9mm 1911 recoil spring and double feeds

[JMPhotog]

I am running an Ed Brown 5" 9mm 1911 that I have specifically set up for IDPA. I had it fine tuned and running awesome with a 124 gr Bayou bullet and 4.3gr Bullseye load that PF'd at about 134,000 and ran a Wolff #10 variable power spring. I shot it well and won my division in a sanctioned match recently. Apparently, that was not good enough as I like to tweak and always fine tune. So I tested some loads with less powered putting me closer to the 131 power factor with a #9 pound spring. They ran nice and noticed a slight bit less muzzle travel. Again, slight. However, I tested it in some local Tier 1 matches and I got a double feed in one match and and another double feed in another match. Never happened before. I know what normally causes double feeds, but I also read that some times too light a recoil spring can cause inertia slap of the slide hitting harder causing the round to pop out. Maybe I have found what runs best in my gun and for me with the 124's and 10# spring and need to leave it alone? But is that a possibility of what caused those 2 double feeds as I never had them before? I am running Chip McCormick XP9 10 rd mags, they have been great. I had problems with both Wilson and Tripp in the 10rd 9mm mags. 

On a side note: I started experimenting with 147gr Bayou's and 3.2 gr of Bullseye and the 9# recoil spring. So far they have been flawless and shoot really nice. But if my logic from above is correct, the 147's have less powder causing less slide slap with the 9# spring, so maybe the inertia double feed is not an issue here? No?

Thanks

[twodownzero]

I would look at your extractor tension and not worry about your recoil spring.

[ltdmstr]

3 hours ago, twodownzero said:

I would look at your extractor tension and not worry about your recoil spring.

+1

[JMPhotog]

Thanks. I did the test to see if it can hold a loaded round and does hold it tightly against the breech face. Are you thinking the tension may be too loose or too tight?

[twodownzero]

31 minutes ago, JMPhotog said:

Thanks. I did the test to see if it can hold a loaded round and does hold it tightly against the breech face. Are you thinking the tension may be too loose or too tight?

While I can't tell you without looking at it, but generally, if it's too tight, it won't feed reliably, and if it's too loose, it won't extract.  Did you shake the slide in your hand?  Did it stay on the extractor when you did?

[JMPhotog]

Yes, I put a loaded 9mm round in and shook it, it did not fall out or really move around. 

Thanks!

[motosapiens]

it makes a difference whether you are having a real double feed (2 live rounds) vs a failure to extract (1 spent case and 1 live round). If the mccormick mags have the same sort of built-in ramp that the dawson mags have, it seems unlikely that anything would cause a round to bounce out early.

9mm seems to be touchier regarding extraction than 45. both of my 9mm guns had occasional failures to extract that I eventually cleared up with wilson combat extractors and a bit more extractor tension. I have never managed to tension the extractor enough to affect feeding, even when it was way more tension than the official testing procedures indicated was necessary,

[wgj3]

I adjusted the tension on my stock Springfield extractor to the point that I know it's "too" tight, but it runs like a top with 147's at about 1.14" over about 3.1gr of Bullseye(128PF). It also runs about 98-99% with 124/5gr bullets at 115PF. I use the Dawson mags after not having a great deal of luck with the Wilsons, Tripps, or XP9 mags...

Edited September 3, 2016 by wgj3