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Posted: 4/26/2012 1:07:42 PM EDT
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Gun: DPMS Oracle 5.56/223 16" Chrome Lined Carbine
Bullet: Hornady 68 gr BTHP Match Case: R P Brass Primer: TulAmmo KVB556M Powder: Ramshot TAC Using OCW test method at 100yds It appears to me that 24.4 is beginning of scatter node and 24.8 is coming out of the node?? 
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Both my 20" chrome lined RRA A4 and my son's 22" Savage love Hornady 68grn HPBT over 25.1grns of TAC with Remington 7½ primers and an OAL of 2.250". At 100 yds, I can do sub MOA with my AR (at 65 yrs old) and my son can do 5/8" with his Savage (at 27 yrs old and great eyes). |
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Quoted:
no chrono. i will make center poi on the target to see. according to quickload 24.9 should be close to 2750 i believe Be sure and adjust the 28.5H20 case vol. parameter in the case data pane to match what you have. Ref. Thd. http://www.ar15.com/forums/t_6_42/368457_Interesting_observation_about_case_volume.html I measured some case volumes, as fired, in the Colt. I got 30.6 H2O. QuickLoad library was using 28.5 H20. Made the correction. Everything fell into place with very close MV predictions to Chrono measurements. Conclusion: Measure your as-fired case volumes and adjust QL accordingly. |
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thanks. the guy who input all the data for me into QL used my fired case H20 volume and TTL and all that kinda stuff. I was wandering about accuracy of MV predictions QL gives out so it should be close to what he gave me. 24.9gr TAC @ 2743 FPS with this bullet. QuickLoad produces an estimate. Period, dot. |
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I shot my first 50 of these yesterday. I loaded them with 23.2-25.2 gr of AA2520 (10 each in increments of .5gr), and Wolf 223 primers. The best load was the hottest, and that is half a grain under max. I put 9 rounds in 1.25" from a DPMS MK12 barrel, and I was in a big hurry.
Don't think the Oracle has a chrome lined barrel. |
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Quoted: COsteve: what type brass you loading that into? I have rp and not sure if it will handle that load unless i switched to mil brass I use NATO LC brass with no signs of pressure at all. The primers show no indication of flattening at all, there is no leakage, no primer excessive indentation, and the cases don't show any swelling at the base. My RRA A4 has a Wylde chamber but my son's Savage has a .223 chamber and rounds fired in his show no issues either. I've used this in winter and summer for 4+ years and a couple thousand rounds and I've yet to see any signs of case distress. My belief is that Ramshot has their liars lawyers driving the ship a bit too much. |
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thanks. the guy who input all the data for me into QL used my fired case H20 volume and TTL and all that kinda stuff. I was wandering about accuracy of MV predictions QL gives out so it should be close to what he gave me. 24.9gr TAC @ 2743 FPS with this bullet. QuickLoad produces an estimate. Period, dot. One that's highly dependent on the inputs you feed it, I might add. |
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I have been finding( although not easy) alot of people are saying 24.7 gr TAC behind this bullet is a sweet load but according to my target doesn't appear it would be. Going to load up 24.5-24.8 again to verify the results from the other day One group of 3 shots at each charge weight isn't going to tell you anything without way more experience than you have right now. Plus there are a hundred other factors that can affect the group size. What I'm seeing on your target is not really deciperable. I recommend you shoot some 10 shot groups. Maybe start with the 24.7 grain load if there is no pressure problem. Look for round groups in order to learn the capability of you, the rifle, and the ammunition. Pay attention to the wind, and whether you get a gust just when a shot is fired so you can understand the reason for a bullet that flies out of a group. The best you'll ever get from a 3 shot group is a hint that a load warrants further investigation. It's folly to pick a load based on 3 shots. Try a different bullet, too. Hornady may have improved their 68 grain HPBT, but in my experience they are not consistent from lot to lot. One box will shoot just great, the next won't. I usually recommend the following load for measuring the accuracy of an AR rifle - Winchester cases, Remington 7 1/2 primers, Sierra 52 grain MatchKing bullets, and 27.0 to 27.4 grains of Reloder 15 gunpowder. 27.0 grains will fill the case to the bottom of the neck, 27.4 grains to the very top. 26.8 grains produces too little pressure to seal the case well in my guns. |
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Quoted: And folks question my suggestion that a chronograph is a must-have piece of reloading equipment. Quoted: thanks. the guy who input all the data for me into QL used my fired case H20 volume and TTL and all that kinda stuff. I was wandering about accuracy of MV predictions QL gives out so it should be close to what he gave me. 24.9gr TAC @ 2743 FPS with this bullet. QuickLoad produces an estimate. Period, dot.  |
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I have been finding( although not easy) alot of people are saying 24.7 gr TAC behind this bullet is a sweet load but according to my target doesn't appear it would be. Going to load up 24.5-24.8 again to verify the results from the other day One group of 3 shots at each charge weight isn't going to tell you anything without way more experience than you have right now. Plus there are a hundred other factors that can affect the group size. What I'm seeing on your target is not really deciperable. I recommend you shoot some 10 shot groups. Maybe start with the 24.7 grain load if there is no pressure problem. Look for round groups in order to learn the capability of you, the rifle, and the ammunition. Pay attention to the wind, and whether you get a gust just when a shot is fired so you can understand the reason for a bullet that flies out of a group. The best you'll ever get from a 3 shot group is a hint that a load warrants further investigation. It's folly to pick a load based on 3 shots. 3-shot groups are a fallacy any way you look at it. Like Aero said, shoot larger numbers of shots in your groups to see if there's really any difference between the loads - I suspect you'll come up with similar group sizes for all, which points to something consistent between the shots dominating your accuracy problem. Could be the bullet, could be the barrel, could be the shooter, but is likely a combination of the three. OP, have you fired factory ammo through your rifle? What kind of accuracy do you get? |
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thanks for the info everyone. I have only fired factory ammo at 25 and 50 yds and am out of that now. It shot very well so far with factory at those short distances
With 55 gr at 100 reloads it gave small 3 shot groups but have not re-tested them yet to see which load I want to go with as my plinking load |
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And folks question my suggestion that a chronograph is a must-have piece of reloading equipment. Quoted:
thanks. the guy who input all the data for me into QL used my fired case H20 volume and TTL and all that kinda stuff. I was wandering about accuracy of MV predictions QL gives out so it should be close to what he gave me. 24.9gr TAC @ 2743 FPS with this bullet. QuickLoad produces an estimate. Period, dot.
A chronograph measures speed and will uncover erratic shot to shot speed. If the speed is similar to the load data for the same charge weight, it provides a secondary measure that the load is safe, but no matter what, it tells us nothing quantitative about pressure. Some manuals still print a chamber pressure, so that also helps confirm the hints, but most don't. Even then, I don't recall seeing piezo pressure in a reloading manual, only CUP, so the quoted value isn't the peak, either. |
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Quoted: Quoted: I have been finding( although not easy) alot of people are saying 24.7 gr TAC behind this bullet is a sweet load but according to my target doesn't appear it would be. Going to load up 24.5-24.8 again to verify the results from the other day One group of 3 shots at each charge weight isn't going to tell you anything without way more experience than you have right now. Plus there are a hundred other factors that can affect the group size. What I'm seeing on your target is not really deciperable. I recommend you shoot some 10 shot groups. Maybe start with the 24.7 grain load if there is no pressure problem. Look for round groups in order to learn the capability of you, the rifle, and the ammunition. Pay attention to the wind, and whether you get a gust just when a shot is fired so you can understand the reason for a bullet that flies out of a group. The best you'll ever get from a 3 shot group is a hint that a load warrants further investigation. It's folly to pick a load based on 3 shots. Try a different bullet, too. Hornady may have improved their 68 grain HPBT, but in my experience they are not consistent from lot to lot. One box will shoot just great, the next won't. I usually recommend the following load for measuring the accuracy of an AR rifle - Winchester cases, Remington 7 1/2 primers, Sierra 52 grain MatchKing bullets, and 27.0 to 27.4 grains of Reloder 15 gunpowder. 27.0 grains will fill the case to the bottom of the neck, 27.4 grains to the very top. 26.8 grains produces too little pressure to seal the case well in my guns. This load is a .5 moa load in my AR. Listen to AeroE. I use 27.0 grs.  10 shot groups will tell you how your loads are really shooting. Using CFE 223 here. I am certainly not the worlds best shot. I am happy with 10 shots in under an inch at 100 yds. |
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nice shooting dryflash
Off topic for one second.....If I FL size my brass and they stretch to 1.757" do I HAVE to trim or only trim when they get 1.760"+? I had been trimming to 1.750 every time but that is getting to be troublesome with manual Lee case trimmer |
anyone know what OAL BH uses for the 68 BTHP? Went out just now and shot 24.4 and 24.6 gr TAC at 2.250" and got 1.25" with 24.6. Shot 6 rounds per group and definately helped show the group better. Both those had same POI(1/2" left and 1/2" low) @100 yrds. Out of bullets so going to get more and work up from there again using 7 shot groups and see if I get good results
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Quoted:
anyone know what OAL BH uses for the 68 BTHP? Went out just now and shot 24.4 and 24.6 gr TAC at 2.250" and got 1.25" with 24.6. Shot 6 rounds per group and definately helped show the group better. Both those had same POI(1/2" left and 1/2" low) @100 yrds. Out of bullets so going to get more and work up from there again using 7 shot groups and see if I get good results I just checked my box of red Black Hills and it measures out at 2.21" https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/35912_596718281606_198500624_31269060_2086293685_n.jpg |
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anyone know what OAL BH uses for the 68 BTHP? Went out just now and shot 24.4 and 24.6 gr TAC at 2.250" and got 1.25" with 24.6. Shot 6 rounds per group and definately helped show the group better. Both those had same POI(1/2" left and 1/2" low) @100 yrds. Out of bullets so going to get more and work up from there again using 7 shot groups and see if I get good results https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc7/35912_596718281606_198500624_31269060_2086293685_n.jpg What Black Hills uses doesn't matter. This bullet is long enough to load out to full magazine length of 2.26 inches. I wouldn't load it shorter than 2.25 inches. There's an awful lot of stringing on that last target you posted. If I had to make a bet on the load that will work out the best, it would be the one on the left, but you have to understand what caused that lateral stringing. If it was wind, then deal with it before you shoot up more components. The target on the right has 2.5 inches of vertical; that could be caused by your methods including the rest, vertical deflections due to wind, parallax error in your scope, a scope that can't hold its setting, mishandling the gun, and others. Same factors apply to the target on the left, too. However, right now there's no way to figure out what is going on. Give us all the details of your scope and shooting set up besides what you've already provided. |
| scope is a 4-12x Nikon Prostaff. Placed a beach towel on bench then gun is on that using the grippod for front support and then a block of wood with my shooting bags ontop of that to support the rear. I am holding the grippod with left hand and gently holding it. Bench might be some of the issues. It is junky(uneven concrete slab probably 4ftx4ft supported on concrete blocks and ground where chair sits is uneven). Trigger is pulled with the middle part of shooting finger between the firs knuckle and finger tip. |
| Sounds like your shooting setup isn't the most stable - if you can, try shooting off of just bags. Might be worth going prone for a group or two to see what happens, if your range allows that. How do these groups compare to your shooting in general? A chronograph will give you a lot more information on how the bullet is flying, but the variation I'm seeing in your latest set of targets suggests to me that there's a problem with the shooting setup - match bullets shouldn't give that kind of deviation. I assume you're using the factory handguard, as opposed to a free-floated set? How many rounds have been fired through the barrel? |
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handguard is aftermarket quad rail. Barrel has probably 300 rounds through it.
Well factory AE 55gr FMJBT black box and rem yellow box 55 gr FMJBT were shooting 12 shout groups that I could cover with a quarter at 25 and 50 yards with no bags using grippod and a cheap red dot open sight on the gun. But dont think I can compart the closer distances to shooting at 100 yrds with the gun. Gun has factory trigger and all that too |
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Yes, the tumbled bullets are bad, and you need to stop whatever you're doing and find out the reason. Did you notice any difference in recoil or muzzle blast when you shot those bullets? Are you sure they are the same bullet as the rest; are they longer? Those grip pods are one of the biggest pieces of crap I've tried to shoot with. We have a member here that lives near me. I helped him get his feet wet in reloading, and then introduced him to the club where I shoot. I tried his rifle with one of those and immediately found one reason his accuracy looked about the targets on page 1. Stuff a small back pack with towels or similar padding then try shooting off that. I think you'll see an immediate improvement despite a wobbly bench. You might try shooting with the pack on the ground. |
| alittle of topic...I will try the back trick. If my rifle comes off target after shooting what could be pointers to help keep it there? Am I not shouldering it with enough pressure or too much pressure? Also today I griped the gun at the top of the magazine well and it felt real solid grip there. Also tried gripping just under the stock but wasn't as stable to me? |
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