280 AI project revisited

[MarkCO]

Only premier line and Pro-Shop assembled in GA. The B14s are still imported.

Now I am not sure about the Wilderness, which is Cerakoted, fluted bolt. I guess that could be a barreled B-14 action imported and put together in GA, but not sure.

[stagpanther]

Nice. I look forward to reading about your rifle when its done.

[Nathan]

I decided to slap the Howa 300 win mag receiver into it this morning just for grins, to make matters more challenging its blowing over 30 mph into a quartering headwind @ 184 yds where I shot this morning. I honestly was expecting lousy results, but instead got this. Go figure.

Good shooting!

[stagpanther]

Good shooting!

You get partial credit since I had abandoned the stock as a good one.

PS--just when I stumbled upon a pretty good load using magpro--I just ran out of the last pound I had. I couldn't believe my luck when I googled for it and up it popped available at powder valley!! I mean these days that's like winning the lottery.

[stagpanther]

Parts finally came in so I can continue working on my 280AI--but the 300 win mag diversion was fun, and I think sticking the howa receiver in the Bell and Carlson stock gives me hope to find some good loads. Here are the very last 5 cartridges I could muster together as the powder and 180 VLD's ran out--might be a while before both return. As usual, I did the obligatory spazz/pull on one of the shots, but otherwise this is promising group at 189 yds, would have been around .5 were it not for the flyer.

[sako2]

Stag have you chronoed your load with magpro?

[stagpanther]

Stag have you chronoed your load with magpro?

Not this particular load in this particular rifle. I'll see if I can find something in my labradar data--though I do intend on getting some chrono data later when I get more powder and bullets.

Quickload has it pegged at about 3,150 fps and in general it is very close to what I actually record.

So far I've had this combo stay well under MOA out to 370 yds, the 82.7 grs of magpro and 180 VLD has done very well in two different rifles of different manufacturers.

[sako2]

I would be interested in the es and sd. I'm using magpro in my 6.5 prc my es and sd aren't that good.

[stagpanther]

I would be interested in the es and sd. I'm using magpro in my 6.5 prc my es and sd aren't that good.

I've read that magpro can be erratic depending on temperature, most of the shooting above was done in cold to cool conditions. I couldn't find a specific test in my labradar data for this load (it might be mixed in with other load tests)--but I do have a note in my load data spreadsheet that I got 9fps SD for 82 grs. I suspect that 82.7 is a good node for my rifle since 82.6 and 82.8 also groups well. I haven't been able to find the 180 gr elite hunter vld's anywhere, I do have some more magpro on order but these days it could be weeks before I actually get it.

PS__I just scoured my supplies and discovered an extra pond of magpro tucked away in a hidden nook--as well as 4 extra vld's--so I'll throw some together and get a crony reading for you. ; )

[stagpanther]

I just got back, unfortunately I couldn't get all 4 shots recorded--my ^%$#%&*& Caldwell (UN)stable table wobbled and hit my tripod holding the labradar knocking it off aim for the last shot. Probably not very helpful, but here's what little I got. I've grown to hate that table--it's almost guaranteed to reduce your control/accuracy. If I had the room for it I would simply weld the whole thing together.

[sako2]

Thanks. The lowest i got my es was 51 with a sd of 14. Do you know if your load is compressed. I'm 4 tenths over published data. I have no pressure sign. I'm going to go a little hotter and see if that helps.

[stagpanther]

Thanks. The lowest i got my es was 51 with a sd of 14. Do you know if your load is compressed. I'm 4 tenths over published data. I have no pressure sign. I'm going to go a little hotter and see if that helps.

I made a mistake with the first estimate I gave you--that was with 26" barrel length input in QL when the actual barrel length is 24", so my actual velocities exceed what QL forecasted. I don't have anymore 180 gr elite hunters--but I do have some 185's; though they are not as "slick" in BC. I did get a 9 fps deviation when I tested just 82 grs but I can't find the actual labradar data; I might have inadvertently erased it or mixed it in with other cartridges tested. I'm seating my bullets as far out as my magazine will allow; around 3.55, but that is still a ways off from engaging the lands the way my freebore is cut. That's 100.2% case powder capacity but according to QL still a ways under max pressure, which QL says is around 83.8
grs for what I'm using. I have seen no signs of pressure in my 300 win mag cases using magpro either, it seems to be a good powder for attaining good velocities in medium weight bullets in my 300 wm.

[sako2]

I'm able to touch the lands in my gun with a 140 gn bullet. My velocity is a little lower than the data say's it should be. I'm trying to get the sd down because i plan on shooting this gun to 1700yds. I don't have QL.

[stagpanther]

So sako, I went out and shot a few 4 shot groups with me "newly discovered" stash of magpro but using the 185 VLDs instead instead of the 180 elite hunters. I actually stepped up to warmer loads since the bullet is shorter and doesn't take as much case capacity. Magpro seems to work well with these medium bullets because the max loads seem to converge right around 100% case powder capacity. I have noticed in almost every group I've shot there always seems to one ED shot way out there that seems to throw the SD and consistency off for the entire group. Why? I don't know--unless I've started choking at the loading press in addition to choking while shooting.

Despite being only 5 grs heavier, the bullet design seemed to result in markedly heavier felt recoil as well as muzzle blast. My labradar was a foot to the side and 6 inches back, but the muzzle blast blew the battery compartment cover off repeatedly as well as blowing the cable connection to the battery off the labradar couple of times. The cases and primers show no signs of stress at all.

The best group I got was also the max charge weight of 83.2 grs. The first shot blew the battery capable loose so it wasn't recorded--but it's the impact just right of the bull's. Unfortunately, I did one of my "spazz" moves and let the rifle butt slip on the rear rest as I pulled the trigger and totally blew the last 4th shot--but it also was within a reasonable deviation since it was recorded. I will go out and try this one again with 5 shots.

[stagpanther]

Not to veer too far off subject--work continues on my 280 AI; here are pics showing my forend extension progress. I know it's ugly as sin compared to the rest of the rifle--plus it adds a good 1.25 lbs weight--but it's rock solid and that's what I was aiming for. The steel cost me $11, the Brazilian hardwood 2" x 2" (which actually turned out to be 1.3 x 1.3) cost $2.89 and I used a bit of C7 to epoxy some pieces together. The most expensive parts were the silly little M-Lok screws and nuts, of which I needed 9 pairs.

The FDE paint I ordered was due last week--but apparently has been beamed up into the USPS's collection of space junk circling the earth, so I don't know where it is or when it will be delivered, maybe this week. I did a test painting with Krylon sand--nope, looks awful and will repaint when the FDE finally splashes down.

[sako2]

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.

[stagpanther]

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.

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 (?).

[sako2]

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.

[stagpanther]

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.



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.

[sako2]

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.

[MarkCO]

Found some new Nosler Brass for not too bad of a price. Should I snag 100 or hold out for Peterson?

[sako2]

These days crab what you can. Before its gone.

[stagpanther]

Found some new Nosler Brass for not too bad of a price. Should I snag 100 or hold out for Peterson?

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.

[stagpanther]

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.

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.

[MarkCO]

Have 100 pieces of new Nosler inbound. Just need the action now.