I'm not quite sure, I do not have a chrono to give you that data.
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AR_Hunter-Reloader Wrote:What would I see the boxed Hornady 123 amax in the 18” barrel with 1:8?
Around 2430fps.
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Klem Wrote:AR-Hunter,
I am looking at three different muzzle pressures (Quickload) for typical supersonic ammunition that your suppressor is going to cool/slow/contain.
13,000lbs for the 12.5" Grendel.
7,500lbs for the 20" Grendel.
4,500lbs for the 16" Blackout.
Your 30cal suppressor will have about .02" clearance between the exiting bullet and the baffles in the Blackout. Using a 30cal on a 6.5mm increases the clearance gap to about .032". I have not tried this myself however have read that having more clearance decreases the back-pressure in a semi-auto which means that less gas is being contained by the suppressor and more is permitted to escape out to the front. More pressure out the front means more sound so it's a compromise idea.
Looking at the muzzle pressures and clearance it is fair to say that your Blackout is going to be the quietest of all three scenarios and your 12.5 is going to be the loudest. I take it your suppressor is rated for the higher pressure of the short barrel? Regardless, it is going to take more punishment and wear-out faster.
One last thought...using suppressors with supersonic rifle ammunition is not hearing safe. You are going from about 170+ decibels down to 140db. I know we would like to think it is hearing safe given the cost and effort but that is just the reality of physics. Around 30db of reduction is the most you can expect with current designs. We used these things at work all the time and always wore hearing protection as part of compulsory PPE. Hearing loss is a cumulative thing so a few shots here and there when hunting may not be noticed in the scheme of growing old but probably not wise to not wear them just to make a point.
That was very helpful Klem, thanks for sharing.
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AR_Hunter-Reloader Wrote:I built a 12.5” pistol setup using a BA Hanson barrel firing through a Deadair Sandman S. It’s just barely hearing safe with the Hornady 123’s. I added a Superlative Arms adjustable gas block to help vent some of the gas. Still just barely hearing safe. I’m considering building a 18” or 20” setup if I can make it quieter. I’m trying to build a rig that can be used with a hunting partner, wife, right next to me without too much noise. The can does a good job on my 16” 300 BLK.
Any advice
Would the -L series help?
I'm thinking of my 12.7 barrel build and wondering what the Deadair Sandman suppressors can actually do. I'm just getting in to this game, so any input would be appreciated.
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Pugsbrew Wrote:Would the -L series help?
I'm thinking of my 12.7 barrel build and wondering what the Deadair Sandman suppressors can actually do. I'm just getting in to this game, so any input would be appreciated.
I suggest doing all of the research you possibly can and take a deep look at what you want the gun to do. Definitely don't settle... if you are looking for a light weight build then a titanium suppressor will be the better option, if you want a little bit of weight then you can't go wrong with alloy. One last tidbit... there is no set standard for suppressor testing. Military do their tests one way, a company does it their own way and another company does it even differently, so just because a company advertises a particular decibel rating doesn't necessarily mean it will work for your application. I have a Q LLC trash panda sitting in jail currently, I picked it for the weight, construction, price and mounting option and ignored the decibel rating since I don't have any first hand accounts/experience for the sound reduction.
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If you live near okeechobee fl you can come to the range and hear my tbac ultra 7 on a 12" grendel
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Furthering Klem's excellent points- yes you need to use ear protection with supersonics. It's silly not to.
Perhaps one of the greatest benefits to suppressor use is the reduction in impact on your neighbors. I shoot in the country, but the closest neighbor is within a few hundred yards. Before I had a suppressor they would mention every time they heard me shoot. They did it in a light-hearted manner, but it was obvious they were less than impressed. After the suppressor I haven't heard a word. It's possible they don't even notice the sound that far away.
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Try a bolt action, the difference is night and day. I love my ARs but if you're really looking for sound suppression bolt action is the way to go. If you want to stay with 6.5G, the Howa seems like a good deal. The cost of a barreled action is pretty close to a new upper. Just google Howa 6.5 grendel.
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Bigs28 Wrote:If you live near okeechobee fl you can come to the range and hear my tbac ultra 7 on a 12" grendel
Have you ran it through a chrony? I'm shooting an 18" suppressed for deer and hogs. I would love to go to a 12" and have an SBR lower. I am just concerned about velocity loss.
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Coty Wrote:Have you ran it through a chrony? I'm shooting an 18" suppressed for deer and hogs. I would love to go to a 12" and have an SBR lower. I am just concerned about velocity loss.
http://www.65grendel.com/forum/showthrea...-Faxon-SBR
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