open17

Not saying this is the answer--but I have seen this before when I was running Glocks Open Major. It did it for me primarily with 170mm mags--and it is indeed an odd malfunction. The Glock slide has a ramp on the bottom that pushes down on the ammo in the mag as it moves to the rear. If the ammo in the mag is still pushed down when the slide hits the rear of it's travel, the loose column will cause the top round to move forward into the chamber. Next round pops up, slide moves forward, picks up live round and slams it into the rear of the live round. Stronger magazine spring was the answer for me--YMMV.

Open---8moa old school C-More on a 90° mount CO---SRO LO--Romeo3 XL

Haven't noticed the Pro Shot/Shooters Connection ones not sticking in cold weather. They do work much better than tape in wet!

APSL looks like it may be fairly local to Colorado??? https://www.mckennadynamics.com/apsl

There are currently 3 divisions that recognize major/minor and impose a capacity "penalty" for major. Revolver, Single Stack and Limited (fewer rounds of 40 in a 140 mag). LO is still a provisional division. Maybe when it is made official the BOD will recognize the V in DVC.

As an old fart with old eyes I LIKE Limited Optics. However my personal opinion is that it should be just like Limited--but with an optic. Specifically Major/Minor scoring.

Don't forget that a Carry Optic gun must be on the Production approved list--it removes some long slide guns from the playing field. I picked up a used 320 X5. Shot it with irons in Production Put the optic plate on it and a TLR1 light and shot Carry Optic Put the magwell on it and shot Limited Optic Decided that Carry Optic is where the Sig fit best for me, but of the 3 divisions I like Limited Optic best. Built a 9 minor/Romeo3 XL top end for one of my 40 Limited gun lowers as a Limited Optic gun. YMMV

The Altra's are good, and the foot shape toe box is interesting. They are a zero rise shoe (flat--no heal) and that takes a bit of getting used to. My last two pair of shooting shoes have been Solomon Wide's. Wish they made them is colors other than plain black--

Everglades load may be with a powder that is unavailable retail. Years ago Atlanta Arms did a 9 major load. Absolutely the most consistent 9 major load I've shot. Soft, plenty of gas, loaded short enough for a Glock and 172pf in everything I tried. The powder turned out to be Win 248? (not sure that's correct) which you could buy bulk but not retail. Lot's of powders out there that work for 9 major. I keep coming back to HS-6. N320 is definitely NOT on the list--really hope that's a typo.

5.4", Brazos Thundercomp 2, 3 .156 (5/32) poppels. KKM barrel. 8.2 gr HS6, 124 gr MG JHP at 1.170 OAL. Works for me.

38 SC will fit in a 38 S&W, but it's a bit undersize. Watch your pressure, a lot of old 38 S&W guns are built for black powder pressures. I used cut down 38 special in a couple of 38 S&W guns before I got dies to reload 38 S&W. They went bang, accuracy sucked (most 38 S&W bores are .360ish). Consider a cast HBWC bullet that will expand to engage the rifling.

I think I've tried them all. N350, 3N37, 3N38, Autocomp, CFE Pistol, 572, AA7, SWMP, HS6, HS7 (I really miss that powder!), Silhouette, SP2 and probably a couple I've forgotten. ALL of them will make Major in a 9mm. 3N38 is great, but a pain to load in 9 major. Case is REALLY full. SWMP/AA7 work well. Silhouette works fine. But the powder I keep coming back to is HS6. Affordable, available, easy to load. 8.1 makes Major in my 5" gun with a 124 at 1.170". 8.9 with a 115, same OAL. Same charge makes minor with a 95 gr in my wife's gun.

N330 is a great 9 minor powder. I actually like it a bit better that N320. It is NOT a 9 major powder. Way too fast.

N320-- more because I use it in 9 minor and I shoot a lot more 9 than 40. I am a bit curious about the OP "burning through roughly 7,000 rounds using a pound of E3". Wasn't aware that a 1.0 gr charge of E3 would make major.

Personally I like the 90° mount from Striplin. My USPSA open guns are set up with 90° sliderides, and the similar sight setup on the 22/45 steel guns makes it easier to transition back and forth.