Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Hunting
The Basics, Starting Out
Probably a stupid question
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="BillNye" data-source="post: 2691791" data-attributes="member: 114642"><p>There's a couple parts to this. Older cartridges, like the 30-06, are typically designed around lighter for caliber bullets with more rounded noses and less pronounced boatails, generally meaning shorter. As a result, the SAMMI specifications usually include slower barrel twist rates (that can't stabilize longer bullets) and less distance from the brass to the start of the rifling (freebore). As a result, the 30-06 is usually made with a 1:10 or 1:11 twist barrel that stabilizes up to around 200 grain lead or 180 grain copper bullets. For comparison the 300 PRC is usually built on a 1:9 twist barrel that will stabilize up to 230 grain lead or 200 grain copper bullets. So the bullets for a PRC or Creedmoor are indeed usually longer.</p><p></p><p>In addition to this, modern cartridge design usually involves seating bullets with the boat tail above or at the neck/shoulder junction of the case in order to maximize use of space within the case for powder and minimize yaw on the bullet as it leaves the case. Cartridges, particularly custom chamberings are designed or built with sufficient freebore to fit relatively long bullets without the bullet being forced into the case or into the rifling. All of this necessitates either the use of longer magazines or shorter brass relative to the magazine length in order to fit the longer bullets seated out further.</p><p></p><p>So to answer your question, a more modern case design like the PRC or Creedmoor both uses longer bullets and seats them further out in the case than a comparable older design. That said, there's no reason a custom barrel chambered in an older design like the 30-06 or 260 remington can't have a faster twist rate and longer freebore and perform just as well as a newer cartridge. A last note though, the design trend has also moved towards cartridges with shorter, wider powder columns to promote more consistent combustion as well as steeper shoulders, less case taper, and longer necks, a design that takes advantage of more consistent modern machining to trade ease of feeding (largely not a problem in modern actions/magazines) for less case stretch and longer barrel life</p></blockquote><p></p>
[QUOTE="BillNye, post: 2691791, member: 114642"] There's a couple parts to this. Older cartridges, like the 30-06, are typically designed around lighter for caliber bullets with more rounded noses and less pronounced boatails, generally meaning shorter. As a result, the SAMMI specifications usually include slower barrel twist rates (that can't stabilize longer bullets) and less distance from the brass to the start of the rifling (freebore). As a result, the 30-06 is usually made with a 1:10 or 1:11 twist barrel that stabilizes up to around 200 grain lead or 180 grain copper bullets. For comparison the 300 PRC is usually built on a 1:9 twist barrel that will stabilize up to 230 grain lead or 200 grain copper bullets. So the bullets for a PRC or Creedmoor are indeed usually longer. In addition to this, modern cartridge design usually involves seating bullets with the boat tail above or at the neck/shoulder junction of the case in order to maximize use of space within the case for powder and minimize yaw on the bullet as it leaves the case. Cartridges, particularly custom chamberings are designed or built with sufficient freebore to fit relatively long bullets without the bullet being forced into the case or into the rifling. All of this necessitates either the use of longer magazines or shorter brass relative to the magazine length in order to fit the longer bullets seated out further. So to answer your question, a more modern case design like the PRC or Creedmoor both uses longer bullets and seats them further out in the case than a comparable older design. That said, there's no reason a custom barrel chambered in an older design like the 30-06 or 260 remington can't have a faster twist rate and longer freebore and perform just as well as a newer cartridge. A last note though, the design trend has also moved towards cartridges with shorter, wider powder columns to promote more consistent combustion as well as steeper shoulders, less case taper, and longer necks, a design that takes advantage of more consistent modern machining to trade ease of feeding (largely not a problem in modern actions/magazines) for less case stretch and longer barrel life [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Hunting
The Basics, Starting Out
Probably a stupid question
Top