Ogive?!?!?! or just jive?


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Old 11-11-2010, 05:34 AM   #1
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Default Ogive?!?!?! or just jive?

I used to work for an ammo company in 2009. We had Ammoload automated machines. One in 9mm and the other in 45 ACP. The owner started off with top shelf components and the machines ran perfectly. Then he started using cheaper components and the machines jammed constantly. one problem that we butted heads about was cartridge over all length. He liked loading to max length citing "reduced pressure issues". I said the loads we were using weren't max loads so we had no problem with pressure. The thing that bothered me was that we changed bullet brands a lot...whatever was cheaper. All 230 gr FMJ's in 45. he said as long as it fit in the gauge it was fine. I said no way. The ogive of the bullets are different, therefore the seating depth must change. I suggested he use a barrel from on of the many new 1911's we had for sale...or even get a cheap GI barrel to use for a test gauge. "No need, as long as it fits in the chamber gauge and doesn't stick out of the top we will be fine!" WRONG!! I was taught that the chamber gauge is fine for checking the fit of the round but not actually the OAL. Ogive is what messes that up. If you have 2 same weight bullets in the same caliber; one with a pointier profile versus a blunt profile, you have to seat the blunt bullet a little deeper or it will touch the lands in the barrel.....Not what you want in an autoloading pistol! THAT's when you get pressure problems! Use a barrel for that caliber...I use my CZ barrel for 9mm and an old Series 70 barrel (with the collet bushing still attached!) for 45 ACP. When you drop in the round you should hear a poik sound (hard to describe.....let alone spell!) and the round should turn freely in the chamber. If it is too long you will hear a very dull sound as the bullet hits the lands and it will not turn easily in the chamber. You can also see scratches from the lands on the bullet when you remove the round from the barrel. Sounds so basic but I only learned it 3 years ago after loading since 1986! Thank you D.K. the master loader of Miami! He is the Yoda reloda! hahaha!



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Old 11-11-2010, 01:25 PM   #2
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i reset my seating die after checking a loaded round to make sure i am jusssst under the MOAL. since i have several different 45's and i use under max loads a little deeper seat isnt going to make any differences. however you should use a gauge or caliper or micrometer to actually judge the oal of the round. not a drop test into a barrel as a final determiner. chambers are all made to a minimum standard size that the MOAL will fit.

your boss should have checked the run to ensure each batch at each component change hadnt chaged.

if you are hand fitting the round to a spefific gun you can exceed the MOAL if your particualr chamber allows it. and chambering a round and adjusting from there is a viable means of doing so.



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Old 11-12-2010, 09:46 PM   #3
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Default The Science of COL

Your boss was a little blase and you worry too much and expect the world to be controlled by rules.
The best gage is the barrel of the gun. No body NEEDS calipers or case gages or such. They help, but aren't needed.
I always start off testing of a new bullet by determining the max COL that works in my guns. Your boss had to worry about all guns, and the case gage was what he should go by.
Some barrels have rifling a LONG way down the barrel. Others have the rifling very CLOSE to the end of the chamber.
Some people believe that there is a science to COL and they measure the bore diameter of the bullet and have their own idea about how much of the bore diameter section has to be beyond the case mouth.
The best test is to load an inert dummy round or two and determine the longest COL that does not push the bullet into the rifling (unless you are firing a lead bullet at light target velocity), fits in the magazine (or the cylinder), and feeds and fully chambers in the gun.

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Old 11-13-2010, 02:10 AM   #4
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i disagree about gages. if your loading commercially a gage must be used since you cant test with the barrel that everyone one of your customers is using.

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