Hey all,
I'm pretty new at reloading 223 and I made a try last evening : I put 40 and 45 grainers from Sierra and Hornady.
What can I expect from a 14.5 M4 barrel ?
Thanks

What do you mean?  Accuracy?  Velocity?

Your reloading manual should give you a decent idea of the muzzle velocity.  Accuracy could be anywhere from great to crap depending on the load.

Take the posted velocity from the manual, and reduce it by about 300-400 fps to accomodate for the difference in action and barrel length.

Want exact numbers?  Get a Chronograph.

Just back from the range:
Accuracy at close range (50 yds) seems Ok but it's too close to figure out.
Penetration is OK, I shot a 8mm steel plate and it's now out of order !
It seems that penetration is greater than 55s
I shot at the same time, might be faster but I couldn't take my chrono with me to  check .
I was afraid of accuracy because the bullet is just slighlty hold by the neck but I must try at longer range.

While your penetration of steel plates is fairly good with light fast projectiles, you will find that that doesn't translate to good penetration in soft targets.

If you are looking for deep penetration against the Animal Kingdom, than you are using the wrong bullet.  The bullets you listed (I'm guessing Blitzkreig and V-Max respectively) won't penetrate deeply in flesh.  They will, instead, violently fragment.  These rounds will retain virtually no mass after initial impact.  That makes these bullets very useful at dispatching small animals at a variety of ranges, but on larger targets, the rounds will fail to penetrate deeply.

A 55 gr. FMJBT w/ cannelure will penetrate far more deeply in flesh than a lighter bullet.  On steel however, lighter bullets have more velocity with which to punch deeper holes.

What are you loading for?  Targets?  Varmints?  Self-Defense?

This is only for Fun.
Here, in France, you get a lot of trouble when it comes to personnal protection, you do not have the right to fight back, and we (civilians) do not have the right to carry firearms. But I think you knows it .
So my research on "the ultimate 223 load" is only for making holes in paper targets and drilling steel plates !
But I still have a mag full of 63grs SP from Sierra :-)
40 grs are from Sierra and 45 grs are from Hornady  

What would be the best "all around" load for 223 ?
69 grs ? 75 grs ? heavier ? Lighter ?

Thanks
Julien

Julien - If I recall French firearms laws, They require the rifle barrels to be serialized. Is that correct, and if so where do they mark AR type Barrels?

Thanks, GAB

edit for spelling
edit #2 - Also, was there a flash hider mounted, or did you have a suppressor?

You can expect very good accuracy from 40-52 grain bullets.  I have not had much luck with anything over 64 grains.  Your mileage may vary.

My favorite accuracy bullet is the Hornady 52 gr. AMAX.  I have gotten my Bushmaster to shoot .8 MOA with them.

Normaly all parts that have a serial number are submitted to autorization.
For Us this mainly concern barrel, slide, frame, receivers, locking mechanism of certain firearms, cylinders.
But when a part has no serial number, it's free of worry.
For example, a stripped upper reciver  for an AR is "paperwork free" but if you put the barrel on it, it's submitted to autorization.
French Firearm laws are maybe the most complicated and restrictive in Europe (Except GB of course).

What would be the best "all around" load for 223 ? 69 grs ? 75 grs ? heavier ? Lighter ?

The best "all around" is usually 55 gr. M193, but being military ammo it isn't the most accurate in the world.  I assume your M4 barrel is 1/7" twist, in which case it'll probably do better with the heavier bullets (55-75 gr).  69gr Sierra MatchKings would be a good place to start.

I'm sure there's lots of good info over on the Competition and Reloading forums too.

I think it's rather a 1/9" twist .