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Post by 153 on Mar 12, 2015 13:23:25 GMT -5
Having trouble getting Accubond to shoot in my 270s. I can get NBT, Seirras, Hornadys and Barnes all to shoot sub MOA. Accubonds both 110 and 130 over 2" 5 shot groups. Anybody have any tips for Accubond.
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Post by muznut on Mar 13, 2015 12:54:39 GMT -5
Did you try accurate 2700? that powder shoots holes touching or stacked in two of my 308's all my 270's, 3006's 300win mag and all my M70 WSM's. Works best with a mag primmer in all of them.
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Accubond
Mar 13, 2015 14:09:40 GMT -5
via mobile
Post by 7mmfreak on Mar 13, 2015 14:09:40 GMT -5
How do you do load development?
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Post by pposey on Mar 17, 2015 9:33:08 GMT -5
the 140s in 7mm shoot the same as the 140 BT's in my 7mm-08, same powder charge everything, although I don't hunt with them, the 120 BT shoots better and kills well
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Post by 153 on Mar 17, 2015 12:55:27 GMT -5
How do you do load development? Same as with other bullets. Start with specs from several reloading manuals, change powder charge, COL, primers. 2" groups not bad but with the Tikka's I am shooting but I have gotten use to .5-1 MOA at 100 yards with the other bullets. I have used only two powders H4381SC and H4350. I have some MagPro and 760 I may try. But first load with the 110TTSX seven shot group was 1". When load testing for accuracy I shot seven shot groups. Once I get a load developed then three shot groups for sighting in. |
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Post by kahuner on Mar 17, 2015 13:58:22 GMT -5
153;
I used to go about load development like you are doing. Grab a bunch of loading manuals, bullets and powder blah, blah, blah. Then I discovered that the length of the bullet is more important than the weight. Length is at least as important as weight.
A 270 should favor a 130 gr bullet if I remember right and if your rifle is a 1:10 twist. You trying to shoot a 110 gr (being shorter) will prove more difficult when trying to shoot 1 MOA or better. Comparing a bullet spinning thru the air to a perfectly thrown football, the length and spin of the football give it balance as it glides thru the air. It doesn't wobble and maintains direction.
There are articles on the net that will help you with this subject. Google Greenhill formula. Secondly use the JBM page to get bullet length info
www.jbmballistics.com/ballistics/lengths/lengths.shtml#Sierra
You strive to have the answer to the Greenhill formula be around 1.8. As the answer goes too high or low, accuracy suffers.
I'm not trying to be short in my explanations, it's that this is a really big subject. If you pay attention to the Greenhill formula, you'll save yourself a TON of money and time.
Bottomline? You can go to the 110 gr bullet but accuracy is going to suffer when compared to a 130 gr w/ a 1:10 twist.
Hope this helps. Didn't mean to confuse.
Kahuner |
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Post by Savage Shooter on Mar 18, 2015 13:50:28 GMT -5
AB's in general testing I have done like to jump to lands. I have not found best accuracy with any Accubond much closer than .050 to lands, and most actually shoot their best at .100 off lands. How far off lands are you running them?
AND +1 on the 130 grain version!!
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Post by 7mmfreak on Mar 20, 2015 8:31:02 GMT -5
A 1:10 is adequate for the 130gn AB based on length. The Greenhill Formula is pretty antiquated and would predict you only need an 11.8" twist for the 130gn AB while the better Miller Rule says a 1:10 is just fast enough. I tend to shoot fast twists and heavy bullets but I have shot some lighter bullets from those same twists with no ill effect. It is true that a fast twist can cause issues but that is when dealing with poor quality bullets (the best way to segregate bullets is by price) where any imperfections will be magnified by twist or when talking fast twist, screaming MV, and light bullet (say 1-8 twist, 22-250 Improved, and 40gn NBT). I had a Sako .270 Win, 1-10 ROT, that shot 110gn Sierra Pro-Hunters very well, and fast, that were coyote smashers so don't take the blanket statement that 1-10 is too fast for a 110gn bullet as gospel truth.
That said, I would prefer a 130gn bullet in a .270 if using it for big game (better yet a 150gn). Two powders I have found work really well in most 270Win with the 130gn bullet are H4831 and RL22; the original lots of H4831 that Jack O'Connor shot had a burn rate that more closely mimicked modern RL22 than H4831. For the 110gn bullet I would try H4350.
I feel like the most straight forward and systematic process for load development is ladder testing. You need access to a longer range; minimum of 300yds. If you only have 100yds then OCW works well. The look at a few books, try a few powders, try a few primers, and play with seating depth seems like too many variables. The Ladder (or Audette Method) is the least consumptive of components and most thorough, the OCW second least consumptive and thorough. Anything else is just trigger time and a hope that things work out to their greatest potential.
That leads me to my last statement about the ladder. When testing a hunting or match rifle I start my accuracy testing at .020" off the lands; I won't shoot jammed bullets anytime it counts. I will back them off as far as .090" in .030" increments (or until I have a compressed load). I have had VLD's that wanted a jump, some that didn't (Hornady A-MAX in particular). Nosler NBT or AB usually get around .030-.040" worth of jump in my guns. So, again, there is no gospel truth except that you must systematically test.
Good luck.
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Post by 153 on Mar 24, 2015 10:28:38 GMT -5
AB's in general testing I have done like to jump to lands. I have not found best accuracy with any Accubond much closer than .050 to lands, and most actually shoot their best at .100 off lands. How far off lands are you running them? AND +1 on the 130 grain version!! Thanks for the heads up. I started at .010 and .020 getting 2"MOA. Upon your results I move back to .050 and got 1.3" group, another group that was .075" off lands and got a 1.2" group. I will try two more loads .100 and .125 back and see if groups continue to get smaller. May go back to the 130AB and move those back. Again thanks for the heads up. Side note also had some 110 Barnes TTSX that I loaded. Shot three groups going .7", .5" and last three went .274". I have only shot one deer with a Barnes centerfire but it was DRT. With the way the 110 TTSX are shooting I am going to have to try them this year. Still will be working on the Accubonds to get a good load. |
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Post by mrbuck on Mar 25, 2015 9:13:33 GMT -5
Take those 110 Barnes TTSX 's and run with 'em ! Especially with DRT results ... don't need any deer getting into those Carolina thickets . JMO
Chris
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Post by deertroy1 on Apr 3, 2016 18:28:47 GMT -5
I'm not trying to be a smart ass but if your rifle don't like the Accubonds then don't use them. There are plenty of good bullets out there and there's no sense in trying to force fed your rifle something it doesn't like. I'm with mrbuck!
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