I am having a problem of FTE/FTF with Lot 13 XM193 from Natchez. I bought a new JT kit (16” standard HBAR, non-chrome lined), and have test-fired several types of surplus ammo through it after break-in to see what worked the best. I shot 50 rounds of each ammo in ten round groups, random order. Here are the results:
Round 1
Winchester White Box 55g FMJ(no problems)
Federal Lake City XM193 lot 13 (2 shots - FTE, 3 more shots-FTF, last 5 shots cycled fine)
Wolf 55g FMJ (no problems, just dirty)
UltraMax 55g FMJ (no problems)
Rounds 2-5
I changed the firing order around on the ammo, but every time I came to a mag with XM193 my rifle would jam/FTF/FTE at least twice during the 10 rounds. BTW, I thoroughly cleaned the rifle before round 3 and fired the XM193 right after this cleaning with similar FTE/FTF results.
It (the rifle) acts like the XM193 rounds are not returning enough gas to cycle the action and eject the spent shell. In almost all of the cases, the spent casings were halfway out of the chamber or just sitting on top of the magazine well blocking the action with a new shell behind/beneath it trying to chamber, like they just about made it out (ejected), but ran out of steam.
Has anyone experienced a similar problem with this ammo or can lend me some advice? If it happened with the other types of ammo I would make the assumption I was having a gas port/tube problem on the rifle, but it is not. I was really surprised. None of these are “match-grade” rounds, but of all of them I would have bet money the XM193 would have performed the best. Any thoughts &/or experiences appreciated.