Well I've got a 11.5" 5.56 that I enjoy plinking with, and I'm wanting to explore some different loads and get some more velocity out of this. Right now, I've got about 12 pounds of Ramshot TAC, but I don't know if I should go with something that burns slower like CFE223, or something a little faster like Ramshot XTerminator.

Below, I've posted the results of a load test I did with TAC, and I can get to 3,000fps, but it's not pretty. I'm sure there's a powder better suited to help me out here.

I took out 11 different loads using Ramshot TAC and 53gr Hornady A-Max in mixed LC brass and using CCI 400 primers. Each different load was a half a grain more than the last. I started with 24.5gr and went up all the way over max to 29.5gr. I didn't chose TAC for any particular reason other than I have a lot of it currently. Here's what I saw:

5.56 stamped chamber
11.5" barrel
1:7 twist
SilencerCo ASR Muzzle Brake
SilencerCo Omega with 5.56 end cap was mounted for all shots
COAL: 2.235"

Avg Velocities:

24.5gr TAC: 2498 fps

25.0gr TAC: 2553 fps

25.5gr TAC: 2625 fps

26.0gr TAC: 2753 fps

26.5gr TAC: 2813 fps

27.0gr TAC: 2844 fps

27.5gr TAC: 2875 fps

28.0gr TAC: 2951 fps

28.5gr TAC: 2973 fps *this is the first load where I saw pressure signs in the form of slightly cratered primers - but still is slightly under book max

29.0gr TAC: 3034 fps *this load is OVER book max, and primers were cratered still

29.5gr TAC: 3072 fps * this load is also OVER book max, and only one round was fired. The firing pin pierced the primer, and testing was discontinued.

When dealing with shorter barrels I always look at the load data for Contender pistols.

This would give you more information, but your velocities are nothing to complain about.

That’s a really good idea. I’ll look into Thompson load data.

I’m not upset with the velocities, but I’d like to get closer to 2,900-3,000 without cratering primers that bad.

I don't even know where to begin so I'll stay out of this one.

Invest in good safety glasses.

I saw a chart some where that showed rifle powders produce all their peak pressure before the bullet travels 2-3". As we all know the bullet still accelerates going down the bore. Faster powders develop higher pressure quicker. How much quicker I have no idea, depends on the weight/bullet/caliber it has to push. With hand gun the powder that produces the fast speed does so with any length barrel. I believe this to be true with rifle too. But with rifle we are dealing with barrel harmonics which is more pronounced when it comes to accuracy.

You might want to try a primer made for higher 556 pressures. CCI's #41 would be my choice. Don't know if it would make a difference or not, but sure would not hurt to try.

quote:

Originally posted by DevlDogs55:
but I’d like to get closer to 2,900-3,000 without cratering primers that bad.

Maybe I'm stepping over the line here...but why?

You want to get a short barrel to come close/closer in performance to a longer barrel by pushing and juggling powders at the expense of safety for one and beating up your rifle for two...looking at the loading data for .223 with TAC in the Western Powder data, your loads are way over the listed max loads...that's just taking a big chance for "plinking loads"...

I am assuming this is in an AR...pushing that far over the recommended max data isn't doing your bolt or gas system any favors...and that hole in your BCG where the cam pin fits is also taking a beating...I've seen cracks on the weak thin sides of the cam pin hole...

This is just me...I would just accept that a shorter barrel is just that...and live in harmony with lower velocities ...find a load that shoots well without crossing the line...your rifle will thank you ...

I agree with NikonUser on the safety glasses investment...

Seriously DevilDogs...think about it.

Edit...please don't think I came into your thread trying to be a know-it-all...but I've been reloading for close to 50 years and over those years I've seen shooters at times (my self included) push things past safety for meager returns and beating themselves up as well as their guns, trying to squeeze a little more out of their loads...I know I didn't answer your question...but please stay safe and don't push the envelope if it's not necessary

This message has been edited. Last edited by: Bisleyblackhawk,

Just some random comments. I do like TAC powder, it's one of my favorites with the 223.

Yes, some of your loads seem 'warm'. I also wonder the reasoning for loading to those levels.

As mentioned I do believe much of the burning with powder happens early in the barrel. The expanding gasses will still be a player to get more velocity with the longer barrel.

Keep it safe.

It appears you're trying to achieve the typical MV of a 16" barrel using factory ammo from a 11.5" barrel using hot handloads. IMO this is neither wise nor safe.

Yep, wrong goal on several levels.. at 28.0 grains you over the mil-spec pressure loads in the Ramshot data. Love me some Tac, but 62K+ pressure is the stop now spot for real

Velocity gains from 26.0 to 27.5 seem meager.
Is the juice worth the squeeze?

Bruce

You have a pistol length gas system with its higher port pressure. Meaning the rifle takes much more pounding than a longer rifle length gas system.

Loading hotter will just pound your rifle more and stress the bolt and related parts.

Your targets will never know if you load more conservatively and the rifle and brass will last much longer.

Below things to ponder and remember reloading is like playing Black Jack, stay light and beat the pressure dealer.



Higher chamber pressure will cause the primer pockets to stretch out much sooner. The person who posted the bolt face photo below said he didn't worry about loose primer pockets and stated he would replace the bolt when it got bad enough.



My practice blasting ammo is loaded 5,000 psi below the max rated pressure of M193 ammo. And the holes in the target don't look any different.

^
This guy is a first class IDIOT
Some day mr Karma will bite his ass,hope he shoot in a range all by himself.

quote:

Originally posted by 45 Cal:
^
This guy is a first class IDIOT
Some day mr Karma will bite his ass,hope he shoot in a range all by himself.

I was given three five gallon buckets of once fired .223/5.56 brass fired by our local police.

I prepped the Federal cases first only to find many loose primer pockets.I now check the primer pockets with pin gauges before doing anything to the cases.

And when seating primers if the primer pocket feels loose I use a Lee depriming tool to check the seated primer. If the primer moves with just finger pressure the case goes in the scrap brass bucket.

[Delete

quote:

Originally posted by bigedp51:
You have a pistol length gas system

Says who? My 10.3" MK18 is a carbine length system.

Still, 3,000fps out of a 11" rifle is STUPID.

Of course if speed is the main attraction, one could go towards a super light bullet. It may not make any sense either, depending on the goals in mind.

I'm curious about how this turned out. It's all fun and games until somebody loses an eye. After that, it's just fun

Bruce

Someone has already experimented with different barrel lengths for you.
You will notice that most calibers listed will gain speed with an increasingly longer barrel up to a point, then taper off. In some cases, like 223, they just didn't start with a long enough barrel to show this in their collected data.

Have a look here -

http://www.ballisticsbytheinch.com/223rifle.html