OAL vs Ogive

SJAdventures · 02-29-2008, 09:18 PM

Who seats their bullets by OAL and who seats by the Ogive measurement? When seating bullets by OAL I could never get any kind of consistant seating depthvia OAL due to the inconsistant tips on bullets. I have went to seating all my bullets using the Hornady's Comparator gauge and am finally getting consistant seating measurements.

02-29-2008, 09:37 PM

Quote:

ORIGINAL: SJAdventures

Who seats their bullets by OCL and who seats by the Ogive measurement? When seating bullets by OCL I could never get any kind of consistant seating depthvia OCL due to the inconsistant tips on bullets. I have went to seating all my bullets using the Hornady's Comparator gauge and am finally getting consistant seating measurements.

absolutely, I have two different ones, one from wilson and the stoney point version. Every reloader should have one.

gunnermhr · 03-01-2008, 06:19 AM

Do you mean OAL Over All Length? I always seat to the Ogive that way you can actually determine how much bullet "jump" You have into the lands of the barrel. Some bullets like to be seated into the lands some just touching and some.010" or 015 thousands off.

HEAD0001 · 03-01-2008, 08:53 AM

I imagine he means Overall Cartridge Length. The proper way to measure is obviously to the Ogive. I use the Sinclair measuring tool, it is simple to use, and works great. But it is also proper to measure the bullet by the weight.

Different bullet mfrs. seem to pay attention to ogive while others seem to pay more attention to overall bullet weight. It has been my experience that Sierra bullets have less weight variation, while Hornady has more weight variation. But then Hornady ogive's have been more consitent than Sierra.

IMO this benefits Hornady in the lighter weight varmint bullets, and it benefits Sierra in the heavier big game bullets. This may sound silly but I have watched it over the years , and it has been fairly consistent. I have went through whole boxes of Sierra 155 grain Palma's that have not varied more than .1 of a grain. Tom.

03-01-2008, 08:58 AM

Quote:

ORIGINAL: gunnermhr

Do you mean OAL Over All Length? I always seat to the Ogive that way you can actually determine how much bullet "jump" You have into the lands of the barrel. Some bullets like to be seated into the lands some just touching and some.010" or 015 thousands off.

Hate to speak for him, but what I think he is asking, when he is setting up his seater die for bullet deapth, do you measure off the tip (from your notes of course), or use a comparitor and set up your seater die off that measurement.

gunnermhr · 03-01-2008, 10:03 AM

I never heard overall length refered as OCL. My bad!

SJAdventures · 03-01-2008, 10:38 AM

Quote:

ORIGINAL: gunnermhr

I never heard overall length refered as OCL. My bad!

Sorry for the confusing typo, meant OAL

SJAdventures · 03-01-2008, 10:40 AM

By measuring off the Ogive which will give the most consistant bullet seating depth why would OAL even be important as long as it cycles in your rifle?

SJAdventures · 03-01-2008, 12:43 PM

I apologise but I had it backwards. I re-read the article and the case neck actually gets thicker with each firing and resizing due to brass flowing forward from the case walls getting thinner from repeated shooting and resizing and thickening case necks can cause a shell to fit too snuggly into a chamber not allowing the bullet to be freely discharged out of the casing properly causing a dangerous increase of pressure. It says when a case needs it's 5th trimming it is usually just best to throw it away. It stresses to maintain awareness of how thickthe case necks are getting with each resizing, how many actually do this? I don'tbut should I be since I do FLS each time?

Tom W. · 03-01-2008, 04:26 PM

I'm just a bit less anal than some, I suppose. The only time I had any trouble with any rifle brass was when I used some probably twice (or more) fired Nickle plated brass when fire forming loads for my 30-06 a.i. Seeing how it's a single shot, I don't have to worry about it cycling in the action. I have a Stoney Point OAL Gage, but generally just seat my bullets to a specified COL that I have predetermined. The GameKings, with their exposed lead tips don't always measure the same, but the polymer tipped bullets usually all measure the same. I still trim the case after each firing and resize, though, just because....