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Reducing ES - 223
So I have been fighting my Bergara 223 to get it true moa - 10 shots in 29.03 at 100M.
The load I've been using is 23.5 of 2206H behind Hornardy 73gn Eldmsvwith Fed 205s, it's shot nice 3 shot groups but isn't doing the business at 10.
I've tried several things and today's effort centred on brass. I had some fresh Sako brass, once fired from factory in the Bergara.
So l neck sized it (Lee collet die) and loaded as per above .
It shot the smallest 10 shot groups yet (1.13 MOA), but with an ES (70 plus fps, SD of 28) well above what I've been seeing.
Thoughts?
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I'm not entirely sure whether anything can legitimately be done to reduce SD. It may just be what it is with the combination of components. You'd need to shoot large samples of any changes to determine whether or not it really changed. You need to shoot large samples to know what it really is in the first place.
My .223 loads are 15-20 fps SD depending on which bullet/brass combo. Lapua, FC, Ammo Inc brass. Lapua isn't necessarily better. SDs measured over 20+ shots.
.223 seems like it may not produce tight SDs due to case design. 15 might be the best you can realistically hope for.
It's also quite irrelevant at any range you'd employ a .223
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oh that last line sings to my soul..thankyou Gimp.
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OK I'll ask another way, changing brass from Hornady, to "old" Lapua, to Sako has reduced my 10 shot groups each time. Velocity as expected due to case capacity has changed a wee bit each time. But ES has gone out. I hear ya on the sample size thing but group shape etc has also changed.
I took the bolt to bits and the firing pin spring was definitely binding inside the bolt body, mainly at the ends so I fixed that. Nothing I can do about it touching in the middle as it kinks. It's frustrating cause I think the rifle will shoot, there's just something I can't find that will allow it to perform.
I took my 224 Valkyrie out today, it put 10 into 0.89 MOA without effort, that sorta gives me confidence in my shooting and reloading.
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Best combo I found with mine was 8208 over CCI 450's. Seemed to give decent ES and SD numbers with a wide range of bullets. But as gimp says, it's a pig. Getting a single digit SD (and sometimes a single digit ES) is pretty much automatic when using premium brass and a good scale in my bigger cartridges with almost any primer, powder, bullet combo. But it's never been a given in any of the the four factory 223's I've owned.
My T3X is now being rebarreled to 223ai with a trueflite barrel. It will be interesting to see if the improved case design and high end barrel makes any difference.
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It's very frustrating, the Valkyrie just shoots, is on a factory barrel and mass produced reloads, the ES is 30 with an SD of 10
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Hmmm, I was just checking notes and bugger me, I didn't clean the necks on the Sako brass. I do have some 450s and Rem BR primers I have yet to try. 8208 did go pretty good, I might revisit it too.
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Quote:
Originally Posted by
Kiwi Greg
More neck tension
Thanks for that, yes the neck tension measurement (and seating feel) for the Sako brass was very low. I'll try that next.
