So shooting factory loaded ammunition in a Krieger barrel is going to have a "good possibility" of having an issue. Even on Arfcom, one manufacturer isn't allowed to slander another manufacturer in a tech forum.
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I'm not slamming Krieger.
All of my Krieger AR barrels back in the day where .218" bore but I didn't run any box ammo. All handloads for my match guns. Shot awesome!
It's just a known fact that you right a tight bore barrel it will drive up pressures and depending on the ammo....you might see issues or your problems get amplified and it's worse with a gas gun vs a bolt gun. I suggested calling Frank down at CLE and talk to him about it if you don't want to take my word for it. Frank will tell you on our barrels and Kriegers for consistency they out shot anything he else for the most part. He will tell you the same thing I'm telling you about pressure issues with ammo etc...
Like I said I use to work there (Krieger). That's why I suggested you call them and give them the s/n of your barrel and ask to confirm the bore size of the barrel. Maybe they no longer make a tight bore AR barrel? It's been a long time now since I worked there. If you call and ask and they lets say confirm it's a .219" bore....then you can rule out the tight bore causing or amplifying the issues. Or ask them if you send it in can they remeasure/double check the bore to confirm the actual bore and groove size.
When we started Bartlein we did tool up for .218" (tight bore 224cal barrels) as we we're use to making them that way as well as we tooled up for .219" because that is Saami standard but as I've learned over time from actual test data on pressure test barrels this can work against you if you run a tight bore/tight groove barrel.
So like I said....as I learned more and more about pressures etc...if a customer calls and spec's out a tight bore barrel. I will ask what the application is for. I don't want a phone call back and the customer is having issues if we could avoid it all together/help the customer out up front.
I do get calls from ammo/bullet makers at time and I will get a generic request for a 224cal barrel. Where they don't want Saami spec or it's not needed but I will ask...what bore size do you want, what twist, what style of rifling etc...at times they will say you pick out the best. So I will give them my recommendation and why and then they make the final call on the specs.
My AR's that I build now...I'm running more of a mix of box ammo as well as handloads. I'm running all .219" bores.
For the last few years now all the barrels we've made for our military and it doesn't matter if it's for a special forces unit using the guns overseas (yes the guns see combat) or for a military match rifle team on AR platforms I've only been doing them as standard .219" bores. No complaints on accuracy or pressure. The guns need to work for them.
Later, Frank