Over-pressure. Causes and Remedies?

[Uglyduck]

Alright WEVO Guru's, I need your input. Am i correct in thinking the signs of over-pressure are blown or flatened primers and that the cause is generally hot ammunition, out of spec chamber dimensions, or the headspace is off? If so, what is/are the remedy/remedies?

[AR Performance]

Other things can cause high pressure signs. Too much oil in the chamber and barrel, run a dry patch through the barrel after cleaning to remove excess.
A heavy crimp can also increase pressure and even slow velocities, I only use a very light crimp. Art at SSA has a new test lab and will post his test results in about a month.
Seating a bullet deeper than needed can also cause higher pressure.

[Eric]

Running 5.56 in a .223 chamber has been known to create pressure issues (flattened/blown primers, F/T extract, etc). If this is the case, the chamber can be reamed by a competent gunsmith.

[Uglyduck]

After firing different ammo in it and talking with the rifle manufacturer I believe its an ammo issue. Its XM193, anyone have these sort of issues with it before? Its all I've ever fired through this rifle and I've never had issues with it before.

[alt154shiver]

I know this might be an obvious question but, are you running a .223 chamber? or a 5.56 chamber?

XM193 is loaded for the 5.56 chamber spec which tolerates around 10,000 more PSI (i think it's psi), than the .223 spec. Running 5.56 in a .223 chamber can cause dangerous over pressures.

[Uglyduck]

.223 wylde and conversation with the rifle manufacturer said it shouldn't be a problem with XM193. I shot a couple mags of a different brand with no problems, another reason I believe its the 193. I've never had problems with it before though.

[AR Performance]

Some say their ammo is M193 and some really is M193, it should hit 3200 from a 20" barrel.
Win white box is, the Malaysian surplus ammo is real.
Most M193 ammo I have fired in the past 15 years does show swipes in most rifles including Colts but does not flatten the primers.

Have you shot the same brand ammo in this rifle before or same brand in other rifles with no problems? If I read correctly above you are blowing primers?

I'll take a wild guess here and say this is a new rifle, high end with a different type of rifling? Try the same ammo in a friends rifle to see if it has the same problem. If the lands of rifling are wider than your friends and his does not blow primers you may have an answer. It could also be thick chrome if it is a chrome-lined barrel.