Ar pistol ammo/reloading

[Skwirl88]

Hi. New here. New to reloading (as in I have some of the equipment but not all of it, so I have never loaded a single round)

So here’s my deal. I’m looking for a round that works well in a PSA 10.5” 556 upper. If I can’t find what I want then I will slowly science my way there within the realm of common sense and reason. Not afraid to science my way there SLOWLY with a LOT of research.

I’m looking to get as close to full size specs as possible. Using a 69gr Sierra blitzking. Yes I’m aware that attainment of this with a 10.5” barrel is impossible since most test barrels are bolt 24” I just want to be to that as reliably as possible this maintaining the expansion properties of the round. Not sure if heavier gr bullets are better for this or not. I would prefer to stick with Sierra blitzking or a vmax or something similarly polymer tipped.
Thanks in advance.

 

[Typetwelve]

That I know of, Sierra doesn't make a 69g BlitzKing projectile, they're only showing weights up to 55 for those in .224" dia. They make a 69g MatchKing, but that's a different deal.

*EDIT*

With that said, you're looking at around -25.34 fps per inch of barrel loss (according to the first thing I saw on the web). Looking directly at Sierra load data, they use a 20" barrel. So, that would mean -240.73 fps per load in your 10.5". Sierra lists load data for a 55g SBK from speeds of 2700-3100 fps. Loading it hot would be taking that 3100 fps - 240.73 = 2859.27 fps or somewhere in that range...that's still cooking right along.

Those are what I use for my 7" AR pistol so I think your 10.5" should be a-ok.

Then again...this site says otherwise:

https://rifleshooter.com/2015/12/22...el-length-and-velocity-26-inches-to-6-inches/

They list a XM193, 55g projectile at 3306 fps from 20", 2767 fps from 10", and a whopper of a drop at 2410 fps from a 7".

Truth be told, this is why I'm swapping mine over to 350 Legend once all of this ammo panic finally passes.

 

[Skwirl88]

I can’t find them either online. But I do have a box from my local Dunham’s to the tune of $35 with nickel plated brass. Yay for reloadIng. That being said. I’ve seen what these did to a gopher @120 yds from a 20” and was satisfied with the results for my intended purposes.

 

[Onewolf]

Any 5.56 or 223 ammo you buy/use will work great in the PSA 10.5" upper. You're making this a lot more difficult than necessary.

 

[BLACKFIN]

Spec Ops use the 10.3” mk18, so the 10.5” should be good to go

 

[Demi-human]

Be careful how you use “Science”.
My governor bastardized it not long ago.
It now just means listening to Scientists you agree with. Using this book, instead of that book, to get a higher maximum could be dangerous. Use actual science and listen to the rifle and brass.



What do you plan to use these for?
200yards, or 15-30 feet?

If the former, then I’d say a pistol is going to be more difficult than average.
If the latter, then get a suitable powder, Hornady VMax 50 grain bullets and work up to a safe and sane maximum.

I’m looking to get as close to full size specs as possible.

They will be. Just that they will be shot out of a short barrel.
Maximum Chamber pressure is maximum.
The chamber doesn’t care how long the barrel is.
The cartridges in that box won’t care they’re in a pistol, they are still “full size”.

I will now make gross assumptions...

An AR pistol for defense will not be so inaccurate that you’ll be looking for precise hair splitting.
Find an upper middle load that functions well in the firearm. Use a hollow point in it. Rock it.
The added weight of a VLD isn’t necessary for penetration in flesh, and the fast velocity rips it apart through barriers, neighbors appreciate that.
If you can take the blast, a 50 grain .223 is about the perfect HD projectile in my opinion.

 

[lordpaxman]

Welcome to the THR!

I would prefer to stick with Sierra blitzking or a vmax or something similarly polymer tipped.

I’ve had good luck with the Hornady Vmax line, but have only employed the 55gr ones. Sierra makes a nice bullet as well but I’ve only used the older SPs.
You mentioned you’re a soon to be new reloader and using science, well there are a lot of choices for components. If you’re shooting for a particular velocity, you’ll obviously need a way to reliably measure that as part of the process. Good luck with your new addiction!