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Posted: 7/9/2012 3:33:09 PM EDT
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I have been trying to duplicate Barnes reloading data in my 16 inch Colt w Nato chamber. 1-9 twist.
I have tried RL-15, Varget and BLC-2 and Remington 6 1/2 primer. I am using Barnes data which is available online. My printed manual only lists 223 chambers and 24 inch barrel. Barnes recommended RL15, and tested using LC brass and 20 inch 1-7 barrel. I substituted Federal cases since I had alot of them, but am getting blown primers at only 2700 fps with RL15 and BLC-2. Varget is OK up to 2750 fps where I stopped. (100% density or close to it). This is about 150-200 fps below what I should be getting. I figured since commercial brass had slightly more case capacity I would be OK, but maybe the thicker web on military brass is more important? Has anyone got anywhere near 2,900 fps with the 62 grain Barnes using commercial brass? Or should I begin swageing primer pockets? 
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1) Use a correct primer 2) You have a 16" barrel 3) The 62gr TSX is longer than the length of the 69gr SMK 4) CorBon's loading of this bullet achieves ~2,975fps +/- 25fps, with a 20" barrel 5) 2,750 fps is about what you are going to get with .223 pressures 6) With a correct primer you could get into the low to mid 2,800's. |
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Here is Barnes data.
They are getting 3019 fps with 62 gr TSX with LC09 brass and 20 inch barrel. Federal 205 primer. http://www.barnesbullets.com/wp-content/uploads/2008/01/5.56-Nato.pdf The 62 grain Barnes is longer than a 77 grain HPBT but they are probably getting over 2,900 fps form a 16 inch barrel. (I am down just 110fps with my 75 grain Hornady from 20 to 16 inch). I am getting 2970 fps from Mk318 ammo (62 grain solid base HP) from same 16 inch barrel. What primers are you guys using? |
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Red,
I just read up on Remington 6 1/2 primer. They are not recommended for high pressure 223/556. So I probably have two problems, one a thin primer cup and commercial brass. Back to loading bench. I have some CCI small magnum primers that are supposed to have a thicker cup. Will try them. Wold still like to hear from you guys who are using comercial brass and 62 grain TSX in a gas gun. |
| There is no hard rule to where 5.56 LC brass lands capacity wise in comparison to commerical 5.56 or .233 brass. It has a higher capacity than many commercial offerings and smaller than just a few, there's a chart availible that I'm to lazy to find and post. Federal is historically alledged to use a softer alloy of brass, which results in loose pockets earlier. There's more to velocity differences in rifles than simply barrel length, chamber dimensions, bore dimensions and imperfections, rifling type, and more can all have an effect on velocity. That long bullet is gonna eat case capacity, 2700 doesn't seem terribly low out of a 16" |
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This is what i got from my Varget Load. I've used the same load with RL-15 and have gotten nearly similar groups. around 1" to 1.5" @ 100 yards
Data: Altitude-951 Temp - 84 Pressure - 30.09 Low - 2694 High- 2799 Avg - 2766 ES - 105 SD - 29.82 I'm not going to post my charge weight. Hornady Case (Factory loaded 75gr. fired, FL sized and trimmed, fired and then collet neck sized) Varget Federal 205m 2.265" C.O.L. all charges were hand thrown. i also used a powder trickle to get the exact weight. LYMAN electronic scale.Redding Measure with the Match Grade dial. |
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Thanks everyone.
I pitted the bolt face of my AR by using the 6 1/2 primer, but fortunately missed the ejector or extractor. Lesson learned. I started over using CCI 450 which I also had in stock. LC brass. I got close to Mk318 velocity at maximum charge listed by Barnes using RL15. Averaged 2895 fps, with low Extreme Spread. (2885-2898). I got to 2950 fps and equaled MK318 by going 3/10 over Barnes data. Flat primers, and probably not worth it. Varget looks like good low pressure load about -100 fps from Barnes RL-15 data. RL-15 and Varget about maxed out case capacity. Also tried BLC-2 which I have used ever since Hornady came out w 75 gr BTHP. Lots of room left with BLC-s but have not got past 2750 fps yet. Thanks again about primer warning. IThink I will be donating 1,000 6 1/2's to my local gun club with suitable warning. |
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I shot some work up loads in my AR using the Barnes TSX 62 gr with CFE 223, Re-15, and IMR-8208. Range was 100 yds. I was getting 1 1/2 to 2 inch 5 shot groups. No chronograph. I won't be trying IMR-8208 again, Re-15 was ok, will concentrate on CFE 223 next time as it shot the best groups. |
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The QL data below reflects my testing almost exactly but I'm posting it for informational purposes only, so please dont use the loads without working them up in your own rifle.
Cartridge : 5.56 mm NATO - 5.56 x 45 mm Bullet : .224, 62, Barnes 'TSX' 22460 Useable Case Capaci: 24.387 grain H2O = 1.583 cm³ Cartridge O.A.L. L6: 2.260 inch = 57.40 mm Barrel Length : 16.0 inch = 406.4 mm Powder : Alliant Reloder-15 Predicted data by increasing and decreasing the given charge, incremented in steps of 2.0% of nominal charge. CAUTION: Figures exceed maximum and minimum recommended loads ! Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time % % Grains fps ft.lbs psi psi % ms -20.0 89 20.00 2240 691 29150 8186 76.9 1.069 -18.0 91 20.50 2300 729 31166 8506 78.5 1.039 -16.0 93 21.00 2361 768 33337 8824 80.0 1.011 -14.0 96 21.50 2423 808 35678 9140 81.6 0.983 -12.0 98 22.00 2485 850 38202 9451 83.1 0.956 -10.0 100 22.50 2548 894 40926 9758 84.5 0.929 -08.0 102 23.00 2611 939 43873 10058 85.9 0.902 -06.0 105 23.50 2675 985 47063 10351 87.3 0.874 -04.0 107 24.00 2740 1034 50520 10635 88.6 0.846 -02.0 109 24.50 2805 1083 54243 10909 89.9 0.819 ! Near Maximum ! +00.0 111 25.00 2871 1134 58253 11171 91.1 0.793 ! Near Maximum ! +02.0 113 25.50 2937 1187 62604 11421 92.2 0.767 !DANGEROUS LOAD-DO NOT USE! +04.0 116 26.00 3003 1242 67336 11657 93.3 0.742 !DANGEROUS LOAD-DO NOT USE! +06.0 118 26.50 3070 1298 72492 11877 94.3 0.719 !DANGEROUS LOAD-DO NOT USE! +08.0 120 27.00 3138 1356 78123 12080 95.3 0.695 !DANGEROUS LOAD-DO NOT USE! +10.0 122 27.50 3206 1415 84287 12264 96.2 0.673 !DANGEROUS LOAD-DO NOT USE! |
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