Anyone use a Dial Indicator Gauge for measuring OAL?

[Quinc]

Using the hornady Comparator set has anyone used a dial indicator gauge with base plate? Like in the picture. I want to try a semi local 2k shoot with my .284 and am looking to get as consistent with lowest SD possible. Yes I know there are bigger and better calibers etc for this distance.. that is not what I am asking.

I want to know about using this:

With this:

 

[Macropod]

Yep.

 

[Macropod]

This uses a section of the same barrel and a chamber cut with the same reamer. Proved to be a very useful device. It has thrust bearings on a pivoting head. A lot of care to achieve precise alignment was taken when I made this.

Particularly useful for setting dies for shoulder bumping. Also acts as a datum for seating depth. At least while the throat is fresh...

 

[Scott Harris]

I bought that exact base off eBay to measure bearing surface: works great.

 

[Quinc]

I bought that exact base off eBay to measure bearing surface: works great.

Any pics or tips on your setup? Also have you used it with the hornady comperator?

 

[carpebeerem]

That looks to me like it is measuring CBTO instead of OAL. Of course without seeing inside you cannot tell for sure. Redding makes an instant CBTO die if you run a turret press. If you want to get the most consistent ammo you can then try measuring off the ogive instead of the bullet tip.

http://www.midwayusa.com/product/191549/redding-instant-indicator-comparator-with-dial-308-winchester

 

[Quinc]

That looks to me like it is measuring CBTO instead of OAL. Of course without seeing inside you cannot tell for sure. Redding makes an instant CBTO die if you run a turret press. If you want to get the most consistent ammo you can then try measuring off the ogive instead of the bullet tip.

http://www.midwayusa.com/product/191549/redding-instant-indicator-comparator-with-dial-308-winchester

This looks like it would be perfect! Only problem is it wont work with my forster co-ax press.

 

[johara1]

i don't measure over all length, but i measure base to ogive. In other words seating depth, works good…….. jim

 

[JohnKielly]

i don't measure over all length, but i measure base to ogive. In other words seating depth, works good…….. jim

But base to ogive isn't necessarily seating depth, depending where your seating plunger addresses the bullet along the ogive point and how consistent the bullet form is there.

 

[BenPerfected]

I measure the using the Forster tool.
www.forsterproducts.com/store.asp?pid=24823

 

[Brians356]

I looked for a PDF manual for Instant Indicator on Redding's web site, they don't provide such downloads.

I did find this review of the product elsewhere:

https://www.riflemagazine.com/magazine/article.cfm?tocid=788&magid=58

 

[Jay Christopherson]

Here's how I measure seating depth/COAL consistency, though I can't take credit for the design.

 

[Brians356]

Here's how I measure seating depth/COAL consistency, though I can't take credit for the design.

Can't really discern the design. "It's what's inside that counts", she said.

 

[Jay Christopherson]

Here's how I measure seating depth/COAL consistency, though I can't take credit for the design.

Can't really discern the design. "It's what's inside that counts", she said.

Right. Not trying to be overly mysterious about it and I'm guessing if you sat down and thought about it, you'd figure it out. I just don't want to overstep my bounds on describing how it works since I wasn't the one who came up with it. Hopefully he'll chime in when he sees it, since I think he was considering selling them. Suffice it to say that it is repeatably accurate to .0001", if you care to measure out to that level. Personally, my tolerance is much wider than that, but it does give you a good deal of confidence. It's also nice that it doesn't require me to be touching it to take the measurement, so it takes me out of the picture. Also very fast.

 

[Brians356]

Right. Not trying to be overly mysterious about it and I'm guessing if you sat down and thought about it, you'd figure it out.

Well, if it's that simple then there's not much intellectual property to protect, the value is in the fabrication and machining work to make any parts to tolerances, and even if I knew exactly how it goes together, I'd pay significantly to have someone make it and sell it to me.

I assume the part sitting to the left is a follower, and maybe it is inverted there relative to it's orientation while it's inside the barrel, above the cartridge. The cartridge base might sit directly on the stone slab. Seems like there needs to be some lateral support for the cartridge, though.

 

[johara1]

i don't measure over all length, but i measure base to ogive. In other words seating depth, works good…….. jim

But base to ogive isn't necessarily seating depth, depending where your seating plunger addresses the bullet along the ogive point and how consistent the bullet form is there.

Well i'm using the same tool i use to measure bearing surface. Once i set my seating depth i set this at zero, it takes me out of the equation and the dial indicator's spring give a more uniform reading. Now you explain to me what is better?

 

[Brians356]

i don't measure over all length, but i measure base to ogive. In other words seating depth, works good…….. jim

But base to ogive isn't necessarily seating depth, depending where your seating plunger addresses the bullet along the ogive point and how consistent the bullet form is there.

All we care about it is knowing that the load shoots best when the cartridge base-to-ogive (CBTO) length = X as measured using some arbitrary comparator. It doesn't matter just where, relative to where the comparator does, the seating stem contacts the bullets. We assume they contact the ogive at different places, i.e there is some delta. If there are significant-enough variations in the bullet ogives that makes that delta between contact points vary significantly bullet-to-bullet, all that means is that you can't trust a single seating stem adjustment to produce the exact same CBTO measurement for a string of seatings. But you can still measure each round using your chosen comparator to make sure the round-to-round CBTO variation is within reason. With most bullets the variation is probably within the measurement error, i.e. less than .001".

 

[BenPerfected]

Right. Not trying to be overly mysterious about it and I'm guessing if you sat down and thought about it, you'd figure it out.

Well, if it's that simple then there's not much intellectual property to protect, the value is in the fabrication and machining work to make any parts to tolerances, and even if I knew exactly how it goes together, I'd pay significantly to have someone make it and sell it to me.

I assume the part sitting to the left is a follower, and maybe it is inverted there relative to it's orientation while it's inside the barrel, above the cartridge. The cartridge base might sit directly on the stone slab. Seems like there needs to be some lateral support for the cartridge, though.

+1

 

[Jay Christopherson]

Right. Not trying to be overly mysterious about it and I'm guessing if you sat down and thought about it, you'd figure it out.

Well, if it's that simple then there's not much intellectual property to protect, the value is in the fabrication and machining work to make any parts to tolerances, and even if I knew exactly how it goes together, I'd pay significantly to have someone make it and sell it to me.

I assume the part sitting to the left is a follower, and maybe it is inverted there relative to it's orientation while it's inside the barrel, above the cartridge. The cartridge base might sit directly on the stone slab. Seems like there needs to be some lateral support for the cartridge, though.

+1

I think that's the idea. I imagine you are probably right, but I was asked to not give out details until he was ready and so I won't. But, I think you are spot on with your comments about where the value is vs. the IP. It's both fast and accurate, which is pretty valuable IMO.

 

[Brians356]

I am very keen to get one of those, please relay my sentiments and those of others. For both CBTO and headspace measurements.