Question About Quickload & A-Frame

derek_hargrave · September 8, 2018, 09:06 AM

Good morning All,

Recently I have been developing a new loads on my .280 AI and trying out different bullets. Yesterday I ran some numbers in QL with a 160 Partition and decided to switch bullets to see what a 160 A Frame looked like...thats when I noticed the pressure curve spike a substantial margin. The bullet lengths according to both websites show the bullet OAL's to be the same.

Can anyone shed some light as to why the shot initiation pressure is much higher. 250 bar (Partition) to 740 bar (A-Frame)--Is the bullet profile that much different that they consider it to touch the lands?

Thanks!

std7mag · September 9, 2018, 09:30 AM

The Swift A Frame is a known pressure spiker.
Bullet construction/material come into play.

disseminator · September 10, 2018, 09:04 PM

I have noticed the same thing with the Hornady XTP bullets vs some other brands.

Different jacket materials and lead hardness.

September 8, 2018, 09:06 AM	#1
derek_hargrave Junior Member Join Date: September 8, 2018 Location: Texas Posts: 1	Question About Quickload & A-Frame Good morning All, Recently I have been developing a new loads on my .280 AI and trying out different bullets. Yesterday I ran some numbers in QL with a 160 Partition and decided to switch bullets to see what a 160 A Frame looked like...thats when I noticed the pressure curve spike a substantial margin. The bullet lengths according to both websites show the bullet OAL's to be the same. Can anyone shed some light as to why the shot initiation pressure is much higher. 250 bar (Partition) to 740 bar (A-Frame)--Is the bullet profile that much different that they consider it to touch the lands? Thanks! Last edited by derek_hargrave; September 8, 2018 at 09:23 AM.

September 9, 2018, 09:30 AM	#2
std7mag Senior Member Join Date: June 23, 2013 Location: Central Taxylvania.. Posts: 3,609	The Swift A Frame is a known pressure spiker. Bullet construction/material come into play. __________________ When our own government declares itself as "tyrannical", where does that leave us??!! "Januarary 6th insurrection". Funny, I didn't see a single piece of rope...

September 10, 2018, 09:04 PM	#3
disseminator Senior Member Join Date: November 26, 2016 Location: Minnesota Posts: 960	I have noticed the same thing with the Hornady XTP bullets vs some other brands. Different jacket materials and lead hardness.