[steve4102]

For those of you that use or have used 3n37 in the 40 S$W, who's data do you use? I would like to try some in my 23 with Zero 180gr JHP, but the data is all over the place.

I have data from Speer #13, Sierra #5 and VV. Speer lists 6.6gr start, Sierra lists 6.1gr Start while VV lists 6.2 as Max. Speer lists 7.2gr as Max, Sierra lists 7.5gr Max.
Not sure were to start as VV's max is less than Speer's Start?? BTW both VV and Speer are using Speer 180gr HP.

Thanks

[jfh]

What bullets did VV use to set its data? Is the bullet seating depth different? etc., etc.

Jim H.

[Walkalong]

http://www.lapua.com/index.php?id=850

Checked with Vihtavuori?

[steve4102]

What bullets did VV use to set its data? Is the bullet seating depth different? etc., etc.


As I stated in my original post, Both VV and Speer used a 180gr Speer HD, sorry I forgot the OAL, Speer lists 1.120 and VV is 1.126. .006 longer than the Speer Data.

Checked with Vihtavuori?

YES, that's the VV data I am referring to, Sorry, I used VV short for Vihtavouri.

[Walkalong]

I see now, I just missed it.

[jfh]

About that Speer 180, versus the Zero 180 you plan to use: The point is, are the profiles / ogives of these two bullets the same? That is, when seated and set up properly to feed in your .40 S&W semiauto, is the seating depth going to be the same?

If the Zero requires a deeper seating depth--i.e., the net depth of the bullet inside the case--obviously, that's going to raise pressure, and should impact the MAX recipe.

With that in mind, I think you need to do some homework first, before you settle on a MAX charge. That is, do some measuring first--measure several of you Zero bullets for LOA to see how much they vary in LOA. Then, build a few dummy rounds and see just how long your gun's cartridges need to be. Calculate a typical seating depth from this data for the Zero bullets. Now, compare the LOA of the Speer 180 bullet (see your manual)--and make an informed decision.

Personally, I have used, and I trust, Vihtavuori's data. If you read closely--look for different characteristics of their test barrells--you may be able to account for the Vv's higher MAX charge. OTOH, I also have, so far, felt the Speer 14 data was "accurate."

But, you are loading a cartridge where, at least in the upper range, LOA / seating depth variances can be critical--i.e., pressures can spike quickly, and you cannot necessarily read the goal entrails (primers) for signs. Primer pressure signs that show up in primers show up long after the .40 S&W design pressure has been reached, IOW.

Caveat: I am not a current .40 S&W loader, but I did quite a bit of work with it early on, when it first came out.

Jim H.

[Shoney]

Jim H:

My dealy departed grandpappy used to loosley translate Caveat. He said it meant,
"Never trust a naked used chariot salesman,"

[steve4102]

Thanks Jim, I have measured the bullets and I am confident that the OAL I have set for my Zero bullets have the same "the net depth of the bullet inside the case".

I think you need to do some homework first, before you settle on a MAX charge.

That's why I'm here, kinda. I'm not even close to a Max charge yet as I haven't been able to find a consistant "start" charge.

you may be able to account for the Vv's higher MAX charge.

VV has a much lower max charge, in fact it is less than Speer's "Start" charge. That's what has me confused.

[jfh]

So, we can assume that you've tried your cartridge dummies for feed and chambering? For crimp / setback?

As for the different MAX charges from Speer 14 and VV: There might be a typo here--so try contacting both companies and find out. I'm not experienced with this particular combination and cannot offer an opinion. IIWIYS (That's If I Were In Your Shoes), that's what I'd do.

added on edit: My apologies about not acknowledging the kind of disparity in start / max charges earlier--I did note it, but a brain fart left it out of the responses.

Jim H.

[Walkalong]

I am looking at the Speer #13 that you got some data from. I am a big fan of this Speer manual and have found it to be pretty close to real world findings in average guns. As they do for much of their data they use a real gun (4" S&W 4006) for their .40 data.

I would use their start data and work up. I don't believe there is enough difference in the 180 Gr Speer bullets used and the 180 Gr Zero (of which I have plenty). I shoot them in .40 as well, but have not used any 3N37. Don't have any.

Speer shows 5.3 to 5.9 Grs of Universal Clays with 180 Gr bullets, and it is pretty close to what I got from a Witness Elite Match which has about a 4 1/2" barrel. IIRC. UC also gives excellent results in my 3" XD SC .40

I also use the Zero 165 Gr JHP in .40 and the Speer data is very close to my actual results as well. Universal is better suited to the 165 if you are looking for velocity, but works well with the 180 and all I want from the 180 is 875 ish from my XD SC & 950ish from a 4 to 5" gun.

Anyway, what I am saying is I would be confident in using the Speer data. I have never gotten into trouble using it. Bottom line is VV shows a smaller max, so only you can decide what you want to load to. I have found the VV velocities in a lot of their data to be way over what I have achieved with the same charges.

jfh's advise to call Speer is a good one. They will be glad to answer any questions.

[RidgwayCO]

steve4102, when faced with a starting load disparity like yours, I like to be conservative and start with the lowest published load (in your case, 5.9gr of 3N37) and chronograph it. If it performs as the source says it should, then that data is the set I'll use. If it performs much slower than advertised, then I feel justified in trying the published data set with the next higher start load.

The "dirty secret" here is that without a chronograph, you're just guessing about performance.