Tool for Measuring Base to Ogive
- Thread starter Poconolg
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Fatelvis
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I really like Redding's "Instant Indicator". It is a die that will measure BTO, OAL, case length, or headspace, and does it with remarkable repeatability. It doesn't require the developed "touch" needed when using a caliper, as the ram on the press stops at the same place for every measurement.
Nature Boy
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I need to get one of those. Getting a consistent and repeatable measurement of bullet base-to-ogive with calipers is outside my capabilities. Trying to get that boat tail base perfectly square is tedious and takes way too long. In the end I just give up on bullet sorting because I never trust my data
GeoDudeFlorida
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When I was working in aerospace as an inspector, we used optical comparators to measure things like curves, angles, distances to break points and such. They aren't terribly expensive on the used market but you can also make you own using a light box and projector. How precise it is depends on how well the light source and mirrors align. Like anything else in precision measuring, having a good standard for calibration means everything.
Image is from https://sipconinstrument.com/2019/06/14/profile-projectors-all-you-need-to-know/
Image is from https://sipconinstrument.com/2019/06/14/profile-projectors-all-you-need-to-know/
WeekendReloader
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I use the Hornady comparator. Seems to work well with a standard set of calipers.
You use different inserts to measure the case shoulder and bullet ogive.
You use different inserts to measure the case shoulder and bullet ogive.
edwardware
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What improvement vs the Sinclair Nut are you hoping for?
I own Hornady's ogive tool kit, and it stays in the toolbox. . . the Sinclair Nut stays on the bench and gets used nearly every day.
I own Hornady's ogive tool kit, and it stays in the toolbox. . . the Sinclair Nut stays on the bench and gets used nearly every day.
Offfhand
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This is somewhat off the OP's question, but perhaps appropriate to the subject of measuring ogives. This instrument is used to quickly sort out variations in ogives of bullets within a lot. Usually, a batch of 100 bullets from the same box will have a range of enough ogive variations to segregate them into three or more batches. Allowing the handloader to select and load them in corresponding groups so as to insure a more uniform shot to shot bullet to lede relation. It is fast to operate, allowing 100 bullets to be be checked in a few minutes. But don't ask if it's worth the bother, that's another subject..
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NMexJim
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The Sinclair nut is a precision tool as are the comparators by Sinclair and Hornady (can't tell the difference between the two myself), but they all come down using a caliper. There will be a difference in reading between all of them because, well, they do depend on drilled bores.
If you have a few extra bucks laying around, check out the Wilson gauge which can be zeroed.
Case Gage Depth Micrometer-CG-MIC (lewilson.com)
If you have a few extra bucks laying around, check out the Wilson gauge which can be zeroed.
Case Gage Depth Micrometer-CG-MIC (lewilson.com)
ParallelCode
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The Hornady comparators have worked well for me thus far.
AJC1
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Are you shooting for aggregate groups in competion or shooting against a buddy for beer money. The level of what matters is directly in proportion to the goal. If you aren't familiar with bullet pointing, and you dont consider weight sorting primers then you may be deeper down the rabbit hole than you need be.
NMexJim
Member
Although bullet seat depth and powder charge changes can be detected at 100 yards, those changes can be small and hard to detect unless something is far out of wack. 200 yards gives more dramatic results especially after wringing out at 100. And, I’m assuming a decent rifle and scope combination from a dead rest.
Without knowing more about where you are in the learning curve, it’d be hard to give much advice for any of us. Based on the number of your post, you’re new to this forum, but how much experience do you have in reloading?
If you’re interested in a high level of accuracy (under 1” groups) and have the equipment, I’d recommend searches on ladder testing. OCW (optimal charge weight) and Scatterlee methods would be good searches and reading. The pursuit of such accuracy can be time consuming and expensive. Most of us would liken it to dropping down the rabbit hole with Alice.
A more basic approach might be https://www.hornady.com/team-hornady/ballistic-calculators/ballistic-resources/internal-ballistics. Having a foundation here is important for both results and safety.
Regardless, keep coming back.
Without knowing more about where you are in the learning curve, it’d be hard to give much advice for any of us. Based on the number of your post, you’re new to this forum, but how much experience do you have in reloading?
If you’re interested in a high level of accuracy (under 1” groups) and have the equipment, I’d recommend searches on ladder testing. OCW (optimal charge weight) and Scatterlee methods would be good searches and reading. The pursuit of such accuracy can be time consuming and expensive. Most of us would liken it to dropping down the rabbit hole with Alice.
A more basic approach might be https://www.hornady.com/team-hornady/ballistic-calculators/ballistic-resources/internal-ballistics. Having a foundation here is important for both results and safety.
Regardless, keep coming back.
garandsrus
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I use a Sinclair nut and several homemade comparators. I use them more for setting the case shoulder when resizing than measuring bullet base to ogive length. Several makers have dies that seat all the bullets to the same OAL, based on location of the ogive. Hornady dies are set up that way.
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