Ogive length vs Overall length in the .222

[elpac3]

Need a reality check here.

Been doing some loading for the Remington 722, .222 Remington. Started measuring overall seated length as well as ogive length in an effort to shrink the groups.

Started with a Sierra 52 grain Matchking. Measured my Ogive length then overall seated length. Backed off .010 off the lands. Round after round came off the press exact overall length and matching ogive length.

Was working with some Nosler, 40 grain ballistic tips tonight. Measured out the ogive length as 1.838 which gave me an overall seated length of 2.238". Back off .010 on the OAL and loaded 20 rounds. When I measured the OAL, all the rounds came out 2.228 +/- .002. Measuring the ogive I expected to see the round measuring 1.828 +/- .002. What I am seeing is my ogive length coming in between 1.826 to 1.821. The variation on ogive length is not necessarily correlating with the overall seated length.

Is what I am seeing just variation from bullet to bullet due to manufacturing tolerances? Did not see the same with the Matchkings.

 

[DWalt]

For bullets of the same style, weight, and manufacturer, the ogive radii should be pretty much identical. If you change any of those three, the ogive radii are very likely to be different, and the cartridge OAL, in order to get to get the same seating in the chamber throat, will have to be adjusted.

 

[H Richard]

What he said, I load the Speer 52 gr. HP and it has a more forward ogive compared to several others. The Hornady (to me) have the most gradual taper reflected in the ogive. Any change of brand will change the OAL.

 

[elpac3]

complete understand changing brands, bullet weights etc. will change ogive - lands distance.

What I seem to be experiencing is for the Nosler 40 grain ballistic tip seated to 2.225, the ogive distance seems to vary even though the seated overall length remains constant.

 

[Nevada Ed]

You can usually go to the maximum OAL with the smaller 52gr bullets and less without ant chamber/rifling problems.

I had to watch the OAL length with a few RN 55gr bullets, the Sierra 63 gr and the blunt 70gr Speer.

Some think if the load will fit a magazine or clip they are good to go............
but not always so.
I had one rifle that the load fit the magazine but the bullet was hitting the rifling !!

Most of my rifles like a little room with full loads while with light target loads, a bullet just off the rifling will get better groups.
Just depends on the rifle. I have a 1903 30-06 that likes a load at 3.34" OAL..........nothing more and nothing less. This leaves out most 150gr bullets or less, in weight.

 

[Ivan the Butcher]

One of the things that causes variations within the same brand and sometimes even the same box of bullets, is the manufacturer has more than on final striking die. When 6.5 x 284 first became popular a friend found that SMK 139 gr had 3 different ogives, only by a couple 1000ths. So he would dump all his 139 grain SMK's in a bowl and measure each bullet, they would all end up in three piles. He usually bought the bullets in 500 or 1000 piece lots, and measuring them was a rainy day job!

Was all this worth it? His first of three rifles in that round would group around 1.5" at 800 yards. He loaned that rifle to 1st Recon Batt. when they did a tour in Afghanistan, he sent about 250 rounds of ammo. They used about 25 rounds and returned the empties along with the gun and ammo two years later. The 25 rounds accounted for sighting in and 8 kills. We don't think the rifle ever went on patrol, as it weighed 19.5 pounds. We all like a good rifle around for when a pest needs taken out!

Ivan

 

[fredj338]

There is always some ogive/point variation in bullets. Match bullets have less variation but dial up 0.002" on your calipers, it means nothing as to accuracy.