Powder: CFE 223

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • VASCAR2
    Chieftain
    • Mar 2011
    • 6219

    #16
    I haven't seen the velocity out of my Shilen or Shaw 6.5 Grendels as others have posted online (my velocities are generally lower). I am at 350' above sea level which will make a difference if someone chrographs in thinner air. The variations in iindividual barrels can also affect velocity. I always view optical chronograph results as a general guide and not abosolutely accurate. The chronographs are very useful for load development and I'm not selling mine but I'd still like to experiment with the Labradar.

    Comment

    • LRRPF52
      Super Moderator
      • Sep 2014
      • 8569

      #17
      Originally posted by Boostmeister View Post
      The more I read, the more confused I get. A 16" tube with a charge of 31.4 gr is producing the same velocity that I am seeing with 31.8 gr in a 20" tube. Hopefully I will be able to get back out to the range tomorrow with some rounds at 31.8 (to repeat my finishing load from the last test), 32.0, 32.2, 32.4, and 32.6 gr. I know those are small increments, but I am cautious by nature,....well sort of. I will shoot the loads over my Oehler 35P at a distance of 10 feet and keep a watchful eye on the primers and brass. Thanks for all the feedback guys.
      Barrels vary from one to the next. They can build pressure differently based on the chamber dimensions, rate of twist (my 16" AA has 1/7.5" twist for example), and close attention to details with the actual groove depth, rifling shape, etc.

      VASCAR also makes a good point about optical sensor technology. I used a Chrony Master placed 15ft from the muzzle, measured with measuring tape. My main goal was to see where the pressure trend departed from being predictable. Even if the chronograph is giving slightly exaggerated numbers, it will still show speeds related to each other in the same conditions.

      That's our real pressure sign. Coincidentally, when I did that ladder, I saw slight cratering in the higher loads that I would never mass-produce. I was also using 2.275" COL without being jammed into the rifling, but clearly closer than 2.245-2.260" COL.
      NRA Basic, Pistol, Rifle, Shotgun, RSO

      CCW, CQM, DM, Long Range Rifle Instructor

      6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

      www.AR15buildbox.com

      Comment

      • Roe
        Warrior
        • Dec 2014
        • 190

        #18
        Originally posted by LRRPF52 View Post

        [...] My main goal was to see where the pressure trend departed from being predictable. Even if the chronograph is giving slightly exaggerated numbers, it will still show speeds related to each other in the same conditions.

        That's our real pressure sign. Coincidentally, when I did that ladder, I saw slight cratering in the higher loads that I would never mass-produce.
        Please advise if I have understood this correctly.

        If I do powder increase 2-4-6-8 I should see a V0 increase 2-4-6-8.
        If I do a powder increase 2-4-6-8 and suddenly see Vo increase 2-4-6-12, then I hit a pressure spike on my last load?

        (the numbers just illustrate a pattern, they have no reference to an actual load or V0)

        Comment

        • LRRPF52
          Super Moderator
          • Sep 2014
          • 8569

          #19
          Originally posted by Roe View Post
          Please advise if I have understood this correctly.

          If I do powder increase 2-4-6-8 I should see a V0 increase 2-4-6-8.
          If I do a powder increase 2-4-6-8 and suddenly see Vo increase 2-4-6-12, then I hit a pressure spike on my last load?

          (the numbers just illustrate a pattern, they have no reference to an actual load or V0)
          Yes. That is the main thing I look at when doing pressure-testing for a particular load and rifle after studying as much of the available load data as possible. I then look at ES obviously for accuracy, and look for accuracy nodes that are not so close to the edge of wide Extreme Spread.

          When I did the pressure ladder with CFE, I saw a departure from the trendline that about coincided with slight cratering.

          31.1gr 2489fps
          31.4gr 2520fps + 31fps
          31.7gr 2532fps + 12fps

          32.0gr 2553fps + 21fps I personally would advise not to load past this point in the AR15. This was just done to see where the trend line would depart.
          32.3gr 2572fps + 19fps
          32.6gr 2598fps + 26fps
          32.9gr 2612fps + 14fps
          33.2gr 2640fps + 28fps Slight Cratering
          33.5gr 2698fps + 58fps Slight Cratering
          33.8gr Cease fire

          I didn't shoot because I saw a 58fps jump and cratering. 58fps jump in the pressure appeared to be a clear departure from the trend line, since I wasn't seeing anything over 31fps increase per .3gr of charge weight. Many people who look at primers only would think that the 33.2gr load is fine, but pressures there are probably in the ~57,000psi range.
          Last edited by LRRPF52; 06-10-2015, 07:10 PM.
          NRA Basic, Pistol, Rifle, Shotgun, RSO

          CCW, CQM, DM, Long Range Rifle Instructor

          6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

          www.AR15buildbox.com

          Comment

          • keystone183
            Warrior
            • Mar 2013
            • 590

            #20
            Originally posted by LRRPF52 View Post

            31.1gr 2489fps
            31.4gr 2520fps + 31fps
            31.7gr 2532fps + 12fps

            32.0gr 2553fps + 21fps I personally would advise not to load past this point in the AR15. This was just done to see where the trend line would depart.
            32.3gr 2572fps + 19fps
            32.6gr 2598fps + 26fps
            32.9gr 2612fps + 14fps
            33.2gr 2640fps + 28fps Slight Cratering
            33.5gr 2698fps + 58fps Slight Cratering
            33.8gr Cease fire
            Curious as to why you draw the line at 32.0gr, when the trend seems to hold till 33.2gr?

            Comment

            • LRRPF52
              Super Moderator
              • Sep 2014
              • 8569

              #21
              Originally posted by keystone183 View Post
              Curious as to why you draw the line at 32.0gr, when the trend seems to hold till 33.2gr?
              Pressure and available load data. Grendel Maximum Average Pressure needs to be taken into account in the AR15. I personally don't want to load higher than 50,000psi for mass-produced loads.

              In a bolt gun, sure. No problem if you want to make a throat scorcher.

              That said, I have a .510 BC pill going 2550fps from a 16" carbine, with half the recoil of a .308, and it all fits in the AR15 receiver set. The Hornady factory 123gr A-MAX clocks 2460fps for me, and is still supersonic out to 1318yds at the lowest place in Utah I can find in my region. This is why I like the 31.2gr load so much, at 2500fps. Pressure is under 47,000psi, supersonic reach is beyond what I normally would ever shoot at, accuracy is 1 MOA out of a Shaw barrel, the gun just runs, and is easy and fun to shoot.
              NRA Basic, Pistol, Rifle, Shotgun, RSO

              CCW, CQM, DM, Long Range Rifle Instructor

              6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

              www.AR15buildbox.com

              Comment

              • Boostmeister
                Bloodstained
                • Sep 2014
                • 63

                #22
                Just returned from the range and wanted to follow up with the results. I loaded four rounds each with CFE 223 under 123gr Lapua Scenar bullets. I started with 31.8 gr to verify that my previous velocity at that load was repeated. I then loaded 32.0 gr, 32.2 gr, 32.4 gr, and 32.6 gr.

                Conditions were:
                Temp 64F & pressure 29.97
                All loads were seated to 2.25" COAL

                As a baseline, I shot five rounds of 28.5 gr of 8208 XBR which had previously resulted in just over 2500 fps. Results were:

                2525
                2524
                2520
                2516
                2517
                Average = 2517 fps

                I then fired five rounds of factory Hornady 123 gr SST ammo with the following results:

                2476
                2440
                2476
                2485
                2460
                Average = 2460 fps

                I then fired each increment of CFE 223 in round robin fashion to eliminate barrel heating or other anomalies. Results as follows:

                31.8 = Avg 2514 fps
                32.0 = Avg 2519 fps Vel Inc 5 fps
                32.2 = Avg 2534 fps Vel Inc 15 fps
                32.4 = Avg 2548 fps Vel Inc 15 fps
                32.6 = Avg 2567 fps Vel Inc 19 fps

                Primers all looked good with no unusual flow or cratering. Tried to post a picture of all primers, but I guess I will have to play around trying to figure out the process. While I saw no outward signs of pressure or velocity spikes, I was reluctant to go any higher. Not having much experience with CFE 223, I have no idea how it plays at higher ambient temperatures. I know that 28.5 gr of 8208 XBR is already a compressed load. Looking at how much a case was filled with the CFE 223, it was obvious that this was a very compressed load. 28.5 gr of 8208 XBR is a very accurate load in my firearm. 31.8 - 32.0 gr of CFE 223 results in the same velocity, so I think I will limit CFE to that as an upper limit. While 28.5 gr of 8208 XBR has the same velocity as 32.0 gr of CFE 223, point of impact for the CFE load is roughly one inch higher and right of POA from 8208 XBR. I suspect that the burn rate changes the barrel harmonic even though the velocity is the same. Time for more testing as there were two accuracy nodes (one around 30.3 and one at 31.8). I may spend some additional effort on the 30.3 gr node. Don't you just hate it when this stuff keeps driving you back to the range?
                Last edited by Boostmeister; 06-13-2015, 04:54 PM.

                Comment

                • rball
                  Unwashed
                  • Nov 2014
                  • 16

                  #23
                  This morning, I conducted the following tests using a Magnetospeed chrony.
                  Temperature: 62-64 F
                  CFE 223, OAL 2.250", Hornady Brass, Prvi Partisan 120g HPBT
                  20" Shilen bbl.
                  Primers: Winchester SR, CCI SR (400)

                  30.0 gr: 2389 fps 30.0 gr: 2389 fps
                  30.2 gr: 2412 fps 30.2 gr: 2413 fps
                  30.4 gr: 2433 fps 30.4 gr: 2424 fps
                  30.6 gr: 2469 fps 30.6 gr: 2456 fps
                  30.8 gr: 2474 fps 30.8 gr: 2460 fps

                  I didn't see any signs of pressure with any of these loads.

                  Comment

                  • GSPHunter
                    Warrior
                    • Jun 2014
                    • 106

                    #24
                    Hi Boostmeister,
                    I get very similar numbers to yours with my 20" J&T. What is the water capacity of your fireformed brass? The measured case capacity for my rifle is 37.4 gn of water with once fired Hornady brass. Like you, I've run up to 32.5 with the 123sst's, and in all honesty, felt like it could keep going, but also, like you decided to keep below 32.0, and get good accuracy with 31.8.

                    The funny thing for me was when I started to shoot the 140Sierra GK's, I didn't start seeing the velocities getting erratic until 31.0gn, and was getting 2480 fps. Again, discretion being the better part of valor, I found good accuracy with 29.2gn and still getting 2360Fps sd8.

                    I'm pretty sure either of these loads would be way too hot in my 14.5" sabre defense upper with a fireformed case capacity of 35.6gn of water.

                    Good luck!

                    Comment

                    • Boostmeister
                      Bloodstained
                      • Sep 2014
                      • 63

                      #25
                      GSP - I admit that I have not measured the fire formed case capacity in either my Lapua, AA (same thing) or Hornady brass. I was just a bit frustrated that the velocity with CFE wasn't higher. I had heard for some time that CFE produced more velocity than 8208 XBR, but in my testing there was almost no difference. At 32.6gr of CFE, I'm sure that I was above SAAMI limits even though there was no outward signs of pressure. As you stated, "discretion being the better part of valor" I have decided to back off and fine tune. If I get a chance today, I stuff a spent primer upside down into a fire formed case and weigh the water capacity.

                      Comment

                      • rickOshay
                        Warrior
                        • Apr 2012
                        • 784

                        #26
                        Originally posted by rball View Post
                        This morning, I conducted the following tests using a Magnetospeed chrony.
                        Thanks for the update!

                        Comment

                        • Boostmeister
                          Bloodstained
                          • Sep 2014
                          • 63

                          #27
                          GSP - Not sure of my test method, but I took five fire formed cases and seated a spent primer upside down. I weighed each case, then filled with water, and weighed again (on an RCBS Chargemaster) to determine the difference. Case capacity ran between 36.2 (two pieces of brass) and 36.3 gr (two pieces of brass) with the remaining piece at 37.2 gr. After I measured these cases, it dawned on me that some had previously been trimmed as I have about 15 loadings on some of this brass. I went back out and measured the OAL of the cases at 1.511, 1.512, 1.512 (2), and 1.515. Looks like I was a bit aggressive on my trimming. I think that in order to provide any meaningful data, I would need to trim some longer fire formed cases to minimum spec and repeat the test. Doesn't make much sense to measure case capacity when the OAL differs.

                          Comment

                          • GSPHunter
                            Warrior
                            • Jun 2014
                            • 106

                            #28
                            That's interesting that you thought to put the primer in upside down...that idea never occurred to me, I've always just took the brass after firing, weighed it empty, added water, then weighed it again. The hardest part to me has always been getting the water just even with the top of the case, waters surface tension and ability to creep is amazing! I bet your chamber is a little bigger than the minimun spec, and lets face it, shilen makes a pretty good barrel. I have a .338 win mag that used to shoot factory ammo slower than book, and would start cratering primers at max book loads with the factory barrel on it, also shooting slower than book....after installing a shilen select barrel that was chambered to saami minimums, I can't put enough 4350 in the case to see the pressure on the primers with 225gn AB's well over 3000 fps, and it shoots both factory and reloads about 50FPS faster than advertised.
                            Last edited by GSPHunter; 07-03-2015, 06:07 PM. Reason: redundant word usage

                            Comment

                            • Boostmeister
                              Bloodstained
                              • Sep 2014
                              • 63

                              #29
                              Dropping the hammer on a .338 Win Mag pumping out 225 gr bullets at 3K fps has got to let you know that you have something in your hand and against your shoulder. Not unlike my deer rifle. Ruger Super Redhawk chambered in 454 Casull pushing out 300 gr bullets at 1750 fps. Makes for a neat fireball at dusk.

                              Comment

                              • lwminton
                                Warrior
                                • Nov 2014
                                • 143

                                #30
                                There is considerable (exclusive) emphasis here with velocity. Is velocity predictive of accuracy? Or could slower loads be more accurate? Does velocity defeat cross wind?

                                Comment

                                Working...
                                X