Bob Green Comparator and bullet sorting

[Jeff Von Rosenberg]

I bought a set of Bob Green comparators and my seating depths are more consistent than ever before. qu
I know lots of people separate by bearing surface I.e. John Hoover and some swear by the BGC I.e. Erik Cortina. My question is should I be separating by bearing surface and then use my BGC or what? I know that variation in seating depth definitely shows up down range. I really don't want to do both operations as I would spend all my time separating bullets! I very much believe in separating trimming and tipping. I don't foresee abandoning my BGC as it with 4 calibers is a sizable investment and seating depth is very, very consistent . What are your thoughts? Always happy to hear from the great minds on this forum!!! You guys are the best. JVON

 

[Jay Christopherson]

Re: BGC question

I just tested this (like, literally this week), after being certain I was right about needing to pre-sort by bearing surface or base-to-ogive. People I trust told me I was wasting my time, but I wanted to be right so I set out to prove it.

I could find no material difference between pre-sorting/BGC sorting, and BGC sorting alone. I'm not sorry to discard a practice that consumed a *lot* of my time that I've proved, to my satisfaction, provides no material benefit.

Don't waste your time pre-sorting before using the BGC. Use the BGC first, last, and only.

 

[lmorrison17]

Re: BGC question

A few years ago I ran out of a lot of 6.5 130 vld's, my new lot was .040 longer in bearing surface.

A fellow shooter told me to shoot the same load and depth, I thought no way are these going to shoot the same.

After a full load workup guess where I ended up?
Right back at my old load and depth.

 

[Cigarcop]

Re: BGC question

I just tested this (like, literally this week), after being certain I was right about needing to pre-sort by bearing surface or base-to-ogive. People I trust told me I was wasting my time, but I wanted to be right so I set out to prove it.

I could find no material difference between pre-sorting/BGC sorting, and BGC sorting alone. I'm not sorry to discard a practice that consumed a *lot* of my time that I've proved, to my satisfaction, provides no material benefit.

Don't waste your time pre-sorting before using the BGC. Use the BGC first, last, and only.

I couldn't agree more Jay,.... and Larry I went thru the same with 130 vld's that were in the neighborhood of .030 longer than my old lot. Marked them and mixed them into my normal loads at the same seating depth, shot them more than once at long range and could see none that were out of my normal groupings. To me it just verified that bearing surface was not an important factor in the already lengthy reloading process to make good ammo.
Bob makes a good tool that is well worth its price.

 

[Alex Wheeler]

Tell me about this tool, what does it measure?

 

[22BRGUY]

Tell me about this tool, what does it measure?

http://www.greensrifles.com/New_Products.html

 

[Steve Blair]

Tell me about this tool, what does it measure?

[br]
It measures the distance between seating stem contact and rifling leade contact. Like Jay and Keith, I could find no difference between BGC and bearing length sorted bullets (using two Sinclair comparators) and BGC alone. It is worth noting that I tested only with Berger 180 Hybrids. The tested lot had a bearing length range of ~.010" with most falling within .006". YMMV

 

[johara1]

I sort with a bearing surface comparator and sort +- .0005 and it has served me very well. I took an old BSC and set it up to measure seating depth and groups got smaller and more consistent, i can now hold .0005 on seating depth and i found i can adjust the one that are out. If i can't they are fowlers or sighters….. James O'Hara

 

[Steve Blair]

If i can't they are fowlers or sighters

[br]
Not a specific criticism of you, Jim, but I see this frequently and folks should know that homophones are not interchangeable. [br]

Fowl´er
n. 1. A sportsman who pursues wild fowl, or takes or kills for food. [br]
As opposed to "fouler", a firearms-specific term for a shot fired to foul a barrel. Other commonly confused terms are "muzzle break" instead of the correct "muzzle brake" or "rifling lead" instead of "rifling leade".

 

[Jeff Von Rosenberg]

Anymore?

 

[bozo699]

BS should still be the first phase IMO. These should be separate sub lots. Further sorting I would recommend, but feel that one should not be left out.

Tom

I sort with a bearing surface comparator and sort +- .0005 and it has served me very well. I took an old BSC and set it up to measure seating depth and groups got smaller and more consistent, i can now hold .0005 on seating depth and i found i can adjust the one that are out. If i can't they are fowlers or sighters….. James O'Hara

I agree with these two men. They have taught me a lot and I get results just like Jim is getting if I can keep my neck tension consistent. I don't always use Bob Green's tools but he does make great stuff and he is a real neat guy to talk to and is very helpful.
Wayne.

 

[johara1]

Steve, You are wrong…… duck hunter or goose hunter maybe. Only out there where you are would it be called a Fowler……LOL That is where Nancy said she didn't believe in hunting,you could get your meat in a store. That way animals wouldn't have to die. She's your leader… i hope you got her set straight ……. …… jim

 

[Steve Blair]

Steve, You are wrong…… duck hunter or goose hunter maybe. Only out there where you are would it be called a Fowler……LOL That is where Nancy said she didn't believe in hunting,you could get your meat in a store. That way animals wouldn't have to die. She's your leader… i hope you got her set straight ……. …… jim

[br]
I'm 500 miles from San Francisco, Jim. By that logic, Chaka Fattah is your leader. :

 

[roadkill61]

OK guys help me out here. How does this tool know where the bullet touches the lands or for that matter the bullet seater?

 

[Erik Cortina]

OK guys help me out here. How does this tool know where the bullet touches the lands or for that matter the bullet seater?

It's a very smart comparator.


Actually, it's easy. Bob uses a sliding seating stem inside his tool that pushes against a dial indicator. The "mouth" of the tool is bored using geometry that matches your barrels leade. So, when you push a bullet into the tool, it pushes up on the seating stem and stops pushing when it gets to the "mouth" of the tool, therefore measuring the distance between the two.

 

[johara1]

Steve, Chesty Puller was….. jim

 

[johara1]

Erik, If you use different neck tension, they at different lengths. So how do you seat to the same seating depth and test different neck tension with that tool?…… jim

 

[Steve Blair]

Erik, If you use different neck tension, they at different lengths. So how do you seat to the same seating depth and test different neck tension with that tool?…… jim

[br]
It's not a seater, Jim. It just measures the distance between seating stem contact and leade contact. Once sorted, you obviously adjust your seating die to whatever is required to achieve the desired seating depth. My bullets, sorted with a BGC and seated in consistent necks, do not vary much in seating depth.

 

[johara1]

Steve, What is not very much ? .0005 or .001...just asking. I think uniformity is very important ……. jim

 

[Steve Blair]

Less than .001". It could be less as Bob's gauge has a .0001" indicator but I only sort to .001" groups.