Originally Posted by Lyricd
The extractor claw is sitting in the grove at the base of the cartridge, where it should be, I think.
If the claw is in the groove then and the magazine is out the remaining options are...
1. This round of Tula has an improper case length or the round is not seated deeply enough to allow the chamber to close.
2. Gunk is preventing the round from fully seating... but I though you said this was the last round of the 1st mag? Doubt 7 rounds... even 7 rounds of Tula would "dirty" it up that quickly.
3. The "last" round you fired before the malfunction was a "squib" round and it's lodged in the barrels entrance eliminating enough head space to prevent the 8th round from fully chambering.
Squibs occur when the powder charge is too light or is not there in a specific cartridge. The expanding gas from the detonation of the primer alone is often "enough" pressure to lodge the round in the barrel "and" cycle the weapon. In military jargon this in knows as a "pop no kick" due to the lack of muzzle report and lighter than normal recoil. Soldiers are trained to watch for it and it is the cause of MANY catastrophic failures. If this happened, you are very luck that the round did not lodge deep "enough" to allow the 8th round to fully seat because pulling the trigger again would have resulted in a Ka-Boom.
Test this with a wooden dowel. First lay it along side the barrel and mark the barrels length from the crown to the end of the chamber. Then insert it into the barrel "keeping hand clear of the muzzle".
If the rod does not insert fully to the chamber mark, you have a squib lodged in the barrel and "definitely" need a gun smith to go any further.
If there is no squib, lube the crap out of it, wedge the slide against a wooded table or work bench "keeping the muzzle and guide rod clear" and shove down hard.