bigger "BANG"

[mark4567]

Ok guys I have a question for you. Semi-non scientific but curious.
I was at the range Sunday,just getting in a little trigger time.Busting up soup cans @ 200yds. I'm shooting my reloads and a buddy of mine is shooting FGMM. My load is Win brass,CCI BR2 primers,44gr Varget, 168smk.
I noticed that my muzzle report was louder than his, OK mines a 20" barrel his is 24" so I figured that was why. Well curiosity got the better of me and I tried a couple of his factory rounds through my rifle. Nope my mild reload still has a bigger BANG than factory ammo. I told my friend about what I was trying and he agreed that my reload BANGED more than factory??
I know the reloads are well under max with no signs of pressure and that FGMM is about 150fps faster out of my rifle. So... why the bigger bang??

 

[gunsnjeeps]

Re: bigger "BANG"

My guess would be different powder. Same as flash/low flash powders.

 

[Powder_Burns]

Re: bigger "BANG"

Proprietary/Blended factory powders > commercially avaliable powders. They probably have flash retardants among other things in their charge that isn't present in your handload. Also the burn rates as mentioned before may be different. Your charge might still be burning after the projectile leaves the muzzle whereas the factory stuff is engineered for a complete burn.

 

[Clark]

Re: bigger "BANG"

https://ccrma.stanford.edu/~jos/Delay/Inverse_Square_Law_Acoustics.html
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Inverse Square Law for Acoustics

The intensity of a sound is proportional to the square of its sound pressure $ p$, where pressure is force per unit area

Therefore, the average intensity at distance $ r_{12}$ away from a point source of average-intensity

$\displaystyle I_1\propto\left<\left\vert p_1\right\vert^2\right>$ is$\displaystyle \qquad \zbox{I(\mathbf{x}_2) = \frac{I_1}{r_{12}^2}} $

This is a so-called inverse square law.

Remember that far away (in wavelengths) from a finite sound source,

* pressure falls off as $ 1/r$
* intensity falls off as $ 1/r^2$

where $ r$ is the distance from the source. </div></div>

That "sphere" means sound goes further with hard things to reflect off.
The "far away" means that the math is different in the near field.

What does it all mean?
You were closer to your muzzle.

 

[MitchAlsup]

Re: bigger "BANG"

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Clark</div><div class="ubbcode-body">You were closer to your muzzle. </div></div>

And the bullet uncorks the barrel while there is a higher pressure inside. The report of a 20" barrel is aobut 2X that of a 24" barrel in 308.

The rest of your report issue is as yet undetermined, but some bullet, powder, primer, seating depth issues are likely to be the culpret.

 

[Short-bus]

Re: bigger "BANG"

I agree with the assessment that the projectile leaves the barrel with a greater pressure behind it in a 20" vs. 24" barrel. I noticed this in shotguns when i was out pheasant hunting, and another hunter let me walk a field with his 22" semi-auto rather than my 28" pump. A cock jumped up in front of me and when i shot him I noticed how much louder the shots where from the shorter barrel. That long 28" barrel affords a lot of extra space for the gases decreasing the pressure when the "cork" is released.

Branden

 

[The Mechanic]

Re: bigger "BANG"

May also be the burn rate of the powder. Have loaded some shotgun shells with red dot and blue dot at differing velocities and red dot is very fast burn rate. It also had a much quieter report. All the powder burned before it got to the muzzle.

 

[mark4567]

Re: bigger "BANG"

As I said guys, I thought it was my shorter 20" tube. But that doesn't explain why a faster factory load is quieter out of my gun than my reloads??? Unless it is the powder Federal uses..