5.7x28 Alternative Propellants

[twarr1]

I’ve only seen load data for 3 propellants for the 5.7x28; AA5,AA7 and Ramshot True Blue. My hypothesis is, FN struck a compromise for the 5.7 to create a cartridge that would work in both the FiveSeven and P90 and the available loads aren’t optimized for either. Perhaps a better load could be made if loaded just for the pistol. Specific, reduce the radical case stretch.
Any thoughts on powders other than the 3 above?

 

[Rule3]

Longshot
Power Pistol

 

[twarr1]

Longshot
Power Pistol

Curious why? Power Pistol being faster and Longshot even slower than AA7. I’m thinking a faster propellant with a similar brisance might be appropriate

 

[thump_rrr]

You do realize that there is an entire forum dedicated to that caliber that goes by the same name.
In my quick search there is a load for CFE Pistol.

I personally found 2lbs.of Accurate No.7 which should be able to produce over 2,000 rounds so I’ll be good for a while.

 

[twarr1]

I asked the question here because of the quality of this forum and the impressive depth of knowledge. There are other (unnamed) forums that I feel are a disservice to the reloading community. And individuals on those forums, in my opinion, and again unnamed, who seem to make it their life purpose to spread misinformation for personal benefit and ‘glory’
Thank goodness we have THR as an alternative.

 

[ericuda]

I'd stick with published loads and powder, if other powders would work better they would be published. The 5.7 is not a round to experiment with.

 

[Rule3]

Curious why? Power Pistol being faster and Longshot even slower than AA7. I’m thinking a faster propellant with a similar brisance might be appropriate

The data is out there by qualified people in one of the many other threads. I am not listing it as I have before and there are some posts from people that give out wrong information and take the reloading of 5.7 with a nonchalant attitude.

 

[GeoDudeFlorida]

I’ve only seen load data for 3 propellants for the 5.7x28; AA5,AA7 and Ramshot True Blue. My hypothesis is, FN struck a compromise for the 5.7 to create a cartridge that would work in both the FiveSeven and P90 and the available loads aren’t optimized for either. Perhaps a better load could be made if loaded just for the pistol. Specific, reduce the radical case stretch.
Any thoughts on powders other than the 3 above?

It could be because FN is based out of Belgium they chose Belgian-made powders for their load development. Factory loadings are typically not optimized for any one platform but to perform adequately on any platform. Given the link between Shooter's World/Lovex and Accurate/Ramshot powders, it's possible.
...from the Comparable powders thread:
Accurate No. 5 and Shooters World Auto Pistol/Lovex D036-03 are comparable, not the same
Accurate No. 7 and Shooters World Major Pistol/Lovex D037-01 ibid.
True Blue is the one loner of those listed. Made in Belgium, though. It is a double-base, spherical powder with properties similar to Unique.

I think before going down the development road it might be good to have a goal in mind: reducing cost, recoil, improving accuracy, case life, etc. I would suggest sticking with True Blue since it is primarily a pistol powder. I guess you could try looking at Silhouette or Green Dot? Maybe. Not sure what you've got in inventory and finding powders right now is NOT a pleasant chore.

 

[twarr1]

I have plenty of True Blue. I’ve worked up an accurate load with it, but my concern now is extending case life.

 

[N555]

I have used HS-6, AA7 and AA9.
I think AA9 would be better in a carbine, sbr. As AA9 produced a spectacular muzzle flash in the fiveseven pistol.
I'm going to try a very tiny charge unique for a pistol only load, somewhere around 3gr or less depending on the bullet weigh.

 

[GeoDudeFlorida]

my concern now is extending case life.

Ah, yes. The dilemma of every handloader: case life, power, accuracy, reliability... what do you sacrifice? Do you have to sacrifice anything? This is why we do it.
I don't own a 5.7 but this topic is fascinating. I'll learn a lot from what you discover. Good luck.