Author Topic: I love the 6TCU but...  (Read 714 times)

0 Members and 2 Guests are viewing this topic.

Offline Moe

  • Trade Count: (0)
  • Contributor
  • ***
  • Posts: 276
I love the 6TCU but...
« on: June 26, 2004, 11:17:35 AM »
I recently acquired two 6mmJDJ#2 barrels. A 14 inch and a 21 inch. They are just a dream to load for. It is without effort through the size die. They are very accurate, although I have only used one powder that I had on hand so far. Having a rimmed case is very user friendly, recoil is non-existant and with 70gr BT's they have a lot of pop on water bottles at 100 yards. These are the first SSK barrels I have ever had, did have a rechamber some years back, and they are wonderful on the workmanship. I have/had Bullberry, VVCG, Reeder, and Van Horn barrels but these SSK ones are NICE. I may have to get rid of my VVCG 6TCU barrel. I have the 14 inch on a Gary Reeder tuned G2 and the 21" on an old blue frame with a 3x9 Tracker scope. Scope is not to good. May end up getting a better one if I keep the 21" barrel. I like handguns mostly. Just thought the board was slow so I would share some of my good fortune. Thanks GB for the board.

Offline 22hornet

  • Trade Count: (0)
  • Avid Poster
  • **
  • Posts: 125
I love the 6TCU but...
« Reply #1 on: June 26, 2004, 11:54:00 AM »
What brass is the 6mm JDJ#2 formed off of?  Also what kind of velocity are you getting with the 14"er?  Just curious.  Thanks in advance.

22hornet
Mike D.
BMET

Offline Moe

  • Trade Count: (0)
  • Contributor
  • ***
  • Posts: 276
I love the 6TCU but...
« Reply #2 on: June 27, 2004, 03:17:53 AM »
.225 Winchester brass. Don't have a chrono, so I don't know the speed.

Offline 22hornet

  • Trade Count: (0)
  • Avid Poster
  • **
  • Posts: 125
I love the 6TCU but...
« Reply #3 on: June 27, 2004, 04:31:58 AM »
Thanks for the info.

Mike
Mike D.
BMET

Offline haroldclark

  • Trade Count: (13)
  • Contributor
  • ***
  • Posts: 460
Velocity of 6mm JDJ #2
« Reply #4 on: June 27, 2004, 12:06:28 PM »
Give me the amount of powder & brand, bullet brand and weight.  I will give you a very close idea of the velocity from both the 14" and the 21".

I have software that has proven by chronographing test to be very accurate.

Harold Clark

Offline Moe

  • Trade Count: (0)
  • Contributor
  • ***
  • Posts: 276
I love the 6TCU but...
« Reply #5 on: June 27, 2004, 02:11:00 PM »
Thanks Harold. Using 32.5 grs of H4895 and the Nosler 70gr BT.

Offline haroldclark

  • Trade Count: (13)
  • Contributor
  • ***
  • Posts: 460
Velocity
« Reply #6 on: July 01, 2004, 04:25:25 PM »
Sorry I took so long to get back to you.  I forgot what posting I was on.

In Necos Quickload program with the following data:

14" barrel
32.5 grains of H4895
Nosler 70 gr BallisticTip bullet
Overall length of the cartridge at 2.487"

Pressure = 48797 psi
Max Pressure: = 52996 psi

Velocity is 2724

You are a tad bit high on pressure, but not in the dangerous area just yet.
If you are cratering primers or flattening them out, you might consider reducing the amount of powder to:

31.4 gr of H4895 with a velocity of 2630 fps.

I have found the software to be very accurate in the pressure and velocity.  I have chronographed a bunch of loads and the velocity is usually within 10 fps of the programs calculations.

With your load of 32.5 grains and summer heat, you may experience extreme pressure.  

My input is only a suggestion and no more.

Harold

Offline Moe

  • Trade Count: (0)
  • Contributor
  • ***
  • Posts: 276
I love the 6TCU but...
« Reply #7 on: July 02, 2004, 08:12:34 AM »
Thanks Harold. How about the 21" barrel? If its not to much trouble. I don't think H4895 is the preferred powder for this round. Its just what I have on hand. When it runs out I'll try something different

Offline rickyp

  • Trade Count: (19)
  • Senior Member
  • *****
  • Posts: 3052
  • Gender: Male
I love the 6TCU but...
« Reply #8 on: July 02, 2004, 03:00:57 PM »
what software are you using and how do we get it?

Offline patw

  • GBO Supporter
  • Trade Count: (3)
  • Avid Poster
  • *****
  • Posts: 212
I love the 6TCU but...
« Reply #9 on: July 04, 2004, 08:45:52 AM »
Sounded interesting, so I went looking and found it, but it is a little more than I want to spend:  http://www.neconos.com/details3.htm

Here is a place that seems to have different programs, but I have not had time to play with them yet:  http://www.snipercountry.com/ballistics/