RimfireCentral.com Forums - View Single Post - 6.5/.264 Information Repository ... Work In-Progress
View Single Post
Old 01-18-2011, 09:52 AM
aom22's Avatar
US Air Force Disabled American Veteran Law Enforcement Officer NRA Member - Click Here To Join!

Join Date: 
Sep 2004
Fort Stockton, TX
TPC Rating: 
0% (0)
260 Remington Ackley Improved ... aka: 6.5mm-08 Ackley Improved

6.5mm-08 Ackley Improved
The 6.5mm-08 Ackley Improved (the model for today's .260 AI) is not a new cartridge.
The main reason to go with an improved version of the .260 Rem, is velocity.
For most people, the standard .260 reaches pressure limits with 140gr class bullets
_well before 2850 fps (with a 24"-26" barrel).
The .260 AI lets you drive those same bullets comfortably at 2930 fps or better.


Terry's Tactical Two-Sixty AI
Pushing 139 Lapuas, the .260 AI (an Ackleyized 6.5mm-08) delivers 6.5-284 ballistics
_in a more efficient, magazine-friendly cartridge.
Terry tells us "Ackleyizing the 260 really improves the round in every way you can imagine

--it gets you into that ideal velocity zone for the 139s or 142s, and the brass is very stable."
  • King of the Hill in Tactical Comps
  • 6.5mm-08 Ackley Improved--A Very Effective Long-Range Cartridge
  • 6.5mm-08 Ackley Improved
  • Procedures for Getting Best Results with Remington Brass
  • Parting Shot--Should the .260 AI Be Used by the Military?
Tilley's 260 Ackley Improved
Ron campaigned a 260 Ackley Improved.
This is based on a 260 Rem case, with the shoulder blown forward to 40 degrees.
Improving the 260 Rem case adds just enough extra capacity to get the 140gr-class bullets
_into the 2900+ fps velocity window where they seem to perform best.
Article posted on Precision Shooting Website about Ackley Improved cartridges


Would you go Ackley Improved?
... and anything under a 6% gain is considered pointless.
260 Remington Ackley 140 grain bullet 4.3%


260 Ackley Case Forming
This article explains how Chris fire-forms his brass to create 260 Ackley Improved cases.

He covers two forming methods--one with bullets and one without projectiles.
  • Brass Selection and Prep | Fire-Forming with and without Bullets
  • The Dreaded Doughnut--Where Does It Come From?
  • 260 Remington Brass Preparation and Traditional Fire-Forming
  • Alternate 'No-Bullet' Fire-Forming Using Inert Filler
260 Rem Neck Testing Results
TechShooter has been testing Remington 260 brass.
Chris reports: “I didn’t like the hassle of the inside neck-reaming the Lapua brass,
_as well as the possibility that this process could cause excessive runout.
TECH TIP: Form Improved Cases with Hydraulic Forming Die
Now, thanks to Hornady, shooters who need to “improve” their cases
_have a bonafied alternative to fire-forming.
Hornady’s custom shop offers a hydraulic case-forming kit
_that allows you to form cases just using water and a conventional reloading press.
W. Edwards Deming ... Quality: It is not enough to do-your-best;
you must know what-to-do, and ... then ... do-your-best.
Ever-Onward ... Through the Fog ---- Fort Stockton TX 79735

Last edited by aom22; 03-31-2013 at 06:23 PM.