Need someone to verify a .40sw load

[possom813]

Every manual I have lists 175gr tc bullet. 4.7/4.8-5.8grs of Unique, with either 1.09, or 1.125" OAL for two similar weight bullets


Ok, so I go with the load data that's close to the 173gr cb. I loaded some up the other day with my last bit of bullseye, and I really like this bullet.


On to today, I'm putting together 50 to plink with. Pull down Unique, as it's a listed powder in the Lyman manuals.

Load up 5grs, and seat to 1.095 OAL.

Does this sound like a decent load and setup? I can't find any info for cast boolits and unique online, and the lyman manuals are the only ones I have that list unique with a 175gr cb.

[ku4hx]

Depending on the round, Ramshot list specific loads for jacketed, plated, cast and copper. Lyman is a good source and if your load is within their start to max range and it functions properly (passes the "ker-plunk" test) with no excess pressure signs I'd say you're good to go. Published OALs is just a guide at best in most cases.

For all practical purposes there's no difference between 175 grain and 173 grain in the same boolit. That being said, Lyman does differentiate between boolits of the same weight but different forms or profile.

Alliant also has some lead boolits loads listed on their website.

[possom813]

Ok, I'm more awake now.

What I loaded is 172-173grs lubed cb.

5grs of Unique with an OAL of 1.095.

Max load for the similar profiled boolit listed is 5.8grs of unique with a 1.125" OAL.

I'm just wanting to make sure that the .03" isn't enough to change the pressure significantly enough that it causes a pressure issue.

I'm extremely new to loading the .40 and fairly new to loading semi-autos with unique.

[ku4hx]

I'm just wanting to make sure that the .03" isn't enough to change the pressure significantly enough that it causes a pressure issue.

The 40 S&W can be sensitive to deep seated boolits; I seat my 175 TC to an OAL of 1.125". Genarally, if the round will fit in the magazine and pass the "ker-plunk" test, you're better off going as long as you can. That's not strictly true in all instances, you have to consider such things as nose profile, lube grooves and etc.. What I aim for is just short enough so the boolit's nose doesn't impinge on the rifling and short enough to fit into, and feed from, the magazine. Why not go with what Lyman suggests for 175 grains boolits: 1.100" and 1.125"?

Lyman does show a loading at 1.090" but that is a 135 grain JHP which is a very short TC style boolit. It has to be a short cartridge so enough of the bullet is in the case to be held properly. 175 grain boolits should go longer. 1.090" and 1.100" are very close, but I prefer to err on the side of caution. And that means no overly deep seated boolits. 1.125" for a 175 grain TC boolit does that for me. And since I never load past mid range charges, I've had excellent success.

[possom813]

I just double checked the load data in the Lyman 49th and what I loaded. I was looking at two different cb's, and confused what I stated earlier.

The bullet that's closer to the profile I used has an OAL of 1.1", and I seated them at 1.095". Not the same weight boolit that has the 1.125" OAL.

I was looking at the data for the other bullet and confused myself and posted without verifying what I'd actually done.



Also, what exactly is the 'kerplunk' test? Is it just dropping the round into the chamber and making sure it goes?

[ku4hx]

Remove you barrel. Hold the barrel vertically and drop a loaded round (or a dummy round if you want) into the chamber. It should completely chamber with a satisfying "ker-plunk" sound. Or, if you will, a definite "plunk" sound. If it does, invert the barrel and the round should immediately drop freely out. Both in and out actions comprise a successful "ker-plunk"/"plunk" test for me. Got to have both.

The idea is to determine if the round's dimensions are correct: cartridge OAL and neck diameter being the most troublesome to me.

Five grains of Unique is a mid-range load and I'd think it'd be fine. But if it were me, I'd load it at 1.125" OAL. But that's just me. If 1.095" is safe for you and works then that's your call.

[Shiloh]

+1 to the above post by ku4hx.
I load my 40 on the lighter side. If it is accurate and functions, I leave it there.

Shiloh

[10mmShooter]

5.5 g Unique for 180 gr Lead bullet from Alliant's 2005 guide for 975fps, page 43. coal 1.125