Reaming 9mm barrels

[drewzer17]

I am trying to reload some berry 147 gr hybrid hp. With the expressed intent on getting some expansion out of them I will need to push them close to 1050 with vv340.



The issue I am running into with the longer ogive of these bullets, using the plunk test the coal I need to keep these above 1020 only passes on 2 of my 7 9mm barrels. I need another .025 to .030 longer chamber. Should I / can I take 9mm finishing reamer and extend my lands lengths pushing my rifling back? Does this affect anything when running other 124 hr shorter coal bullet weights and cartridges? See chamber reamers and finishing reamers will be reaming approx .030 off 7-8 different 9 mm barrels.



If so I’m seeing very different prices on reamers, again I plan to do 7-9 barrel by hand but I do have access to lots of equipment and can prob get my hands on a lathe if need be.

 

[hpshooter]

The 9x19MM head spaces off of the case mouth using a finish chamber reamer would not work well and could cause problems with ignition and headspace with shorter BTO rounds. You need to locate a throating reamer, for 9x19mm Luger to lengthen the throat to accommodate the longer BTO rounds which would not change the chamber proper.

The simpler solution is to seat them deeper and experiment with different powders to get the velocity you need without excessive pressure.

I would use ballistic gelatin, load and fire some of the proposed rounds in one of the barrels they fit, and see if they actually expand before I modified any of the barrels.

 

[troupe]

Two things, the Berry's are not the bullet for expansion, even though they are hollowpoints. and you will need a throating reamer as mentioned. Common practice in USPSA open pistols as well as PCC carbines.

 

[Rwfish]

I ran into the same thing with a CZ Checkmate I ran in competition. As others have stated a throating reamer will correct the issue. For the removal you’re looking at it will take very little to get the results you want. I ran 115gr to 147gr coated and plated with no issues as long as I kept similar bullet profiles. As an aside, have You tried to run a bullet with a cone profile similar to Montana Golds or Precision Delta offers? The tend to feed really well loaded short or long…

 

[625-8]

I have the same problem with a CZ Shadow 2. With their Melonited? barrels most gunsmiths won’t even consider throating those barrels. I like the pistol but don’t like having to change bullet profiles and seating depths.

 

[drewzer17]

I have the same problem with a CZ Shadow 2. With their Melonited? barrels most gunsmiths won’t even consider throating those barrels. I like the pistol but don’t like having to change bullet profiles and seating depths.

How can you find out if a say p320, cz’a and m&p’s are melonited is mean the out coating will also be in the inside throating ? I understand it will need a carbide reamer ?

 

[625-8]

You would need to check with the individual manufacturer to be sure. Those carbide reamers are a must based on anything I have read or been told.