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To combat this I've been using dial calipers and I've had much more consistent findings. I check in about 8 spots around the neck and cull as you mentioned if I have more than a .0015" difference.
How do you measure neck wall thickness with calipers? Casey
Casey
Not being married to any particular political party sure makes it a lot easier to look at the world more objectively...
Having said that, MAGA.
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Campfire 'Bwana
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To combat this I've been using dial calipers and I've had much more consistent findings. I check in about 8 spots around the neck and cull as you mentioned if I have more than a .0015" difference.
How do you measure neck wall thickness with calipers? Casey Use something like this: http://www.midwayusa.com/product/544254/rcbs-vernier-ball-micrometer-1?cm_vc=ProductFinding ![[Linked Image]](http://media.midwayusa.com/productimages/880x660/Primary/544/544254.jpg)
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
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Campfire Ranger
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That's a tubing micrometer, not a caliper.
A tubing micrometer is the correct tool to use, calipers are not.
Casey
Casey
Not being married to any particular political party sure makes it a lot easier to look at the world more objectively...
Having said that, MAGA.
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Campfire Regular
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The numbers mentioned in the OP where for Winchester 2x fired 6.5x55 brass. I tested some Winchester 2x fired 7mm Rem Mag brass yesterday and today. I only tested and loaded 6 rounds as a sanity check on a new lot of RL-22 powder (3 shots of previous lot, 3 shots of new lot at 6% below max).
Here are some numbers:
Neck Thickness Variation - Pre-sizing
1. 0.004"
2. 0.004"
3. 0.001"
4. 0.001"
5. 0.0025"
6. 0.001"
Neck Thickness Variation - Post-sizing
1. 0.003"
2. 0.0045"
3. 0.0015"
4. 0.001"
5. 0.0025"
6. 0.001"
Case Neck Run-out - Pre-sizing
1. 0.0005"
2. 0.0035"
3. 0.001"
4. 0.0005"
5. 0.0005"
6. 0.0005"
Case Neck Run-out - Post-sizing
1. 0.0015"
2. 0.001"
3. 0.001"
4. 0.0015"
5. 0.002"
6. 0.001"
Bullet Run-out
1. 0.005"
2. 0.007"
3. 0.002"
4. 0.001"
5. 0.006"
6. 0.0035"
All ammo was corrected using the Tru-Angle tool to have <= 0.0025" run-out.
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”
― Patrick Rothfuss, The Wise Man's Fear
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It's a very small sample size, I know. But there are still some things I find interesting. Two cases (#1 & 2) that had a large variation in neck thickness showed changes between their fired state and post-sizing state. In one case the difference lessened by 0.001" and in another increased by 0.0005". Case neck run-out generally increased between the fired state and post-sizing state (RCBS FL dies doing a partial re-size). The exception being the one case (#2) that had high run-out (0.0035") was resized down to acceptable levels (0.001"). All cases that had 0.0025" or greater case neck thickness variation had unacceptable loaded run-out. All cases below this threshold had acceptable loaded run-out for the rifle in question (factory grade Ruger M77 Mk.II 7mm Rem Mag). Lastly, toying with the RCBS CaseMaster can be quite enlightening and fun. 
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”
― Patrick Rothfuss, The Wise Man's Fear
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Campfire 'Bwana
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Campfire 'Bwana
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It's a very small sample size, I know. But there are still some things I find interesting. Two cases (#1 & 2) that had a large variation in neck thickness showed changes between their fired state and post-sizing state. In one case the difference lessened by 0.001" and in another increased by 0.0005". Case neck run-out generally increased between the fired state and post-sizing state (RCBS FL dies doing a partial re-size). The exception being the one case (#2) that had high run-out (0.0035") was resized down to acceptable levels (0.001"). All cases that had 0.0025" or greater case neck thickness variation had unacceptable loaded run-out. All cases below this threshold had acceptable loaded run-out for the rifle in question (factory grade Ruger M77 Mk.II 7mm Rem Mag). Lastly, toying with the RCBS CaseMaster can be quite enlightening and fun. Azar: Great little experiment. Thanks for posting. Here's my question for you. What does it all mean? Do you think some upgraded dies may be in your future? Once I got my run-out gauge, it didn't take very long for some new dies to start appearing in my loading room.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
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Campfire Greenhorn
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This thread is fascinating to me as I just bought a Forster Case station and nowfins myself glued to my loaded ammo run out numbers. It gets expensive going this route.
Question if I may: do I NEED to measureneck thickness? or can I simply turn /trim the neck on any case that shows a high number for neck run out on the gauge? (Say .002 or great neck wobble gets outside neck turned?) Or are these two issues not related?
Since poster above sees all his ammo corrected with the Tru Angle case corrector tool does that matter in the end?
Thank you for sharing your experiences!
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Here's my question for you.
What does it all mean?
Do you think some upgraded dies may be in your future? Honestly, at this point it's too early to tell. I'd like to get more familiar with the tool and see what it can tell me over the next year or two. I think this little exercise has encouraged me to keep detailed notes similar to how I did here, but on a much larger scale. It will be interesting to see how it plays out with a much larger sample of brass.
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”
― Patrick Rothfuss, The Wise Man's Fear
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Round #2. I grabbed 10* more 7mm Rem Mag cases and took measurements pre-sizing, post-sizing, and loaded with Hornady 154g SP. Pre Neck Thk Pst Neck Thk Pre Neck RO Pst Neck RO Post Case Len Loaded RO
1. 0.0015" 0.0015" <0.001" <0.001" 2.494" <0.002"
2. 0.0025" 0.0025" <0.002" <0.002" 2.493" 0.0075"
3. 0.001" <0.001" 0.001" 0.0015" 2.493" 0.003"
4. 0.0015" 0.000" 0.0015" <0.002" Hornady Frontier brass, not used
5. 0.002" 0.002" 0.0025" 0.001" 2.492" <0.002"
6. 0.001" 0.0015" 0.001" 0.0015" 2.493" 0.002"
7. 0.004" 0.0045" 0.002" 0.0025" 2.489" 0.007"
8. 0.003" 0.003" 0.001" 0.003" 2.490" 0.0085"
9. 0.001" <0.001" <0.001" <0.002" 2.500" (2.489") 0.004"
10. 0.002" 0.002" 0.001" 0.0015" 2.491" 0.003"
11. 0.0015" 0.002" 0.001" <0.002" 2.492" 0.003"
* Case #4 was Hornady Frontier brass mixed in with Winchester. It wasn't measured for length or loaded. Neck thickness variation mostly stayed the same between pre-sizing and post-sizing. Again, in some cases it decreased (#3, #4, #9) in others it increased (#6, #7, #11). It appears as if every case that had pre-sized necks with a thickness variation <= 0.002" made reasonably straight ammo. Anything above that made very crooked ammo. The biggest surprises were #2 and #9. #2 had only 0.0025" neck thickness variation and less than 0.002" neck run-out. However, when fully assembled it had a whopping 0.0075" loaded run-out. #9 had excellent neck thickness consistency and reasonably low post-sizing neck run-out, however it's loaded run-out was 0.004". Not bad, but higher than I expected. I loaded all 10 rounds with the same primers, powder charge, and bullets and separated the best 5 rounds and the worst 5 rounds into two groups. I will use the Tru-Angle tool to correct the worst 5 rounds so all have a loaded run-out of 0.003" or better. Then I'll shoot both groups at 100 yards (the furthest any close range around here goes) and see if there is any measurable difference between corrected rounds and non-corrected rounds. It's nice being able to measure neck thickness variation and case neck run-out. It shows another piece of the puzzle in loaded ammo run-out.
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”
― Patrick Rothfuss, The Wise Man's Fear
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Round #3. Grabbed 8 more Winchester 7mm Rem Mag cases and took measurements pre-sizing, post-sizing, and loaded with Hornady 162g BTSP.
Pre Neck Thk Pst Neck Thk Pre Neck RO Pst Neck RO Post Case Len Loaded RO
1. 0.002" 0.0015" <0.001" 0.001" 2.493" <0.002"
2. 0.003" 0.003" 0.001" <0.0015" 2.493" 0.006"
3. 0.003" 0.003" <0.001" 0.002" 2.496" 0.006"
4. 0.001" 0.001" 0.0015" 0.001" 2.497" 0.002"
5. 0.0015" 0.0015" 0.0005" 0.002" 2.493" 0.003"
6. 0.001" 0.0015" 0.0005" <0.002" 2.490" 0.005"
7. 0.001" <0.001" <0.001" 0.0015" 2.490" 0.001"
8. 0.0015" 0.0015" 0.001" <0.002" 2.494" 0.0025"
This is the first time case neck thickness variation did not increase at all between pre and post sizing. In two cases it decreased slightly. Usually the variation is around 0.0005" and is very negligible. Neck run-out did increase by a fair margin on rounds 5 & 6, and some on 2, 3, 7, & 8. The only big surprise to me was round 6 having a loaded run-out of 0.005". All of it's measurements were good with perhaps the exception of post-sizing neck run-out coming in at 0.002". A "big" jump from the pre-sizing run-out of 0.0005".
Last edited by Azar; 03/17/15. Reason: 162g BTSP, not 154g SP
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”
― Patrick Rothfuss, The Wise Man's Fear
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Round #4. 9 More 7mm Rem Mag cases were measured pre-sizing, post-sizing, and loaded with Hornady 162g BTSP.
Pre Neck Thk Pst Neck Thk Pre Neck RO Pst Neck RO Post Case Len Loaded RO
1. 0.001" 0.0005" <0.0005" 0.001" 2.494" 0.001"
2. 0.0005" 0.001" <0.001" <0.001" 2.474" *
3. 0.001" 0.0005" 0.0015" 0.0015" 2.491" 0.002"
4. 0.001" 0.001" <0.001" <0.0015" 2.496" <0.003"
5. <0.001" <0.0005" 0.001" 0.001" 2.492" 0.001"
6. 0.003" 0.003" 0.001" 0.0005" 2.489" 0.045"
7. 0.0015" 0.0015" <0.002" 0.002" 2.493" 0.002"
8. 0.0045" 0.0045" <0.002" 0.004" 2.492" 0.0115"
9. 0.002" <0.002" <0.002" <0.0015" 2.493" 0.001"
* Culled, too short. Replaced by #9
Again, it appears as if 0.002" is a reasonable max for case neck thickness using my equipment. Cases that measure at or below this seem to consistently give total loaded run-out of 0.005" or less (anything above 0.003" gets corrected anyway). Case #6 had a neck thickness variation of 0.003" and still came in under 0.005". That's a first. Case #8 tied for the worst neck thickness variation so far measured and broke a record for most crooked reload yet measured. Reloading rifle rounds sure takes a lot longer doing all these measurements, but I find it very interesting to see the effects of differing case dimensions throughout the process.
“There are three things all wise men fear: the sea in storm, a night with no moon, and the anger of a gentle man.”
― Patrick Rothfuss, The Wise Man's Fear
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