I was having some trouble with my LC9 and was missing targets I had no business missing. My current stash of ammo was cheap Remington UMC and I'm trying to figure out if it's the gun, the ammo, or the shooter. I weighed out a bunch of Remington rounds on my reloading scale and noticed a lack of consistency, the unfired rounds typically varied by 2 - 3 grains in weight. I then weighed some of my Winchester white box ammo and it was much closer and much more consistent, though I need to actually fire some and see if I do better with it to confirm the problem.

Is Remington ammo that bad? Does that 2 - 3 grains in cartridge weight really matter that much when shooting at 15 yards?

Bump for interest.  I know how much my reloads vary but I never took the time to weigh out a box of factory nor weigh the components.

when you say you were missing, do you mean completely, or your groups were not so great. The LC9 has a long trigger pull. Try off a bench, but I am guessing you will find the same issue with other ammo.

I was shooting a steel ladder target at maybe 15 yards. The targets were about 4 inches.

Even off a bench I was having trouble. The groups were definitely larger than my target. I've had this gun for quite a while now, but I never really shot it a lot and became proficient until late last year, and now I feel it's holding me back. Just trying to determine what exactly the problem is. Something in my fundamentals I don't realize is off? Worn barrel/rifling? Poor ammo? I have shot a few thousand rounds through it, at least.

The big thing is I'm trying to get my accuracy up. I've been doing IDPA for a little while and I'm starting to get fast, but I don't quite have the accuracy to back it up, especially at longer distances.

The LC9 is not the firearm for IDPA imho. It's a pocket 9. The long pull might be messing with your fundamentals. Get a paper target and see where you're hitting. See where your groups are. Also, dry fire practice at home, focusing on keeping the front sight steady through the pull.

I agree 110 % with this statement I had an lc9 and the trigger pull was absolutely atrocious.

25 TO 35 on loaded rounds is nothing.
The brass and the bullet are going to be all the variation.