Reduce loads with Ammoload and IMT brass?

[higgite]

I don't want to hijack 41wheelgun's thread on IMT brass, so I'm starting a new one.

A common warning I see is to use extreme caution when seating bullets below loading manual recommended OAL. The reason being that less internal case volume under the bullet results in higher pressure, sometimes much higher, for a given amount of powder. This is of particular concern with "high pressure" rounds like 9mm.

Since Ammoload and IMT brass have what I'll call a partial inner "liner" that forms a step in the interior case wall, isn't that tantamount to seating the bullet shorter than normal with regard to case volume? That is, with the bullet seated to a manual's given OAL, the volume of space under the bullet will be less with Ammoload/IMT brass than with the "standard" brass that manuals' min/max powder charge recommendations are typically based on.

That said, should min/max loads given in loading manuals be adjusted downward to account for the decreased case capacity of Ammoload/IMT brass? Or am I making much ado about nothing? What do you guys who reload Ammoload/IMT brass do?

 

[moxie]

Agree with your analysis. My conclusion is to toss them. Certainly not worth the trouble.

 

[higgite]

I've tossed the few Ammoloads that I've run across so far, but they seem to be getting more prevalent in range brass around here.

 

[Mad Chemist]

I have some that I have been loaded 3-5 times without incident. Overall case volume is similar to R&P, Fed, Win, CBC, and all the others. Much ado about nothing.

 

[Mad Chemist]

I just finished a very rough volume comparison between 3 of my ammoload cases and 3 pieces of WCC military 9x19 Nato brass. The ammoload held a greater volume of water than the WCC. I'll see if I can borrow a pipette from work and get a more precise measurement.

Regardless, if the premise is that this brass is dangerous due to decreased case volume then the premise is moot because the ammoload brass has a greater case volume than my military brass.

I believe that it is generally accepted that US Military 9x19 brass is as strong or stronger than regular commercial grade brass.

I am willing to wager that the ammoload brass is just as strong and possibly more robust than most of the common commercial brands.

 

[2 Horse]

I just finished a very rough volume comparison between 3 of my ammoload cases and 3 pieces of WCC military 9x19 Nato brass. The ammoload held a greater volume of water than the WCC. I'll see if I can borrow a pipette from work and get a more precise measurement.

Regardless, if the premise is that this brass is dangerous due to decreased case volume then the premise is moot because the ammoload brass has a greater case volume than my military brass.

I believe that it is generally accepted that US Military 9x19 brass is as strong or stronger than regular commercial grade brass.

I am willing to wager that the ammoload brass is just as strong and possibly more robust than most of the common commercial brands.

Can't wait to see your results, I did a rough test too and got 13.5 gr of H2O in the standard cases and 13.1 gr in the IMT cases. In terms of volume it's just about the same

 

[RussellC]

I have some that I have been loaded 3-5 times without incident. Overall case volume is similar to R&P, Fed, Win, CBC, and all the others. Much ado about nothing.

Same results here. I have reloaded a ton of them just like any other brass. In fact, they seem to be a little heavier than most, and to them naysayers, 2 things 1 measure their capacity as compared to your favs, and 2 send them to me!

Russellc

 

[918v]

Overall case volume is similar to R&P, Fed, Win, CBC

When Ammoload first hit the dirt at my range, I picked some up to test. Over time I got some more, but noticed they were different inside. The height of the internal ledge was less. I saw as much as .050" difference. I currently have just a few and am not going to dig for more. The one I have in front of me weighs 61.4 grains. I remember the early ones weighed 65 grains. As a reference, my FC brass weighs 55 grains and I have a couple "WW" cases that weigh only 50 grains.

So please don't generalize that these cases have similar capacities when there is a 20-30% difference in weight.

 

[918v]

OK,

A 61.4gr Ammoload holds 13.2 grains of water.

A 54.6gr FC case holds 14.1 grains of water.

That's 7%.

 

[RussellC]

Then you will find similar discrepancies between military brass Madchemist tested and FC. I have horrible luck with FC getting loose primers. I load them all the same.

Russellc

 

[918v]

That's cuz u load them too hot.

 

[RussellC]

Not at all, quite moderate in fact. You are failing to consider OAL. These loads are anything but hot. Again, send them to me. Plus, I loaded with Unique, very forgiving powder within reason, which these are.

Russellc

 

[RussellC]

Can't wait to see your results, I did a rough test too and got 13.5 gr of H2O in the standard cases and 13.1 gr in the IMT cases. In terms of volume it's just about the same

Same results here. Just like always, just start low and work your way up. Nothing wrong with the brass at all.

Russellc

 

[918v]

If you are loosening primer pockets then your load is too hot. I have reloaded FC brass in excess of 20 times using near max loads without loosening primer pockets.

 

[Mad Chemist]

My FC brass has loosened more than my R&P, CBC, Speer, or Win. They are looser to begin with than many other common brands. Certain brands will have predominate traits. S&B have tight primer pockets. Tula have very tight case neck tension and will easily bulge during the first few sizings.


918v, you are making a few hasty generalizations regarding others' practices.

 

[Mad Chemist]

I didn't have time to snag any precision pipettes from work. I did weigh a large sample of brass. I can post the weights tomorrow.

Regarding water fill, or more precisely, internal case volume. This metric doesn't really mean much unless the piece of brass has been sized. Otherwise, you are dealing with a case that has expanded to the chamber dimensions of whatever pistol fired it which of course affects internal case volume.

 

[Mad Chemist]

Here's some of the case weights that I observed. All weights are in grains.

Ammoload: 66.0 66.2 65.9 66.0
Win: 61.9
WCC 90 mil: 64.4
WCC 88 mil: 64.7 63.6
FC: 57.9
FC 96 mil: 62.5
FC 88 mil: 61.6
CBC: 62.0
HRTRS: 60.6
Speer +P 62.7 62.5
S&B: 62.7
R&P: 60.2

Averaging the set using only the mean value for the Ammoload brass so as not to bias the sample avg (n=14) yields avg case wt of 62.4gr.

This means that the Ammoload cases weigh 5.49% greater than the sample avg. The FC civilian case weighed 7.78% less than the sample avg.
Of course I'd need to measure many more samples for the data set to have greater validity. I'd especially be interested in weighing more FC civ brass since it seems to be significantly lighter than the rest of the sample set.

 

[2 Horse]

Case volume is what matters and yes all cases should be sized before testing.

If you can post the results of your findings

 

[918v]

More food for thought:

In a 9mm carbine, using a pre-dotFCdot 55gr case as a baseline, a 57gr Starline is 20 FPS faster, a 58gr Win is 30 FPS faster, and a 62gr WCC is 50 FPS faster.

 

[Mad Chemist]

Can't use FC as a baseline since it is the lightest of all brands tested and appears to be significantly lighter than the caliber avg. This biases the whole premise to support your argument. I could have done the same for the weight averages but I wanted honest data. That's why I only uses one data point for the ammoload case weight and set the average from that.

Also for chono data you need many more samples to get out of the error margin for the chrono.

But in all honesty, I don't intend to waste any more of my time on this. I have very little of it to spare these days. If you are uncomfortable using a brand of brass that many of us have have reloaded dozens of time then toss it or donate it to somebody else. But please don't try to convince the rest of us that it is going to blow up our guns.

I use brand new brass when working up max, near max, or exceeding max loads and I don't sub any range pick up for these loads as it would be foolish to do so. SAAMI approved data allows one standard deviation of as a safety margin for there max established pressure for all calibers. Therefore, modern published data is extremely safe and has a wide error margin for safety. Part of the reasoning for this is due to the fact that components and firearms do have a significant degree of variation. Hence why we work up our loads.

 

[918v]

Can't use FC as a baseline since it is the lightest of all brands tested and appears to be significantly lighter than the caliber avg. This biases the whole premise to support your argument. I could have done the same for the weight averages but I wanted honest data. That's why I only uses one data point for the ammoload case weight and set the average from that.

So my data is dishonest?

BTW, FC is not the lightest 9mm case. WW is the lightest weighing in at a mere 50 grains.

Maybe you should gain a bit more experience before trashing other people's work.

 

[Mad Chemist]

Your data is misleading.

Whether it is dishonest or not depends on the sincerity of the pursuit. An error in design of experiment does not imply dishonesty. If the error and its significance are known by the designer, and the designer continues to promote the validity of the results regardless of the known error, then the designer must be dishonest.

I make no claim to your personal integrity. I don't know you personally and I'll likely never meet you.

If pointing out an obvious flaw in experimental design is "trashing your work", then I would point out that the scientific and engineering community make a consistent habit of trashing each other's work on a regular basis. They call it peer review.

 

[918v]

Before criticizing, know what you are talking about.

 

[RussellC]

My FC brass has loosened more than my R&P, CBC, Speer, or Win. They are looser to begin with than many other common brands. Certain brands will have predominate traits. S&B have tight primer pockets. Tula have very tight case neck tension and will easily bulge during the first few sizings.


918v, you are making a few hasty generalizations regarding others' practices.

Agreed here too. I have loose primers on lots of once fired FC brass I have bought, more than any other label. No primer blow outs here...again 918v, these loads are not hot in the least...And they are not loose in other brass, with the same primers

 

[RussellC]

I have found that brass, even from the same brand, varies over lot numbers and time....especially with .223 brass, I'm sure it happens with other calibers as well. You know, you could have a smaller brass and still not overload it....918v, my loads are not too hot. In fact, some border on "kitten poots"! lol


Russellc