I should just make a handout of this.
This is why I don't like Sig.....among tons of other things there are so many lemons in their barrel lotteries.
Let's start with my Gen 2 MPX 16" with a red dot. These are typical groups 6-8" out of it at 50yds, 115gr, 147gr, match ammo etc. doesn't matter. It runs fairly reliable as far as MPX's go but the accuracy is abysmal. $500 combat handguns print better groups than this in a rest with match ammo at 50yds. Shot off an accutac bipod and rear bag. Tried all the tricks, removing the muzzle device, making sure the barrel was torqued properly, adjustable gas block, even tried a different bolt since I had one replaced when Sig changed firing pins. Doesn't matter if it's off a bipod or bags. It's a shotgun. I would expect something like this, especially with better match ammo to easily hold 3-4" at 50yds. I've seen JP-5's do close to that at 100yds with match ammo. Some of these almost look like the bullets are starting to tumble.

Then let's move onto my MCX Legacy 16".......these are two sets of groups at 50yds. Both are 3 separate groups of 5 rounds each (the far left round on the right target is actually part of the left target's groups). The one on the left with typical 55gr AE ammo (no one expects much out of that) the group on the right is Barnes 69gr. No sight adjustments mind you, shot off an accutac bipod and rear bag. Actually worse than the groups shot out of the MPX.....that alone is impressive! This barrel was actually returned to Sig a couple years ago and I was told it tested to their specs. I've done all the things, barrel nut torque, removed the flash hider in case it was torqued on too hard, all the things. It's a shotgun even with match ammo. I can say without a doubt this is the worst shooting barrel accuracy wise I've ever had. No tumbling here, the bullet holes you can find on a target at 100 are still clean holes.

Now you might just say "Oh that guy just bitter and doesn't know how to shoot. Well here's a 20rd group (4 separate groups of 5 shots) with the same 69gr Barnes ammo shot out of a virtus barrel installed on the exact same optic (1-6x)/upper/lower (different tapered bolt of course for the virtus) today as well, shot off the same bipod and rear bag. Except this group is at 100 yds. Still not as impressive as a couple of my JP barreled AR's with match ammo (especially considering Sig charges $900 for a barrel) but for a 1:7 Sig barrel, of a bipod and rear bag, and 4 separate groups, It's more than acceptable.. The downside is the weight of the Virtus barrel destroys the gun's balance and you lose the best part of the MCX (light weight and balance) in the process.

I could go on, we could get into the issues I had to solve with my 320 X-five to get it to run, but those were fairly easily solvable.
Let's start with my Gen 2 MPX 16" with a red dot. These are typical groups 6-8" out of it at 50yds, 115gr, 147gr, match ammo etc. doesn't matter. It runs fairly reliable as far as MPX's go but the accuracy is abysmal. $500 combat handguns print better groups than this in a rest with match ammo at 50yds. Shot off an accutac bipod and rear bag. Tried all the tricks, removing the muzzle device, making sure the barrel was torqued properly, adjustable gas block, even tried a different bolt since I had one replaced when Sig changed firing pins. Doesn't matter if it's off a bipod or bags. It's a shotgun. I would expect something like this, especially with better match ammo to easily hold 3-4" at 50yds. I've seen JP-5's do close to that at 100yds with match ammo. Some of these almost look like the bullets are starting to tumble.

Then let's move onto my MCX Legacy 16".......these are two sets of groups at 50yds. Both are 3 separate groups of 5 rounds each (the far left round on the right target is actually part of the left target's groups). The one on the left with typical 55gr AE ammo (no one expects much out of that) the group on the right is Barnes 69gr. No sight adjustments mind you, shot off an accutac bipod and rear bag. Actually worse than the groups shot out of the MPX.....that alone is impressive! This barrel was actually returned to Sig a couple years ago and I was told it tested to their specs. I've done all the things, barrel nut torque, removed the flash hider in case it was torqued on too hard, all the things. It's a shotgun even with match ammo. I can say without a doubt this is the worst shooting barrel accuracy wise I've ever had. No tumbling here, the bullet holes you can find on a target at 100 are still clean holes.

Now you might just say "Oh that guy just bitter and doesn't know how to shoot. Well here's a 20rd group (4 separate groups of 5 shots) with the same 69gr Barnes ammo shot out of a virtus barrel installed on the exact same optic (1-6x)/upper/lower (different tapered bolt of course for the virtus) today as well, shot off the same bipod and rear bag. Except this group is at 100 yds. Still not as impressive as a couple of my JP barreled AR's with match ammo (especially considering Sig charges $900 for a barrel) but for a 1:7 Sig barrel, of a bipod and rear bag, and 4 separate groups, It's more than acceptable.. The downside is the weight of the Virtus barrel destroys the gun's balance and you lose the best part of the MCX (light weight and balance) in the process.

I could go on, we could get into the issues I had to solve with my 320 X-five to get it to run, but those were fairly easily solvable.
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