question on a future 9mm build

[brutis]

Greetings to all.

A friend at work has a question or two about a 9mm build he wants to do.

I showed him my 9mm SBR with the can on it the other day and he fell in love, he wants to build one for himself but doesn't want to go the SBR or pistol route. He would like to have a 5" barrel like mine so I told him he needs to permanently attach a 11" flash hider or fake suppressor to it to make it a non NFA item or he could just go with a 16" barrel and wa lah. His concern is that the 16" barrel would give him lower velocities but I told him that it would be OK and not a problem.

So he's thinking he could take a 16" barrel and drill the bore out from the muzzle leaving 5" of rifling in it and be good to go. I said I wouldn't try it because most if not all 9mm barrels 16" long have 1/2-36 threads and that wouldn't leave much material at the muzzle for the flash hider.

What do you think?

[IMGrunt]

Generally speaking...just the opposite. Just stick with a 9mm 16" barrel if he's set on a non NFA setup.
http://www.ballisticsbytheinch.com/9luger.html

[John A.]

His concern is that the 16" barrel would give him lower velocities but I told him that it would be OK and not a problem.

16 inch barrel actually increases velocity over a 5 inch barrel.

I have an uzi with a 16 inch barrel. It gets about 100 more feet per second using standard 115 gr bullets compared to my 5.5" barrel mp5k.

Perhaps he'd like to view this. The federal 115 gr data would be about what most commercial ammo would run, so that's the one that he should be looking at.

http://www.ballisticsbytheinch.com/9luger.html

If he were to load his own bullets, it's entirely possible to get into 357 magnum velocities with certain recipes and powder choice with a 16 inch barrel.

[brutis]

Thanks guys, just what I needed for him to go the 16" unaltered barrel length

[wildfowler]

So he's thinking he could take a 16" barrel and drill the bore out from the muzzle leaving 5" of rifling in it and be good to go. I said I wouldn't try it because most if not all 9mm barrels 16" long have 1/2-36 threads and that wouldn't leave much material at the muzzle for the flash hider.

What do you think?

I know it sounds like you've already helped with the decisions for him, but can you please explain in a little greater detail what he was considering doing to his 16 inch barrel?

Thanks.

[brutis]

So he's thinking he could take a 16" barrel and drill the bore out from the muzzle leaving 5" of rifling in it and be good to go. I said I wouldn't try it because most if not all 9mm barrels 16" long have 1/2-36 threads and that wouldn't leave much material at the muzzle for the flash hider.

What do you think?

I know it sounds like you've already helped with the decisions for him, but can you please explain in a little greater detail what he was considering doing to his 16 inch barrel?

Thanks.

Sure, no problem but I'll try to do it with a poorly rendered paint jpeg.

Red is the unaltered chamber and rifling (.355 bore), yellow is the bored out rifling...lets say .400

[wildfowler]

Interesting. I've never seen or heard of doing that before. Thanks.

[John A.]

I have heard of integral suppressor barrels being done like that.

[A-Game]

That can happen with machine guns. Portions of the bore will be smooth. Sometimes it's on the chamber end sometimes on the muzzle end.

Full out Uzi ideally will use a 10.5 inch barrel. Uzi's are nice and heavy to handle the recoil well...unless you let a 9 year old shoot it...by herself...without help...Don't stand in front of or next to her...just sayin.
I have shot a lot of Uzi in the last year.

IF, he does not want a SBR then go with a 16" barrel. It sounds a bit too mall ninja for my taste. You don't drill out the bore of a barrel, you ream it. You ream it good!

[brutis]

Just to let everyone know he's going to go with an unaltered 16" barrel, the ballistic charts linked to by others confirmed what I was trying to tell him.

He's been a tool maker for over 30 years and I'm sure if he would have altered the barrel it would have come out with a mirror finish...he's that meticulous.