I’m curious if there’s a resource where i can find this type of info?
For starters,i’m looking for the point at which added barrel length becomes nothing more than a drag on a typical 147gr 9mm…
Approx what barrel length would offer the maximum velocity?
A 147 grain 9x19mm round will continue to gain velocity through at least 16" of barrel.
From a defensive perspective, the more relevant question is what velocity was the projectile designed to perform at. From that, you can select a barrel length appropriate to be in that velocity window. For most 9 mm loads, a 4" barrel will work well.
Much appreciated.
I realize that faster doesnt necessarily make for better performance.
What i’m really looking at is possibly a suppressed SBR in a handgun caliber.
Sort of a PDW?Which may not be the most practical idea to begin with.I’m really just looking for the best barrel length for such a project…Yet to even decide on caliber(leaning-9mm).
Unless you have a need for a handgun caliber, you would be much better off from a terminal performance perspective suppressing a rifle caliber SBR…
If we are talking like really silly short barrels, like a 7.5in with 5.56 ammo, would you still take the SBR (and which ammo) over a 45acp or 9mm?
I thought I had read somewhere that the minimum suggested barrel length for a 5.56 suppressor was 10.5 inches?
Thanks Doc!
My thinking would lead me to similar questions.
I was thinking that a handgun caliber weapon and suppressor could make for a noticably lighter/smaller(more “discreet”) package than a 10.5" suppressed AR.
Maybe a piston system(suppressed 10.5") in 5.56,with a folding stock,might be a better option…20 round mag…
For SBR’s with sub 10.5" barrels, then the 6.8 mm or 6x35mm are better choices than either 5.56 mm or service handgun calibers.
As Doc pointed out, you’re much better off going with an actual rifle caliber which gives you significant improvements on terminal effects.
Just to throw it out there, most 9mm, .40S&W, and .357sig JHPs are designed around the 4" barrel. So, that is generally your sweet spot. As for the .45acp, JHPs are designed around the 1911 5" barrel. As you shorten your barrel length from these standards, you will decrease the reliabilty of your hollow point opening up the shorter you go.
All bullet designs are different but what would be the suggested high end velocity for 115 & 124 gr 9mm H/P’s in general before they start fragmenting and failing to penetrate as needed. I think I recall someone a while back suggesting 1250fps but I could be wrong.
Doc is 100% right here.
To answer your question tho, there was a group of guys who tested handgun velocities per inch of barrel. I looked at them all and it seems that with that data set, there is a consistent break over point where the velocity gain becomes inconsistent or insignificant or unreliable with additional inches added to barrel length. It appears to be around 14" almost across the board with the pistol cartridges tested.
if it were me, I’d probably not go any longer than 14" of barrel length, unless you wanted to do some special slower burning powder handloads to take advantage.