19.5" carbine length 9mm Luger loads??

[sniper58]

124 grain Campro HP bullets over 6.6 grains of HS6 (WW brass, CCI primer, 1.110 OAL) gives 1374 fps from my TNW carbine.
No pistol to compare velocity vs carbine

 

[VanMan]

Ran some batches through my K100 and 9mm AR (10.5" barrel) today. Below is the chrono results. First batch is from Custom Reloading Services. I find their ammo is really consistent so I use it to establish a benchmark for each test session. Very little increase in fps, so looks like it's really optimized for pistol. Ran through some of my batches of my 147gr match ammo, 124gr HP ammo, and 124gr +P+ ammo. Most significant increase in FPS was the +P+ ammo with an increase of 12.13%. No over pressure signs from the brass, primers looked ok.

View attachment 39034

 

[JR Hartman]

thanks guys, especially Vanman, that's the stuff I am looking for.

 

[FreedomIsn'tFree]

They fixed that problem. The gen 2 jr carbines can shoot +p

I just bought a used JR 9mm, how do I tell if it's a Gen1 or Gen2?

 

[Andy]

so, knowing that 9mm Luger is designed to reach its full velocity in a 5" or so tube, I am assuming that using a longer barrel won't do much for pistol loads.........

Where do things like this come from? Is it because most 9mm Luger is used in pistols, and someone just jumps to that conclusion? The same kind of "logic" has lead thousands to assume that magnum cartridges "need" longer barrels than non-magnum, simply because most factory magnum rifles are sold with longer barrels.

This has been more or less answered - even the tiny 22 Short can benefit from barrels much longer than 5". It might be only 10-15 fps per inch, but it's an increase.

 

[Grawfr]

Here's some information that might help, from Ballistics By The Inch (http://www.ballisticsbytheinch.com/9luger.html)

Basically, it looks as if for the 9mm ammo they tested, a barrel length of about 14" to 17" gives the maximum in muzzle energy. You could extrapolate and say that the commercial loads are pretty close to optimal already for the 19" barrel. You can do better with a personnalized load, but the improvement might not be noticeable.

 

[Wolf@TS]

I just bought a used JR 9mm, how do I tell if it's a Gen1 or Gen2?

"Gen 1" Angled slots in handguard, scalloped barrel conture

"Gen 2" Round holes in handguard, round barrel profile.

 

[Ganderite]

If you handload, the max velocity in a carbine will be the same load that gets max velocity in a a handgun, assuming you are not using a fast powder like titegroup.

Something like PowerPistol would be fine.

 

[FreedomIsn'tFree]

"Gen 1" Angled slots in handguard, scalloped barrel conture

"Gen 2" Round holes in handguard, round barrel profile.

Thanks for that. Mine is a Gen 2.

 

[JR Hartman]

Ganderite, any ideas on specifics? Powder type? basic weight?