January 5, 2009, 06:18 PM | #1 |
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Load Development
Finally got all of my gear in and I'm ready to do some accuracy testing with my .270 win. How do ya'll usually beging testing? I am using Barnes tipped TSX bullets, H4891, fed 210M primers and Remington fire formed brass.
I am thinking of loading 5 groups of 5 cartridges for a toatal of 25 rounds. I have heard it is best to seat the TSX bullets a little deep, so I think I will seat the first 25 rounds .030" off the lands. I plan on making 5 rounds at the starting load, and then five more at .5 grains heavier, etc., etc. Does this sound about right to you guys, or should I keep the powder charge constant and make bullet seating depth the variable? How do ya'll start accuracy testing? At $30 a box for the TSX bullets, I want to wrap testing up asap. BTW, anybody have any good load data for the above mentioned components? The Barnes website does not list H4891. |
January 5, 2009, 06:37 PM | #2 |
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Tex
What weight bullet?
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January 5, 2009, 06:42 PM | #3 |
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January 5, 2009, 06:47 PM | #4 |
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Tex
Are you sure about the number of that powder??????? I have no data on any cartridge for H4891.
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January 5, 2009, 06:55 PM | #5 |
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Your approach to relaoding sounds reasonable, If I may make a suggestion, Most reloading books will have an asterik(*) on the load that shot best with their test rifle with any given bullet and powder combination.This is generally a good place to start.I would seat all bullets to their OAL reccomended by your reloading manual(SAMMI) find the one that shoots the best.
I like starting with mid rate powders,those that are in the middle of the page and heavier bullets with the slow powders. Fireformed brass at least needs to be neck sized to hold the bullets. |
January 5, 2009, 07:05 PM | #6 |
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I have switched from the Audette ladder to Dan Newberry's round robin method whether I am trying to find one of his chocolate ice cream loads or just one good for my particular gun. It takes fouling changes and so forth into account. I prefer to use 0.3 grain increments, as Newberry does. That is because, if your scale is accurate ±0.1 grains from charge to charge, then 0.3 grains is the smallest charge you can weigh that is certain to be different from the previous charge (if the last one weigh 01 grain high and the current one weighted 0.1 grains low).
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January 5, 2009, 07:22 PM | #7 |
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Do yourself a favor and seat those Barnes bullets deeper. I have been using them for a long time in 3 different calibres and the minimum I have been able to get away with is .040 setback. Barnes states .050 as their recommended seating off of the lands and has proved to be pretty accurate in 2 of my best loads. As for your load data I am thinking you have a typo on your powder, is possibly either H4895 or H4831 . You really need to be careful here. As for the Federal primers you should be fine. Of note too if you are using load data from anyone other than Barnes or data specifically for any of the Barnes TSX series bullets you will not get the same results as bullets of the same weight produced by other manufacturers. The reason for this is the ring and groove configuration of the TSX bullets have less load bearing surface of the bullet contacting the barrel and the pressures will be reduced. Again as per Barnes you can expect to have to add 1 to 2 additional grs. of powder to your load workups and watch for pressure signs .
Last edited by 10 Spot Terminator; January 6, 2009 at 06:58 AM. |
January 5, 2009, 07:32 PM | #8 |
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Excuse me... powder is H4831 and the bullets are of the 130gr. variety.
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January 5, 2009, 08:19 PM | #9 |
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Tex
Whenever I developed a load,, I would use a 24X target scope on the weapon. My experiences with both H and IMR 4831 in the 270 show most accuracy loads near or at max. Since there is such a wide range from Min to Max, if I were doing it, I would go to 3 rounds per same charge, and bypass lower end increments. see below Hodgedon lists: 130 GR__BAR TSX__H4831"__3.230"OAL Start__54.0gr_2747fps_45,500 PSI Max___60.0C_3025fps_59,000 PSI 3== 55.0 3== 56.0 3== 57.0 3== 58.0 3== 58.5 3== 59.0 3== 59.5 3== 60.0 Typically the groups will tighten as you go up, then have similar accuracy from one to the next, and then get wider. Obviously, you should work with the smallest groups. If you are not getting the accuracy you want (some of the Barns would not shoot less than 3" groups in some of my weapons.), you may have to change powders or bullets or both. Good Shooting!
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