280 AI project revisited

Stag that's what I'm experiencing with magpro. My first 4 shots will be within 25 fps then 1 60fps faster or slower. Drives me crazy.
 
Stag that's what I'm experiencing with magpro. My first 4 shots will be within 25 fps then 1 60fps faster or slower. Drives me crazy.
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Yeah, I've seen it pretty often too, though sometimes it's the very first shot that greatly exceeds the rest of them. I generally keep my bores sparkling clean. Compact powders like magpro I like to keep at or near case capacity since unpredictable "funkiness" can ensue in ignition characteristics if there's much spare space. Assuming the cartridges are uniform, the only thing I can think of is temperature differences causing the velocity spikes (?).
 
I see it on warm or cold days. I wait 5 minutes between shots and see. I've been seating my bullets long. I'm going to shorten them.
 
I just fired 2x 5 shot groups at 363 yds, the first group was terrible and sprayed about 12" randomly, and the labradar numbers were equally wild in deviations. I wasn't shooting well today--plus I just applied the first application of militec-1 to the bore so that might have been a factor--I also noticed a drop in average velocity by about 25 fps in both 5 shot groups. The second group had much better consistency in velocities--and I managed 4 of the 5 shots to group MOA but pulled 1 way wide, that was purely me.

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Not great--but not too bad either. I'm not sure if I'll stick with magpro, I am having difficulty with maintaining consistency with it.
 

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seems like it wants to compressed. seated my bullets .020 deeper and it looked good until the 10th shot. I'll stay with this seating depth and up the charge some. I dropped down to 59.7gn. I'll let you know what happens. I still have about 9lbs of it.
 
Found some new Nosler Brass for not too bad of a price. Should I snag 100 or hold out for Peterson?
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If you're talking 280 AI--most definitely buy it, you won't find any 280 rem either. I assume your bergara receiver is more than likely reamed to Nosler's SAAMI-submitted spec. You may also want to contact Quality Cartridge and talk to the fellow there. If you need some additional quantity to make an order I could be talked into it as my collection of 280 AI brass is small and only going to hold out for so many more resizings.
 
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seems like it wants to compressed. seated my bullets .020 deeper and it looked good until the 10th shot. I'll stay with this seating depth and up the charge some. I dropped down to 59.7gn. I'll let you know what happens. I still have about 9lbs of it.
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I ran your numbers through QL compared to your original ones--it says you actually decreased your fill ratio--correspondingly pressure, velocity etc also dropped.
 
Stag i dropped it to make sure i wasn't going overboard. I will start upping the charge now to see what happens.
 
UPS, after canceling delivery date three times, has updated the info on my paint package--they don't know where it is. So ordered some stuff from Brownells this time, it too will likely be shipped by UPS but maybe it will get here anyway, my "problem" shipments seem to be mostly with stuff originating from Midway, which is ironic since their "nitro" shipping used to get to me very fast.
 
Stag i dropped it to make sure i wasn't going overboard. I will start upping the charge now to see what happens.
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Just out pf curiosity--I switched up to H4831 today and the results were pretty much the same, one shot out of each group was a way out deviation in velocity. So my conclusion is that there is either something wrong with my cartridges not being equalized or something in my set-up is changing pretty dramatically with warm up. I notice it's the first shot that usually is the "deviant"--but sometimes it's extra slow, other times it's extra fast. Magpro combined with the 180 to 185 gr VLDs makes for some very impressive velocity and energy, not really behind the 300 wby magnum by very much.
 
We're headed down the same road. The other day when i shot it was drizzling. I don't know if that affected the last shot. I did notice some of my cases have a lot of powder residue on the outside of the neck. Others are spotless.
 
PS--The package with paint mysteriously showed up today (!)--even though it still hasn't been updated on the tracking info. Whatever, just glad to finally have it after 2 weeks. The paint didn't quite match, but it's acceptable IMO. I have truck repair issues to attend to; but as soon as I can I'll whip up some cartridges and see how it runs. The forend extension remains easily removable.


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Couldn't help myself--took a break from working on the truck and got a few shots off--noticed the difference immediately in being able to hold the reticle steady and virtually eliminating any muzzle lift. The only drawback I realize is I now have one less thing to blame for lousy groups.
 
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