Advantage Arms Target Conversion & CCI SV - fails to feed second round

My new to me Advantage Arms Target conversion consistently fails to feed the second round in a magazine using CCI SV ammo. However, it works perfectly well with Eley Target. Unfortunately, I have 8000+ rounds of CCI and just 200 rounds left of Eley. The irony...
I have purchased and installed the reduced power recoil spring from AA even before I used the conversion for the first time and from the first attempt the picture has been the same.
The lower I use is from my Sig Sauer 1911.
With CCI SV, the first round chambers and fires fine but the second one jams at about 45 degree angle and not even enters the chamber.
I called Advantage Arms and they advised me to change the mainspring to a lower weight - 18lb. I have the factory mainspring, which I believe is 23lb. I ordered the 18lb spring from Wolff and will try it this weekend.
I would like to know, if anyone in the community had a similar issue and can offer a helpful advice.

Best Regards,
Oleg.

I predict you'll be a happy camper when you install the 18lb mainspring. Just don't shoot hardball when you convert back to your 45.

JKR wrote:I predict you'll be a happy camper when you install the 18lb mainspring. Just don't shoot hardball when you convert back to your 45.

+1

I have a Marvel with a 19lb main spring and a 7lb recoil spring.

Softening the mainspring will probably solve it - by letting the slide travel all the way back and leaving more return energy for the round to be stripped from the magazine.   If it does, it shows that the problem was because the CCI is a slightly longer round than the Eley.

Also from my measurements, the rim of CCI is wider than that of Eley.   A wider rim MIGHT be causing the round to be released later and that is contributing to your problem.   I can barely get 10 CCI rounds in my Browning magazine, but easily get 10 European rounds in with some room to spare.

If you want to use up the CCI (and the mainspring swap doesn't cure it), consider opening up the magazine feed lips slightly, to release the CCI slightly earlier.

Don't go overthinking it. Once you get the springs balanced, it will work.

Thanks for the suggestions, guys! I really hope this solves the issue. I like the conversion very much. The combination of the conversion and KC's roll trigger kit worked out so well for me that I took it to the 900 match last weekend after only trying it for the first time at the local league. Even though I have a 4.25 lb trigger in my Sig lower, the roll trigger and the conversion (and lots and lots of dry fire training) helped me to shoot my first ever Sharpshooter score in the 50 feet 900 match. This is a big achievement for me and I want to be able to shoot the conversion with the ammo I have on hand.

I don't shoot CCI but I did swap out the main spring with a 19 lb before I even installed the Advantage Arms kit and have never had an issue.