Red Dot in .40SW

[grumman581]

I was helping a friend last week who was just getting into reloading. The Lee kit that he bought came with the Lee balance beam type scale. We were aiming for a powder charge of 6.6 gr for a 135 gr jacketed bullet. I had found a 6.0 to 6.7 gr recommended loading for that powder and bullet in .40SW. After trying various of the powder disks, we came up with one that we measured to be 6.6 gr or less and we test fired it in his garage into a 5g bucket of dirt. It cycled the action and the brass looked good afterwards, so we figured it was a good loading and he proceeded to make up some more for his next trip to the range. He did not particularly like the Lee balance beam type of scale, so he bought an electronic one. He then measured the charges that the powder measure was dropping that we thought had been 6.6 gr and it turned out to be 7.1 gr instead.

So, I guess my questions are: Has anyone any information on a 7.1 gr load? Does it exceed the SAAMI specs on pressure for the .40SW? Possible velocity?

[gtgeorge]

I suggest pulling the bullets. Seems 6.7 would be pushing the upper ed already. Now working up to the load maybe but not as a guess.

[grumman581]

I suggest pulling the bullets. Seems 6.7 would be pushing the upper ed already. Now working up to the load maybe but not as a guess.

Someone posted on one site that the Sierra or Lyman manual gives a listing for 7.2gr of Red Dot in a 10mm -- 1375 fps, 567 ft-lbs. They didn't list the pressure though.

[35remington]

A man with one scale knows the weight of the powder charge. A man with two scales is never sure.

Get some check weights. Find out which one was off. Reexamine the Lee scale for misnotching of the razor blade in the balance notch. There may be a stray bit of aluminum "tailing" messing up the reading.

If it's a cheap electronic scale or one with a single check weight to calibrate it, suspect that one too.

[gtgeorge]

Someone posted on one site that the Sierra or Lyman manual gives a listing for 7.2gr of Red Dot in a 10mm -- 1375 fps, 567 ft-lbs. They didn't list the pressure though.
Comparing load data for a 10mm would be irrelevant and very unsafe. If the load is in question....do not shoot them is a simple answer. But the ball is in your court.

[Nickle]

No, I think it's very relevant. If that's the load for a 10mm, you can take it to the bank that it's way too hot for the 40 S&W. First off, the bullet is seated "deeper" (less OAL). That alone increases pressure. 10mm guns are generally built stronger too.

So, pull the bullets. I see no other way to go.

[grumman581]

He's already pulled them, but I was curious... Not having the relevant Lyman or Sierra manual, I do not know the pressure. 567 ft-lbs is not a particularly hot 10mm load, but it would be a bit on the upper side for a .40SW load. According to the wiki page on the .40SW (https://en.wikipedia.org/wiki/.40_S%26W), there a couple of commercial loads that are hotter, but of course, we do not know what powder they are using. Here's a chart (http://www.ballistics101.com/40_caliber_sw.php) with a few more brands of commercial ammo and some of them exceed the 567 ft-lbs also.

[9.3X62AL]

Having a 10mm pistol in the safe already, I have ZERO INTEREST in pushing the 40 S&W anywhere past its performance with my authorized carry ammo (W-W Ranger SXT 180 grainers), which get about 950 FPS from 4" barrels. I use the Lee 175 TC (conventional lube groove) OAL 1.135", 4.7 grains of WW-231 gives right at 950-975 FPS in my CZ-75B. OEM specs show the 40 S&W to be largely "loaded out" already. There are no flies on these loads, either--they do the job on ne'er-do-wells right proper in my experience, 1-2 half-decent hits tending to send the message succinctly. The SXT bullets look like ad copy for Winchester ammo in the trauma center or autopsy theater after removal, too. No real need to gild this lily, at all.

[MT Gianni]

Another voice for getting a check weight set. My lee cheapo scale is as accurate as my Ly 1200 dps. In fact I use it to verify loads occasionally. I do this because I have verified most weights on it with my Ly check weight set.

[grumman581]

Having a 10mm pistol in the safe already, I have ZERO INTEREST in pushing the 40 S&W anywhere past its performance with my authorized carry ammo (W-W Ranger SXT 180 grainers), which get about 950 FPS from 4" barrels. I use the Lee 175 TC (conventional lube groove) OAL 1.135", 4.7 grains of WW-231 gives right at 950-975 FPS in my CZ-75B. OEM specs show the 40 S&W to be largely "loaded out" already. There are no flies on these loads, either--they do the job on ne'er-do-wells right proper in my experience, 1-2 half-decent hits tending to send the message succinctly. The SXT bullets look like ad copy for Winchester ammo in the trauma center or autopsy theater after removal, too. No real need to gild this lily, at all.

Saying that you have a 10mm and as such would not push the .40 is not pertinent to the question at hand. The question was simply whether anyone had any experience with such a load given that there were no obvious overpressure signs (i.e. it is not flattening primers or bulging cases).

To reiterate, the person in question:

is brand new to reloading
owns a SINGLE handgun (a Sig P226 in .40SW)
does not have a chrono, so I have no idea what he was getting out of those rounds
owns a single handgun, a Sig P226 in .40SW
has a single powder (Alliant Red Dot)
has a single type of primer (Federal small pistol magnum)
is using 135 gr jacketed truncated cone bullets because that was all that he could find that anyone had in stock currently
*thought* he was loading 6.6 gr of Red Dot, but when checking it against a digital scale learned he was loading 7.1 gr
experienced no overpressure signs during the 100 or so rounds that he fired with this loading
has subsequently pulled the bullets and reloaded the rounds with less than 6.6 gr of Red Dot


Now, personally, *I* would not do this for various reasons:

I don't buy jacketed bullets, I cast my own and they are heavier than 135 gr.
I have a 10mm, so I can load it to a hot .40 level and it is still within SAAMI specs.
I can use .40 brass in my 10mm at 10mm pressures by just loading the bullets long (I have a Glock).
I can shoot regular .40 rounds in my Glock also.


What I was interested in from an academic standpoint was whether anyone had seen this loading for the 10 mm and what was the pressures stated for it. I am well aware that it would be higher for the shorter cased .40SW round.

[grumman581]

No, I think it's very relevant. If that's the load for a 10mm, you can take it to the bank that it's way too hot for the 40 S&W. First off, the bullet is seated "deeper" (less OAL). That alone increases pressure. 10mm guns are generally built stronger too.


Just because a load is listed as a 10mm load, it doesn't mean that it would not be an acceptable .40SW load. Something could be listed as a light 10mm load, but it would be a slightly upper level .40SW load. Sure, the load will be higher pressure in the .40SW due to the reduce case capacity, but that in itself does not mean that it would not still be within SAAMI specs. For this particular load though, I have no idea. It *seemed* to work without any adverse affects, but my gut feeling is that it is a bit too hot for that particular powder and that if anyone was actually wanting to use it, there's a chance that it should be used with a heavier spring.

Does anyone have the Lyman or Sierra reloading manuals to see what the pressures were for this load in 10mm? Of course, it will be even higher in .40SW.

[9.3X62AL]

Safety is NEVER impertinent, Grumman--and if my statements aren't up to your standards of topicality you are always welcome to ignore both them and me. I regard attempts to re-make the 40 S&W into a 10mm Short as unsafe practices, since the OEM round is almost maxed out from the git-go. I have no idea of the experience levels of the readers perusing my text, so if I err on the side of caution and safety......so be it. The 40 S&W, 9mm, and 10mm ARE NOT "beginner calibers", esp. if stoked with cast boolits.

[grumman581]

Safety is NEVER impertinent, Grumman--and if my statements aren't up to your standards of topicality you are always welcome to ignore both them and me. I regard attempts to re-make the 40 S&W into a 10mm Short as unsafe practices, since the OEM round is almost maxed out from the git-go. I have no idea of the experience levels of the readers perusing my text, so if I err on the side of caution and safety......so be it. The 40 S&W, 9mm, and 10mm ARE NOT "beginner calibers", esp. if stoked with cast boolits.

So, are you saying that you have NEVER used a load that wasn't published by a powder or bullet manufacturer? You have NEVER substituted a powder with a similar burn rate for a specified powder that was not readily available and worked up a new load? You have NEVER substituted one brand of bullets for the one specified in the official load? You have NEVER created your own powder puff loads for introducing new shooters to the sport? The fact of the matter is though that unless someone posts the pressures of that load in 10mm, we don't know if it would be obviously an overpressure in a .40 or just possibly an overpressure.

On a side note, I personally do not like to use the term "impertinent" since it's too likely that someone might mistake my intended meaning for the other meaning (http://www.merriam-webster.com/dictionary/impertinent) of that word (i.e. "not pertinent / not relevant" vs "rude"). Funny how that word has such vastly different meanings...

[9.3X62AL]

Stop being such a troll. My meaning is very clear, if read with an objective outlook. It is responses like yours that cause me to regret posting ANY information on ANY thread in this nest of basement dwellers and loon units. Your texts have been chiding, insulting, and obnoxious. You ask for assistance, then slap down those who attempt to lend a hand in good faith. You're welcome.

[MBTcustom]

I was helping a friend last week who was just getting into reloading. The Lee kit that he bought came with the Lee balance beam type scale. We were aiming for a powder charge of 6.6 gr for a 135 gr jacketed bullet. I had found a 6.0 to 6.7 gr recommended loading for that powder and bullet in .40SW. After trying various of the powder disks, we came up with one that we measured to be 6.6 gr or less and we test fired it in his garage into a 5g bucket of dirt. It cycled the action and the brass looked good afterwards, so we figured it was a good loading and he proceeded to make up some more for his next trip to the range. He did not particularly like the Lee balance beam type of scale, so he bought an electronic one. He then measured the charges that the powder measure was dropping that we thought had been 6.6 gr and it turned out to be 7.1 gr instead.

So, I guess my questions are: Has anyone any information on a 7.1 gr load? Does it exceed the SAAMI specs on pressure for the .40SW? Possible velocity?

To your original question: There are many people that load over stated book pressures, and most book loads err on the safe side of the pressure in case some jackleg is trying to load for an old and busted gun.

At 7.1grains you were probably getting close or over factory pressures. It can work most of the time, and guns are build stronger than they need to be.

I'll leave you with a picture of my buddies new glock Like I said, it works most of the time:
74453
Now he knows for sure that he threw too much powder in the case, and has decided to back off the charge some.
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[grumman581]

Stop being such a troll. My meaning is very clear, if read with an objective outlook. It is responses like yours that cause me to regret posting ANY information on ANY thread in this nest of basement dwellers and loon units. Your texts have been chiding, insulting, and obnoxious. You ask for assistance, then slap down those who attempt to lend a hand in good faith. You're welcome.

So, you choose not to answer the question that was proposed, but it is somehow *my* fault?

There have been some useful responses to this question, but I do not feel that yours was one of them. We all know that you can't just take the load data for one caliber and substitute it for another caliber. On the other hand, we can use it as a data point in deciding whether to choose to pursue it or whether to automatically reject it. Back when it was still possible to find ammo on the shelves of the local sporting goods stores, I was looking at some .40SW and 10mm ammo and that particular manufacturer had virtually no difference between their loads for the .40SW and 10mm. Didn't really make sense to me that someone would pay more and get the same performance, but other manufacturers were not that close on their loads for the two calibers. On the other hand, given the same bullet weight, I've seen the .40SW load with more velocity with one manufacturer than the 10mm with another manufacturer. As such, just saying that all 10mm loads are not appropriate for .40SW is not correct. You need the pressure data and then attempt to make an informed decision from that point. It's no different than other potentially hazardous situations that we deal with on a day to day basis. Like crossing a road at a stop sign or railroad tracks at a non-gated crossing when a car or train is coming -- you judge their distance and speed and decide whether you can made it with an acceptable safety margin. If you choose wrongly, it will have a detrimental effect upon you.

I have had my friend recheck his Lee scale against the check weight that came with his digital scale and other known weights. They now agree, so either he had the beam balanced incorrectly on the knife edge, some contamination on the knife edge, or it was just a reading error. Whatever it was, he now has two scales that agree to within 0.1 gr on measurements.

[grumman581]

To your original question: There are many people that load over stated book pressures, and most book loads err on the safe side of the pressure in case some jackleg is trying to load for an old and busted gun.

At 7.1grains you were probably getting close or over factory pressures. It can work most of the time, and guns are build stronger than they need to be.

I'll leave you with a picture of my buddies new glock Like I said, it works most of the time:
<snip>
Now he knows for sure that he threw too much powder in the case, and has decided to back off the charge some.
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One of the disadvantages of plastic guns, I guess... ;)

Was that due to the supposedly unsupported chambers in the previous generation Glocks?

[MBTcustom]

One of the disadvantages of plastic guns, I guess... ;)

Was that due to the supposedly unsupported chambers in the previous generation Glocks?

No, that would be one of the disadvantages of not understanding that pressure and speed are two unrelated ballistic concepts, as they pertain to case capacity.

[grumman581]

No, that would be one of the disadvantages of not understanding that pressure and speed are two unrelated ballistic concepts, as they pertain to case capacity.

So, it wasn't a measuring error?

Do you remember the load that he was using? Knowing the loads that blow up a gun is probably a pretty useful fact also, come to think of it. :) Did he work up the load? If so, were there any signs of overpressure before it did a KB on him?

[rsrocket1]

grumman, are you sure the electronic scale is accurate?
If your friend paid less than about $200 for the electronic scale, I would put my money on the Lee scale being more accurate (unless you are bumping the sliding window all over the place. There is a small plastic lock tab that will prevent that. The $30-$50 scales are notoriously inaccurate and are often off by several 10th's of a grain. They are great for checking bullet weights and counting bullets in bulk and even for shotshell loading where 0.2-0.4g doesn't really make much difference but not for metallic cartridge loading.

[grumman581]

grumman, are you sure the electronic scale is accurate?
If your friend paid less than about $200 for the electronic scale, I would put my money on the Lee scale being more accurate (unless you are bumping the sliding window all over the place. There is a small plastic lock tab that will prevent that. The $30-$50 scales are notoriously inaccurate and are often off by several 10th's of a grain. They are great for checking bullet weights and counting bullets in bulk and even for shotshell loading where 0.2-0.4g doesn't really make much difference but not for metallic cartridge loading.

Are we really truly *sure* of anything in life? :)

The latest information that I have from my friend is that the Lee and the Hornady GS-1500 (http://www.midwayusa.com/product/438260/hornady-gs-1500-electronic-powder-scale-1500-grain-capacity) that he bought now agree when measuring the test weight and other items. I have a Lyman (XP 1000, IIRC) (http://www.lymanproducts.com/lyman/scales-measures/1000-XP.php) and I have been satisfied with it. Unfortunately, I did not have it with me when I was at his house a couple of weeks ago when I was showing him how to setup his new press. Although he also lives in Texas, it's about 4 hours away from where I live.

[grumman581]

Thanks to some offline help from goodsteel (http://castboolits.gunloads.com/member.php?17771-goodsteel), we ran the numbers through QuickLoad and came up with some interesting results.

135 gr copper jacketed bullet:


Caliber
Powder Charge
Muzzle Velocity
Max Pressure


.40SW
7.1 gr Red Dot
1663
38,500


10mm
7.1 gr Red Dot
1633
31,761


.40SW
6.7 gr Red Dot
1611
34,374

10mm
6.7 gr Red Dot
1582
28,451



QuickLoad flagged the 7.1 gr Red Dot load on the .40SW as being too hot of a load.

Now, the QuickLoad value for 7.1 gr in 10mm does not jive with the 7.2 gr load that I had seen repeated from the Lyman or Sierra manuals (1375 fps), so that kind of makes me wonder which might be right. Either the load from the manual was wrong / relayed incorrectly or the various parameters on the QuickLoad simulation are not exactly perfect yet.
http://glocktalk.com/forums/showpost.php?p=1994705&postcount=8

I find it interesting that there was this much of a reduction in pressure when you use the same load in both .40SW and 10mm. I had suspected a bit of a reduction, but not *this* much.

So, what does this tell us? That's easy... Be careful out there... Sometimes you'll get lucky and Darwin will be asleep on the job... But, sometimes NOT...

Thanks for the help, Tim...

[MBTcustom]

My pleasure! Yeah, we had a great conversation. We fired up Quickload and ran some sudo tests. We both knew there would be a pressure difference between the two cases, but now we know how much.

It's about science, reasoning, and understanding why we do what we do. I have to remind myself of that occasionally.

Certainly, no 10mm load should be used in a 40S&W, but seeing as how the same guns are chambered for both calibers, and the only difference is the length of the cartridge, it does make you wonder just how far apart the two of them are.
Surprisingly, 10mm is actually the safer cartridge because even when it's loaded hot, it is barely beginning to operate at 40S&W pressures. That is situation "normal". (Seems to me, it would be easier to shoot cast boolits in the 10mm because of this, but I digress).
Interesting discussion. Certainly got me to thinking.