Case Comparator Gauges?

[in2deep]

The nice thing about the Larry Willis unit is that you can measure case length base to shoulder, base to ogive on a loaded round, and sort bullets ogive to ogive per se for bearing surface comparison. It is adjustable and no need to buy any extra parts or colletts except if you want to use it as a bullet comparator as shown in the picture- then you would need a Sinclair bullet comparator available in many sizes and reasonably priced. the adjustable screw allows it to adjust to most sizes in a few seconds.
The photo shows how to use a fired case secured in the unit and a bullet comparator for sorting bullets by ogive length and the neck of the bullet can be sized according to your needs for a good fit. Insert bullet in comparator, let case drop and give bullet a 1/2 turn and it repeats very well and precise. I only shoot 6mm cases and a much larger caliber may no fit for this purpose and then you would just use it as intended with the bullet oriented up and down and bullet captured by the set screw. (I like using a fired case better).
For checking base to shoulder length when setting up a resizing die using your fired case to set shoulders back a certain amount this unit really shines as you just zero it to your fired case length and work back from there.
This combined with a cheap pair of digital calipers and your ready for bear as you need calipers sometimes to measure length which the unit below can't do readily for some things.

 

[bozo699]

The nice thing about the Larry Willis unit is that you can measure case length base to shoulder, base to ogive on a loaded round, and sort bullets ogive to ogive per se for bearing surface comparison. It is adjustable and no need to buy any extra parts or colletts except if you want to use it as a bullet comparator as shown in the picture- then you would need a Sinclair bullet comparator available in many sizes and reasonably priced. the adjustable screw allows it to adjust to most sizes in a few seconds.
The photo shows how to use a fired case secured in the unit and a bullet comparator for sorting bullets by ogive length and the neck of the bullet can be sized according to your needs for a good fit. Insert bullet in comparator, let case drop and give bullet a 1/2 turn and it repeats very well and precise. I only shoot 6mm cases and a much larger caliber may no fit for this purpose and then you would just use it as intended with the bullet oriented up and down and bullet captured by the set screw. (I like using a fired case better).
For checking base to shoulder length when setting up a resizing die using your fired case to set shoulders back a certain amount this unit really shines as you just zero it to your fired case length and work back from there.
This combined with a cheap pair of digital calipers and your ready for bear as you need calipers sometimes to measure length which the unit below can't do readily for some things.

I agree with you this really is a nice unit and I have used it for bullet measuring also but I much prefer Buhay from Mark King, to add to your bullet measuring system with the Larry Willis tool I did it a little different then you but got satisfactory results using a seating stem out of my Redding dies chucked in the shoulder holder of the tool and put the base of the bullet on the platform, get a average and zero it just like you do for shoulder bump and it did a very precise job, great tool almost a must IMO.
Wayne.

 

[Rtheurer]

Lawrence

My gunsmith does this for me on every barrel now. I order a barrel an inch longer and that gives him enough material when he cuts off the end to give me a nice case gage. Though I dont have him cut that nice looking window in the side. Very neat. You can tell how much throat erosion you are getting from when it was new as well. The most usefull item on my loading bench next to a calipers.

Everyone should have a case gage made by there smith if you have a new barrel put on.

RussT

 

[Forum Boss]

Joe,

The Green system is more exact, but in terms of loading consistent ammo, the Hornady system will suffice, because all that matters is that you hit the same diameter on the ogive.

You'll want to get two (2) comparator bodies and at least two inserts for the caliber you want to measure. That way you can measure bearing surface of boat-tail bullets.

Also--here's a tip. Though two Hornady comparator inserts may be marked the same, they are likely not exactly the same. So, if you switch between your two comparator bodies (with different inserts) you may get slightly different measurements. I mark my comparators and the inserts so they are always used the same way (one for top of bullet, one for bottom.) If you change inserts to measure different calibers, again, be sure to match up the exact insert with the same comparator body -- otherwise your reference measurements may be off by a few thousandths. Meaning if you have taken all your measurements with 6mm insert No. 1 and comparator body No. 1, you can get a slightly different measurement with insert No. 2 in comparator body No. 1, or with either #1 or #2 insert in comparator body No. 2.

 

[bozo699]

Joe,

The Green system is more exact, but in terms of loading consistent ammo, the Hornady system will suffice, because all that matters is that you hit the same diameter on the ogive.

You'll want to get two (2) comparator bodies and at least two inserts for the caliber you want to measure. That way you can measure bearing surface of boat-tail bullets.

Also--here's a tip. Though two Hornady comparator inserts may be marked the same, they are likely not exactly the same. So, if you switch between your two comparator bodies (with different inserts) you may get slightly different measurements. I mark my comparators and the inserts so they are always used the same way (one for top of bullet, one for bottom.) If you change inserts to measure different calibers, again, be sure to match up the exact insert with the same comparator body -- otherwise your reference measurements may be off by a few thousandths. Meaning if you have taken all your measurements with 6mm insert No. 1 and comparator body No. 1, you can get a slightly different measurement with insert No. 2 in comparator body No. 1, or with either #1 or #2 insert in comparator body No. 2.

Spot on, that is how I do it as well when I use the caliper style tools, I only shoot 6mm in competition anymore so I bought two bodies and two inserts, one Hornaday red colored body, it ALWAYS goes on the stationary blade and a green colored Sinclair body for the sliding jaw, I never remove the inserts and never remove them off that particular caliper, I made a box for it to fit in and it stays in my range box, I use the Mark king while I am at home. I have another full set for other rarely used calibers
Wayne.

 

[Steve Blair]

The problem with sorting by bearing length is a matter of percentage. A Berger 105 Hybrid, with its short bearing surface, is a best case scenario for bearing length sorting. It has a bearing surface of ~.415". If you find a variance of .005" among the bullets, that only represents 1.2% of the bearing surface length. So, you have an effect that is 1.2% of the percentage that bearing surface length affects velocity and grouping. Using Green's tool, if you discover a .005" variance and are seating to .020" from the lands, that variance represents 25% of the distance to the lands. My experience is that seating depth variation has a direct causal relationship with grouping and velocity spread. Sorting bullets to the distance between leade contact and seating stem contact is the only way to get very consistent seating depth, relative to the rifling leade. Sorting base to leade contact or bearing length may reduce seating depth variance in the same way that sorting cases to weight reduces velocity variance, by eliminating outliers at each end of the sample population. But, the only direct way to affect seating depth consistency, relative to the rifling leade, is to sort with Green's tool. My cartridges now have <=.001" seating depth variance as measured with a Sinclair caliper tool. The only other significant parameter is weight. Bullets are more weight consistent than they have been previously but there is still the occasional light or heavy oddbal. All trimming and pointing should be done prior to either weighing or sorting with the Green tool in case the pointing die causes some distortion to the seating stem contact point. [br]
The other problem with all of these measuring methods, except weighing, is to develop a technique or feel. The comparators have a 1½° angle where they contact the bullet ogive and it takes very little pressure variance to cause a few thousandths change. This is probably the greatest trouble source when trying to measure such small differences. I will also note that the pressure variation problem is doubled when measuring bearing surface length because two comparators are involved. If insufficient pressure is used, some minute surface anomaly may be what is actually measured. If too much pressure is used, the bullet could be distorted at the contact ring. In the end, everyone must make their own decisions about cost/benefit for the amount of time and effort versus the realized benefit. It pays to keep an open mind and continue to investigate new techniques as they become available or known. All of the above is from my viewpoint as a long range, F-Class competitor and implies no application to any other discipline. [br]
Just for the record, I have and use the following measuring tools. [br]
Two Sinclair comparator nuts
Two sets of Sinclair caliper comparator bodies and two bullet inserts for calibers .22, 6mm. 6.5mm, 7mm and .308
Sinclair case inserts for every cartridge that I reload (too many)
An Innovative Technologies gauge, which is a wonderful tool
Four Mitutoyo micrometers, a ball, two standard and a blade
Three Mitutoyo calipers, one digital and two dial, inch and metric. The dials are from pre-digital days
Sinclair digital neck micrometer
Neco gauge for TIR and case wall thickness
Hornady Concentricity Gauge, primarily used for straightening
RCBS 10-10
Ohaus Dial-O-Gram
VIC 123 digital scale
Sartorius GD503
RCBS Chargemaster 1500

 

[mikecr]

So to sum up what you're saying related Steve; We should be qualifying ogive radius before accepting other affected parameters as valid.
If so, I agree, and have argued for it here for some time.

Some get all concerned about bearing variance, but this is only their apparent bearing variance, given that they haven't even qualified their datums.

 

[bozo699]

The problem with sorting by bearing length is a matter of percentage. A Berger 105 Hybrid, with its short bearing surface, is a best case scenario for bearing length sorting. It has a bearing surface of ~.415". If you find a variance of .005" among the bullets, that only represents 1.2% of the bearing surface length. So, you have an effect that is 1.2% of the percentage that bearing surface length affects velocity and grouping. Using Green's tool, if you discover a .005" variance and are seating to .020" from the lands, that variance represents 25% of the distance to the lands. My experience is that seating depth variation has a direct causal relationship with grouping and velocity spread. Sorting bullets to the distance between leade contact and seating stem contact is the only way to get very consistent seating depth, relative to the rifling leade. Sorting base to leade contact or bearing length may reduce seating depth variance in the same way that sorting cases to weight reduces velocity variance, by eliminating outliers at each end of the sample population. But, the only direct way to affect seating depth consistency, relative to the rifling leade, is to sort with Green's tool. My cartridges now have <=.001" seating depth variance as measured with a Sinclair caliper tool. The only other significant parameter is weight. Bullets are more weight consistent than they have been previously but there is still the occasional light or heavy oddbal. All trimming and pointing should be done prior to either weighing or sorting with the Green tool in case the pointing die causes some distortion to the seating stem contact point. [br]
The other problem with all of these measuring methods, except weighing, is to develop a technique or feel. The comparators have a 1½° angle where they contact the bullet ogive and it takes very little pressure variance to cause a few thousandths change. This is probably the greatest trouble source when trying to measure such small differences. I will also note that the pressure variation problem is doubled when measuring bearing surface length because two comparators are involved. If insufficient pressure is used, some minute surface anomaly may be what is actually measured. If too much pressure is used, the bullet could be distorted at the contact ring. In the end, everyone must make their own decisions about cost/benefit for the amount of time and effort versus the realized benefit. It pays to keep an open mind and continue to investigate new techniques as they become available or known. All of the above is from my viewpoint as a long range, F-Class competitor and implies no application to any other discipline. [br]
Just for the record, I have and use the following measuring tools. [br]
Two Sinclair comparator nuts
Two sets of Sinclair caliper comparator bodies and two bullet inserts for calibers .22, 6mm. 6.5mm, 7mm and .308
Sinclair case inserts for every cartridge that I reload (too many)
An Innovative Technologies gauge, which is a wonderful tool
Four Mitutoyo micrometers, a ball, two standard and a blade
Three Mitutoyo calipers, one digital and two dial, inch and metric. The dials are from pre-digital days
Sinclair digital neck micrometer
Neco gauge for TIR and case wall thickness
Hornady Concentricity Gauge, primarily used for straightening
RCBS 10-10
Ohaus Dial-O-Gram
VIC 123 digital scale
Sartorius GD503
RCBS Chargemaster 1500

Steve,
Most complete and best overall post on the subject I have read to date, thank you for sharing your valued thoughts
Wayne.

 

[Steve Blair]

Mike,
That is a reasonable way to put it. We do not seat by leade/ogive datum and do not, except for Green's tool, measure by seating stem contact. So, unless those two are measured and synchronized, seating depth will vary. Ideally, we would seat by the leade contact point but that would jam bullets into the seater.

 

[Scott_B]

Mike,

So are you using the BGC comparator that does just the bullet so you can sort them out or are you also using his caliper measuring tool that is similar to the Hornady and Sinclair?

Hmmmm...decisions, decisions...do you guys know if the sinclair inserts fit in the Hornady base? If so, a person could get the hornady base and try both then...unless a smokin' deal comes along on the sinclairs of course.

Yes. I have both a can insert either insert in ether base. Just a slight difference sized allen screw to tighten down the insert to keep it from moving. The Hornady inserts are aluminum and the Sinclair inserts are steel. Sinclair parts are sometimes backordered and only available thru Brownell's since Brownell's bought Sinclair some number of years ago.

 

[JMayo]

I use the hornady ...it does what it does.

 

[varget204]

I use the sinclair,their's are made of steel,the hornady are made of aluminum,The B Green one may be a Great one;But it costs 10 to 20 times as much as the Hornady or Sinclair

 

[Jefferson]

How does the holland bullet comparator with the inserts and the stand compare

looks like it holds the bullet for you properly

thoughts