Reloading the 9mm, 40S&W and 10mm

[Harley Quinn]

While checking some of the reloading books, I noticed how low the pressures are with the 40 S&W compared to the 9mm luger and 10mm that they came up with, for the Bren Ten.

It strikes me as odd, considering the 40 is a fairly new round in compared to the other 2, especially the 9mm.

I am starting a thread to see if anyone else has a thought about this. The Police depts are falling all over the 40 S&W as of late. As one writer put it "the fabulous 40".

Seems to me it could be quite a bit better. If reloaded.

HQ

 

[1911user]

I never expected to see low pressure and 40S&W used in the same sentance. It may have been the particular data you were looking at, but 40 and 9mm have about the same max. pressure. Don't go making up load data for 40, you'll get in trouble quickly. IMO, it is less tolerent of reloading errors than many other calibers especially for bullet setback. Many reloaders toss 40 brass after a few full power reloads just to be safe. It's not like 45 auto where you can shoot it until the mouth splits or you lose it.

If you want a hot 40S&W round, just go directly to the 10mm.

 

[Harley Quinn]

Not looking for that much hotter

Was just curious as to others findings. Most of my older books have no data, because the 40 S&W is fairly new and has taken the LEO world by storm. The latest book I have is the Lyman book #48.

I have recently purchased a 6" barrel that has a very tight and very good chamber for reloading. I am using it in my mdl 22 Glock. The rifling is ok for reloads, it is ported. Someone mentioned not to shoot lead in a ported barrel

Thanks for the information.

HQ

 

[Ol` Joe]

I noticed how low the pressures are with the 40 S&W compared to the 9mm luger and 10mm that they came up with

I don`t see the same in my books.
According to Speers #13 the 9mm and 40 are both loaded to the same 35,000psi and the 10mm 37,500 psi piezo.

The VihtaVuori #3 shows CIP max for the 9mm as 34,075 psi, the 40 and 10mm both rate 36,200 psi piezo

Not much difference in any of them.

 

[Harley Quinn]

Ol' Joe

I am going to have to get another reloading book and look up some of the loads on the web.

The latest book I have for loading is the Lyman #48. The loads are so much lower pressured you would think they are for a cartridge that came out of the early 1900's, not the latest and one of the greatest to hit the scene.

You are talking pressures that the Lyman book does not even come within 15% with the 9mm or the 10mm, let alone the 40 S&W which is about 30% lower.

One of the reasons might be that Lyman is known for shooting lead. The top end of the scale is certainly nothing close to pressures you are showing.

HQ

 

[Ol` Joe]

You are talking pressures that the Lyman book does not even come within 15% with the 9mm or the 10mm, let alone the 40 S&W which is about 30% lower

Harley the pressures I listed are the SAAMI max allowed pressures or industry standard max. Lyman is listing the average pressure they found with the load they are offering. These are two different values. The books don`t always load to these SAAMI max pressures for various reasons such as finding pressure spikes, not enough room in the case for enough of the listed powder to reach these pressures, not wanting the velocity any higher such as when shooting lead, ect.

Keep in mind too, pressures are not cut in stone for a given load. Not only do different guns give different pressure with the same loads but each cartridge will vary some in the pressure given. Pressure in a cartridge will vary just as velocities will. There is an "extreem spread" in pressure that has to be taken into acount when developing a load. The load in a manual may show the pressure of that paticular load in their lab as giveing 25,000 psi average, but if you check the acual data from the test the load may vary from 23,500 psi to 27,600 psi. There is also a SAAMI INDIVIDUAL MAX value. No load can excede this pressure no matter what the average psi is. If in the example given above the max allowed is 27K and the max average is 26K the load would have to be dropped lower because of the 27,600psi found as the top pressure recorded. The loads you are looking at may look light, but there is a reason Lyman didn`t go higher with that paticular powder/bullet combination in that cartridge.

If you can, pick up the A-Square manual. Midway sells it. The book has very little load data and it is all rifle, but has an extreemly large amount of data on pressure and their findings in their lab. They show what happens when we change a primer from the one listed, use different bullets, how much new powder lots alter pressure, ect. The book is worth triple the money for this reason alone.

 

[Harley Quinn]

Ol' Joe

Thanks for the information.
I have been checking around and it does appear that the SAAMI are pretty close with the various rounds we are discussing.

What I have been thinking about is to get a 10 mm. But since I have a 6 " barrel on my mdl 22. I am just going to go with some of the hotter stuff for carry and stick with the various that is out there in the loaded world of cartridges. I feel they are plenty good for what I need at this date and time.

I read books for information and what I found in the Lyman was a very low loading as a general rule for the 40. It surprised me so I started this thread.

In the world of pressure and volume it is apple and oranges. The slower burning create one thing and the faster burning can create something quite different. The double based powders that are available to the public have changed reloading from the days of 2400, Unique and Bullseye.

Some advocate them and others don't. I think you are going to have to go with what you are capable of achiving if you are experienced! Or just buy the item that is available across the counter.

I am thinking of going with some 10 mm cases, cut them down to 40 and see the weight difference's and then based on that. I might or might not want to push the pellet any faster. I'll have to do a water capacity test also. So much to do, so little time. One of many things I would like to do, but never seem to have the time. To much time spent typing of late.

HQ

 

[RecoilRob]

Glock .40's became somewhat famous (infamous?) for their 'generous' chamber feed ramps that left the case unsupported. This can lead to blowing out the case in front of the web.

Looking at fired .40's, you can often spot the Glocks by the bulges (yes, ignore the square firing pin marks).

Lyman data has always been very safe in any gun I have used it. I suspect they are playing it safe with unsupported chambers in mind on their .40 loads.

Pushing the high end loads might be an interesting thing to do with the Glock. Be careful.

 

[Harley Quinn]

RecoilRob

What you are mentioning about the chambers, very true. I actually got a different barrel because of it.
After reading and realizing the built in problem, I got the 6" barrel and compared the two chambers, Boy what a difference. At first I felt that I might experience some problems from the tighter chamber in the 6".

I did have two failure to feed out of 100 rounds fired. Not reloads, new in the box Winchester.

I always try and check my brass, (an old habit from days gone by). When shooting the glock stock barrel I noticed the slight bulge as you have mentioned.

Then I started looking around and wanted to find another barrel by someone other then Glock. I got this new one off of E-bay. Good barrel, saved some money and had a good time bidding.

One of the situations people are not aware is the Glock barrel adds insult to injury (they are smaller by a very small amount, the way they produce the "land and grove" they don't remove they beat um in) but coupled with the loose chambers that can be a disaster looking to happen when you figure someone reloading, does not read the warnings. Then shoots the lead of reloads it makes the barrel smaller. Does not clean it (very good), then shoots some copper jacketed and higher pressures because of sloppy depth of bullet. Or just a hot factory round.

It is usually not one thing that gets you, it is the mulitple mess ups

But I will start with the better brass of nickelplated 10mm. The tighter chamber, a slightly larger barrel and very careful reloading. (if I choose to do it)

Regards, HQ

 

[Shoney]

Just for clarification, here are the SAAMI specs:

9mm Luger 35,000 psi
9mm Luger +P 38,500
40 S&W 35,000
no +P for 40 S&W
45 ACP