6mm AR turbo 40, 6mm fat rat, 6mm grinch

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • hydrotech
    Warrior
    • Sep 2014
    • 115

    6mm AR turbo 40, 6mm fat rat, 6mm grinch

    one case, one caliber, so many options....anyone have a critique of the differenes between these 3? all pretty similar i am guessing. I have a rifle length .223 AR i have been thinking bout switching it over to 6mm....so many choices. 6mm AR, .243LBC, etc...I think i'd rather go for getting every bit of powder i can though and go with an A.I. type of round
  • 204 AR
    Warrior
    • Sep 2015
    • 239

    #2
    I have the LBC and just ordered a second, ARperformance 6mm Predator, which I'm led to believe is the same thing. There were some Fat Rats in the classifieds here that look pretty tempting.

    Comment

    • rwh
      Warrior
      • Jun 2014
      • 188

      #3
      I have two rifles, a 6BR in an Eliseo R5 chassis with a 27 inch barrel which I love dearly, and a SAAMI grendel space gun with a 28 inch barrel which is growing on me. My 6BR load is a 108gr Berger BT at 2780 fps. My grendel load is a 130 gr Berger AR hybrid at 2560 fps. My grendel load fits in a magazine. The ballistics calculator on the Berger web site shows about 5 inches more drift at 1000 yards in a 10mph cross wind with the grendel compared to the 6BR. The 6BR delivers better accuracy but both of these rifles shoot sub 0.5 MOA. I would expect the performance from a 6mm AR Turbo 40 or a FatRat to be similar to the 6BR. I've seen claims of higher velocities and I don't dispute those claims. I just don't expect to see a much higher velocity out of one of my barrels. Based on what I've seen the grendel is competitive with these wildcats and you don't have to fire form your brass. Go grendel.
      Last edited by rwh; 04-21-2017, 09:43 PM.

      Comment

      • SG4247
        Warrior
        • Aug 2013
        • 497

        #4
        I really dont like a ton of reloading work, so the standard 6AR is my pick. (Really dont like reloading at all)

        I can size the 6.5 Grendel neck to 6mm in one shot, no fireforming required.

        The others are definitely faster, and very similar to themselves, but not enough difference for what I do - to matter.
        NRA F-Class Mid Range High Master

        Comment

        • SG4247
          Warrior
          • Aug 2013
          • 497

          #5
          Look at this way:

          Built it as a 6AR, by the time you master loading for it, and shooting it youll be having so much fun that it will be shot out before you know it.

          Then at that point you can decide if you have the desire to upgrade the barrel to the 40 Degree turbo.
          NRA F-Class Mid Range High Master

          Comment

          • hydrotech
            Warrior
            • Sep 2014
            • 115

            #6
            I have 3 AR's, one of which is a grendel i have had about 3 years. I like it. I was just thinking about turning one of my 5.56's into a 6mm.....so many 6mm's now available based on a grendel case....I can't imagine they are that different in performance...

            Comment

            • Blazin
              Bloodstained
              • Sep 2013
              • 68

              #7
              All good points here. I'm a shooting match competitor and not a hunter, and always loved the 243 Win due to light recoil and great long range ballistics. My 243 load (out of bolt gun) was a Sierra 107 at 2870 fps. I own a DPMS LR-243 (accurate gun), but I always wanted to have 243 Win ballistics out of a nice & handy small frame AR. To that end I recently built a 6mm Grendel upper and bought a 6mm Fat Rat upper and plan to test them side by side; I don't think they'll replicate my 243 Win ballistics but I'll be happy if I get close, especially given I'll only be burning about 30 grains of powder. My 6.5 Grendel load is a 123 bullet at 2529 fps, and it's a great gun, but I'd rather have a 0.5 BC bullet going 2700+ fps.

              Comment

              • Rickc
                Warrior
                • Aug 2016
                • 311

                #8
                Originally posted by Blazin View Post
                All good points here. I'm a shooting match competitor and not a hunter, and always loved the 243 Win due to light recoil and great long range ballistics. My 243 load (out of bolt gun) was a Sierra 107 at 2870 fps. I own a DPMS LR-243 (accurate gun), but I always wanted to have 243 Win ballistics out of a nice & handy small frame AR. To that end I recently built a 6mm Grendel upper and bought a 6mm Fat Rat upper and plan to test them side by side; I don't think they'll replicate my 243 Win ballistics but I'll be happy if I get close, especially given I'll only be burning about 30 grains of powder. My 6.5 Grendel load is a 123 bullet at 2529 fps, and it's a great gun, but I'd rather have a 0.5 BC bullet going 2700+ fps.
                I have one of Robert Whitley's 6mm AR turbo 40 improved. With 28.6 gr. of H4895 it is pushing the 105 Lapua Senar L at 2850 on my magnitospeed.

                Accurate too!

                [IMG][/IMG]

                Comment

                • Blazin
                  Bloodstained
                  • Sep 2013
                  • 68

                  #9
                  Rickc: that is inspiring!

                  Comment

                  • rwh
                    Warrior
                    • Jun 2014
                    • 188

                    #10
                    The berger ballistics calculator shows the 105 scenar L at 2850 fps has 97.6 inches of drift at 1000 yards compared to only 90 inches of drift for the 130 AR hybrid at 2560 fps. I might have some small group pictures somewhere, but here's a 20 shot group from a 300 yard reduced slow fire prone course I shot with my grendel this weekend. Wind was 10-15 from 10 o'clock. The grendel can still keep up with the wildcats.
                    Attached Files

                    Comment

                    • Blazin
                      Bloodstained
                      • Sep 2013
                      • 68

                      #11
                      Originally posted by rwh View Post
                      The berger ballistics calculator shows the 105 scenar L at 2850 fps has 97.6 inches of drift at 1000 yards compared to only 90 inches of drift for the 130 AR hybrid at 2560 fps. I might have some small group pictures somewhere, but here's a 20 shot group from a 300 yard reduced slow fire prone course I shot with my grendel this weekend. Wind was 10-15 from 10 o'clock. The grendel can still keep up with the wildcats.
                      I'm unsure what inputs you used for drift stats so I can't replicate your #'s. But sure, you chose a higher BC bullet in the 6.5 Grendel; try it with a 6mm Sierra 110 grain bullet (.617 BC) at 2800 fps and see what happens. Whatever the case, to each his own. My shooting games are time based so the more hits you can make within the allotted time the better, so less recoil with good ballistics helps. Plus with less recoil it's easier to spot your hits (or misses to readjust).

                      Comment

                      • rwh
                        Warrior
                        • Jun 2014
                        • 188

                        #12
                        I used the G1 BC of 0.472 from http://www.lapua.com/en/reloading-co...llets/scenar-l with a muzzle velocity of 2850 and a 10 mph cross wind in the calculator at http://bergerbullets.com/ballistics/ to get those numbers. Using the berger 105 hybrid throws the advantage clearly to the 6mm. The berger 105 hybrid will be my go to bullet for 6mm once I use up my stock of 108 BT bullets. I admit I am one of those grendel fanboys. I like to point out that the standard grendel cartridge can come close to the performance of the wildcats with the right bullet.

                        Comment

                        • Blazin
                          Bloodstained
                          • Sep 2013
                          • 68

                          #13
                          Originally posted by rwh View Post
                          I used the G1 BC of 0.472 from http://www.lapua.com/en/reloading-co...llets/scenar-l with a muzzle velocity of 2850 and a 10 mph cross wind in the calculator at http://bergerbullets.com/ballistics/ to get those numbers. Using the berger 105 hybrid throws the advantage clearly to the 6mm. The berger 105 hybrid will be my go to bullet for 6mm once I use up my stock of 108 BT bullets. I admit I am one of those grendel fanboys. I like to point out that the standard grendel cartridge can come close to the performance of the wildcats with the right bullet.
                          Don't disagree with you one bit. I've been a fanboy of the 6mm since the 90's when I read of Tubb winning the LR championship with a 243. Plus I used to read about all the benchrest guys with their 6mm's. But a 6.5 (in the form of a 260 Rem) is typically what I compete with, for right now anyway.

                          Comment

                          • SG4247
                            Warrior
                            • Aug 2013
                            • 497

                            #14
                            Originally posted by rwh View Post
                            The berger ballistics calculator shows the 105 scenar L at 2850 fps has 97.6 inches of drift at 1000 yards compared to only 90 inches of drift for the 130 AR hybrid at 2560 fps. I might have some small group pictures somewhere, but here's a 20 shot group from a 300 yard reduced slow fire prone course I shot with my grendel this weekend. Wind was 10-15 from 10 o'clock. The grendel can still keep up with the wildcats.

                            Dont be so sure the std Grendel can hang with the 6mm AR wildcats.

                            These guys do some "not in the book stuff", and get velocities that are crazy fast.

                            Just FYI, for my 6mm ARs here, most guys use the 105 Berger BTT or the 105 Berger Hybrid. No reason to use Scenars when they arent cheap, and generally dont perform as well. I have the 115 DTAC and the 105 Barts as well. Both have very high BCs for 6mm bullets.
                            NRA F-Class Mid Range High Master

                            Comment

                            • Blazin
                              Bloodstained
                              • Sep 2013
                              • 68

                              #15
                              If anyone has load data for 6mm Fat Rat using Sierra 107's and 8208 I'd appreciate it.

                              Comment

                              Working...
                              X