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7/10/2008 12:14:51 PM EDT
Alright, I got off my butt and finally got out to the range today and tried out my reloads. I started working up in .5gr increments of IMR4895 using Win brass/CCI BR2/155 scenars and once I got up around 44gr I noted a few rounds showing a bulge (ring) about 1/4" above the bottom of the case (around 2700fps). I assumed this meant I was hitting the edge of the pressure curve, so just to switch off to plinking, put in a magazine of 175gr Black Hills match factory ammo (avg 2575fps).  Out of one magazine, I had three blown primers and most showed the same ring. What the heck might this be??? I bought the barrel (supposedly new) off of someone who said it was a 24" chrome-moly Eagle T barrel. Do I have a chamber issue or am I overgassing?
7/11/2008 8:40:13 AM EDT
[#1]
Try shooting some good quality military ammo through and then make a comparison.  Measure brass and do comparisons.
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I noted that you didn't state the charge weight with the 155 gr. bullets.

Then, a heavier bullet (175 gr) and a heavy charge (?).........normally, would also lead to higher pressure.
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Then, "bulge."

You sure? That you're not seeing just the "frosting" (on the case) that sometimes happens?
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Then, I must mention your special, "Eagle T" barrel.............chamber reamer and leade?  And, who did the install...........can I ASSUME that headspace was checked?

Then, since it's 24".........the bullet will stay in the barrel longer (vs. when fired out of a 20").  So, loads should be adjusted for that fact.

And, you could, do a chamber caste.  That, would tell a lot.
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Just my .02.

Aloha, Mark

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