Sub 2000 blowback action question

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drift1122

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I was looking at a chart of 9mm velocity by the inch and noticed that after 16" of barrel the bullet actually begins to slow down. Now for our Canadian sub 2k the barrel is 18.7", does this mean the bullet is slowing down and the bolt opening at the same time? Is this going to cause a substantial loss in velocity and can it be reduced with +p loads!?

Or am I over thinking and should just go plink :p
 
handloading with a powder on the slower end for 9mm is likely to solve that problem for you.
on all blowback, non API guns, the bolt starts traveling backwards as soon as the bullet starts moving forward out of the case mouth, dont worry about it
 
scott585 said:
handloading with a powder on the slower end for 9mm is likely to solve that problem for you.
on all blowback, non API guns, the bolt starts traveling backwards as soon as the bullet starts moving forward out of the case mouth, dont worry about it
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Makes sense, I wonder if a lighter bullet would help too. I'm guessing the bullet leaves the barrel before the case is ejected.
 
drift1122 said:
I was looking at a chart of 9mm velocity by the inch and noticed that after 16" of barrel the bullet actually begins to slow down. Now for our Canadian sub 2k the barrel is 18.7", does this mean the bullet is slowing down and the bolt opening at the same time? Is this going to cause a substantial loss in velocity and can it be reduced with +p loads!?

Or am I over thinking and should just go plink :p
Click to expand...

Hmm, odd that just about everyone who talks about PCC's says you gain FPS over a pistol and I think they are blowback designs.
 
I'd be inclined to get a metal trigger guard / barrel catch from M*Carbo before trying any +P loads.
The barrel break point is where I suspect the Sub2K is weakest.
Personally, I'm preferring 147g to slow down. The weaker sonic crack doesn't bother nearby livestock as much.
Can't tell it from hammering on a barn door hinge pin, and shoots just as flat at 30 yards.
 
Bubba Yugga said:
I'd be inclined to get a metal trigger guard / barrel catch from M*Carbo before trying any +P loads.
The barrel break point is where I suspect the Sub2K is weakest.
Personally, I'm preferring 147g to slow down. The weaker sonic crack doesn't bother nearby livestock as much.
Can't tell it from hammering on a barn door hinge pin, and shoots just as flat at 30 yards.
Click to expand...

I think I might try reloading with slower powder first, I did notice over pressure signs on the primers when I shot some factory 115gr and 147gr
 
drift1122 said:
Yeah I don't plan to push it but I think I can potentially reload to find a more efficient round.
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It's a plinker, pure and simple...so what exactly is a more efficient plinker? What will you gain?

I can see doing this type of work with a long-range hunter, target gun, race gun, whatever...but this thing? Just shoot the crap out of it and smile! :)
 
jjohnwm said:
It's a plinker, pure and simple...so what exactly is a more efficient plinker? What will you gain?

I can see doing this type of work with a long-range hunter, target gun, race gun, whatever...but this thing? Just shoot the crap out of it and smile! :)
Click to expand...

Your right, I'll be shooting the crap out of this for sure! It's fun to think about the technical aspect of things sometimes too :)
 
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