Seating depth

[JEFFPPC]

So then you measure that square Mark with a caliber and that is your initial seating depth off the lands

Why measure it? I start there then back in the case.003 at a time until I have repeatable 3 shot groups in the zeros and ones. I shot 2 shots, if the go pretty much in the same hole I shoot a third. If they aren't what I want for 2 it's certain 3 shots won't make it better.Just keep backing the bullet in the case till you get what you want. Go back next day to be sure it repeats. Measure base of case to ogive to record and your good to go.

 

[Mikemci]

do not limit yourself to one opinion, start at the touch, and work in and out from there,'
without an optical comparator, "square" is NOT a real value, but an opinion, with no numeric value.'
work from facts

Square IS a value. You want a number, measure the bullet depth, with a comparator, when you get square marks. That is a starting point, extrapolated to a "real value", as you say.
These are "facts".

 

[FiftyOuts]

Anyone doing a Seating Depth Test at .003" Intervals is wasting time... There is No discernable difference in POI with that Little bit of Seating Difference. A more Realistic difference is more like .008-010" on each interval...

 

[JEFFPPC]

Anyone doing a Seating Depth Test at .003" Intervals is wasting time... There is No discernable difference in POI with that Little bit of Seating Difference. A more Realistic difference is more like .008-010" on each interval...

My man you do not have a clue about real accuracy. If you want to learn you need to listen and read, and ask questions when you are puzzled. To me youe statement screams clueless. I am not trying to be smart but to point you in the right direction. Your lost right now, just now aware of it.

 

[FiftyOuts]

You Think You can Make a Square on a Bullet less than 1/16" , then You are the One who needs to get out the Calipers !!!

 

[JEFFPPC]

You Think You can Make a Square on a Bullet less than 1/16" , then You are the One who needs to get out the Calipers !!!

I am going to consider that you asked a question. The reference to a square mark in this discussion is the mark made on the bullets where it engages the lands of the rifeling as a visual reference point. If you find this spot and start backing up .003 at a time, meaning seating the bullet deeper into the case you will at some point find a sweet spot.

 

[FiftyOuts]

Show Me some 100 yard groups of rounds that are Seated .003" (less than the Thickness of a Sheet of Paper) apart and You can Prove Your Point... After all It's Your Bullets and Components that You're Wasting...

 

[JEFFPPC]

Show Me some 100 yard groups of rounds that are Seated .003" (less than the Thickness of a Sheet of Paper) apart and You can Prove Your Point... After all It's Your Bullets and Components that You're Wasting...

I do not have time for this conversation. I have a friend who explains things with this , and I quote"You cant fix supid."

 

[FiftyOuts]

You Made My Point !!!

 

[Ned Ludd]

Anyone doing a Seating Depth Test at .003" Intervals is wasting time... There is No discernable difference in POI with that Little bit of Seating Difference. A more Realistic difference is more like .008-010" on each interval...

I'm afraid that is not correct. You're wasting time if you don't test in small increments. It is quite easy to see huge differences in group size/shape over as little as one or two .003" seating depth increments. In fact, it's not at all uncommon to observe such behavior. If you use .008" to .010" intervals, you will may miss the optimal window completely.

There is certainly a place for testing in larger increments. For example, Berger reported a method years ago designed for testing seating depth with VLD bullets that are sometimes difficult to tune. The method uses very large seating depth increments initially, to cover a very wide window in order find a seating depth region that better than the others. Then you go back and re-test over just that one region using smaller increments.

https://bergerbullets.com/getting-the-best-precision-and-accuracy-from-vld-bullets-in-your-rifle/

 

[eric n]

Show Me some 100 yard groups of rounds that are Seated .003" (less than the Thickness of a Sheet of Paper) apart and You can Prove Your Point... After all It's Your Bullets and Components that You're Wasting...

200 with a dasher. It repeated close enough...

 

[FiftyOuts]

Ned, The Berger Article makes Perfect Sense. Like Eric said, You will take too much time seating at .003" until you find the Sweet Spot... Then Fine Tune ...

 

[Richard Coody]

I can see .003 increments with a 6ppc or 30 br or.some other rifle shooting in the 1's. You are going to be chasing tune with those daily anyway.

But for most a seating depth window that is .003 or less is too narrow to deal with. Just like powder charges. I have found powder charge variations often that were 0.10 or.greater and seating depth variations that had .010 and greater variation . much more forgiving with wider.windows.both for.seating depth and powder charges.

Of course if you are.shooting i the 1's and going for.0's then everything is critical.

 

[JFrank]

I find that .005 increments allows me to identify tendencies quite easily

 

[pingunit]

Hi Everyone!

On a site I visit quite regularly, there are some great articles discussing this same topic. Here are links to the topics for your viewing pleasures -->

https://precisionrifleblog.com/2020/03/21/bullet-jump-and-seating-depth-reloading-best-practices/
https://precisionrifleblog.com/2020/03/24/how-fast-does-a-barrel-wear/
https://precisionrifleblog.com/2020/03/29/bullet-jump-load-development/

There's also an older article describing two ways to very accurately and repeatedly measure the distance to the lands on your rifle, here -->

https://precisionrifleblog.com/how-to-measure-the-distance-to-the-lands-on-your-rifle-barrel/

Hopefully something in there helps!

 

[KY_Windage]

Anyone doing a Seating Depth Test at .003" Intervals is wasting time... There is No discernable difference in POI with that Little bit of Seating Difference. A more Realistic difference is more like .008-010" on each interval...

That's funny, I was just about to say that unless they were testing at .001" intervals they were wasting their time.

 

[DHuffman]

Show Me some 100 yard groups of rounds that are Seated .003" (less than the Thickness of a Sheet of Paper) apart and You can Prove Your Point... After all It's Your Bullets and Components that You're Wasting...

Like this ??? I've got a better one hang on.

 

[KY_Windage]

Square IS a value. You want a number, measure the bullet depth, with a comparator, when you get square marks. That is a starting point, extrapolated to a "real value", as you say.
These are "facts".

But what is the point? Why not just find the "touch" depth and use that as the baseline?

 

[DHuffman]

@FiftyOuts or this ?? Much better example.

I don't really think it's a waste of time to cut my groups in half with a little seating depth tuning!

 

[PeteB]

hi Dave,
just inquiring if you found any groups in the 2's under .020" off, or is that where things started to come together.
cheers Pete