December 25, 2020, 11:18 AM
snorisP320 Failure to Feed Using Slide Release
First---Merry Christmas to all!
I have a call into our Sig Armorer Robert Burke on this, but also wanted to get some opinions from our SigForum brain trust.
I practiced with my P320C yesterday and experienced feeding problems with Speer Lawman .40 S&W 180 gr.
Each time, it was the top round from a 13-round magazine loaded with 10 rounds, starting with the slide back and using the slide release to chamber the round. The typical “case rim where the case meets the bullet caught on the bottom of the feed ramp” occurred. This happened a total of three or four times out of the 10 times I loaded the magazine. I only took one mag to the range, so I can't narrow the problem down to the magazine itself.
There were no feeding problems once I got the first shot off, though---the pistol cycled fine every time I pulled the trigger, and I shot 100 rounds of .40 S&W.
I then put my .357 Sig barrel in and went through the same drill, but obviously had no feeding problems because of the bullet shape.
Is the most likely culprit:
a) Less-than-stellar quality control on Speer’s part;
b) Starting with a less-than topped off magazine; or
c) My 2500-round count recoil spring?
December 25, 2020, 11:31 AM
12131quote:
Originally posted by snoris:
First---Merry Christmas to all!
I have a call into our Sig Armorer Robert Burke on this, but also wanted to get some opinions from our SigForum brain trust.
I practiced with my P320C yesterday and experienced feeding problems with Speer Lawman .40 S&W 180 gr.
Each time, it was the top round from a 13-round magazine loaded with 10 rounds, starting with the slide back and using the slide release to chamber the round. The typical “case rim where the case meets the bullet caught on the bottom of the feed ramp” occurred. This happened a total of three or four times out of the 10 times I loaded the magazine. I only took one mag to the range, so I can't narrow the problem down to the magazine itself.
There were no feeding problems once I got the first shot off, though---the pistol cycled fine every time I pulled the trigger, and I shot 100 rounds of .40 S&W.
I then put my .357 Sig barrel in and went through the same drill, but obviously had no feeding problems because of the bullet shape.
Is the most likely culprit:
a) Less-than-stellar quality control on Speer’s part; Easily prove or disprove by using other ammo brands
b) Starting with a less-than topped off magazine; or Makes no sense. How about starting with 9 rounds in the mag? Or, fully load it with 13 rounds?
c) My 2500-round count recoil spring? Change this and find out.
December 25, 2020, 11:33 AM
92fstechIf you follow the same steps, do you have the same problem with other brands of .40 ammo in that gun?
December 25, 2020, 11:57 AM
snorisThe only thing that makes me think the ammunition is not the problem is that I've put about 2,000 rounds of Speer Lawman in that P320 with no failures until now.
I carry three spare magazines on duty, so in the next few days I'll shoot with the other three and see if that makes a difference.
What about the recoil spring? Could that be a possible cause even if the pistol cycles an entire magazine properly?
December 25, 2020, 12:13 PM
sns3guppySome P320 magazines are hard to seat because there's so much pressure compressing the top round, when driving it into the mag well to lock the mag in place, when the mag is full. On new mags, and mags with extra power springs, I find that more to be the case. A full magazine will press up harder on the underside of the slide, reducing velocity from a standing start, when locked back.
Personally, I "slingshot" the slide to release it from lock-back, rather than using the slide release, though I do sometimes use the release, too.
In the P320, if one jams a magazine, especially a larger capacity magazine, into the pistol when the slide is locked back, it is possible to overdrive the magazine and damage the ejector. That's going to cause function problems; either a stoppage, or a slight bend may cause a reduction in slide velocity.
Add together the potential for a bent ejector reducing slide velocity, a full magazine reducing slide velocity, a weakened recoil spring, and then bullet profile, plus the potential for overinsertion if the slide was locked back at the time the magazine was seated...any or all, or a combination might contribute to the problem.
As above, try reduced round counts in the same mag; see if it reoccurs. Swap out for a new recoil spring assembly. I doubt it's speer, but one never knows. Check your ejector. Check the magazine feed lips. Try "sling shotting" to see if there's a change.
December 25, 2020, 12:16 PM
12131^^^ He only has 10 rounds in the mag of 13-rd capacity.
December 25, 2020, 12:19 PM
12131quote:
Originally posted by snoris:
The only thing that makes me think the ammunition is not the problem is that I've put about 2,000 rounds of Speer Lawman in that P320 with no failures until now.
What about the recoil spring? Could that be a possible cause even if the pistol cycles an entire magazine properly?
Did you read what I wrote in red?
December 25, 2020, 01:07 PM
snorisquote:
Originally posted by 12131:
quote:
Originally posted by snoris:
The only thing that makes me think the ammunition is not the problem is that I've put about 2,000 rounds of Speer Lawman in that P320 with no failures until now.
What about the recoil spring? Could that be a possible cause even if the pistol cycles an entire magazine properly?
Did you read what I wrote in red?
I meant to type "magazine spring," but got distracted watching the Nashville vehicle bomb coverage and mis-typed. My error, sorry.
December 25, 2020, 02:06 PM
12131Anything is possible. You simply have to go through the process of elimination. Btw, what's the rationale for loading only 10 rounds in a 13-rd mag? What happened when you loaded it to full capacity? Did the same issue occur? And, who the hell takes only one mag to the range?
