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New Contest Starting Now! This Target Haunts Me
Tell us about the one that got away, the flier that ruined your group, the zero that drifted, the shot you still see when you close your eyes. Winner will receive a free scope!
Yes, I have and that's an excellent point. You're correct - there is not a lot of difference. Thanks, I think I will start the entire load development process all over again with a much lower starting point. Fortunately, I stocked up on several boxes of Lapua before the $$ went up. ;)
That's great to know. What barrel are you using? If it's not too much trouble - would be curious to know what your headspace measurement off the shoulder datum line and neck dimensions of your fired brass is.
I'm struggling with load development now with a .260 Rem Gas gun and I think it's mostly my own limited experience with reloading for gassers compared to many years w/ Bolt guns. I know intuitively that you're not going to get the same speeds in a semi as you do in a bolt gun, but I can't seem...
It was not a custom barrel but it was definitely expected to be a “match” barrel. I’m not complaining, I knew it was going to be tight to achieve the accuracy that is claimed. But I sorta was unprepared for Lapua to end up being TOO tight and require that level of prep to make it shoot well...
Soooo.... the answer was..... wait for it.... Wait for it...... Neck thickness. @308sako was kind enough to neck turn some of the offending Lapua brass down a bit given I didn't have the tools on hand to be able to run a test. First he did a mandrel to uniform the inside of the necks and...
Ah, gotcha. The problem is obviously trying to find a box of Berger 130 OTMs with Lapua brass in this current market. It could be months before I get lucky enough to score one.
Yeah, my FL bushing die will not size the entire neck. I think I'll go back to my neck only bushing die (Redding also) and size all the way to the neck/shoulder juncture.
Reference the red bolded statement.....No a fired bullet will not slide into a fired case mouth as stated in the OP. This is what started me down the whole "donut" rabbit hole in the first place.
I'm using Lapua .260 brass. And yes I'm getting deep ejector plunger marks. Even with the gas turned off. With the gas on, at the higher end of my OCW tests, the bolt then shears off the plunger mark when the bolt rotates. I'll try to get some pics.....
OK, fair enough. Any other suggestions to investigate? I'm pretty confident it's not a Headspace issue - I've been meticulous to measure fired cases from that chamber with a Hornady HS gauge and then FL size and shoulder bump to about .002 under. I'm running a JP High pressure bolt headspaced...
Here are the loaded bullets with a bullet next to it for depth comparison. I'm stuck with seating about 2.840ish OAL due to the ACS mag lengths. Other hide folks have said you can seat out to 2.60-2.70 in those mags - but if I go much over 2.845 the tip is sticking over the lip of the mag...
Yeah, this one is baffling to me as well. I assumed it was a chamber tightness issue. But am now thinking it is more of a neck thickness issue. I'm going to scope the chamber again it in a bit to make sure there isn't some buildup in the chamber I'm missing.
I think this may be the issue - i.e. seating deep. On my .260 AI-AT - I seat 140 Hybrids at 2.950-2.955 because the AI mags are long. With the new gas gun, I'm mag length limited to about 2.840 with 130 Berger AR Hybrids. With the 123 Scenars I'm jam limited to 2.839 with the way the chamber...
I've not ever turned a neck. It could be that maybe I'm not sizing far enough down the neck and there is some thickness starting right at the line where the bushing stops. I have not been sizing all the way down to the shoulder and instead leaving a tiny bit of the neck unsized. Supposedly it...
Redding Type S- Bushing dies. I full length size to bump the shoulder .002 under fired case. Neck bushing is a .291 for the gas gun .260. I have the usual expander button in the FL sizing die stem. No mandrels yet, but I just ordered a set of Wilson Mandrel expander dies to uniform the...
So what is the donut, how does it get there and what effect does it have on loading and load performance?? I suspect I have donuts in my Lapua case neck as I'm getting signs of pressure in a gas gun when there should be none. Due to some pressure signs of swipe and ejector marks in what I...