IMT brass headstamp-confusion/misinformation?

[DeadEye9]

Ok so I have heard many things about the IMT/Freedom Munitions brass that I want to try and clear up. I also am never against any new information coming my way as well. The issue has been stated that because of the "ledge" inside the case for their 9mm and 45 ACP (possibly other calibers too) they aren't worth reloading and will blow up your guns and blah blah blah. I've heard people say the purpose of this ledge is to prevent bullet setback, I've even heard others say it's a two piece case "welded" together. First I will clear this up, the ledge is the result of how the brass is made pure and simple. It's called forced extrusion and is a common process for metals here in the US. This process leads to the case being heavier than most other head stamps while offering slightly LESS case volume. BecUse of the volume difference (~5%) many people say this brass is dangerous to handload. This is false. In my initial testing I too fell to this belief and worked up entirely new recipes for this IMT brass. Totally uneccesary though as any standard manual load works totally safe in these cases. (I've tried 5 powders and over a dozen charge weights from min to max in 9mm)
Due to the case being significantly heavier than most other brass, many have thought that means the case is inherently stronger and therefore is a good choice for +P or 9mm Major loads. THIS and only THIS is where problems arise. When subjected to extreme pressures, these cases will fail. They split in a way that almost looks like it was intentionally cut. I'm sure this is why some believe it is a two piece case design. This is also leading to people assuming the case itself is bad for reloading/handloading but in fact it just can't take excess pressure. With any normal load, even max manual loads, these "ledged" cases are fine and safe. With custom high pressure loads, as with ANY headstamp case, failure can/will occur so work up loads safely and carefully. I just wanted to put a little info out there because this brass is often tossed aside by people who truly have no idea what it is, and for no good reason. I have been getting excellent deals on this stuff for about a year now so my 9mm loads have been almost exclusively IMT headstamped lately and I have zero issues to speak of. I will post some loads below that I use regularly with this brass in case anyone is looking to test some on their own as it is very affordable and many times even free. (I get 500 ct bags primed and ready to load for under $40 and regularly find large amounts of it left behind at the range in my area.)

IMT Brass, Winchester 124gr FMJ, Remington 1 1/2 primers
4.5gr W231/HP-38. Decent accuracy, mild recoil, velocities around 1090fps average from Glock 19, closer to 1150 from my 17 and around 1065 from my M&P Shield.

IMT brass, Winchester 124gr FMJ, Remington 1 1/2, 6.4gr Power Pistol
Very accurate, moderate recoil. 1133 from Glock 19, 1191 Glock 17

IMT Brass, Speer 115 GDHP, Winchester SP primer, 5.2gr HP-38/W231. Nice groups, moderate to mild recoil, 1178 from Glock 19, 1211 from Glock 17, 1124 from M&P Shield

I've also done quite a bit of loading with TiteGroup and some other bullets as well if anyone is interested. 124 JHP, 147 JHP, 147 FMJ-FP etc. Just let me know.

 

[hdwhit]

IMT Brass, Speer 115 GDHP, Winchester SP primer, 5.2gr HP-38/W231.

Please note that this load in excess of the published maximum per the Hodgdon website.

 

[hdwhit]

Totally uneccesary though as any standard manual load works totally safe in these cases.

How was it determined that the load is "totally safe"?

• Was a pressure transducer used to determine that chamber pressures were below SAAMI maximum?
• Or was it determined that the loads were "totally safe" because they were fired and the gun didn't blow up?
• Or was some other method used?

I ask this because the original post says the IMT cases have about 5% less volume than other cases, yet the Speer manual, number 11, on page 385, points out that bullets set back as little as 3/1000 inch (a reduction in volume under 2%) was sufficient to send loads that normally produced 28,000 cup soaring to 62,000 cup.

 

[DeadEye9]

Bullets set back .3 from what OAL sent pressure to 62k? Minimum I assume? I never load to minimum length, and I don't really know anyone who does. And pressures were recorded with an Omega. None of the above loads reached over 37,500 psi in my experience. (Higher than standard but less than +P, which is where I set my own limits) Your mileage and preferences may vary, which is why it's always recommended to work up any load, even to a manual load let alone a forum load. I'm not speaking gospel Just sharing information.

 

[DeadEye9]

Please note that this load in excess of the published maximum per the Hodgdon website.

It is still well within pressure limits considered "standard". If you notice Hodgon lists 5.1gr behind a .355 115 GDHP with a 1.125" OAL, producing around 28k psi. With the same powder and weight load switching to a .356 LRN and 4.8gr produces 31k psi and that is still a published load. Well 5.2gr and 115 GDHP @ 1.125" read 30,300psi. Well within standard pressure realm.

 

[DeadEye9]

Pictures of what others have had happen with these loads when over pressured. Case head desperation right at the "ledge". I have loaded literally almost 5k rounds of IMT 9mm with standard manual loads and have never experienced this personally. Also, I may have mislead some with the 5% difference stated in my first post. After sizing a bunch of IMT and various other cases, there seems to be a variation in water capacity between ALL brands of cases tested from various lots. I.e. WCC different lot to lot, FC different lot to lot, Blazer different, etc. There are plenty of reloaders who use mixed headstamp brass with the same loads and don't see KBs so I don't see that as any different than loading an entire batch of the IMT cases. I've seen failures with every major brand over the years so no brass is perfect.

 

[Rule3]

Bullets set back .3 from what OAL sent pressure to 62k? Minimum I assume? I never load to minimum length, and I don't really know anyone who does. And pressures were recorded with an Omega. None of the above loads reached over 37,500 psi in my experience. (Higher than standard but less than +P, which is where I set my own limits) Your mileage and preferences may vary, which is why it's always recommended to work up any load, even to a manual load let alone a forum load. I'm not speaking gospel Just sharing information.

You own or have access to a Pressure Transducer???

How many actual sample loads have you "tested" to make a statistically valid report on this type of brass??

With the "gazillion" amounts of brass and headstamps (especially 9mm)out there why spend the time, money and energy on this one odd ball form of brass??

Just curious.

 

[Blue68f100]

Depending on Bullet used you can hit the ledge with the base of the bullet and bulge the case. This can happen with the heavier bullets which are longer, 147gr and some 124gr in 9mm. I save all of the stepped ones for a nothing to do day. I don't need to load them since I have over 10k 9mm brass. I did a water capacity test and they were pretty much the same ( when measured to the rim) as to the ones I tested against. The main difference is the area that holds the bullets indicates to be thinner being straight wall vs std taper. I load them but you must workup you load due to the smaller volume where the powder goes.

 

[Muddydogs]

Good write up OP, I like to read about guys getting out there and trying things for themselves instead of taking the internets word for it.

 

[Walkalong]

The space seems to be less than a 5% difference just going by the eyeball test, although not as bad as that Maxxtech brass in the othe thhread, so I would start even lower and use a chrono to verify FPS to make sure I am not getting more than I should, which would mean pressure is up. Brass like this can be used, (or the factory wouldn't load it ), but we need to be aware of the reduced capacity and what it will do to pressures. Pressures we cannot guess, or see on the brass, and really don't know what it is without pressure equipment.

 

[DeadEye9]

Ballistics testing and "pushing the envelope" with loads is just as much a hobby of mine as shooting is. I could just as easily be happy spending a day cooking up something in the "lab" and testing as spending a day beating up steel on the range. The reason I did this initially is because at the start I was getting 550-600 primed and processed and ready to go for under $40. After a while tho I started getting a ton of this stuff for free because no one wanted to mess with it because they all said it was "so dangerous". So I started doing more thorough testing and found it behaves not much different than other brass.

 

[Wreck-n-Crew]

I really am at a loss here as to why a case with a smaller in capacity would not be a caution to load capacity. It's about volume if we are talking about the same caliber under standard pressure limits is it not! If the Volume of the the case is smaller than a standard loaded case then there is a rise in pressure if loaded with standard published data!

 

[DeadEye9]

I just looked at my notes. I've loaded and fired a total of 2350 rounds of IMT 9mm and actually ran pressure testing on the first 40 of various loads and out of the ones I ended up with, the 6.4gr of Power Pistol and 124 Winchester FMJ proved to be the favorite load for majority of my service pistols in the 9mm chambering.
One thing I will note is even in my own reloading notes I designated not to use this brass for any of my home grown "+P" loads and to keep the OAL as long as possible with reliable feeding, which is usually my MO anyway.

 

[DeadEye9]

I really am at a loss here as to why a case with a smaller in capacity would not be a caution to load capacity. It's about volume if we are talking about the same caliber under standard pressure limits is it not! If the Volume of the the case is smaller than a standard loaded case then there is a rise in pressure if loaded with standard published data!

There really isn't much internal difference in volume with these cases, that's the point. Various 9mm brass differs in capacity anyway, and many people load mixed brass loads the same despite this. I'm not saying different cases won't run slightly different pressures with the same load, I'm saying that if loaded sanely the pressure doesn't exceed anything that will cause harm to you or your firearm.

 

[higgite]

Pictures of what others have had happen with these loads when over pressured. Case head desperation right at the "ledge".
View attachment 226093 View attachment 226094

As those rounds weren't yours, how do you know for sure they failed from "over pressure" and not from multiple firings at "normal" pressures?

I just looked at my notes. I've loaded and fired a total of 2350 rounds of IMT 9mm and .........

In your 2350 rounds, how many times was the brass recycled?

 

[Blue68f100]

I really am at a loss here as to why a case with a smaller in capacity would not be a caution to load capacity. It's about volume if we are talking about the same caliber under standard pressure limits is it not! If the Volume of the the case is smaller than a standard loaded case then there is a rise in pressure if loaded with standard published data!

While the over all case volume is near the same, where the powder rides is not. These cases are thinner at the top where the bullets rides, not tapered. If you look at the base it's real heavy, lower volume. But it kinds of depends as to what OAL you use and bullet combo.

 

[DeadEye9]

Because I know the owner of the weapon they were fired through, a Rock River 9mm upper/PSA lower and he told me his load which was nearly half a grain above manual max of Unique. Also the fact that the weapon was not a breech lock but a blow back with a very loose chamber was a partial factor im sure. (Owner claims that same load runs fine in his M&P 9 VTAC.)
As for how many times fired, I'm not one to load the same case 10+ times and record the results, I don't much care how many loads I get out of each cAse. I lose them faster than I could ever wear them out, so I would say at 5 maybe 6 loads on a single case would be the max I've done with the average being more like 3-4 loads per case. Not exactly a lot, but I don't see any pressure signs and have not split any cases at this point. Also I've noticed high pressure rounds don't give you as many reloads in general as low velocity/pressure loads. I have some .45 Colt cases I know I've loaded 10+ times because I use only my nickel cases for my load of LilGun, yet I've worn out commercial .223 and .300 brass in about half a dozen loads at times. I don't spring for the fancy stuff though, so I can't speak for Nosler, Norma, Lapua etc brass. I get perfectly acceptable accuracy with commercial cases and reload for economy not really precision. I have used SSA (from Nosler) rifle cases once, paying around $50 for 100 cases when I was looking to duplicate a super accurate version of MK262 mod1. They were nice brass cases, but the loads I did in regular IMI and Federal .223 cases proved just as accurate after processing.

 

[DeadEye9]

While the over all case volume is near the same, where the powder rides is not. These cases are thinner at the top where the bullets rides, not tapered. If you look at the base it's real heavy, lower volume. But it kinds of depends as to what OAL you use and bullet combo.

You are certainly correct about this. The base is where all the extra weight comes In and these are a good 6-7 grains heavier per case than your average FC, WCC etc head stamps. Maybe the saving grace for my particular loads in the IMT brass is the OAL being as long as possible. That could be, as I've never tried seating deep and testing the waters. Maybe now I will though, because it has me thinking. In any event, all I wanted to share with my original thread was that people don't have to be afraid of this brass, as when proper guidelines are followed it can be used just fine. In my area at least I'm seeing more and more people using the Freedom stuff, so the cases are everywhere and on a regular basis I was hearing range goers complain that they keep getting this "useless" brass. BecUse of this I figured there may be others with the same issues and wanted to share that it can indeed be reloaded and shot safely, within reason. Is it a good choice for your max "hot rod" loads? Absolutely not, but for a basic target load this is good brass you can usually get in large quantities for free.

 

[forrest r]

Bullets set back .3 from what OAL sent pressure to 62k? Minimum I assume? I never load to minimum length, and I don't really know anyone who does. And pressures were recorded with an Omega. None of the above loads reached over 37,500 psi in my experience. (Higher than standard but less than +P, which is where I set my own limits) Your mileage and preferences may vary, which is why it's always recommended to work up any load, even to a manual load let alone a forum load. I'm not speaking gospel Just sharing information.

It is still well within pressure limits considered "standard". If you notice Hodgon lists 5.1gr behind a .355 115 GDHP with a 1.125" OAL, producing around 28k psi. With the same powder and weight load switching to a .356 LRN and 4.8gr produces 31k psi and that is still a published load. Well 5.2gr and 115 GDHP @ 1.125" read 30,300psi. Well within standard pressure realm.

I'm glad to see you thinking outside the box, but. You might want to rethink what you think you know. I'd start with:
Hodgdon uses CUP pressure measurements for their 9mm loads, not psi.
When a mfg lists a oal it's the Minimum oal!!! So when you say you never load to minimum oal, I just shake my head.

Common knowledge:
The deeper a bullet is seated the more the pressure increases. A common 9mm bullet/powder combo, (lee 120gr tc cast bullet/unique) note the increase in pressure as the oal shortens.


Ramshot has been putting things like this in their free reloading manuals for years now. Same thing shorter oal ='s more pressure.


Not all bullets are created equal, a reloader should not look at a long bodied lead bullet and a short jacketed bullet and assume they are safe because they use the same oal. (like in your statement above). 2 different 124gr jacketed bullets for the 9mm, they both have the same oal. But as you can see 1 takes up a lot more case volume than the other. Less case volume + same powder charge for both bullets ='s different pressures. That's why the lead bullet in your example used less powder and had higher pressures, namely 32,000cup (not 31,000psi).


A piece of !MT brass next to a standard/common piece of brass, take a good hard look at the shelf/thicker web of the imt brass.


The important part!!!!
YOU ARE COMPARING APPLES AND ORANGES WHEN YOU SAY THE DIFFERENCE BETWEEN A STANDARD CASE AND A IMT CASE VOLUME IS ONLY 5%.
Empty, yes.
But that doesn't mean anything!!!! You are putting a bullet in both cases. IT'S THE VOLUME IN THE CASE THAT IS LEFT THAT COUNTS AFTER THE BULLET IS SEATED!!!!
Do you really think there is still only a 5% difference in the volume of the 2 cases after the same bullet is seated to the same oal in both cases???


My wavy black line is supposed to represent the depth/base of the seated bullets. The space below the line what's left of the case volume for the powder charge. The volume difference that is left in the imt vs standard case sure and heck isn't 5%!!!

You should re-think what you're doing at the reloading bench. Because right now the only thing I personally got from this post is that:
Glocks are extremely tolerant of the people that reload for them.
Glocks are a lot stronger than I gave them credit for.

 

[Walkalong]

and actually ran pressure testing

With what equipment?

Anyway, we stress safe reloading procedures here and not pushing the envelope. People are free to do so of course, and I wish them luck, like folks loading 9MM to make Major, but as a general rule we like to keep things safe here for all the new reloaders and readers out there. Just causal mentioning things like loading "hot" and pushing the envelope all the time etc isn't responsible IMHO.

Y'all be safe out there.

 

[higgite]

As those rounds weren't yours, how do you know for sure they failed from "over pressure" and not from multiple firings at "normal" pressures?

Because I know the owner of the weapon they were fired through, a Rock River 9mm upper/PSA lower and he told me his load which was nearly half a grain above manual max of Unique. Also the fact that the weapon was not a breech lock but a blow back with a very loose chamber was a partial factor im sure. (Owner claims that same load runs fine in his M&P 9 VTAC.)

So, the brass is okay in some guns, but in others, not so much. That's good info to have. Thanks.

 

[Walkalong]

So, the brass is okay in some guns, but in others, not so much. That's good info to have. Thanks.

No such thing of course, if it fails consistently in any gun there is a problem. Just because one gun is stronger and didn't fail, yet, doesn't matter.

 

[DeadEye9]

No guns have failed yet that I personally know of, when I said failure I was talking about the case head separation/case failure. Cooper units mean nothing to me. There is a simple mathematical correlation between CUP and PSI and I choose to use PSI because it's familiar. The fact of the matter is, 32-34k PSI is completely safe in the weakest of 9mm firearms provided they are in good condition. Most modern firearms, not just Glocks, can easily handle pressures in the 38-40k range and many factory rounds are loaded to this pressure. The HIGHEST pressure load that I saw presented a chamber pressure of only around 37,500psi in a factory Glock 9mm barrel/chamber. (Actual number was like 37,46xpsi) Meaning the loads I specified were well within the tolerance of what normal service pistols will handle. I'm not guessing here, these are actual pressure readings from an actual factory Glock chamber. Taking the standard loading logic of working up your load, you can easily start with a 7-10% less than manual load for testing and see the results, then work up accordingly. Nowhere in my post did I state that any bullet at any OAL is safe with IMT brass, that isn't the case with ANY brass. 9mm case capacity being what it is, it tends to be very forgiving in general but still obvious reloading responsibility should still be taken. What I am pointing out is that this brass who many seem to think is "worthless or dangerous" is in fact completely useable and safe with the RIght components. This is the same for any and all brass really which is all my point was, that the IMT brass is no different than any other case. With the right loading practices they can be used just fine. With the wrong practices they will have problems, but again any case will, so my point is still valid that IMT cases are just another case and nothing more or less.

 

[higgite]

DeadEye9, do you use the handle "JeepHammer" on another forum?

 

[DeadEye9]

With what equipment?

Anyway, we stress safe reloading procedures here and not pushing the envelope. People are free to do so of course, and I wish them luck, like folks loading 9MM to make Major, but as a general rule we like to keep things safe here for all the new reloaders and readers out there. Just causal mentioning things like loading "hot" and pushing the envelope all the time etc isn't responsible IMHO.

Y'all be safe out there.

We have an Omega setup with multiple pressure transducers and ALOT of empty warehouse and field space. Anyway, I'm not advocating doing anything dangerous. I have been reloading and testing ballistics for the better part of the last decade and have yet to KB a gun despite sometimes loading hot. None of the loads I have listed are really wild and I wouldn't list anything wild without specifying "hey this is such and such"
By pushing the envelope I simply mean I use the tools at my disposal to test things outside of the normal realm. I don't feel there is anything wrong with this personally because if others had not done the same we wouldn't have half of the great cartridges/calibers we have today. Magnum pistols would not exist without someone willing to see what you can get away with in a special case first.
I am also an avid hunter and believe in the most humane and efficient kill possible. For this I use ballistic gel and my loading experience To custom tailor loads for certain rifles, certain animals, certain locations/distances etc. I'm not out to create the fastest 9mm round in the world or the hottest .308 or anything like that but I do like to test and learn. For instance before I owned anything in .308 I had a .300 Savage. Case capacity is similar between the two so I loaded for the ballistics of the factory loads I planned to try in .308, in my .300 brass. There isn't much data out there save for a few loads in this realm so I had to test and evaluate various loads. For my daily carry handguns I like to practice atlwast once a week at my action pistol club and for that I like the same power factor and POI as my carry ammo. Shooting 200+ rounds a week of 124/147 HST +P is expensive, so I tested untill I found equal loads I could make myself for much less. Doing so required going a couple tenths above manual data, but to this day has shown me no pressure signs or ill effects so I still practice with and make that same load. This is a brief explanation of what I mean when I say hot ammo or pushing the envelope. I'm not out here seeing how much powder I can throw in a random case and still seat a projectile or advocating anything of the sort. I am however a fan of outside of the box logic and also a huge fan of self reliance when it comes to testing things so I can actually trust the results. I'm far from a professional, but I'm not some 18 y/0 YouTube amateur, either.