Trying to get my head around O-Give

[LongRanger]

I do understand what it is and have for many years but now I know more than I ever wanted thanks to an OCD friend of mine and after researching it for the last few weeks but what I don't understand is the advantage of trimming my bullet tips to a uniform length from the O-Give to the tip of the projectile. Since the bullet seating die uses the O-Give portion of the bullet to press it into the shell, what difference could the .002 to .004 variation in over all length of the finished product make? The bullet will engage the riffling at the same point if you are using quality bullets and seating dies so why should I care if the tip is a few thou longer from cartridge to cartridge? I have the necessary tools to both measure and trim them all the same but why add an extra step to the process if all I'm doing is following in the footsteps of the OCD friend that got me wondering about this. I know quite a few re-loader's and have been reloading since the mid 70s. Some of the people I've asked this question to have either told me they don't worry about such things or have no idea what I'm talking about. I reload mostly .308 for my Remington 700 SPS and 45 ACP for my Sig P-220 and have never heard of this process until about a month ago, did I miss something? Maybe I spend too much time in the basement reloading and not enough posting and reading forums.

Thanks

 

[P7id10t]

Preface:
This is a sniper's forum so in theory, the people visiting and contributing are better than your average shooters. I've never competed, so don't know but figure I'd have my ass handed to me.

That said:
If you think making your bullets uniform will increase your accuracy, more power to you. Just more OCD crap in my mind.

 

[azimutha]

I can't see how it could possible matter. Some people uniform the meplat, which can have a slight effect on accuracy. Beyond a certain point to assure uniformity, you're just better off getting more time firing than tuning handloads.

 

[ksthomas]

LongRanger,

It's pronounced, "oh-jive", and is a French architectural term meaning "pointed arch." Look at the windows in cathedrals, and you get the idea. Pointing and tipping are attempts to bring the BC in a greater degree of uniformity, which can be of some importance at long range. If you look at a bunch of new, factory HPBT Match bullets, you'll see that there's a certain degree on non-uniformity among them. This is due to the way the bullets form, differences in the amount of lube in the form die, differences in the material or a dozen other minor details. These variances create some difference in measured BCs, which translate into vertical dispersion at distance. For most shooting, these differences are insignificant, and you probably shouldn't bother worrying about them. If you're actually doing some serious 1,000 yard competition, it's something at which you may want to take a closer look. Uniforming involves trimming the tips back to where they are the same size at the meplat (the flat at the very point of the ogive), thus bringing the BCs into line, but lowering it by some degree. Pointing repoints the bullet in an attempt to close the hollow point down just a bit further, thus raising the BC by a bit. Most serious LR shooters use both, uniforming first, and then pointing as a finishing step.

Hope that helps.

 

[LongRanger]

Thanks to all, I shoot Long Range steel and have for over 20 years and always work up my own loads. When I first heard of this I thought it was a bunch of bull but you don't know unless you ask. There are even companies selling jigs to accomplish this with little effort. As for Range Time I shoot almost every day. We have a 1500 meter Range here on the farm and I'm always looking for an edge like everyone else.

 

[bodywerks]

If you're shooting a 308 at 1500 meters you need all the help you can get! Vertical dispersion at that distance on a 308 has to already be pretty bad, anything to reduce it is a plus.

PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg

 

[armorpl8chikn]

If you're shooting a 308 at 1500 meters you need all the help you can get! Vertical dispersion at that distance on a 308 has to already be pretty bad, anything to reduce it is a plus.

PCR/XLR/TAC338 http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111453_255_zps1b498f0d.jpg http://i813.photobucket.com/albums/zz53/bodywerks/IMG_20130816_111325_951_zps290ebdd0.jpg

A different gun would be far more effective in this scenario than pointing your bullets.


The only answer I can give is predicated on experience, I know that isn't very popular in our virtual world. The way my rifle shoots plain jane unpointed, unsorted, un voodooed, SMKs right out of the box? Lets just say they make me look like a much better shooter than I think I am. I can't imagine ever needing more accuracy than I am getting now at any range I shoot out past 1000yd.

 

[Country]

LongRanger,

It's pronounced, "oh-jive", and is a French architectural term meaning "pointed arch." Look at the windows in cathedrals, and you get the idea. Pointing and tipping are attempts to bring the BC in a greater degree of uniformity, which can be of some importance at long range. If you look at a bunch of new, factory HPBT Match bullets, you'll see that there's a certain degree on non-uniformity among them. This is due to the way the bullets form, differences in the amount of lube in the form die, differences in the material or a dozen other minor details. These variances create some difference in measured BCs, which translate into vertical dispersion at distance. For most shooting, these differences are insignificant, and you probably shouldn't bother worrying about them. If you're actually doing some serious 1,000 yard competition, it's something at which you may want to take a closer look. Uniforming involves trimming the tips back to where they are the same size at the meplat (the flat at the very point of the ogive), thus bringing the BCs into line, but lowering it by some degree. Pointing repoints the bullet in an attempt to close the hollow point down just a bit further, thus raising the BC by a bit. Most serious LR shooters use both, uniforming first, and then pointing as a finishing step.

Hope that helps.

Excellent reply .