How hot for 223/556?

[craigkim]

Hi guys. I just started reloading and worked up my first ladder for 223. My intent is to use the ammunition for 3 gun in one of several rifles, most of which are 16" barrels.

Ramshot TAC

HNDY 55 FMJ BT w/ C

Lake City 1x, swaged, trimmed

WSR primers

My ladder was in .2-.3 grain increments from 24.0 to 26.9 grains. Fired through my JP-15 with 18" barrel and a friends 16" barreled AR.

My intent was to test the ammunition for accuracy first. Upon determining accuracy and which load(s) I wish to explore further, I will chronograph them. If you look the max for 223 stops short of the apex of my ladder, however 556 continues up to about 27.0. We had gotten 2950 FPS out of 26.3 grains TAC in a past experiement.

My question is.... how fast/hot do I WANT the ammunition to be? I got best results between the two rifles at 26.6, 25.7, and 24.8. So, I was trying to determine which makes the most sense to pursue. I wish they had been closer together in the ladder. The JP seemed to like hotter ammo and the more mil spec rifle seemed to like it midranged in my ladder. All of my ammunition shot better than the xm193 for comparison, which I was pleased about because this was my first attempt. I got about a 2-2.25" group out of the xm193 and my best group for my ammo was .4" at 100 yards, using a lead sled. The average for my loads were probably about 1.3-1.5" groups.

Advice or suggestions please...? Thanks in advance.

[Hi-Power Jack]

I'd chrono them and test for accuracy at the same time - eliminates a step.

Sounds like some excellent accuracy - congrats.

[blairmckenzie1]

Do you plan on shooting 1 bullet all the time? How far are "long range" targets for your matches?

I shoot a fairly mild load of Tac with 55's for paper targets and steel out to 100 and 77's for anything past that.

If you are just punching paper in a bay it doesn't make sense to have the heavier recoil of the hotter load.

If you are shooting one bullet for everything something in the middle would probably be best.

I shoot 24gr of TAc, not sure what they Chrono at off the top of my head

[craigkim]

It is soooo much work to set up a chrono AND accuracy test at the same time. I wanted to do it, but it would double to triple the time involved. I did not necessarily plan on shooting 1 load all the time, but that would be nice. I am also going to work up a ladder with the Hornady 60 Vmax to use at longer ranges if need be. I think that 400 yards is a pretty long shot around here for matches. I am not opposed to loading 3 different rounds though either.

I just wondered what a good speed is to try to achieve on this round. It seems that some guys want the higher velocity for reliable cycling, but, despite having adjustable gas, I think it makes sense to have less recoil. I don't think that being less than 1/2 MOA is critical enough to justify the extra recoil on a round for 100 yards or less. I think I will load one softer round and one faster round. Probably make some more of these three that I liked and then chrono them.

[thermobollocks]

There's no speed requirement other than whatever hits the targets most reliably. If another 100 fps makes it easier to ring a 400y plate, neat. Otherwise, meh.

[bwikel]

I would not run them any hotter than necessary to get what you determine is acceptable accuracy. If you have to choose a load I would go with the one that runs the best in the rifle that YOU are going to shoot most in matches.

[wgj3]

What bwikel said.

Each of your guns/barrels may prefer a different load. Gotta pick one and develop a load(s) for that gun.

[blairmckenzie1]

For what its worth in most "local" 3 gun matches 90% of your rifle rounds are at pistol distances, its the 10% that are at distance that make the big difference. missing ten times at 400 years makes a bigger difference than the "accuracy" of your load at seven yards.

[dauntedfuture]

I just use the same load and powder for my 55s that i use for the 77's. I just checked to make sure accuracy was "good enough" and stuck with that. There is no need for speed for my short range ammo. Hornday 55's, as well as they shoot reletive to other 55's are still not math bullets and your not likely to get much under 1.5" at 100 yds for 10, yes, TEN, shot groups. You can go through the trouble of a ladder test and all if they dont shoot good enough but most of the time your not shooting enough in a ladder test when you consider our 3G rifles and bullets for any real statistical data, your just happening to catch a "good group" There are some combinations of powder and bullets that will just not work well for some reason so you still need to test ammo.

[12glocks]

There are a number of considerations I make/made when deciding how "hot" to have a match load. In an ideal world one would probably want something that shoots flat like a laser. That is probably one of the considerations of the AMU using MK262 ammo in competition. So the upside is it is flatter shooting.

The downside is there is a theoretical degradation in accuracy as the barrel gets hotter, hot loads will make a barrel hotter quicker obviously. Also I have pooped a couple primers in AR's with warmer loads and I believe it to be a bigger risk with hotter loads. I personally have the philosophy that I want to do everything I can to keep the bolt in battery a little longer so the pressure will start to abate before the bolt unlocks. Military 5.56 in known for pooping primers even with crimped pockets. I also use only once fired military brass that I have swaged the pockets on as you are. There tighter than domestic commercial brass.

I have pierced a couple of primers as well, WSR's specifically, getting into warm load territory. I switched to CCI 400's for the harder cup (to reduce the risk of slam fires too)

Another consideration is bullet drop and reticle choices. It helps to have multiple match loads when evaluating reticles.

FWIW the only thing good about 55 gr projectiles is price. Long range shooters use heavy bullets for good reasons BUT they are significantly more accurate in general. I am not sure of the distances you routinely shoot at. By your post I judge you to be an experienced shooter/reloader so I am guessing you are shooting primarily short range. Heavy bullets are advantageous at 400 yards. Accuracy is my first priority in match ammo. I do like the velocity but it can take a while to get those primers out of the fire control group. My present match load is .8 grains below max for 223 pressure using a Hornady 75.

My 2 cents.

[wgj3]

I hate it when I poop a primer...

That said, I have a load with a case full of H335 under a 52/53gr Amax that runs about 3200fps out of my 14.5" and 3300+ out of my 18". I'm a fan of getting the bullet there quickly. Also allows for shoddy range estimation/guesstimation. And, it provides a FANTASTIC fireball when the sun isn't very bright.

I run 19.5grs of H335 for my paper-punching ammo for bay/hoser stages. This runs about 2000-2100fps. It's kinda like cheating a smidge...

I run TAC under the 75-77gr bullets for the matches that make us actually shoot past 350yds or so or activate Larue's, etc.

[Kosh75287]

I hate it when I poop a primer...

WHY would you EAT them in the FIRST place?

MY inclination would be to try to find the most accurate load using the components and rifle you specify. If the round's power equates to 55 gr. at 2750 f/s or above, it'll have the desired effect on-target (animate or otherwise). If you attempt to load hotter than where your "accuracy sweet-spot" is, groups can get big in a hurry. At double-digit yardages, this isn't a huge matter, but it can be disastrous at extended ranges.

I have a Mini-14 that shoots 2.0 MOA , when I do MY part and I use a particular load, with 55 gr. Hornady FMJBTs. I'd LIKE to find a comparably priced 60 - 65 gr. BT projectile that isn't as hard on the steel targets as the M855 ball. I get the impression that the heavier projectile's momentum will send the steel down a bit more surely, and I suspect I'd get better groups beyond 300 yards (which is somewhat problematic, already). Until I find a BETTER projectile, though, I'll stick with the Hornadys.

Edited March 6, 2016 by Kosh75287

[dauntedfuture]

"The downside is there is a theoretical degradation in accuracy as the barrel gets hotter, hot loads will make a barrel hotter quicker obviously. Also I have pooped a couple primers in AR's with warmer loads and I believe it to be a bigger risk with hotter loads. I personally have the philosophy that I want to do everything I can to keep the bolt in battery a little longer so the pressure will start to abate before the bolt unlocks. Military 5.56 in known for pooping primers even with crimped pockets. I also use only once fired military brass that I have swaged the pockets on as you are. There tighter than domestic commercial brass"

Not exactly......

- The type of powder you use has more to do with barrel heat. another .2g of powder will not make a (practical) difference in barrel heat over 10 rounds, the type of powder will.

- Poping primers will happen when you are pushing pressures too high. Reliability is paramount, if primers are coming out your too hot.

- The amount of powder, practically speaking, has little to nothing to do with pressure curves and or port pressure. Yes, hotter loads produce more pressure and more port pressure but the pressure curve of the powder and amount relate to port pressure. 24.0g of XX powder does not delay bolt opening measurably then 26g,

- If you want to keep the bolt closed longer, use a slower powder.

- Not all MIL primer pockets are smaller than all comercial brass

[12glocks]

"The downside is there is a theoretical degradation in accuracy as the barrel gets hotter, hot loads will make a barrel hotter quicker obviously. Also I have pooped a couple primers in AR's with warmer loads and I believe it to be a bigger risk with hotter loads. I personally have the philosophy that I want to do everything I can to keep the bolt in battery a little longer so the pressure will start to abate before the bolt unlocks. Military 5.56 in known for pooping primers even with crimped pockets. I also use only once fired military brass that I have swaged the pockets on as you are. There tighter than domestic commercial brass"

Not exactly......

- The type of powder you use has more to do with barrel heat. another .2g of powder will not make a (practical) difference in barrel heat over 10 rounds, the type of powder will.

- Poping primers will happen when you are pushing pressures too high. Reliability is paramount, if primers are coming out your too hot.

- The amount of powder, practically speaking, has little to nothing to do with pressure curves and or port pressure. Yes, hotter loads produce more pressure and more port pressure but the pressure curve of the powder and amount relate to port pressure. 24.0g of XX powder does not delay bolt opening measurably then 26g,

- If you want to keep the bolt closed longer, use a slower powder.

- Not all MIL primer pockets are smaller than all comercial brass

And a longer gas system, full mass bolt. adjustable gas block, heavier buffer and buffer spring.

As to the other points I was speaking in general terms. I personally don't go to the ragged edge. I do think, in general terms, MIL brass has tighter pockets. One of these days I am going to do a mag dump and then check accuracy. Perhaps a properly stress relieved barrel would have minimal degradation in accuracy? I would be interested to hear your experience as to barrel heating with propellant speed vs rounds fired? Thats not a snarky comment either. I honestly don't know. I like slower powders in rifle and pistol for some reason.

[dauntedfuture]

Depending on the powder that you are using, leaving a case in the chamber can increase velocity by up by over 100 fps, or enough to put you a few inches high at 600 plus yds. Since we are shooing a given number of rounds in competition in a stated time period we simply do not have the option of letting the rifle barrel cool completely between shots.

As such, it is prudent to shoot for groups and or test you ammunition in a condition "close" to your match conditions. If were talking NRA highpower, thats 10 shots in about 5-6 minutes; you have a minute per shot but 5-6 minutes is about what it takes provided the pullers are up to snuff.

It is also important to note what ammounition you are planning on shooting before you are shooting LR. As such, its common to shoot some short range ammo first through your barrel to see what if any effect there is on your LR ammo. Or in three gun, shoot a little of your short range stuff and heat your rifle up before testing your LR ammunition. As such, you are testing ammunition in a match-like condition.

Reference stress relief and accuracy; decades of competition have determined that thicker barrels are better for competition because they are more ridid and to not warp or bend with heat as much as a skinner barrel will. There is a limit to this of course. As a result, i am more skeptical of a light profile barrels ability to shoot well hot then i am of a medium contour barrel. A light vs. heavy barrel might both shoot the same 10 shot groups but how will they shoot after 30 rounds in a short range portion of 3 gun match stage. All things to consider and there are no absolutes.