RS52 and 308W load data

[22lrman]

On 8/13/2018 at 1:46 PM, Malxwal said:

Looking at this change to burn rate, has piqued my interest, mainly in understanding more. I tried changing the burn rate for my own load using Nosler 125gr bullets, and see that only a change up to 0.5100 is required to match my chrono'd velocities of 3010. Looking at it, the given value of 0.5045 gives a velocity of 20fps lower for my load.

So, modifying burn rate only applies to a given load, , in this case the 150gr and up bullets; if using 0.55 in my other loads/rounds, they subsequently appear to be over pressure.

What other factor should be changed as a constant so that RS52 QL data can be more accurate across the board ?

This was ONLY adjusted for the RS52 powder batch I have and in my gun/ chrono combination. As QL was no where near on velocity to what I measured.

if your QL is within 20fps I would leave the Ba alone. Mine was around 100fps out. 

i leave settings the same for all other powders.

I don’t reccomend changing it  unless you know exactly what you are doing . It can get you in to trouble pressure wise. If you are only playing around with QL for learning that’s a great way to learn, but please make a clearly labelled copy of the powder file in case you accidentally save your new settings in to the original powder file name. And get it mixed up later . 

Happy learning. 

[JK987]

Hello,

I happened to find this thread with google. I've been reloading about two years now.

I did some load development with RS52 & 155gr Lapua Scenar, here are my results:

CZ550 .308Win Varmint, 520mm / ~20,5" (from breech to muzzle) stock CZ barrel with 1/12"twist, installed suppressor and shortened barrel from 660mm -> 520mm.

New Lapua Full-sized case, capacity 56,0gr H20 on fired case.

Magtech 9½ Large Rifle Primers

LOA 72,4mm / 2.850" Slightly touching lands.

Velocities does not make any sense when compared to Quickload predictions.

I got a primer cratering at 47,5gr. Also noticed few minor cratering on the lower loads here and there when I did some further inspection at home. No flattened primers, all look equally good, small stamps on the primers still visible. No stiff bolt lift. I've noticed that the bolt lift is always a little bit stiffer after firing compared to chambering a new round.

Best grouping was at 45,1gr and the velocity was pretty consistent too.

When analyzed my results at home, I got a bit confused because the velocities are far more than they should be, when compared with quickload. To get +850ms or 2800fps from short barrel like mine, the pressure should be over CIP Max. Maybe a "fast" barrel or excessive pressure, or both.

Any ideas? Tips?

Cheers!

 

[Re-Pete]

What Laurie said.........do not trust Quickload when using RS52. Always start at least 15% lower than suggested and look for pressure signs.

Having said that, I've found it to be a brilliant powder for 308, 223, 6.5x47L, and 6BR, but a bit heavy on barrels.

Pete

[VarmLR]

I use RS50 which I find betters N140 in that it doesn't appear to give the same pressure spikes when a little hot and appears to give higher velocities despite being almost the same in terms of energy.  I've found that you can safely substitute N140 loads direct to RS50, but I have loaded up RS50 a little higher without the pressure signs I got from N140.  It's now my go-to powder for the .308 and the heavy .223 bullets over 70gr.