Re: neck bushing dies - runout
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: perazzisc3</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: YAOG</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: perazzisc3</div><div class="ubbcode-body">EXPANDER BALL, that was the culprit.
Now .00005 - .001 runout. Will shoot to see if
the lowered runout makes a positive difference. </div></div>
I said removing the expander ball would help your TIR but I can't guarantee it will improve your shooting. Just kidding!
But seriously unless you had a major TIR problem shooting very concentric ammo out of a production rifle chamber may not produce a huge improvement in group sizes all other things being equal. This kind of small change usually needs some longer distance shooting to see any real consistent improvements in shooting precision. But I'm happy you resolved your TIR issue.
</div></div> you are very correct!! I had separated 4 loaded rounds that had .005 runout to shoot as sighters and got a one hole group with them and the straight rounds with .0005 or less did not group as tight ( I do have a production rifle chamber) YAOG whats your thoughts on this?? </div></div>
perazzisc3,
Well I guess I was lucky and you had a bad day at the range. Just kidding! IMO short of someone getting hurt at the range there are very few bad days at the range.
LOL! I did the same thing months ago! I handloaded some of my pet load up and sorted the finished cases by TIR using my trusty Sinclair runout tool. I had to make some high TIR rounds by finding the cases with the most uneven neck thickness, 0.0003" was the worst in this lot of cases. Then I had to jam a piece of shim stock where it doesn't belong and lock the Redding Type S full die in the wrong place and set the 550's clamping Whidden floating toolhead off center to make some cases each with enough TIR to test.
I shot the bad loads with added TIR against rounds loaded during the same loading session (before I purposely messed up my press settings) in the two stock Remington 700 actions that I own, a 40 year old 24" 700 BDL w/varmint barrel that is getting tired and a low round count 5R/AICS. It really surprised me that I didn't see a large change in group size that I could blame on the increased TIR when compared with the 0.000"-0.001" TIR rounds, at least not at 100 yards anyway.
But what was even more interesting to see was that what differences I think I might have seen were more noticeable in the low round count 5R/AICS barrel. The old 700 groups have been getting bigger the last few years and I have a hard time producing groups under 3/4MOA. The 5R on the other hand can reliably shoot under a 1/2MOA like the BDL used to 10,000 rounds ago using the same pet loads. This leads me to think a good custom chamber with tighter chamber specs will show more improvement with low TIR rounds than a production Remington chamber will.
This all happened on different days and under slightly different weather conditions so I'm not 100% certain this is 100% right. But what I think these results showed is that with real world use in a typical factory barrel very low TIR does not make a big difference at least not with factory Remington chambers at 100 yards anyway. But maybe Remington is on to something with their really long throated chambers.
I don't have a Tac-Ops rifle yet (my trusty old 700 BDL is at TacOps to be reborn as a Kilo51) but with the new rifle there might be a more consistently demonstrable improvement in group size results with the higher precision chamber. l'll have to revisit this when my TacOps Kilo51 comes in.
Hope this helps!
