6.5 cartridge for the AR-15.

This is a discussion on 6.5 cartridge for the AR-15. within the Cartridges & Calibers forums, part of the Sniping Related category; After much thought, gnashing of teeth and discussion, here's a possible answer to the 6.5mm AR-15 problem. JD Jones and SSK Industries produces a round ...

Page 1 of 6 123 ... LastLast
Results 1 to 10 of 55
  1. #1
    Senior Member madgunsmith's Avatar
    Join Date
    Oct 2004
    Posts
    1,797

    6.5 cartridge for the AR-15.

    After much thought, gnashing of teeth and discussion, here's a possible answer to the 6.5mm AR-15 problem.

    JD Jones and SSK Industries produces a round called the 6.5 mm Whisper. This round is a necked up version of the .221 Fireball.

    The 6.5 mm Whisper has a case that is 1.36" long. The maximum magazine length of the .223 is about 2.25" long. Thus the 6.5mm Whisper has lots of room for long 120 grain 6.5mm bullets. And said loaded rounds would easily fit a standard AR-15 magazine.

    According to Cartridges of the World, in a 6.5 Whisper, 19.0 grains of A-1680 powder will push a 120 grain Nosler ballistic tip at 2150 fps from a 10' barrel. Now from a 20" barrel, we'd have 2400 fps easily.

    Now 6.5 Whisper brass could easily be formed. You would run .223 Remington brass through a 6.5 Whisper resizing die and then you would trim the case to length. You could use a custom made trim die to trim the cases. Fireforming would not be needed to form the 6.5 Whisper.

    Now what about the proprietory cartridge problem: I'm looking at the 6.5mm Whisper picture and it seems that the cartridge shoulder is about 35 degrees or so. It would not be too difficult to design a different version of the Whisper using a slightly different case shoulder. I would like to use a shoulder of around 30 degrees or so.

    And a slightly different version of the 6.5 Whisper would be a different cartridge--one that could be called the 6.5 SC.

    RCBS makes custom dies and it would not be too difficult to make a reamer. In fact the same reamer used to form the resizing die could also be used to ream the chamber.

    And such a 6.5mm round would use standard AR-15 bolts and magazines. I will contact RCBS and see what it would cost to produce the dies for the 6.5SC.

  2. #2
    Senior Member Recoil's Avatar
    Join Date
    Apr 2005
    Posts
    3,851
    Now we're talking...5.56 brass, heavy bullets, mid-2,000s, stock AR-15 with a different barrel. What's not to love?

    Heck mad, call it the 6.5 MG after yourself. It was your idea!

  3. #3
    Senior Member madgunsmith's Avatar
    Join Date
    Oct 2004
    Posts
    1,797
    It is JD Jones' idea. But we have to change his idea slightly and give it another name.

    The downside of the 6.5 SC is that it needs a 20 inch barrel. The case does not have a lot of capacity and we have to be careful in powder selection.

    And right away, I can tell you what the very best bullet would be. The Sierra 120 grain Pro Hunter is the shortest 120 grain 6,5mm bullet and this bullet would not protrude too deeply into the case.

    A 120 grain 6.5 bullet has the same sectional density as a 165 grain .30 caliber bullet. A 120 grain 6.5mm has a similar ballistics coefficient to a 165 grain .30 cal bullet.

    Nobody would sneeze at a 165 grain .30 caliber bullet moving at 2400 fps.

  4. #4
    Senior Member Recoil's Avatar
    Join Date
    Apr 2005
    Posts
    3,851
    How about a 100 and 110 grain bullet? I'd be shooting these out of 16" barrels, so I need to squeeze every ounce of velocity out that I can.

    Does anyone make straight walled (unformed) .223 brass?

    ETA: What about fitting a light .308? The case is wide enough, with room to spare. I'd think the expansion might crack the neck, but then again, the brass was straight to begin with before it was formed, so...?

  5. #5
    Senior Member madgunsmith's Avatar
    Join Date
    Oct 2004
    Posts
    1,797
    If you wanted a .30 caliber AR-15 round, you should build a .300 Fireball.

    This round is also based on the .221 case. The .300 Fireball can be made by running a .223 Remington case through a .300 Fireball resizing die. The you trim the round to length. Fire-forming is not necessary.

    .300 Fireball barrels for the AR-15 are available from ar15barrels.com.

    The .300 Fireball would also use ordinary AR-15 bolts and magazines.

    The .300 Fireball would give you about 2300 fps with a 120 grain bullet.

    With a 16" bullet, you would probably get about 2400 or 2500 fps with a 100 grain Nosler Ballistic tip with the 6.5 SC.

  6. #6
    Senior Member Recoil's Avatar
    Join Date
    Apr 2005
    Posts
    3,851
    The .300 Fireball is also known as the .300 Whisper, correct?

    ETA: Nevermind, I found the answer to my question.

    I never realized you could load the Whisper at high speeds...I thought it was sub-sonic only, as that's all anyone talks about. ops:

  7. #7
    Senior Member jeffdorr's Avatar
    Join Date
    Apr 2006
    Location
    Watertown,N.Y.
    Posts
    5,046
    I'm with Mad on the 6.5mm round,and with a 30 degree shoulder,it should load and extract easier, a handy thing for a semi-auto.And 6.5 SC has a nice ring to it.

    Jeff
    Jeff passed away on July 17th, 2009, he will be GREATLY missed by everyone here at Sniper Central. Video Thread

    " We cannot direct the wind,but we can adjust the sails." -Bertha Calloway

    www.second-amendment.org

  8. #8
    Senior Member Recoil's Avatar
    Join Date
    Apr 2005
    Posts
    3,851
    I'm still for the 6.5 round myself...I'm just equally interested in the .308 bullet because I'm already invested in that caliber.

    On the topic of potential copyright infringements, the only thing that's copyrighted (presumably anyway) is the name "6.5 MPC." When SSK came out with the .300 Whisper, people simply got around that by calling it either the ".300 Fireball" or the ".300-221." Regardless of the name, it's still the same cartridge and is being sold by all sorts of people.

    I suspect the same could be done with the 6.5 MPC. Just use the same form factor and call it something else...Like 6.5 SC.

    Not that I don't think a new cartridge with a 30 degree shoulder angle is a bad thing, I just think the legalities are being over-thought a bit. As long as the round is for your own personal use and you're not going to sell it, it doesn't matter what you do, what you call it, or anything else; you're still free to have dies made up and barrels chambered for the round.

  9. #9
    Sponsors mele's Avatar
    Join Date
    Apr 2004
    Location
    Montana
    Posts
    9,846
    Very interesting topic gents. I have often thought about a 6.5 in a .223 case to be used in the AR. Let us know what you find out Mad about the RCBS dies and the reamers. Perhaps AR15barrels.com would be willing to do the barrels for us.

    MEL

  10. #10
    Senior Member jeffdorr's Avatar
    Join Date
    Apr 2006
    Location
    Watertown,N.Y.
    Posts
    5,046
    Pacific Tool And Gauge says on their site that they can grind a carbide reamer for $60 an hour.They make a lot of reamers from their website.I'll give them a call and see what it would cost to make a custom reamer.

    www.pacifictoolandgauge.com

    Jeff
    Jeff passed away on July 17th, 2009, he will be GREATLY missed by everyone here at Sniper Central. Video Thread

    " We cannot direct the wind,but we can adjust the sails." -Bertha Calloway

    www.second-amendment.org

Page 1 of 6 123 ... LastLast

Ads

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Similar Threads

  1. New .50 cal cartridge
    By madgunsmith in forum Cartridges & Calibers
    Replies: 18
    Last Post: 08-14-2012, 06:46 PM
  2. .224 AR Cartridge
    By monteboy84 in forum Cartridges & Calibers
    Replies: 0
    Last Post: 11-12-2009, 02:52 PM
  3. Cartridge stability
    By Steelghost in forum SOP
    Replies: 11
    Last Post: 05-13-2008, 03:35 PM
  4. New Cartridge, 6.5 Creedmoor
    By tylerw02 in forum Cartridges & Calibers
    Replies: 5
    Last Post: 11-10-2007, 05:15 AM
  5. Cartridge seating
    By clinker in forum Cartridges & Calibers
    Replies: 13
    Last Post: 10-24-2007, 01:52 PM

Search tags for this page

6.5 mm whisper
,

6.5 whisper

,

6.5 whisper ballistics

,

6.5 whisper cartridge

,
6.5-221 fireball
,
6.5-221 whisper
,

6.5mm whisper

,
ar 6.5 cartridges
Click on a term to search for related topics.