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Rifles, Reloading, Optics, Equipment
Reloading
Gordon’s reloading tool
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<blockquote data-quote="GBA1776" data-source="post: 2983959" data-attributes="member: 20522"><p>Since you have a ton of experience with GRT I figure you would be the one to ask I am having some issues getting accurate velocity data for particular loads. I have measured case capacity, COAL, projectile length/weight, seating depth, barrel length, twist rate and even powder temp while at the range by using an infrared thermometer to measure case temp. </p><p></p><p>My AR has a .223 Wylde chamber so I put it as a 5.56 chamber and with some projectiles and loads like the 75 Berger VLD I get predictions that are spot on (within 5fps of avg) with what I am seeing in the real world but with Hornady 73 ELD's my predicted velocity is 80fps slower than real world results and despite me pulling the load I am using from the Hornady reloading manual and being .5gr below max load with zero pressure signs (no flattened primers, extractor/ejector marks, easy extraction, good ejection pattern) GRT is telling me that I am at max pressure at the much lower velocity.</p><p></p><p> I know you can mess with powder factors but since I don't know what I am doing in that respect I don't want to blindly make changes to make the software to fudge it to match what I am seeing especially since I am getting good results that match what I am seeing during testing while using the same powder out of the same jar.</p><p></p><p>Any suggestions?</p></blockquote><p></p>
[QUOTE="GBA1776, post: 2983959, member: 20522"] Since you have a ton of experience with GRT I figure you would be the one to ask I am having some issues getting accurate velocity data for particular loads. I have measured case capacity, COAL, projectile length/weight, seating depth, barrel length, twist rate and even powder temp while at the range by using an infrared thermometer to measure case temp. My AR has a .223 Wylde chamber so I put it as a 5.56 chamber and with some projectiles and loads like the 75 Berger VLD I get predictions that are spot on (within 5fps of avg) with what I am seeing in the real world but with Hornady 73 ELD's my predicted velocity is 80fps slower than real world results and despite me pulling the load I am using from the Hornady reloading manual and being .5gr below max load with zero pressure signs (no flattened primers, extractor/ejector marks, easy extraction, good ejection pattern) GRT is telling me that I am at max pressure at the much lower velocity. I know you can mess with powder factors but since I don't know what I am doing in that respect I don't want to blindly make changes to make the software to fudge it to match what I am seeing especially since I am getting good results that match what I am seeing during testing while using the same powder out of the same jar. Any suggestions? [/QUOTE]
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Rifles, Reloading, Optics, Equipment
Reloading
Gordon’s reloading tool
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