9mm longer barrels

[AgentAdam]

What is the most practical barrel length on a 9mm pistol to get the most fps. I have noticed that 16" barreled 9mm carbines only gain about 100fps and might actually slow down the bullet a little with weaker loads. I might get a 9mm upper for my AR15 pistol but i cant decide between 5,7,and 10-11.5". What are some good powders for longer barrels?

 

[joneb]

I have noticed that 16" barreled 9mm carbines only gain about 100fps and might actually slow down the bullet

It depends on the type of action. As for the AR I would go with the longer barrel, as for powders I would use HS-6 or AA#7 .

 

[rg1]

I get a little over 150 fps increase from a 4" pistol and a 16" barrel carbine using Unique powder. I'd go with the longer barrel on your AR and I prefer to use the same load in both pistol and carbine. Prevents a mix-up. The slower for caliber powders may give a slight velocity increase. Power Pistol and AA#7 would be good choices for just the carbine but Unique and 124-125 grain bullets works well in both for me.

 

[Walkalong]

The same powders that give the best velocities in my 9MM handguns give the best velocities in my 9MM AR. The slower powders give the best velocity increases over the faster ones.

AA #5, HS-6, Power Pistol, 3N37, etc will all do quite well.

 

[AgentAdam]

Would Herco or 2400 be over kill? Would Unique be to fast? I think im going to get a 10.5" upper. I know the MP5 is about 9ish.

 

[Galil5.56]

I used mostly HS-6 in a 16" UZI carbine, and gained about 150-175 fps over a Beretta 92. Functioning with 7 grains was perfect and accuracy very good. You may find some off beat data for 2400, but IMO that is way to slow to be consistent across a lot of variables. Unique or Herco would seem a good choice for good velocity, and for great metering, great velocity and clean burning I would go with Power Pistol.

 

[AgentAdam]

What was PowerPistol designed for? What burn rate is it similar to? Could i also shoot these rounds loaded w/ PowerPistol threw a 4-5" glock/beretta?

 

[JDGray]

What was PowerPistol designed for?

High performance loads in 40 S&W, 9MM. I use it for 9,40,45ACP. Very accurate, clean burning, great for max loads. I also gained 200fps over a 4.75" CZ75, when shot through my 16" AR.

 

[Loomis]

After 10 inches, I doubt you are gaining enough to make it worth the extra length. Can't back it up with numbers though.

 

[JDGray]

After 10 inches, I doubt you are gaining enough to make it worth the extra length. Can't back it up with numbers though.

Would be nice to know if the bullet was slowing down. A test with 2" increments of barrel lenght, would be handy

 

[Walkalong]

After 10 inches you will gain velocity. Enought to matter? Dunno. How much matters?

 

[Galil5.56]

Here is cut-out from a 1986 "Handloader" magazine demonstrating velocities achieved with 4"-24" barrels. Interesting reading IMO, and note some velocities suffer with the longest barrel.

Click to enlarge:

View attachment 88109

 

[Walkalong]

Yep. One actually loses a bit of velocity in the 24" barrel, but for the most part, more barrel gave more velocity. The faster powders use longer barrels less efficiently than slower powders.

 

[JDGray]

Well that answers that Thanks for that info