40 S&W - Constantly jamming

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PoFF

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I've recently taken on the task of reloading the 40S&W cartridge, the load is the following :

Cases : Winchester or Federal
Primer : CCI 500
Powder : 7.2 grains of Longshot
Bullet : Frontier .400" 180 grains Truncated Cone

The first batch was done with a COAL of 1.120", which jammed every single shot (failure to chamber), the second batch was made a tad longer at 1.125", with almost the same result. My last batch was made at 1.135", which is the MAX COL published in my book for this cartridge. The results were a bit better, 50% less jams, but still 50% too much.

I'm already at the max COL, what's left to do?

The firearm is a S&W M&P40.
 
Maybe the bullet design is the problem? See if you can get a handfull of roundnose or hollowpopints to try out. I generally load a lot longer for my Para p.16 - I've gone out to 1.18, but my current load is around 1.16" (29.5mm) OAL with 180gr roundnose lead.

I don't think theres any harm in going longer, it will generally reduce pressures... however if you go too long the round will jam into the rifling and could cause bullet setback.
 
Do the cartridges drop fully into your chamber ok? If not, or they're tight, then sizing of the completed cartridge may be a problem. If they do, then the bullet may indeed be the problem. I use the Lee Factory Crimp die on the last station of my press for all my pistol cartridge reloading.
 
The cartridges drop freely in the chamber, that's the first thing I've checked. The kind of 'jamming' I've got is with the cartridge partially chambered and the rear of the cartridge 'hangs' in the magazine, to clear the jam, I just have to pull the slide 1/8" or 1/4", the rear of the cartridge lifts up, then I release the slide and the cartridge fully and easily chambers.

It's kind of hard to describe with words, I picture would have been better... :(

I doubt the crimp is the problem, I'm using Dillon dies which got a separate crimping die, and the cartridge mouth is nicely flattened against the bullet, no remnants of the 'bell'.
 
Based on what you describe, I will go for a bit more crimp.
Make sure your sizing die is adjusted all the way down with almost no clearance between the die body and the shell holder or shell plate.
I use the same Frontier bullet without any problem. Oal on mine are 1.125. Crimp on case is .4175. The case body should be no more than .423 at the base. If more, the sizng die is not doing it's job or your casing are blow out out of spec and need to be replaced.
 
make sure the lips of the magazine are not spread to wide as well...(feeds the shell at to high an angle) I don't know the history of your gun, but I had a problem start with mine after a while (I thought it was the new load, but it ended up being 2 out of the 4 mags that only did it)
 
As you increased your OAL you had less jams.
Make up a few dummy rounds at a yet longer AOL
than 1.135.
See if they fit in your mag,then if they do,hand cycle them through the pistol and see if the pistol will take them and eject them,without setting back the bullet.
Perhaps,try some round nose bullets.
Maybe your gun won,t function well with truncated cone bullets.
You've said you tried dropping all the rounds in the barrel and they fit fine.
Keep doing that.
I've got an STI Trojan in .40.
I reload once fired brass.
Some of them shot through a Glock will not chamber in the STI.
Bulged base that my Dillon won,t totally resize.
I throw those away.
I load Frontier 180 gr.RNFP at an OAL of 1.190 and use Wilson 47D mags.
No problems.
Just keep troubleshooting,checking mags,etc.
You'll come up with the answer
 
What type of gun are you reloading the 40 SW for (stock or cutom gun)? What kind of barrel do you have (stock or competition barrel)?
Is it a brand new gun?
How many shots have you fired through this baby????? give us as much information so we can asses your problem. :confused: :confused:

Doe the gun behave this way when using factory rounds? does it jam like it does now?
There could be a lot of factor...
With the information you have given so far.
If the gun is already been used.... It sounds like you need to crimp your reload.

Or you need a heavier recoil spring.... :) :)
Give us more info. please
 
The gun is a Smith and Wesson M&P40, in absolute stock condition. It could be considered as brand spanking new : It had fired exactly 150 shots so far. 75 shots of factory ammo without a single failure, and 75 of reloads with the problems described above.

For the bullets, I've bought those Truncated Cones by mistake, but now I'm caught with them...

As for the sizing die adjustment, the die almost touch the shellplate so the case is fully sized. For the brass, all reloads were made from once-fired brass fired from this gun.
 
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"...the rear of the cartridge 'hangs' in the magazine..." Try another mag and use a taper crimp. I doubt the bullet shape is the problem. TC's feed just fine in my Inglis HP.
 
Many years ago in the late 80's I had the same problem with my Colt Delta Elite 10mm.....

When I asked Joe Dlask of Dlask Arms Corp what my problem was he recommended that I get a Lee Carbide Factory Crimp die.

The die not only crimps the cases better then standard roll crimps but it will also resize the bullet and brass to factory specs if they are the slightest amount over specs which is most likely your problem.

So go find/buy a Lee Carbide Factory Crimp die and your problems will most definately be solved... It cured the problem for me and I now use Lee Factory Crimp dies for every handgun cartridge that I reload for.

Powder has nothing to do with feeding so don't waste your time considering that as part of the problem.
 
Well, problem partially solved, I guess.

I increased the OAL to 1.145", a tad longer than max recommended OAL, but no problems chambering.

Then I Slightly increased the powder charge (by .2 grains).

Results, on 150 rounds fired with this recipe, I only got 3 jams, which ain't bad considering previous results. I guess that things will be improved by switching to round nose bullets when I'll have wasted those TCs
 
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Well, in that case, I doubt that the powder (or lack of) was the problem as the slide was able to pull back enough to engage the following cartridge from the magazine.
 
My Steyr had feeding problem my with my reloads, I thought the OAL was too long or the gun doesn't like the bullet shape, so I tried the load in my Beretta and got the same results and my Beretta hever jamed before!. It didn't take me too long to figure out that the problem was the light charge. (sometimes the slide wouldn't even go back far enough to eject the case). Later I tied load with increased charge and an even longer OAL and the gun never missed the beat :)
 
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Yeah I agree with the low charge weight, and I would swich to a different powder, but thats just me. Anywho, say the slide goes back, but not far enough. It does not give the cartrige enough time to come up when it wants to strip off another, and it just barely catches it?
 
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