6.5 Sherman Short Tactical (6.5SST, 6.5 SST)

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by MGN, Dec 15, 2017.


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  1. MGN

    MGN New Member

    Messages:
    4
    Joined:
    Nov 17, 2017
    Let me start by saying that this is my first true wildcat cartridge. I don’t count the 6x47 Lapua as you just run 6.5x47 Lapua through a sizer and shoot it. At the time of writing this I have 350 rounds of fire forming, load development, and torture testing down this barrel. This rifle is built on a Defiance Deviant short action with the mid-length port opening with a magnum boltface and a small firing pin, Bartlein barrel 1-8 twist 4 groove heavy Palma contour at 26”, and a McMillan A-5 adjustable stock. All work was done by AxisWorks LLC. All fire forming was done using Hodgdon H1000 and 147 ELD M. I wanted a rough idea of what was going to work, pressure wise, as I needed to fire form the brass and do load development in order to shoot a match within a week of receiving the rifle and I would be traveling for work the entire week. Charges were from 57.0 to 59.5 in .5 grain increments jumping the bullet .015 to the lands. The length, using Hornady Compatator 26 with a zeroed Mitutoyo calipers, was 2.210. Charges were weighed on a Satorius Entris scale and all groups were shot off of a bipod and rear bag.
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    Before I shoot for load development I like to do barrel break in just for my own peace of mind, but nothing too dramatic. I shoot one round and then I patch the barrel until clean, shoot two rounds then patch till clean, until I am up to ten rounds between cleanings. While doing this I use it as trigger squeeze practice. With this cartridge, it held the same hole for the first six shots at 100 yards.
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    For the next 49 shots I held in another area to see what it would do.
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    After this process was complete I felt everything was working well and I then loaded 5 rounds in the following charges and shot for groups using a Magnetospeed attached to the rifle. Velocities were as follows after brass was fire formed:

    57.0 – 2934
    57.5 – 2944
    58.0 – 2960
    58.5 – 2995
    59.5 – 3046

    Groups were 5 shots
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    As you can see this rifle, even with the exhaustion I was feeling from putting so many rounds down range in a very short period of time, shoots very well. The combination of the guys at AxisWorks and the cartridge design by Richard Sherman has been great. This cartridge has been really easy to work with. At this time I have settled on 53.5 gr of RL26 which is producing a velocity of 2981 at an elevation of 1230ft. At this elevation this bullet is supersonic to 1760. This means it will outpace a 300 Win Mag running 210 VLD Hunting Bullets that are going 2958.
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    I plan on playing with the Berger 130 AR Hybrid next in this rifle to see how it does.
     

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    Last edited: Dec 18, 2017
  2. elkaholic

    elkaholic Official LRH Sponsor

    Messages:
    7,916
    Joined:
    Dec 4, 2008
    Nice write up Michael! I hear your scores are pretty good too. Eric says you are making the competition nervous ☺️
     
  3. Bigstrap3

    Bigstrap3 Well-Known Member

    Messages:
    51
    Joined:
    Dec 14, 2010
    I am glad to here that your doing well with the SST. Eric helped me get my scope mounted and stock adjusted on mine this week. He is going to help me with the reloading right after the first of the year. I am anxious to get this rifle smoking , but life gets in the way some times Anyway enjoyed the recent PRS shoot up there at big sandy. Take care George B.