Jump to content

Best loads for short barrelled 5.56/.223?


Recommended Posts

Does anyone know of any good loads for these?

 

Not a Saiga, but I recently bought an AR-pattern 5.56 Pistol with a 7.5" barrel, 1:9 twist. I'm wondering if any reloaders have worked-up some good loads with a faster-burning powder that gives good pistol and bullet performance, without the fireball and muzzle blast of a cartridge designed for a rifle?

 

I wish I had noticed the faster twist rate before I bought it, but "oh well." I'm hoping I might be able to work up a decent load with a 60gr. bullet or so. It will take some testing to see if a 60-70 gr. bullet will stabilize at all out of this...

Link to post
Share on other sites

Your best bet is to get some standard, bulk, NATO spec rounds.  The 5.56 round SUCKS out of short barrel rifles, sorry to say.  I have an AR15 with a 10.5" barrel and with I had at least an 11.5".  You might ask why and all I can give you is my opinion as I'm not an expert although I have owned many AR's with different barrel lengths over the past 15 years.  Your optimal length is 20", an minimum FED APPROVED length is 16", and shortest the Marine Corps has is 14.5".  Anything under 14.5" simply wastes too much powder.

 

Wish I had a better answer for you.

 

 

Respectfully,

Gunny NR 

Link to post
Share on other sites

Hard to say how well heavier rounds will stabilize out of that short of a barrel with that twist. Especially at a distance. Best thing to do is test it yourself, and see what works best. Im going to guess that your going to have better results with lighter loads, but its hard to say. You wont get rid of the fireball much either. Too much unused powder. Keep us posted, as Im curious of your findings.

Link to post
Share on other sites

Yeah, with more research I'm thinking this might be a "less than ideal" combination. Since it's an AR though, I'll just change the barrel or get a new upper if needed. ;)

I am already planning on getting one of the forward-facing muzzle brakes for it, like the Noveske, maybe.

Edited by Ronin38
Link to post
Share on other sites

http://ballisticsbytheinch.com/ is a web page that shows how various calibers perform at different barrel lengths. I have a sig P 516 with a 10.5 inch barrel and BBI show it performing better than many seemed to think it would. So far it has been interesting to shoot and the "fireball" isn't really discernable when shooting the gun.

 

If you want to dissipate the fireball, consider a Smith Vortex or Phantom style muzzle brake. They do a surprisingly good job of minimizing the flash.

Link to post
Share on other sites

Thanks, I've been using bbti for a couple years! Great site, sometimes I just plug things in there out of curiosity.  :D

 

I like what I've seen of the newer, forward-facing muzzle brakes. I'd like to try one out just because I have not had one before.  ;)

Not sure I'll pay the bucks for the actual Noveske, though...  :unsure:

Link to post
Share on other sites

The 1:9 twist barrel is definitely going to be your limiting factor with that short a barrel. Typically out of a 16" 1:9, any 5.56/.223 bullet higher than 68 gr can start having stability issues. The issue will be more prominent with the shorter barrel. Lighter bullets will stabilize better. The other option is to replace the barrel with a faster 1:7 twist. With the current barrel, I would start at 55 gr and if you notice any keyholing work your way down in weight from there.

Link to post
Share on other sites

To maximize velocity, and therefore bullet energy, you'll need to go with a faster powder.

 

22gr AA2230 gets you ~2200FPS out of a 7.5" barrel with 85% loading density and a 60 gr Sierra HP bullet.

 

645 ft/lbs muzzle energy

 

I ran the numbers to get the best burn in that short barrel.

 

AA2230 was designed for .223 Remington.

 

A 60gr bullet is the lightest you can expect any accuracy out of with a 1-9" twist. If it doesn't stabilize in your particular barrel, try this 62gr recipie:

 

22gr AA2230 gets you ~2130FPS out of a 7.5" barrel with 85% loading density and a 63 gr Sierra HP bullet.

 

635 ft/lbs muzzle energy

 

Any heavier bullets may not fit/feed properly.

 

With either load, you're still going to get a pretty good muzzle signature. It's the nature of the beast. Rifle caliber in a pistol.

 

Verify this against a loading manual to make sure you're safe. I am not responsible for what you do with this data.

Edited by patriot
  • Like 1
Link to post
Share on other sites

Thanks!  :up:

 

Oh, I'll definitely check that with the loading manuals!  ;)

 

I have a whole bag full of 55 gr. HP bullets, so I'll definitely be working up some loads for those. I also have 100-count boxes of various other bullets in many different sizes. Not sure if I have that powder, I'll check the powder-box later.

Link to post
Share on other sites

Also, most flash suppressors will increase muzzle noise for the shooter.

...and of course a brake is even worse.

 

Either a regular or recessed crown will minimize that muzzle blast for the shooter. Most of the noise will go downrange.

Link to post
Share on other sites

Yeah, that'll work.


Thanks!  032.gif

 

Oh, I'll definitely check that with the loading manuals!  wink.png

 

I have a whole bag full of 55 gr. HP bullets, so I'll definitely be working up some loads for those. I also have 100-count boxes of various other bullets in many different sizes. Not sure if I have that powder, I'll check the powder-box later.

 

Run those 55gr bullets around 2300FPS. You may get lucky.

Link to post
Share on other sites

Also, most flash suppressors will increase muzzle noise for the shooter.

...and of course a brake is even worse.

 

Either a regular or recessed crown will minimize that muzzle blast for the shooter. Most of the noise will go downrange.

 

Not 100% correct.  Battlecomp brakes are AMAZING!!

 

Link to post
Share on other sites

Well, I had to order a replacement belt for my brass tumbler today, so I added one of these:

(Probably going to grind off the silly pointy-things on the end, though.)

 

http://www.brownells.com/userdocs/products/p_100008088_2.jpg

 

I'll let you guys know how it compares to the flash-hider the gun came with, hopefully in just a couple of days here...

Edited by Ronin38
Link to post
Share on other sites

To maximize velocity, and therefore bullet energy, you'll need to go with a faster powder.

 

22gr AA2230 gets you ~2200FPS out of a 7.5" barrel with 85% loading density and a 60 gr Sierra HP bullet.

 

Forgot to update this... I don't have any AA2230, but I do have H335, which is very close on the "burn rate" chart. I can look up loads for that powder and go from there.  wink.png

Also- the new belt for my Tumbler came today, second batch of brass is almost done. That's a couple-hundred clean brass now, that should get me started.  smile.png

Edited by Ronin38
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Chatbox

    Load More
    You don't have permission to chat.
×
×
  • Create New...