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Vertical stringing
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<blockquote data-quote="Blackhawk" data-source="post: 1848821" data-attributes="member: 105459"><p>Please establish your bullets starting jump dimension. This is where your bullets ojive will make contact with your barrels lands.After removing the bullet attached to your brass case carefully measure your COAL. It will be easier to use a Stony Point (now Horandy) LNL straight OAL Gauge. simply by using a Horandy Modified Case( or by making your own which is a better and more accurate choice) Simply use an I or L drill and open your primer pocket to receive a 5/36TPI tap and tap out your primer pocket hole.(Plenty of How - to's on the WEB)</p><p>Using both the OAL gage and the Horandy Bullet Comparator Set (insert #8 = .30 Cal you can now establish a guide line COAL. This established number will not co inside with any other numbers ,especially a pair of calipers. This number will be a reference figure only to aid in establishing your rifle and only this rifles chamber to your rifle's chamber to land dimensions using a given bullet.</p><p>You must use both the Horandy OAL gage with the the #8 - .030 insert and by using your presses bullet seating die keep reducing your COAL by first -.003" for the first five cartridges then reduce by .010" increments of 5 ea. until you have manufactured 25 cartridges.</p><p>Example: Case OAL = 2.742" touching lands</p><p> -.003" = 2.729" load 5 rounds</p><p> -.010" = 2.732" load 5 more rounds</p><p> -.020" = 2.722" load 5 more rounds etc.</p><p> REPEAT until all 25 rounds have been made.</p><p>Now go to the range and set up your Chronograph and record your ES and SD figures.</p><p>PLEASE BE PATIENT you may have to repeat this test several times</p><p>As you can see these numbers are not a constant but rather a variable and might require a fine tuning as shown below.</p><p>One rifle preferred an .008" jump</p><p>Another rifle in the same caliber preferred a jump of .040"</p><p>Same brand and same BLUE PRINTED ACTIONS.</p><p>Your ES and SD numbers will tell the story.</p><p>Once you have established your SD and ES numbers( the tightest and smallest groupings) you can repeat this with your powder.</p><p>I moved in 1/3 of a grain increments and again marked these loads in separate plastic ammo boxes and again went back to the range. ( I found my best results were achieved by almost compressing my powder) </p><p>So just be patient and let your chronograph perform its duties.</p><p>At some point you will see a node where your bullets will show your best velocity and ES as well as SD numbers.</p><p>Now you have found your optimum powder, bullet and jump settings!</p><p>Just move slowly , but deliberately and you will achieve your goal.</p><p>Just remember to document everything and download your chronograph readings to your computer for further reference.</p><p>If you need more guidance PM me.</p></blockquote><p></p>
[QUOTE="Blackhawk, post: 1848821, member: 105459"] Please establish your bullets starting jump dimension. This is where your bullets ojive will make contact with your barrels lands.After removing the bullet attached to your brass case carefully measure your COAL. It will be easier to use a Stony Point (now Horandy) LNL straight OAL Gauge. simply by using a Horandy Modified Case( or by making your own which is a better and more accurate choice) Simply use an I or L drill and open your primer pocket to receive a 5/36TPI tap and tap out your primer pocket hole.(Plenty of How - to's on the WEB) Using both the OAL gage and the Horandy Bullet Comparator Set (insert #8 = .30 Cal you can now establish a guide line COAL. This established number will not co inside with any other numbers ,especially a pair of calipers. This number will be a reference figure only to aid in establishing your rifle and only this rifles chamber to your rifle's chamber to land dimensions using a given bullet. You must use both the Horandy OAL gage with the the #8 - .030 insert and by using your presses bullet seating die keep reducing your COAL by first -.003" for the first five cartridges then reduce by .010" increments of 5 ea. until you have manufactured 25 cartridges. Example: Case OAL = 2.742" touching lands -.003" = 2.729" load 5 rounds -.010" = 2.732" load 5 more rounds -.020" = 2.722" load 5 more rounds etc. REPEAT until all 25 rounds have been made. Now go to the range and set up your Chronograph and record your ES and SD figures. PLEASE BE PATIENT you may have to repeat this test several times As you can see these numbers are not a constant but rather a variable and might require a fine tuning as shown below. One rifle preferred an .008" jump Another rifle in the same caliber preferred a jump of .040" Same brand and same BLUE PRINTED ACTIONS. Your ES and SD numbers will tell the story. Once you have established your SD and ES numbers( the tightest and smallest groupings) you can repeat this with your powder. I moved in 1/3 of a grain increments and again marked these loads in separate plastic ammo boxes and again went back to the range. ( I found my best results were achieved by almost compressing my powder) So just be patient and let your chronograph perform its duties. At some point you will see a node where your bullets will show your best velocity and ES as well as SD numbers. Now you have found your optimum powder, bullet and jump settings! Just move slowly , but deliberately and you will achieve your goal. Just remember to document everything and download your chronograph readings to your computer for further reference. If you need more guidance PM me. [/QUOTE]
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