Agree with Dthomas you likely need to adjust the feed lips. More info would help trouble shoot though.
Has your AW mag always done this, or a recent thing? Have you tried other AW mags? Adjusted the mag catch? How long have you had this rifle? What caliber? Put this together yourself or bought from a 'smith?
Regarding AICS and upward pressure:
- All AW cut actions leave metal at the front of the mag opening to prevent the narrower AICS mag from over-inserting. With your current set up, when you apply pressure to the AICS mag, the back-end is unsupported and binds against the bolt. The action is stopping the AICS up front, but nothing is stopping it from the rear.
- Some chassis/stocks will not have this issue as their mag catch opening is smaller and stops AICS mags from over-inserting.
- For example, I run my Curtis in an MPA chassis. With an out-of-the-box MPA chassis, I experience the same issue- binding against the bolt when applying pressure on an AICS mag.
- MPA sells a little insert that reduces the size of the mag catch opening. This blocks the mag catch and prevents the magazine from over inserting. With this insert in place, I can now apply full weight of the rifle against the AICS mag and no binding.
- I've attached a pic to illustrate. (it's not the greatest pic but hopefully you get the idea)
What stock/chassis you running?
The Curtis Vector is new, I traded a used Trued Up Rem 700 barreled action + $ for it. It was in 260 rem but was rechambered for 6.5 Creedmoor by the guy trying to sell it. It has a proof SS barrel and is in a Manners stock with the gen 2 mini chassis.
From what I can tell, the AW mag is wider then the AICS and thus will bottom out on the Vector action mag cut (mag lip-ish area on the sides of the Vector mag cut). It seems like the spring pressure is not enough to keep the last round from dipping down and the second to last round from pivoting off of it. If you are behind the gun, the second to last is on the left and the last is on the right. So the last dips down and the second to last pivots off of it and the bullet points to the right side of the breach face and gets stuck.
The first, third, 5th, 7th rounds all feed fine as does the 10th, but the spring pressure on #10 is weak and the nose will dip while stripping #9 out and #9 will sort of pivot off the body of 10 since it is now angled down instead of remaining straight. The AW mag seems WAY easier to load to 10 rounds then all my AICS magazines (ARC, AI, Alpha {Alphas fucking bow out when loaded so they are basically paper weights right now}) so I am not sure if a stronger spring might help, and if so who sells aftermarket springs/followers for AW mags (I got it from Area 419).
I had to file down the mag catch on the AW mag a ton, nothing was needed for the AICS so I did not want to mess with the mag catch on the stock since it would make AICS super loose. Right now it takes a small amount of upward pressure to lock in the AW and it is nice and snug. I am not sure opening up the feed lips is a good idea as it would then cause the AW to block the bolt (vs right now I can skip the bolt off the lips and feed over it with the weight of the rifle on the magazine), also the nose dips down on #10 which is yet to be in contact with the feed lips.
Here is a video of what happens:
Later today I can try to get video of the actual thing happening but adjusting the feed lips up in any way will fuck me on running the bolt with upward pressure on the mag, in which case it removes the benefit of the AW over the AICS.