Comments on: Berger Article on Cartridge Overall Length and Base-to-Ogive

By: John Miller

John Miller — Thu, 23 May 2013 12:03:04 +0000

RCBS precision mics are a great tool for this. I have a set for every cal. I load.

By: Dave White

Dave White — Mon, 20 May 2013 19:43:14 +0000

Obviously, COAL does matter for magazine feeding…

By: Dave White

Dave White — Mon, 20 May 2013 17:26:46 +0000

Good article, and one which shows that the COAL is an ineffective term, at best. My own loading terminology is to use the term “OCOAL”, which is the Cartridge Overall Length, as measured to the Ojive. I also use Sinclair Comparitor (nuts), that add about 1 inch to that measurement; the result I document as COCOAL (Comparitor Ojive COAL). It really does not matter where the end of the bullet is, thus COAL is really meaningless, and potentially problematic is comparing the various bullet tapers…

By: bob

bob — Mon, 20 May 2013 04:18:28 +0000

I have been doing this for years except using a slighter slower powder to gain results.

By: Steve Hurt

Steve Hurt — Sun, 19 May 2013 23:43:25 +0000

These principles explained so well by Mr. Lytz have been included in the QuickLoad program, at least in working principle, even if the numbers are not absolute.
That this program has no capacity to introduce individual jump to the lands numbers, or the pressure increases that seating into the lands at various tensions might generate, may present an insurmountable mathematical challenge for the program, but it is a great starting point.
As Mr Litz so rightly points out, since the original SAAMI standards were developed, so much has changed. Just look at the variances in Shot Start Initiation Pressures (SSIP)for different projectiles today, compared to when most bullets used to be swaged, jacketed lead.
This variance alone has expanded by a factor of six times (6,000 psi!)over the last 20 years, due to changes in materials and designs used in modern projectiles today. I have never seen this issue discussed and would love to see the relationship between SSIP and bullet seating depth explored in greater detail.
Genuinely looking forward to part two and more…