IMR 8208 XBR - question- properties

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  • IMR 8208 XBR - question- properties

    WELLLL....
    decide to go to several stores in the Little Rock area and score some Vihtavuori N133 and N322 Powder. No Go however IMR 8208 was on hand and I do want to try it as well the primary purpose was temp stability is better than TAC, AA2520, most everything I have on my shelf.
    Prior to June when I was stationed in the northen panhandle of WV these powders worked well. Now that I am back in the Southwest I am relooking my powder selection. From what everyone is saying I should like the IMR however the question is the temp stability of IMR as good as Vihtavuori?
  • bwaites
    Moderator
    • Mar 2011
    • 4445

    #2
    8208 is one of the Extreme family, and most of us have found it very stable. I shot the same loads I developed last spring in August in near 100 degree temps without any discernible difference in pressure or performance.

    Comment

    • sneaky one
      Chieftain
      • Mar 2011
      • 3077

      #3
      Bill, on the 8208... I found a lb. this wknd., must be the hot thing, as no-store has it in stock , (sold out) near me. 3 million people here, and they must read this forum, LOL. 2 guys on the forum state it's also , almost piston gun clean,, I'll find out after sat. Really like the idea of temp. stability too. Did you try it with 100 gr. bullets ? Any luck ? It sure fills a case= almost all are crunch- compressed a bit,,, yet after bullet loading I can still hear the shake rattle inside= nice. X-term is still hard to beat..... we'll see what's up with 8208. Oh,,, still in it for the 3 k ? Dare? It's just for fun.

      Comment


      • #4
        Humm I do have those 100gr sierria's Varmit.
        I guess the reason for difficult to find in some regions is the powder is supposed to be the cat meow for .308

        after posting this I went and loaded 40 rounds.
        AA Brass Virgin, CCI450, 100gr Sierria Varmit over 29.3grs IMR 8208 XBR for 20 rounds.
        AA Brass Virgin CCI450, 120 SMK over 27.4grs IMR 8208 XBR for 20 rounds.
        What really took me by surprise is how well it (IMR 8208 XBR) meters out of my old Lyman 55. The throw was consistant, over a spread of 20 no charge deviated more than a tenth.

        Let's see how they (the load) do with that ER Shaw 24" AA chamber I have. Maybe some of the recommendations that Warped, LR1955 and other have mentioned will produce closer to 1 MOA, than the MOA of a Barn I have been getting, let's hope. Once I get to fire I post results here to keep the clutter down on the posting.

        On a side note: yeah sneaky ya know I wish ya the best on the 3K.
        Last edited by Guest; 10-11-2011, 02:38 PM. Reason: loaded some after posting

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        • #5
          Reloading for my son's Grendel for the first time (coming home from college for the weekend to shoot with the old man ), just got a couple pounds of the 8208 and a few boxes of 123 AMax's...
          If anyone has tried that combination before, sure would like to hear about it!

          Comment


          • #6
            Originally posted by tobnpr View Post
            Reloading for my son's Grendel for the first time (coming home from college for the weekend to shoot with the old man ), just got a couple pounds of the 8208 and a few boxes of 123 AMax's...
            If anyone has tried that combination before, sure would like to hear about it!
            In my 24 inch Grendel, it shot crazy accurate with 29gr and the Amax123 seated to 2.29. I have a range report up here in the reloading section with spreadsheet and target images. Search on the term "absolution".

            Hoot

            Comment


            • #7
              8208 with the A Max was most accurate out of my 24" Cut rifle Satern barrel at 26.0gr. For me, no better shot than I am, it seemed to be a very narrow accuracy range. .2gr more & .2gr less were not nearly as accurate. This could very well have been operator error but still, those were my results. My suggestion is to try a number of loads, + & - in .2gr or maybe even .1gr up & down the scale a little bit after you start closing in on the load that works best with your gun. In my rifle, 28.5 was showing pressure signs so I quit there. I was loaded a little bit shorter than Hoot, 2.250 give or take. At 200yds, I shot a 1.94" 5 shot group with the 26.0gr load.
              In my load testing, & again, I'm not the most experienced or accurate shooter, I had a little better results with the Leverevolution powder. Again at 200yds, I shot a 1.64" group with it at 29.2gr. The groups with Leverevolution didn't open up quite as fast with lighter & heavier charges but they did open up & pretty quickly. IOW, it seems to me the A Max bullet can be loaded very accurately but in a very narrow powder charge range.
              MLM

              Comment

              • RangerRick

                #8
                Originally posted by Hoot View Post
                In my 24 inch Grendel, it shot crazy accurate with 29gr and the Amax123 seated to 2.29. I have a range report up here in the reloading section with spreadsheet and target images. Search on the term "absolution".

                Hoot
                Can you get them to feed out of a full mag at 2.29? Or do you shoot ne or two at a time?

                RR

                Comment

                • LR1955
                  Super Moderator
                  • Mar 2011
                  • 3355

                  #9
                  Originally posted by sgt_murf View Post
                  Humm I do have those 100gr sierria's Varmit.
                  I guess the reason for difficult to find in some regions is the powder is supposed to be the cat meow for .308

                  after posting this I went and loaded 40 rounds.
                  AA Brass Virgin, CCI450, 100gr Sierria Varmit over 29.3grs IMR 8208 XBR for 20 rounds.
                  AA Brass Virgin CCI450, 120 SMK over 27.4grs IMR 8208 XBR for 20 rounds.
                  What really took me by surprise is how well it (IMR 8208 XBR) meters out of my old Lyman 55. The throw was consistant, over a spread of 20 no charge deviated more than a tenth.

                  Let's see how they (the load) do with that ER Shaw 24" AA chamber I have. Maybe some of the recommendations that Warped, LR1955 and other have mentioned will produce closer to 1 MOA, than the MOA of a Barn I have been getting, let's hope. Once I get to fire I post results here to keep the clutter down on the posting.

                  On a side note: yeah sneaky ya know I wish ya the best on the 3K.

                  Murf:

                  Just load some and toss ten shots into a zip lock bag and then into a MRE heater for about fifteen minutes and another ten into a ice chest of dry ice for ten or fifteen minutes. Use a cheapo Radio Shack indoor / outdoor thermometer with a wire sensor to measure their temperatures. Pluck them out and shoot them over a chronograph. I do this periodically as part of a POI when we get into environmental effects.

                  I do believe the commercial ball powders are extremely temp sensitive. All of them. The military ball powders, not very temp sensitive, but you will still see that at the extremes you have a much higher extreme spread in velocities. The question is, does it really matter in practical terms?

                  LR1955

                  Comment


                  • #10
                    Originally posted by LR1955 View Post
                    Murf:

                    Just load some and toss ten shots into a zip lock bag and then into a MRE heater for about fifteen minutes and another ten into a ice chest of dry ice for ten or fifteen minutes. Use a cheapo Radio Shack indoor / outdoor thermometer with a wire sensor to measure their temperatures. Pluck them out and shoot them over a chronograph. I do this periodically as part of a POI when we get into environmental effects.

                    I do believe the commercial ball powders are extremely temp sensitive. All of them. The military ball powders, not very temp sensitive, but you will still see that at the extremes you have a much higher extreme spread in velocities. The question is, does it really matter in practical terms?

                    LR1955
                    LOL actually I called my HVAC man to install a heating/cooling system in the barrel chamber to keep the temps at a constant.
                    On a serious note LR1955 I see your point and agree. I'm really not attempting to get picky rather figger out a decent powder and the 8208 was mentioned because of the "temp sensitivity" and the spread you mentioned, as arecommendation by another shooter in order to acheive a more constant. nromally in the service rifle matches (BTW I'm really not that good at it) I use a thrown charge that net the best accuracy reguadless the Velocity unless I go 600 and beyond and the need the extra ummph to get the pil there supersonic.
                    Last edited by Guest; 10-14-2011, 03:22 PM.

                    Comment


                    • #11
                      Originally posted by RangerRick View Post
                      Can you get them to feed out of a full mag at 2.29? Or do you shoot ne or two at a time?

                      RR
                      2.29 is as long as my magazine will tolerate without the tip dragging on the inside of the wall. That will vary from manufacturer to manufacturer. We're only talking 3 one hundredths over spec, so it's not much longer and in all likelihood insignificant, but yes they feed the entire stack.

                      Hoot

                      Comment


                      • #12
                        Originally posted by sgt_murf View Post
                        From what everyone is saying I should like the IMR however the question is the temp stability of IMR as good as Vihtavuori?
                        8208XBR " is totally insensitive to changes in temperature

                        Comment

                        • sneaky one
                          Chieftain
                          • Mar 2011
                          • 3077

                          #13
                          We will find out, tomorrow- I loaded a few., shot them- all was fine-- awhile back...... so maybe better to work up the load for fall hunts, in the heat of summer.---- then you will be fine for fall= less temp== no worries. Accuracy shooting tomorrow.

                          Comment

                          • sneaky one
                            Chieftain
                            • Mar 2011
                            • 3077

                            #14
                            Well, we went shooting all right. The wind took my targets to the bottom of the hill, then over, then??? 30-50 mph. I decided to focus on the small rocks on the huge berm we use as a back stop==== my only immoble targets. I hit every one. I had pre-loaded many diff. bullets-powders- combinations, etc. for acc. yet to no avail. on an actual paper target. We went for speed checks , primer diam.- press. checks, seating depths. As to the other 3000 k, thread, yes, I did hit 3000 fps., with an awesome short range deer load. It was a 76 grn. GMX, with a flat base, and 32.0 of x-term, seated at 2.260 oal. I call it my new spine-neck tap, 75 y. or less unit .. It was accurate, but would lose energy too fast at longer ranges. The ranges I usually take deer , are less than 50y.- On sat. We were shooting at 100-110yds. I wanted to h2o test it, with extra jugs- but my van was full, no more room, as Mse will attest to==omg. that things packed! anyway, Still better than a 5.56 with a 70gr. barney at 27-2800. Many options with monolithic, and gilding metal bullets- with no lead, or wt. loss issues .OOOOOOOOOPPS, the 8208 is great. Accurate as I could tell, used the same scale wts. as x-term.,= same primer pressure results., same speed results with lighter bullets as x-term. and ULTRA -clean! Probably would be better results as compared to say- x-term in a 120 lead core unit. I'll be loading and testing 1 more time from data gathered that day. I'll be shooting in a giant culvert tube at Ahlmans in s. mn.==== Quite the ear ringer, even with protect. Why? No side winds, to trully know what's up. blab, blab
                            Last edited by sneaky one; 10-19-2011, 12:02 AM.

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