How far over book max to load when velocity is down?

[RetiredUSNChief]

If we define efficiency as the relationship of the potential energy of the powder to the resulting kinetic energy of the bullet, I want to know why the X-Terminator load is so much less efficient than expected.

This is laudable.

However, the reality is that all you can possibly get here is suppositions and postulations. You will not get a definitive answer.

The people who might be able to provide that answer are the makers of the powder, and they're not likely to go beyond a simple layman's phrasing that amounts to something akin to "it's intended to give the performance stated under the specified load conditions". And they're not going to change the powder for two reasons: the existing powder does what it's designed to and changing the powder actually results in a new and different powder with its own characteristics.

I look at your question in the same manner I look at ammunition in general. Whenever I buy a new gun, I run a variety of ammo through it to see how it operates with different types and brands.

If it eats everything I feed it, great. If it likes some ammunition and not others, I simply don't feed it the ammunition it doesn't like. I can't change the design/manufacture of that ammunition, so what would be the point? It would just be an exercise in frustration.


So the best we can do here really amounts to "guess".

 

[westernrover]

My conclusion is that the most likely explanation is that the X-Terminator I received has lower energy per-grain than what the load data was developed with. This is not unreasonable considering that X-Terminator has been changed several times just in the last few years. For a long time, it was produced by Bofors in Belgium. It was also identical to Accurate 2230. In recent memory it was changed to include both a flash suppressant and a copper fouling reducer, whereas 2230 was given the flash suppressant but not the copper fouling additive, so they diverged. Notice that Hodgdon's data is still identical for both. Accurate 2230 ceased to be produced by Bofors and was reformulated to be produced by St. Marks. Again, the data never changed. Then, according to some sources, X-Terminator's production was also changed to St. Marks. However, it may have changed back again to Bofors. My bottle, according to the label was produced in 2023 and in Belgium. Hodgdon's load data (and that for any bullet maker) is most likely from the X-Terminator that was produced more than a decade ago. If it has changed as significantly as my results appear to indicate, it's a pity they don't provide accurate load data. I blame this on Hodgdon (not so much the bullet makers) because Hodgdon is responsible for the powder changes they've made as well as any changes made by Western that they acquired. If the powder they're delivering is less energetic than it was in the past, they've managed to keep their customers safe, but the performance delivered is lacking. If this were to be the case, I would be safe to load it over published maximums, but I would be ill-advised to do so for all the reasons and experiences witnessed in this thread.

A less likely but still possible explanation is that X-Terminator is faster burning than the available published data indicates. In this case, it is unsuitable for my purpose.

In either case, Hodgdon is misrepresenting it and I would be foolish to adapt my loads to the evidence I see. I don't believe X-Terminator is a lousy powder. I believe if I loaded another grain of it, it would perform excellently, but I can't do that except foolishly.

 

[P Flados]

I took a look at the 4 powders mentioned in Quickload (QL). The results in QL actually seem reasonable and the three that are closest in burn rates performed in a very similar fashion. However, the predictions do not match up good for pressures with the Hodgdon data. Then I noted that some of the Hodgdon data was cup and some was psi. I noted that Hodgdon data shows a much higher charge for Benchmark than I expected based on the QL results. The X-Terminator prediction was the opposite (QL indicates a higher acceptable charge than Hodgdon).

Part of you issue may be "goofy test data". Some amount of "goofiness" is expected when the testing was done in different to entirely different standards using different test equipment. Some of it was done by totally different folks (the old Ramshot data). And do not forget that batches of powder can vary a good bit.

For this example, I would actually be concerned that your Benchmark loads may be "hotter" than you think. With 223/5.56, overpressure usually does show up in details than can be seen in the fired brass. If the brass shows more "pressure signs" for these loads than for the loads from the other powders, I would back off a tad.

For the X-Terminator loads, if the brass is definitely showing less "pressure signs", then going up some is not out of the question if you feel confident in what you are doing.

Cartridge          : .223 Rem. (SAAMI)
Bullet             : .224, 55, Speer SP 1047
Useable Case Capaci: 26.819 grain H2O = 1.741 cm³
Cartridge O.A.L. L6: 2.260 inch = 57.40 mm
Barrel Length      : 16.5 inch = 419.1 mm

C A U T I O N : any load listed can result in a powder charge that falls below minimum suggested
loads or exceeds maximum suggested loads as presented in current handloading manuals. Understand
that all of the listed powders can be unsuitable for the given combination of cartridge, bullet
and gun. Actual load order can vary, depending upon lot-to-lot powder and component variations.
USE ONLY FOR COMPARISON !

Powder type          Filling/Loading Ratio  Charge    Charge   Vel. Prop.Burnt P max  P muzz  B_Time
                                      %     Grains    Gramm   fps     %       psi     psi    ms
---------------------------------  -----------------------------------------------------------------
Hodgdon Benchmark                   98.7     24.0     1.56    2864    92.2    50000    9988   0.825  ! Near Maximum !
Hodgdon H335                        93.3     25.2     1.63    2934    94.6    50000   10671   0.818  ! Near Maximum !
Ramshot X-Terminator *C             97.0     25.6     1.66    2862    88.9    50000   10147   0.828  ! Near Maximum !
Winchester 6,5 StaBall *T*C        110.0     29.3     1.90    2641    80.8    42021    9245   0.891

 

[LiveLife]

Well, why am I in one place with H335, Benchmark, and StaBALL Match, but a different place with X-Terminator?

Why does different factory ammunition using same 55 gr FMJ produce different velocities and different group size?

I think it has to do with differences in shooting variables and reloading variables.

The people who might be able to provide that answer are the makers of the powder

So the best we can do here really amounts to "guess".

My conclusion is that the most likely explanation is that the X-Terminator I received has lower energy per-grain than what the load data was developed with.

Hodgdon is misrepresenting it and I would be foolish to adapt my loads to the evidence I see. I don't believe X-Terminator is a lousy powder. I believe if I loaded another grain of it, it would perform excellently, but I can't do that except foolishly.

Instead of guessing, have you tried asking Hodgdon customer service? Since they are the manufacturer of the powder, they may know something we don't.

 

[Walkalong]

Also, consider that our government goes far over and above published 223 load data.

How do you figure that? You have no idea what powder they are using. You’ve been given some excellent advice here, the main thing being don’t force it with a powder that didn’t get you there.

 

[thump_rrr]

If you want to learn more try downloading Gordon’s Reloading Tool. It’s free.

Input all the data you have from internal case volume to bullet used, seating depth, barrel length etc. And see what the pressure curve for each powder you used looks like.

It will also give you estimated velocity. And a way to input your chronograph data.

 

[ballman6711]

Also, consider that our government goes far over and above published 223 load data.

To the best of my knowledge our government doesn't load any .223 ammunition. So they do go "over and above" .223 load data, but how far over is anybody's guess. I would think that they want ammo to perform within a certain window and still be safe for our soldiers to shoot, as well as keeping pressures low enough that the guns will be able to last a reasonable length of time or number of rounds fired before being retired or rebuilt.

And unless I'm mistaken, they specify a minimum velocity for a given type of ammunition, and it's up to the ammo manufacture to meet that spec along with any other specifications the government has. And I really doubt they are using the same powder that reloaders can buy.

To answer why your reloads don't perform like the load data would really require pressure testing equipment. The X-Terminator data could have been developed using a test fixture vs. an actual gun. That alone would give higher velocities at a given pressure, and that's just one possible reason out of many. Maybe your chamber is larger/longer than the one used to develop the data, giving different results again, which would imply that you could go over max published data and still be safe, BUT again without pressure testing equipment there is simply no way to be sure.

IMO, just like others have said, no reason to push the boundaries of pressure.

Out of curiosity, what are these loads going to be used for?

chris

 

[jmorris]

What powders would you use and why?

I use what gives the the results I am after, because I am content when get what I want out of something.

 

[jmr40]

All of the powder is burned within the 1st 8-10" of barrel with even the slowest powder. Additional barrel length gives the powder more time for the bullet to accelerate before leaving the muzzle. If you are shooting a pistol with a barrel shorter than about 10" then faster powder might make a difference.

The powder that gives you the best speeds at 26" of barrel will also be the fastest at 16". As a rule, faster burning powder does result in more speed with light bullets and slower burning powder generally works better with heavier bullets. So in this case with 55 gr bullets a faster powder may well help. A slower powder would generally be better with 75 gr or heavier bullets. But that would be true regardless of barrel length.

The only way to know for sure how much speed the shorter barrel is costing you is to start with a long barrel with a known velocity then measure it as you cut THAT barrel shorter. When that is done 10-35 fps/inch is typical. But it isn't linear. You may see an average loss of 20 fps/inch. But at some lengths you only see 5-10 fps loss. At other lengths you may see 40 fps loss.

But when you measure 2 different barrels all bets are off. Even if they are the same length 25-50 fps difference is perfectly normal and I've seen examples with well over 100 fps difference.

When you see published velocity numbers they are almost always measured from match barrels and chambers cut to close tolerances. This almost always results in more speed than is possible from common production barrels. I'd expect a typical AR, even with a longer barrel, to give a bit slower speed than a 223 with a match barrel and chamber. Most AR's are built with looser tolerances to aid reliability.

 

[jmorris]

Why does different factory ammunition using same 55 gr FMJ produce different velocities and different group size?

If all of the variables didn't matter, all load manuals would have the exact same data.

Some account for small changes, some can widen the difference.

 

[rfwobbly]

Zero over. If you have to have that velocity, try another powder.

Here's the unseen problem....
We use Velocity as an indicator of Chamber Pressure. And within the safe loading zone, those 2 qualities are indeed running pretty much 1:1. But, sometimes we forget that while Velocity is nice to know, it's Chamber Pressure that will kill us.

When you focus solely on Velocity and start chasing a certain number, it easy to forget that at some point these 2 important qualities are no longer 1:1 and diverge significantly. I'm no rocket scientist, but I try to get this point across in the following cartoon...

When loading above the prescribed "safe" loading zone (the green area), Velocity tends to flatten out. That is, more powder DOES NOT produce the same jump in Velocity, as it did lower in the load range. However, at the same time, unseen by the user, Chamber Pressure continues to "sky rocket" out of control. This is how/when chasing a number can be a ticket to Kaboom Land.

I'm not saying my cartoon is accurate for the shape or slope of the curves. Only confirming that when you reach max powder weight, then it's time to STOP !

 

[entropy]

I recently loaded some 223 and fired them through a chronograph with my 5.56 NATO rifle. The published data was for 55 grain Speer SP and a 24" barrel. I used 55 grain Hornady SP and a 16.5" barrel. I'm skipping over a lot of details of my process to get to the point:

The cartridges loaded with 24.9 grains of Ramshot X-Terminator achieved a mean of less than 2640 fps vs. published data of 3278 fps.
The short barrel achieved 80% of the published velocity.

However,

The cartridges loaded with 25.3 grains of H-335 achieved a mean of 2820 fps vs. published data of 3203 fps.
The short barrel achieved 88% of the published velocity.

The cartridges loaded with 25.6 grains of Benchmark achieved 2956 fps vs. published data of 3264 fps.
The short barrel achieved 90% of the published velocity.

I was also able to achieve 90% of published velocity with StaBALL Match, albeit the data was for a different bullet.

I can understand that some powders are going to be more dependent on barrel length than others to achieve velocity. This should be true of slower burning and more progressive burn rate powders. However, X-Terminator is neither particularly slower or more progressive than the other powders I used.

Why is Ramshot X-Terminator delivering velocities 10% farther below published velocities than the other powders? On a comparative basis, the published data shows it should deliver velocities higher than H-335 or Benchmark, but I am getting velocities 200 or 300 fps slower. That's a LOT slower.

Should I keep loading it higher until I see pressure signs or velocities 90% lower than published? Or should I just write it off and load the remaining pound for plinkers?

Read the barrel length used in the test data. Often powders marketed towards long range and/or target shooters are tested in 26" barrels, and other powders tested in shorter barrels. (24" or 22")

Since you have several more efficient powders, use them for serious use, and load plinkers with the X-Terminator. Or find another of your guns that likes it better.

 

[jmorris]

We use Velocity as an indicator of Chamber Pressure. And within the safe loading zone, those 2 qualities are indeed running pretty much 1:1.

I think that is what gets people. They view the relationship as linear and it is not. There are low value pressures that wont move a bullet out the barrel at any velocity.



As well as very high ones that wont either.



Why load data has minimums and maximums, to keep people within the "safe" range.

 

[AJC1]

Load manuals effectively use Extreme spread to make load tables. If they make a test batch and one of the group goes over the pressure limit, they go lower and do it again. Powders with the most consistency get the benifit of a higher charge and pressure.... that may be just one of the factors your seeing.

 

[horsemen61]

Zero over. If you have to have that velocity, try another powder.

This right here

 

[irishlad]

It would be great if I had published load data for all the powders and all the bullets, but it doesn't work that way. The data I used and quoted is all from Hodgdon, not Speer or Hornady. I used Hornady bullets, but Hornady does not provide data for all the powders that Hodgdon does. They provide extraordinarily little data at all, and even that they charge for. It's reasonable that I use Hodgdon's data with Hodgdon's powders. Now Hodgdon provides data for a lot of powders, but not every bullet in existence. I decided that the Speer 55 gr. SP is reasonably similar to Hornady's 55 gr. SP and that I could use that data. If a person were to be a stickler about not using anything but data for a specific powder and a specific bullet, I'm ok with that, but I would feel pity for them.

I mentioned that I omitted a lot of details to get to the point. I didn't neglect to start at a lower charge mass and work up. That procedure is always worth following and even more so when changing a variable like the bullet maker.

Consider also that the published data is for 223 and my rifle is 5.56 NATO which should allow for several thousand more psi. I'm aware that I have no way of knowing how much more psi any additional charge mass would result in. I can model it in Quick Load, but I don't have anything like an RSI pressure trace. Nevertheless, I do have the means to look for pressure signs like hard extraction, extractor marks, primer cratering and flow. I didn't observe any of those things in any of my loads. I'm not surprised because there is a safety factor in the components and rifle chamber that published loads are unlikely to exceed.

I have these for every caliber I load.

The Complete Reloading Manual for 223 Remington

The Complete Reloading Manual for 223 Remington All Loadbooks USA, Inc. manuals are printed on heavyweight paper and spiral bound so they will lay flat on any surface. The manuals list many useful loads using different powders and jacketed bullets as well as some lead bullets. With...

www.creedmoorsports.com

 

[buck460XVR]

The published data was for 55 grain Speer SP and a 24" barrel. I used 55 grain Hornady SP and a 16.5" barrel. I'm skipping over a lot of details of my process to get to the point:

I think part of the issue is, you are using a Speer recipe for a Hornady bullet?

The cartridges loaded with 25.3 grains of H-335 achieved a mean of 2820 fps vs. published data of 3203 fps.

My Hornady manual states that the max load for their 55gr SP is 23.2 of H-335 and velocity is 3100fps

The cartridges loaded with 25.6 grains of Benchmark achieved 2956 fps vs. published data of 3264 fps.

My Hornady manual states that their max load for their 55 gr SP is 24.5 of Benchmark and velocity is 3100fps.

How far over max?

It appears to me, you are already over max, or am I missing something? My Hornady manual does not give any recipes for Ramshot X-Terminator with their bullet, but your other loads are over Hornady max. Sometimes extrapolation is not an exact science.

 

[GeoDudeFlorida]

I think part of the issue is, you are using a Speer recipe for a Hornady bullet?

My Hornady manual states that the max load for their 55gr SP is 23.2 of H-335 and velocity is 3100fps

My Hornady manual states that their max load for their 55 gr SP is 24.5 of Benchmark and velocity is 3100fps.



It appears to me, you are already over max, or am I missing something? My Hornady manual does not give any recipes for Ramshot X-Terminator with their bullet, but your other loads are over Hornady max. Sometimes extrapolation is not an exact science.

I tried pointing this out also, but without the Hornady loading data, and it was not received well.
Hornady and Speer bullets are not interchangeable. Just ask them.

 

[ballman6711]

Hornady and Speer bullets are not interchangeable

Different jacket thickness and composition, different bearing surface, and whatever else doe's make a difference.

I try to use data from the bullet manufacture, but that's not always possible. When I can't, I use somebody else's data, start low, and work my way up to an acceptable load without exceeding the max data listed. I usually stop around the middle of the data, although sometimes I end up with a load near max. If I can't find a load that's accurate and functions well in a semi-auto, I try a different powder. If I can't find an acceptable load after trying a few or several different powders, I try a different bullet and start over. Sometimes the type or brand of primer makes a difference. I use the same process for revolvers and rifles.

As an example, my "perfect" target 45acp load using a 185gr swc and W231 with any brand of LPP (magnum or standard) and any brand of brass go's downhill fast (functioning) when using small primer brass.

I'll ask again what is this load going to be used for? For target shooting at reasonable distances velocity shouldn't really matter unless you have to make a power factor for competition.

chris

 

[AJC1]

24.9 is the 55 fmj max load right out of the western load manual free for download.... why were having pages od debate blows my mind, its safe.... further in the same manual 26.3 is max for 556. No need to go over, ask where the data is...

 

[Soonerpesek]

View attachment 1197242

I HATE when that happens when you’re on the interstate……

 

[Mostly Lead]

Should I keep loading it higher until I see pressure signs or velocities 90% lower than published?

No.

 

[gwpercle]

I never go over book maximum ...
Barrel length has a lot to do with velocity ... but noting to do with Pressure ...
And pressure is what takes guns apart .
If I can't get the velocity I want I try a different Powder .
Usually a faster powder with a shorter barrel will get the velocity ... But ... I still never exceed book maximum charges .
50 + years reloading with no mishaps .
Gary

 

[GeoDudeFlorida]

24.9 is the 55 fmj max load right out of the western load manual free for download.... why were having pages od debate blows my mind, its safe.... further in the same manual 26.3 is max for 556. No need to go over, ask where the data is...View attachment 1197354

He’s asking why X-Terminator is only achieving 80% of what Hodgdon says it should vs other powders which are getting 90% of the listed velocities. Part 2 of the question was whether or not to load up until he got the listed velocity even if it means going over. For Part 1, the obvious answer is because it’s not a good combination. That happens and trying to force a bad combination to work is almost always a bad idea. I think the only people who can explain the Why’s are the ballisticians at Hodgdons. For Part 2, the answer depends on the answer to the question: How are the lower loads performing on target? Still have not seen the answer to that question. Can’t think it matters to the OP as a result. If accuracy matters, velocity is secondary.

 

[film495]

just use up that powder with range/practice rounds. maybe don't get that one again if it seems to not meet your expectations. possilbe that powder is a bit slower and benefits from the longer barrel more, and that shows as a result in your testing, that it really doesn't like a shorter barrel even more than the others. just to guess - the peak pressure is delayed a fraction of a nanosecond compared to the other powders being tested, and it maybe needs the extra barrel lenght to get going. more so than the other powders.