Long newbie question--40S&W and pressure

[rhino210]

I am wanting to load some .40S&W for the first time. A friend gave me a set of dies, small primers and some180gr Ranier flat points. The loading info from Ranier says to treat them as you would plain lead. I will be using Clay’s or Win 231. I want to push the round at about 950-1000fps in an H&K USP.

I compared the Lyman 47th and the Hogdons manuals but they don’t agree. Both manuals warn about pressures with the .40S&W. The Lyman’s puts max pressure up around 22Kcup and the Hogdons is up around 34K cup. That seems to be a big difference.

Here is my problem. The load data that comes closest is a 180gr Hornady XTP. The XTP is about 0.030 longer than the Ranier. If I seat the Ranier to an OAL of 1.125” then the case volume will be larger by 0.030 which “may or may not” increase pressure. Right? OR am I making much ado about nothing.

As long as the ammo will feed from the magazine, then I could use an OAL of 1.095” which is one of the possible lengths given on a lighter bullet. Am I right?

 

[Walkalong]

Arghh...wish I had my load data here. I have loaded that bullet in the .40. I wish I could remember what O.A.L. I used. The 1.095 may be to short and the 1.125 sounds a bit long. How deep in the case the bullet seats is going to determine its effects on pressure, not O.A.L. by itself. You are not going to get it to 1000 FPS (more like 800 to 850) with Clays, but you could push 900 or so with W231. Universal Clays could get you to where you want to go (and some others as well), but I would suggest pushing it around 850 for a nice range load.

Sounds like you need to read a bit more on reloading before you get started.

Having said that, I would start with that bullet loaded to 1.120 with 4.5 Grs W231 and work up to 4.8 or 4.9 Grs. if all seems OK. Hodgdon gives 5.0 Grs W231 as max on the 180 Gr. XTP with W231.

With the Ranier being .030 shorter that will decrease pressure as far as case volume, but this is a plated bullet instead of jacketed as well.

I assume you have a scale to check powder charges and you more experienced buddy is going to help you. Be safe and have fun.

 

[Shoney]

rhino210
Go back and look at the pressure designations. The 22K is in CUP, the 34K is in PSI. Do a search and read up on differences.

Reading my notes for W231 loads for my USPc40, I see that a 180 gr lead TC bullet was the most accurate at 0.1 gr above the minimum load listed in the current Hodgdon/Win/IMR data for the XTP.
http://data.hodgdon.com

COL was 1.125"

Use the lightest crimp that you can apply without allowing the bullet to set back (in the magazine of course) during firing.

Good shooting!

 

[Clark]

CAUTION: The following post includes loading data beyond currently published maximums for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The High Road, nor the staff of THR assume any liability for any damage or injury resulting from use of this information.

What I do for pressure is to check the empty cases.
To catch an empty case at the range, sometimes I loosely wrap a towel around the pistol.
The things I look for:
1) primer piercing
2) primer falling out from primer pocket expansion
3) case bulge from lack of support in the feed ramp area

When I try out a new load, I look at the brass with jeweler's eye loop

Actually, I use a eye piece salvaged from binoculars that someone threw away, as a jeweler's loop.

What I am looking for with the magnification is the beginning of a case bulge.

To measure case support:
1) I take the barrel out of the pistol
2) I put an empty case in the chamber
3) I scribe a line on the brass case with a needle to trace the outline of the feed ramp
4) I measure, with calipers or height gauge, from the rear of the case to the scribed line.

Evaluating the case support.
1) In 40 S&W brass, the web is ~.180" thick.
2) Subtracting this number from typical feed ramp support: .235" - .180" = .055".

My experience with 40 S&W is that [usually, but not always] the brass starts to bulge before the primer pocket gives up, or before the primer gives up. The case bulge being the weak link:

1) Case support .235" ..... case bulge ~40 kpsi
2) Case support .180" ..... case bulge ~70 kpsi

What does it all mean?
1) We can look for pressure.
2) We can evaluate the threshold of pressure problems with a given barrel
3) We can buy an after market barrel with better case support.

Political Correctness is a doctrine fostered by a delusional, illogical liberal minority, and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Yeah, political correctness is the thought police.

 

[sargenv]

Generally, when I load for 40 S&W, I tend to load the cartridge as long as I can for the intended gun it will be fired in.

In a Para P16, I can load 40's as long as 1.190", this is about the maximum length that can be loaded into the magazines and with a factory barrel, will allow the bullet to seat and not touch the lands of the barrel.

For my Sig 229, I load them to 1.140" which is the maximum length that the magazines will allow and the bullet to not contact the lands of the barrel.

For a Glock 35 I need to seat them to 1.135" since they have shorter magazines and they too will not contact the lands.

When they say that you are pushing limits of pressure and the over pressure problems stated, it usually means you are tending to load a case with a relatively fast burning powder, to a minimum length. As usual, if you seat the bullet deeper, pressure will rise. The longer the overall length of the cartridge, the lower the pressure will be, all things remaining the same (powder, bullet weight, etc).

If I were you, I would load a few rounds to as long as I could in your gun/magazine and see if they function. If so, then load to that length. 1.125" is not all that long in the scheme of things and SAAMI lists Max OAL for factory ammo to be I believe 1.135". If you have a different frame (ie 1911) you can load them longer as long as the barrel is cut that way and they feed in your magazine. I've found that guns tend to like the ammo loaded longer more than shorter.

For the 40 and crimping, you only need remove the "bell" from seating the bullet, a slight taper crimp can be used but realize that this is how the cartridge head spaces.

You can take this info with a grain of salt, but this is what works for me

Vince

 

[CZ57]

There may be a reason for the differences. I don't have the Lyman 47, but I suspect that the 22K CUP data is for #2 alloy Cast bullet loads and would be suitable for your plated bullets. 22K is a bit on the low side when you consider that SPEER uses 25 - 28,000 PSI For Medium Velocity loads. The Hodgdon data you mention at 34K seems a bit high because the SAAMI max average pressure is 35,000 PSI which is 33,000 CUP. Most of the data I see does not go above 34,000 PSI which would look more like 32,000 CUP.

Case bulges are definitely worth looking for in the case of .40 S&W. Clark's approach sounds like a good one. I definitely recommend a Max. Cartridge Gauge for the .40 S&W. If it don't fit in the gauge after resizing, set it aside until you have a way to resize to spec. Another way to go about this and comparing the affect of pressure on the casehead is to use a micrometer and measure casehead expansion with various powders and charges thereof. Since it is an external measurement, it won't tell you a lot about web integrity with a case that has bulged. I like Clark's method, or something even stronger optically, because it might allow for a better examination of the web after bulging has occurred, and specifically in the case of guys that do reload for Glocks in .40 S&W. The bulge is known to weaken the casehead and by using an optical device of higher magnification, it would allow you to see if bulging has affected web thickness.

 

[LexDiamonds]

Clark--

I know you catch a lot of crap around here for being an "extremest", but that is one of the best posts I have ever read regarding detailed process for anyone wanting to experiment with the potenial of the .40.

I love the 10mm dearly, but I have nearly matched its performance with lighter bullets in my XD 5" due to its excellent case support.

Cheers!

 

[Clark]

Thanks Lex, I like THR, I am treated well here.

 

[kidcoltoutlaw]

Clark

I tried some Power Pistol in the 9mm with 115 JHP and you were right it is top dog. I get 1390 with a low SD and ES the load looks sound by the numbers I'm getting. It is in a Baby Eagle barrel is 4.4 I did not go anywhere near as high as you did but still it is good. I would have went higher if I were using a Bar-Sto barrel for it.