COL?

[1911 guy]

O.K., trick explained and tech. correct.

The case will headspace off the shoulder, as normal for a .223. The ring of brass is held on by a bullet seated LONGER than max. OAL. When chambered, the brass ring is pushed down by your rifle, as is the bullet. You now have a "dummy" round that will tell you max case length for your rifle and max OAL for your rifle. Max. OAL is specific to that particular bullet, due to the ogive. Sorry for being too practical.

 

[Bullet]

“Final case position will depend on chamber dimensions and case length - assuming here a rimless. The case mouth will headspace according to the chamber. Following that is the need for no slack or space between bolt face and round once chambered. These factors are why case trimming when reloading is important - the stretch of a fired case making it slightly longer and so affecting headspacing.”

While your cartridge should headspace on the shoulder if your neck length was to become to long your cartridge would try to headspace from the neck. This is why you need to check Max case length and trim your cases as needed. Most listed trim lengths are probably shorter than necessary.

 

[SgtRock04]

How far off the lands?

Ok USSR, i've read all posts here & reloading methods of Lee,Hornady 7th,Nosler 6th,Speer 14th,Lyman 48 & 49th(reloading for about 3 years rifle & pistol,consider myself an intermediate student of this game).They are all talking about "safe" distance from the lands for obvious liability reasons,I understand their position.What i'm finding is: after measuring OAL to the lands & then coming back say 10-15thousands that sometimes it feels & looks like bullets are touching lands?I base this observation on marks on bullets' ogive after loading into chamber with bolt closed.Now, I've also learned that each Bullet manufact'r has diff/several machines that (extrude?) make these bullets,& therefore their ogives are diff.All i'm really trying to determine is variance of ogives(Sierra matchking bthp .223 69gr Savage Model 12) & of course Best accuracy while remaining "safe".I have friends who are competitive long distance rifle guys who load .223 onto lands??!! which i would never do!, but,it's very confusing to try to extrapolate the real truth from all this info & come out "safe" & on top of Best accuracy? SgtRock04

 

[LiveLife]

SgtRock04, USSR made his post on November 25-26, 2005 - yes, 2005.

 

[Walkalong]

it's very confusing to try to extrapolate the real truth from all this

It's very confusing reading run on sentences with poor punctuation etc.

USSR is active, by the way.

USSR made his post on November 25-26, 2005 - yes, 2005.

A new thread with a well thought out and written question would be the way to go.

 

[LiveLife]

A new thread with a well thought out and written question would be the way to go.

And make it a sticky, once and for all.

 

[918v]

To find the rifling, I use the slit case method. I tale a neck-sized case, cut a slit lengthwise in the neck. The resulting case will hold the bullet firmly, but will allow bullet seating under finger pressure.

I seat the bullet long, chamber, and close the bolt. I carefully eject the dummy round. I do this three times and measure the OAL.

Understand that bullets are made on many machines and a box of 100 may contain seven or eight different ones. They may differ in ogjive position and profile as much as .010" and will frustrate your efforts. If you use custom bullets, made on a single die, then you can load them just to touch the rifling, or jam it in there a fixed amount, or jump to the rifling from a fixed distance- consistently.

I have found that jumping bullets can be just as accurate as jamming bullets into the rifling. Jumping is less of a hassle, so I load to magazine length and jump them.

 

[918v]

There are various ways to check in rifle but - easy way for me is to load and seat a bullet in a sized but empty case - just neck tension hold, no crimp - leaving excessive COL - then chamber the round slowly to bolt lock up. Remove and inspect for signs of rifling.

The problem with this is a case sized using a conventional standard die will have so much neck tension on the bullet that it will not allow the bullet to slide deeper in the neck as the round is chambered. Instead, the case will force the bullet deeper into the rifling, mangling the ogjive, and giving you a false reading if you are ever able to eject the round in one piece.

 

[SgtRock04]

I didn't realize I was in English class & being marked by Mrs.Lubner.I'll try harder next time.

 

[918v]

Remaining "safe" means working up the load from min to max. If you wanna have your bullets loaded into the lands, then work-up your load THAT way. If you wanna jump the bullets, work-up your load THAT way. But don't work-up a load by jumping bullets and then change your mind mid stream.

 

[Walkalong]

I didn't realize I was in English class & being marked by Mrs.Lubner.I'll try harder next time

Your not. Just saying your garbled post was hard to read and decipher exactly what you really wanted to know.

Take it or leave it, but good clear questions get better answers.

 

[USSR]

SgtRock04,

I replied to your PM. Hope it is of some help.

Don

 

[243winxb]

SftRock04 http://www.brownells.com/.aspx/lid=11470/guntechdetail/Gauging_Success___Minimum_Headspace_and_Maximum_COL

 

[SgtRock04]

USSR & 243winxb, Thanks for your help,much appreciated! Article & information both are top notch! Walkalong,..... move to the classroom. SgtRock04

 

[Walkalong]

I hear ya sarge. Guess I'm just cranky today.

 

[SgtRock04]

How far off the lands?

Na, your right, i was just trying to formulate. Shoot'em Long 'n Straight Walkalong! SgtRock04

 

[243winxb]

On thing i find interesting is the Quickload program data. A guy on here, Afy, said seating into the lands can raise pressure 10,000 psi. on a bottle neck case. If your running maximum pressure with the bullet seated off the lands, then go to a jam, this could not be good pressure wise. This is if the Quickload program is correct?? I think this happens a lot with the 223/5.56 when shooters are loading heavy 80gr bullets for 600 yds and pushing them to the maximum. I see to many photos of the brass coming apart. See some here > http://photobucket.com/joe1944usa