Trouble with 40 swc feeding


February 23, 2010, 11:42 AM
Hello to all,

I am a fairly new reloader, less than a year, but I have been reloading a lot. Recently I purchased a box of 500 175 gr swc in 40. The reloading part is not the problem, its the feeding of the round that is the problem. All of the reloads were to specs as far as load and OAL.

My gun is a Sigma Series 40. It seems more that the magazine does not like the round rather than the gun does not like the round. When the rounds did chamber they reacted perfectly.

Any adivce would be helpful!


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February 23, 2010, 12:45 PM
Hi Marshall
Can you give us a few more details? If this is a problem in feeding, exactly what is happening to the cartridges? Are they stovepiping, catching on the feed ramp, or sticking in the magazine? Does the bullet nose enter the chamber at all, but fail to lock in battery? Are these lead or jacketed bullets?

For myself, I've experience two main problems with feeding. When loading light for caliber .45's, my pistol did not like the OAL too short. It wouldn't feed till I made the OAL longer than the published maximum.

With lead bullet loads, I've found that the case mouth to be too wide for the slide to go into battery. Taper crimping solved that problem.

A problem common in the 40S&W is inadequate resizing to factory specs. A slight bulge near the rim of the cartridge may let the round start to feed into the chamber, but freezes up the slide before lockup.

February 23, 2010, 01:27 PM
Michael thanks for the response.

The rounds seem to be getting stuck on the feed ramp. When the slide returns to closed the round will not allow it to close and cycle completley.

I also noticed that the magazine did not accept the lead rounds very well. When the magazine was full it seemed as if they would get stuck at certain points in the magazine.

I really hope that I can figure this out, I didn't spend a whole lot of money but I spent the money.

Thanks, MarshallU

February 23, 2010, 01:31 PM
Try a shorter O.A.L. for starters.

February 23, 2010, 01:41 PM
How short do you suggest, I am running at 1.17 OAL currently. When does safety of the round come in to play?

Thanks for the info!

February 23, 2010, 02:50 PM
If you are working up the load, you should be at or near the minimum charge weight. At the minimum, over pressure shouldn't be a problem while you fine tune the OAL or your reloads. The first problem that you have to overcome is the feeding. What you are describing sounds like the OAL is too long for your firearm.

I would load up some dummy rounds (no primers and no powder) and incrementally increase the seating depth until they will cycle by hand through the firearm.

Yes, increasing the seating depth will increase pressure, but don't worry about that until you start working up your load. Odds are that you will find a comfortable power level before you hit the max pressure load for your handgun.

Now, the thing about Sigmas (as far as I remember) is that they don't have a fully supported chamber. You gotta watch this, like you do with the Glocks. Keep an eye out for bulged cases.

February 23, 2010, 02:52 PM
Try this test ( to see if your loaded round will fit the chamber first and find the max they can be loaded to for your barrel.

I have been loading Truncated Flat Points in .40 cal at 1.135 O.A.L. with good luck.

I have not tried any true SWC's in .40. It is possible your gun does not like SWC's, but it may be simply a case of finding the O.A.L. that your gun likes with this bullet.

February 23, 2010, 05:50 PM
I've had reliable feeding for my .40 M&P using an OAL of 1.125" using either rounded or truncated cone bullets.


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Samuel Adams

February 23, 2010, 06:53 PM
Yup , shorter OAL is what ya need. I have the Sigma 9mm and thats what I needed to do. Just went to the range today to test and everything went fine. Just remember to start on the lower end and work up. I was loading 115gr LRN.

February 23, 2010, 08:22 PM
I have loaded thousands of LSWC's in .40 S&W and .45 ACP.

If you want to eliminate the cartridge as the problem, seat the bullet to a point where the shoulder is .030-.040 above the case mouth and taper crimp to .419 with a Lee FCD. This gives the bullet a bearing surface for feeding and a case profile that is correct. Unless there is some other issue with the pistol or mag, your feeding problems will be gone.

February 24, 2010, 12:04 PM
I've loaded some of these in my SW40VE. They ran fine. I seated them to leave about 1/32" of the full diameter of the bullet above the case mouth. This prevents the case mouth from "hooking" on the feed ramp and provides a nice slippery spot of lead for the bullet to slide up the feed ramp. This is similar to what I've seen with LSWC's in 45 ACP. I did not load by overall length.

These were Missouri Bullet Co. bullets with 3.1 grains of Clays.

All the Best,
D. White

February 24, 2010, 03:00 PM
Thanks for all of the help, I will put all of the advice to good use!

It does sound as though the OAL is a bit much.


June 16, 2010, 01:01 PM

I was just wanting to know if you were able to resolve your problem and what your OAL ended up being?


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