+0.030" chamber neck length in .223 wylde AR barrel: How bad is that?

[Oreo]

So I took a chamber cast of my AR barrel today. I bought the barrel new as a Wilson match grade barrel. Haven't shot it much yet. Its 20" stainless hbar style, 1:7 twist. Anyway, the one thing that stands out to me on the chamber cast is that the case neck portion is about .030" longer then SAAMI cartridge spec. How bad is that for accuracy?

If I could find good brass with necks that long I'd say it is an advantage but I've never seen such brass. It would take a lot of firings to get brass to grow that much to fill the chamber neck.

Any thoughts on the matter?

[GabbyM]

Should work fine IMHO. Actually in my experience with AR's and 223 bolt guns. You'll be close to that length in one firing and FL sizing. What chamber is it aka 223 Rem, 5.56mm NATO, Wylde and the likes. Wilson may also have there proprietary chamber dimensions as there are many who do. Whatever chamber you have I'll bet it's cut just the way Wilsons print says to cut it.

Best thing I bought for AR's and brass is a set of RCBS X dies. Standard not small based. Very impressed with them. They do control the case stretch and do not overwork the necks diameter. Directions call to trim the brass short initially then let length stabilize. Numbers are in the directions but I think your chamber length would place most new brass length right at the start point.

2nd favorite thing is a cheap ten dollar brass catcher bag. Looks a little silly but so does a sixty year old man crawling around on his hands and knees plucking brass off the ground.

[Oreo]

I've got all those things. I do have my suspicions that the x-die works in a way that is counter productive to fine accuracy but I haven't tested it much yet.

Its a wylde chamber.