What's the best way to measure Case Neck Thickness

[rsplante]

Half way through Glen Zediker's book, Handloading for Competition, I think I finally understand the need for neck turning. I initially thought it was only for benchresters who had very tight neck to chamber tolerances. Now I understand that variances in case neck thickness can have a very large effect on concentricity (relatively speaking.) He claims that Hornady found that "neck wall variations of 13 percent very notably opened up groups. That's about 0.0015 on most cases."

I first looked at the Sinclair/Starrett Case Neck Gage, but they want about $170 at Midway. Then I looked at the cheap option, a Frankford Arsenal ball micrometer; however, one review said that they got different readings everytime they measured the same spot. Cheap and accurate do not belong in the same sentence. Apparently you really do get what you pay for. So right now, I am leaning back towards the Sinclair/Starrett, plus, it has a built in stand which acts as a "third hand." Any suggestions? Also, I heard that Midway offers a discount code to readers of this site. Where would I find that code?

 

[taseal]

Re: What's the best way to measure Case Neck Thickness

I haven't heard too many bad things about the micrometer by FA

i mean there is a way to measure it...

some people don't use the same amount of pressure and with those tolerances they will get wrong readings.

same thing happens with the caliper. I was going nuts until I figured out you need consistent pressure on it, otherwise you can't get the right reading.

 

[shoepop]

Re: What's the best way to measure Case Neck Thickness

Don't get hung up on just gun related sources ball Mic's are commom google up get the best price. Also don't get hung up on exact neck thickness a decent dial caliper will get you close enough. Get a K&M neck trimmer and it will cut the same case after case and that's all your looking for.

 

[rsplante]

Re: What's the best way to measure Case Neck Thickness

OOps, apparently I quoted the wrong site. It appears that Midway does not carry the Sinclair/Starrett Case Neck gage. I found it on Sinclair's site for $160. http://www.sinclairintl.com/.aspx/pid=38...Neck-Micrometer
Anyone have a better suggestion for measurement or a better price?

 

[sandwarrior]

Re: What's the best way to measure Case Neck Thickness

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Mark S</div><div class="ubbcode-body">Don't get hung up on just gun related sources ball Mic's are commom google up get the best price. Also don't get hung up on exact neck thickness a decent dial caliper will get you close enough. Get a K&M neck trimmer and it will cut the same case after case and that's all your looking for.</div></div>

+1

Measure the outside with a caliper and then the inside with the ball guage and check that with the caliper. Make sure to take at least two measurments 90 deg. apart if not more to allow for thickness difference. That's a lot cheaper than a neck guage.

 

[rsplante]

Re: What's the best way to measure Case Neck Thickness

Thanks for the inputs. I have considered the dial indicator approach (that's what I am using for concentricity); however, part of the reason I am leaning towards an actual micrometer is that I want to determine the relative quality of different cases. I tried sorting my weight, but Glen Zediker's book convinced me that just sorting by weight might not do it, since there could be a inconsistent thickness. In fact, he went so far as to say that an inconsistent neck thickness would also point to an inconsistent thickness in the entire case which would result in cases stretching unevenly (banana shape). I have looked at non-gun sources of ball micrometers, but am intrigued by the idea of the stand which constitutes a "third hand". Not sure of the need, but sounds logical.

 

[Rthur]

Re: What's the best way to measure Case Neck Thickness

Fully, I spent the coin on midways digital neck micrometer. It is easy to zero and get a feel for measuring. It has made a pita chore easy.

 

[Fuzzball]

Re: What's the best way to measure Case Neck Thickness

"...a Frankford Arsenal ball micrometer; however, one review said that they got different readings"

I smile when I see such 'reviews' by one user. Fact is, using any micrometer seems to be more than some people can accomplish; it does take practice. And, for those not willing to learn how to hold a mic correctly, the stand used as a third hand IS a nice addition.

Mics are precision measuring devices but some guys work 'em like C clamps! Only way to learn how tight to make the thimble is to practice measuring a known thickness until we can do it consistantly. Most of us use a leaf of a simple auto mechanic's 'feeler' gage tool.

A ball mic IS the better way to check the thickness of tubing, that's what they are made for. A caliper is okay for checking immediately at the case mouth but there's no way it can accurately check further inside.

 

[MNtadpole]

All,

 

[spife7980]

All,

This might go for the best necro bump of all time.

 

[MNtadpole]

This might go for the best necro bump of all time.

Lol I commented on a wrong post and couldn't figure out how to delete it. LOL I was hoping no one witnessed my mistake. PFFFT.

 

[Steel head]

Lol I commented on a wrong post and couldn't figure out how to delete it. LOL I was hoping no one witnessed my mistake. PFFFT.

 

[lightman]

I use a tubing mic from Starett.

 

[charliehorse27]

I've got one of the Redding neck thickness gauges. The only downside is you need to size the case first to get the neck small enough that it will spin on the pilot without slop.

 

[Steel head]

I use a tubing mic from Starett.