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Discussion Starter · #1 ·
I have my first suppressor on order and had a question. I think I know the answer but just wanted to confirm. Does the bullet weight and subsequent speed affect the suppressed sound or is it all the same once it breaks the sound barrier? In other words, in a 6.8, will a 120 CBB have a quieter sound signature than a 105 CBB when shooting suppressed?
 

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The bullet speed will make a tremendous difference if your are talking subsonic to supersonic. Once you cross that super sonic threshold, I doubt you would be able to notice any difference between a 120 grain and a 105 grain of the same caliber, without some really high tech expensive decibel metering equipment.
 

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Discussion Starter · #4 ·
Muzzle pressure is where the sound difference will come in . It's about how much at what pressure it's released when the bullet clears . If it's low enough all you have is bullet crack which might happen inside the can .
Thanks that helps! I should have clarified that I wasn't referring to subsonic rounds but rather if there is any difference between 2 bullets when both are supersonic but one is heavier thus moving slower.
 

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I could go into powder curves and an example in one I loaded for where it was short stroking and increasing the charge made ie worse . Which at first glance doesn't seem related but if you let the gears turn a while makes a good relationship.

You have a pressure limit with a desired pressure window at a particular point . In principle with a 50kpsi peak and 15 kpsi at the gas port both bullets should depart the muzzle with the same pressure . But some powders look like ^ and some are more like ✓\ while a 3rd is more like ✓~~\ .... One hits fast to peak and drops off just as quickly with just enough left to cycle , the second has a a nice fluid arc with a moderate rise to peak and the back side is coming down just in time to trip the action while the 3rd powder has a slow rise to peak , long hold and is still pushing with the bolt unlocking . A might only have 2000-2500 psi left at the muzzle with the lighter bullet something like 10x . H 322 or 335 might have 5k left with either bullet but 322 is likely to be lower with the heavier bullet . Meanwhile H4198 will be slow to peak with a very long hold and still have 10k at the muzzle with the heavy and 9-11 k with the light bullet . These 4 powders live in about 10 steps on the burn rate charts .
This assumes for example a 90/95 gr vs a 130/140 gr at 2400 and 2200 fps MV from my work w/o pressure tools and with 10x,322 and 4198 base against action function and velocity. Ok
 
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