Max cartridge lenght? - The Firearms Forum

danurve · 02-10-2004, 09:17 AM

Question for you guys who've determined max overall cartridge length for custom reloading. I tried to follow some unofficial steps on how to do this. Using a prepped case (unprimed & no charge) I started a bullet in the neck. Then placed the round in the chamber and slowly closed the bolt/action with my thumb against the end of the action for a little support / pressure. Then I slowly ejected the cartridge. Did this twice, no stuck bullets and the end result measured the same. I wrote these down but i'm not posting this from home, the rounds were aprox 3/16" longer then the guide sheet from Lee.
This can't be right. Is it? I mean a big caution flag goes up in my mind. The end of the bullet even on the boat-tail / spitzer is still under where the neck begins to taper so the bullet is in the neck, but this just does not seem right. My first thought was the neck was to tight and the bullet is to far up in the chamber. For now I'm continuing to load not exceeding factory max lenghts. But the idea is to eliminate the bullet 'jump' and increase accuracy by taking advantage of the rifle's chamber if I'm not mistaken. Any thoughts or advice on this would be appriciated, thanx. Was I bored or what?
Rifle: Remington 700 vls .243
Bullets: Nosler 90 gr.bt / Sierra 85 gr. bthp

inplanotx · 02-11-2004, 01:23 AM

Danurve,
A lot of rifles will accept long cartridges due to a lot of freebore. To find out just how much, take a flat based bullet, not boattail and fit it into the neck backward, base toward the rifling. This will tell you how much freebore you have. I would not seat a bullet out any farther than the bottom of the case neck. You may want to try a longer bullet, meaning heavier. If this works, then figure out your twist rate to see if the rifling will stabilize it. Let us know.

armedandsafe · 02-15-2004, 04:40 PM

Using a flat-base bullet backwards is an easy way to figure actual freebore. Just make sure that the cartridges you produce with long dimensions will fit in the magazine, as well as the chamber. So long as the bullet does not bear on the forward part of the chamber before firing, you are not toooooo long. Some rifles will shoot more accurately with very little freebore and others like a bit more freebore. Leave a few thousandths free bore to avoid excessive chamber pressure and you should be alright. Remember to make up the long master with warm components (100 F or so) and receiver to account for ambient temperature changes. Start with light or medium loads and work up, watching for signs of excessive pressure along the way.

Pops

02-10-2004, 09:17 AM	#1
danurve V.I.P. Member Join Date: Feb 2004 Location: Syracuse (central) NY Posts: 195	Max cartridge lenght? Question for you guys who've determined max overall cartridge length for custom reloading. I tried to follow some unofficial steps on how to do this. Using a prepped case (unprimed & no charge) I started a bullet in the neck. Then placed the round in the chamber and slowly closed the bolt/action with my thumb against the end of the action for a little support / pressure. Then I slowly ejected the cartridge. Did this twice, no stuck bullets and the end result measured the same. I wrote these down but i'm not posting this from home, the rounds were aprox 3/16" longer then the guide sheet from Lee. This can't be right. Is it? I mean a big caution flag goes up in my mind. The end of the bullet even on the boat-tail / spitzer is still under where the neck begins to taper so the bullet is in the neck, but this just does not seem right. My first thought was the neck was to tight and the bullet is to far up in the chamber. For now I'm continuing to load not exceeding factory max lenghts. But the idea is to eliminate the bullet 'jump' and increase accuracy by taking advantage of the rifle's chamber if I'm not mistaken. Any thoughts or advice on this would be appriciated, thanx. Was I bored or what? Rifle: Remington 700 vls .243 Bullets: Nosler 90 gr.bt / Sierra 85 gr. bthp __________________ huntNY.US In Memory of Ronald Reagan 1911 - 2004 Success is a well placed shot, don't screw it up. -->

02-11-2004, 01:23 AM	#2
inplanotx Advanced Senior Member Join Date: Jan 2002 Location: Texas Posts: 8,897	Danurve, A lot of rifles will accept long cartridges due to a lot of freebore. To find out just how much, take a flat based bullet, not boattail and fit it into the neck backward, base toward the rifling. This will tell you how much freebore you have. I would not seat a bullet out any farther than the bottom of the case neck. You may want to try a longer bullet, meaning heavier. If this works, then figure out your twist rate to see if the rifling will stabilize it. Let us know. __________________

02-15-2004, 04:40 PM	#3
armedandsafe Former Guest Join Date: Dec 2002 Location: Moses Lake, WA Posts: 10,344	Using a flat-base bullet backwards is an easy way to figure actual freebore. Just make sure that the cartridges you produce with long dimensions will fit in the magazine, as well as the chamber. So long as the bullet does not bear on the forward part of the chamber before firing, you are not toooooo long. Some rifles will shoot more accurately with very little freebore and others like a bit more freebore. Leave a few thousandths free bore to avoid excessive chamber pressure and you should be alright. Remember to make up the long master with warm components (100 F or so) and receiver to account for ambient temperature changes. Start with light or medium loads and work up, watching for signs of excessive pressure along the way. Pops