Thread: QL or GRT help please

Am trying to work up load for 7PRC using RL22 & 165gn Norma BondStrike pills…. ‘Cos I have decent supply of both. COL is 3.285in, Hornady brass. Hard to find much data on RL22. I’ve got a long range load worked out for 180 ELDMS & RL26 in ADG brass. But want to save the good stuff for long range & find a close range load in Hornady brass. Have run a ladder w RL22 from 65gn up to 66.5, no pressure signs and 66.5gn gets 2900 fps which’s seems slow for 165gn pills (22in bbl). Found some info suggesting that 66.2g RL22 was close to max for 160-165 gn pills ? But speed observed suggests I should be able to up the charge. Any one that could run QL or GRT to get a read on max limits would be much appreciated.

There's no 7 PRC in GRT. What's the parent case? Have you measured case volume?

Originally Posted by bjp

There's no 7 PRC in GRT. What's the parent case? Have you measured case volume?

Ok just looked it up, excuse my ignorance. Not a 5min job in GRT as have to add all the cartridge and chamber dimensions... unless someone else has done it already, or downloaded it from somewhere?

Iv got the file for 7prc send me an email and il flick it threw buildbespokeltd@gmail.com

According to published data case capacity is 83gn water

Any luck ?

Originally Posted by Kelton

Iv got the file for 7prc send me an email and il flick it threw buildbespokeltd@gmail.com

did you get my email, sent yesterday?

Originally Posted by bjp

did you get my email, sent yesterday?

just did another internet search and found a copy of the cartridge profile online, so have imported that. Next issue, the Bondstrike pill isn't in GRT either. Can you provide some measurements?
Overall length
Length of boatail
diameter at base of bullet (i.e. the end of the boatail)

I took a stab at projectile dimensions and chucked it in GRT, had to adjust case volume down to get the velocity of 2900 at 66.5gn, here's the results:


would need actual measured case volume, bullet dimensions, and jump to lands to tweak it some more, but looks like it might be possible to go slighter higher. Bear in mind its based on a downloaded cartridge file done by someone else, not checked in detail by me either, so use info with caution!

At 67.0gn, velocity increases by 20 fps, pressure increases to 63200 psi...

But it does look like the ideal powder for the load.

165 BS is 1.458 OAL
0.200 length of BT
Base of BT 0.245”

correct projectile values, 67gn, attached:

Many thanks, I’ll try a grouping at 66.5 to see what that looks like & extend ladder in 0.3gn steps as well to see what happens to speed & pressure. Based on GRT data looks like velocity gains are modest at best.