5.56 10.5 inch barrel reloading idea

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I have a new 10.5 inch 5.56 upper from PSA for my pistol lower.
I have been playing with Quickload to find a way to have NO flash, No super loudness or percussion from the short 10.5 inch barrel.

Flash comes from unburned powder in a standard 5.56 round.
Excessive loudness is from the bullet leaving the barrel at roughly 15,000 psi instead of something normal like half of that.

So far, a promising load candidate is:

Cartridge: 5.56x45 NATO
OAL 2.2 inches
Barrel Length 10.5 inches
Default case capacity of 28.50
Alliant HERCO powder - 10.5 grains. Case filled 73.3 percent. (might first try 10 grains)
Bullet Hornady 55 gr GMX #22273 (this should expand at velocities over 2000 fps)
Max Pressure 49525 psi
Velocity 2199 fps (yes have to give up some velocity to get no excess loudness/flash)
Muzzle Pressure 8664 psi
Propellant Burnt 100% (no flash)

I have not tried this load.
I do not know if it will cycle the AR.
I do not know for sure it is safe.
I do not even own any HERCO powder yet.
I do not want to go to the gunclub during this pandemic.
This is all theoretical for now.
 
What you're trying to achieve is counterproductive to the stated load. You're trying to turn a Corvette into a Honda Civic.

Go with the heaviest head that'll fit in a magazine. 69 or 70 gr. That'll take up some case capacity.
Herco looks a little to fast as is so you might want to put a filler in there like a cotton ball.
Cut your velocity down to sonic or sub-sonic. If you're trying to cut down noise.
Get a tax stamp, and get a can. That'll remove some noise and most of your flash.
 
Actually, you're almost better off doing that-
Build another upper around a sonic or sub-sonic low pressure cartridge (.45, .40, 9mm, .22) and put a can on it.
Trying to neuter a 5.56 results in a ton of lost energy and velocity.
 
Load up some 77 grain pills to 2.260" OAL
follow hodgdons load data for reduced loads of H4895 and see where it gets you. You may or maynot get full function with fast powder.

using quick loads you can find a powder that will not exceed max chamber pressure.
When i did my cast load experiments I found my best function with H4895 , 20" barrel so no muzzle flash to be had. i did try some pistol powders.
You can also get idea of the gas port pressure using quick loads.
A 300blackout with 220 grain bullets might fit into your needs a little better?

google hodgdon reduced loads with H4895 and follow the instructions. No idea if you can get reduced flash but i was able to get full function with 55gn cast with a rifle length gas system on a light charge. Go with heavier bullets you might get better function and complete burn. Good thing is you have QL so you can rule out a lot of powders by input of some parameters.
 
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Well, I posted to get people's thoughts and alternative ideas.

But, you are way off.

If I want non expanding bullet performance, I'd buy a 22LR.

Almost all Hornady bullets will not expand under 2000 fps.
The 55 grain GMX bullet passes all FBI tests (windshield, car door, heavy clothing, etc..) while expanding over .40 inches.
Will not get high velocity ( > 2000 fps) along with my goals using heavy bullets.

Good penetrating and expanding bullet.
Which needs velocity over 2000 fps.
Faster does not help as far as I know, except for further range - and range is not what a 10.5 inch barrel is for.

What I was expecting:
Possibly information that HERCO powder is unsuitable due to temperature inconsistant (never heard stories that it is temperature inconsistent)

Possibly information that it will not cycle the AR BCG -
It is possible that 10.5 inch barrels are purposely gas port sized to work with the double of normal gas port pressure psi.
So there might be functioning problems when the gas port pressure is reduced to what is normal for a 20" AR rifle?

General experience with HERCO powder in rifles?

Maybe a better load or choice of powder which fills the case to 80 or 90% ?

Too many minds here who ramble with no relative experience in this.
Just typing here to read their own useless words.

At least this future experimental load is documented should I someday need to look it up.
 
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I have a new 10.5 inch 5.56 upper from PSA for my pistol lower.
I have been playing with Quickload to find a way to have NO flash, No super loudness or percussion from the short 10.5 inch barrel.

Flash comes from unburned powder in a standard 5.56 round.
Excessive loudness is from the bullet leaving the barrel at roughly 15,000 psi instead of something normal like half of that.

So far, a promising load candidate is:

Cartridge: 5.56x45 NATO
OAL 2.2 inches
Barrel Length 10.5 inches
Default case capacity of 28.50
Alliant HERCO powder - 10.5 grains. Case filled 73.3 percent. (might first try 10 grains)
Bullet Hornady 55 gr GMX #22273 (this should expand at velocities over 2000 fps)
Max Pressure 49525 psi
Velocity 2199 fps (yes have to give up some velocity to get no excess loudness/flash)
Muzzle Pressure 8664 psi
Propellant Burnt 100% (no flash)

I have not tried this load.
I do not know if it will cycle the AR.
I do not know for sure it is safe.
I do not even own any HERCO powder yet.
I do not want to go to the gunclub during this pandemic.
This is all theoretical for now.

Doubt you could get away with that unless you had tunable gas block, and piston.

Or did the bolt action conversion.

What's the point here? Why not just pay and get a can?
 
I took a different approach. I have a 7.5 inch upper on an AR pistol as an "office gun". I don't load 5.56 (yet?); so I run factory 55 grn 5.56 or .223 in it. I put a heavy linear comp on it to direct the sound forward (away from me).

It cycles reliably and the noise is seriously reduced, (as perceived by me), when shooting at an outdoor range with ear pro.
 
fshalor,

Why don't you sell all your guns and use bows and arrows?
I can probably find a thousand reasons why this is good for YOU!

Better yet, buy a tent and live a minimalist life in a park?
I can find you equipment and tons of people who love this way of living?

Just go away and stop telling me to NOT do what I am trying to do.
Everything you type is totally irrelevant.

I am asking about RELOADING, and QuickLoad, and finding a good powder/bullet/load.

Go create your own thread about how wonderful it is to own a supressor.

You people are just too much!
 
I loaded up some book loads with Clays (3.2gr. 1,060 FPS 3,700 CUP). These likely won't cycle an AR and the performance would probably rival a .22 LR, so it probably wouldn't make much sense. They should provide little flash and noise, but I'll have to see if my friend with an "other' will run them for a test.
 
Well, I posted to get people's thoughts and alternative ideas.

But, you are way off.

If I want non expanding bullet performance, I'd buy a 22LR.

Almost all Hornady bullets will not expand under 2000 fps.
The 55 grain GMX bullet passes all FBI tests (windshield, car door, heavy clothing, etc..) while expanding over .40 inches.
Will not get high velocity ( > 2000 fps) along with my goals using heavy bullets.

Good penetrating and expanding bullet.
Which needs velocity over 2000 fps.
Faster does not help as far as I know, except for further range - and range is not what a 10.5 inch barrel is for.

What I was expecting:
Possibly information that HERCO powder is unsuitable due to temperature inconsistant (never heard stories that it is temperature inconsistent)

Possibly information that it will not cycle the AR BCG -
It is possible that 10.5 inch barrels are purposely gas port sized to work with the double of normal gas port pressure psi.
So there might be functioning problems when the gas port pressure is reduced to what is normal for a 20" AR rifle?

General experience with HERCO powder in rifles?

Maybe a better load or choice of powder which fills the case to 80 or 90% ?

Too many minds here who ramble with no relative experience in this.
Just typing here to read their own useless words.

At least this future experimental load is documented should I someday need to look it up.
Why not push a lighter varmint bullet as fast as you can with some fast pistol powders. ?
Are you tied to hornady ? Do you have to have expansion ?
layout more details in your Original post will keep some suggestions to a min.

The only 2 dead fast requirements you laid out was NO flash NO super loudness

your first 2 sentences from your OP
"I have a new 10.5 inch 5.56 upper from PSA for my pistol lower.
I have been playing with Quickload to find a way to have NO flash, No super loudness or percussion from the short 10.5 inch barrel."

maybe a thinner jacket varmint style bullet. >

loudness is a hard one to "reduce" you can start with just a crowned barrel with no brake. or one of those brakes that push the report forward?
A can works as does subsonic ?

I think what you need to do is find a bullet weight and powder and charge weight that will fill your needs of no flash and not as load. then find a bullet that has the best possible expansion rate at those velocities.
2400 can get you the velocities you seek and have powder burned up inside 10 inches.

Im not big on Expanding bullets basically from the times of soft points and thin jackets. There has to be something out there that gets reasonable expansion at lower velocities.

I have a jug of sealed Herco that iirc is dated 1994--- you want it?
 
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I have requested my thread be deleted.
Nobody here can be useful.

I have requested my thread be deleted.
Nobody here can be useful.
not for nothing your original post was not very useful either?
maybe start over and be more specific of what you really want to do.

more than No flash and NO super loudness?

Basically going back you want a penetrating/expanding load that will cycle your 10.5" with 55 grain bullets ? thats quiet and no flash

you can get higher "low" velocities with heavy bullets . QL gets a 77 grain bullet with 2400 to 2000fps+
 
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fshalor,

Why don't you sell all your guns and use bows and arrows?
I can probably find a thousand reasons why this is good for YOU!

Better yet, buy a tent and live a minimalist life in a park?
I can find you equipment and tons of people who love this way of living?

Just go away and stop telling me to NOT do what I am trying to do.
Everything you type is totally irrelevant.

I am asking about RELOADING, and QuickLoad, and finding a good powder/bullet/load.

Go create your own thread about how wonderful it is to own a supressor.

You people are just too much!


pet•u•lant pĕch′ə-lənt


  • adj.
    Unreasonably irritable or ill-tempered; peevish.
  • adj.
    Contemptuous in speech or behavior.

  • Manifesting peevish impatience, irritation, or caprice; peevishly pert or saucy; peevish; capricious: said of persons or things: as, a petulant youth; a petulant answer.
More at Wordnik from The American Heritage® Dictionary of the English Language, 5th Edition.
 
Almost all Hornady bullets will not expand under 2000 fps.
The 55 grain GMX bullet passes all FBI tests (windshield, car door, heavy clothing, etc..) while expanding over .40 inches.
Will not get high velocity ( > 2000 fps) along with my goals using heavy bullets.

do you want to stick to this one bullet thats passes FBI test ? That is loaded to what I would call "normal" but expect to work at lower velocities?
 
You won't get the gun to cycle with what you want to do.

What you're describing is why they created the 300 Blackout.

Also, OP - Is this your first day on a forum? These are mild-to-typical responses. If this bothers you enough to report the thread, you need to stay off social media.
 
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