.280 AI load development

[WKR]

Working up a new load for a new rifle, just curious if anyone here has tried reloader 22 in there .280 ai.
I'm using 145 barnes lrx over 58.2 grains Of rl 22 and I had good results on paper but I stuck my chrono on my barrel and the es was really bad.
But I also didn't really let the barrel cool down so I'm thinking it might have been from the heat speeding it up.

 

[WKR]

Anybody have input?

 

[KU_Geo]

I’ve had good luck and low ES with 145 lrx and h4831ss or h4350. Might need to try a different powder

 

[WKR]

Well took the .280 out for some more load development and once again had good results on paper, now I really hope the chronograph will show good results as well.

How much should I even pay attention to the numbers anyhow? If it groups well isn't that what I should care about?

But the perfectionist in me want to have good numbers and i worry about long distance shots if my es and sd are no good.

 

[EdP]

Why are you shooting for groups and not doing it over a chrono? My best groups don't always have the best stats, but they are cIose and I never get good groups with bad stats.

 

[Pickettpuncher]

I would expect 22 to give you good velocity, but what I found was it being temp sensitive, my groups did funny things. This was in a 300wm, not a 280ai. I do have a 280ai, but I use h4831sc. I also don’t shoot barnes but would think they’ll do just fine. Your group above looks good

 

[WKR]

Why are you shooting for groups and not doing it over a chrono? My best groups don't always have the best stats, but they are cIose and I never get good groups with bad stats.

my chrono is a magnetospeed and it attaches to my barrel so I dont shoot groups over it because it throws off my barrel harmonics and point of impact

 

[Pickettpuncher]

my chrono is a magnetospeed and it attaches to my barrel so I dont shoot groups over it because it throws off my barrel harmonics and point of impact

Even with my Magnetospeed I still get good groups, but they ain’t where they supposed to be lol

 

[Slugz]

4831ssc and 7828 is what has produced the best results for us.

 

[EdP]

Why are you shooting for groups and not doing it over a chrono? My best groups don't always have the best stats, but they are cIose and I never get good groups with bad stats.

my chrono is a magnetospeed and it attaches to my barrel so I dont shoot groups over it because it throws off my barrel harmonics and point of impact

Exactly why I don't use a magnetospeed, but all chronos have their advantages and disadvantages. I have to set mine up down range and step down range to change strings. I am often the only person on the shooting range, but when there are others shooting it is inconvenient.

 

[Harvey_NW]

Well took the .280 out for some more load development and once again had good results on paper, now I really hope the chronograph will show good results as well.

Without making any adjustments I would send a cold bore and a few more at that same target/POA the next time you go out, just to confirm it's going to hold together and for a more valid aggregate POI for zeroing.

How much should I even pay attention to the numbers anyhow? If it groups well isn't that what I should care about?

But the perfectionist in me want to have good numbers and i worry about long distance shots if my es and sd are no good.

Velocity is a biproduct of the load and rifle combo. There has never been documented proof of a statistically valid "node" where the velocity was more consistent than it was at a different charge weight or seating depth, without changing something. I would define what you consider good or no good, and shoot a decent sample size (this is where the magnetospeed sucks) and determine your results.

The truth is it does take a valid sample size to see what's going on. Just 2 weeks ago I recorded 10 and 14 shots each on 2 different rifles, they went from an ES of 8 and 20 something @ 4 shots, to 30's and 75 at the 10 and 14 shot sample size. Once you understand how sample size will effect the dispersion of a rifle systems capability, or the velocity numbers, a .8 rifle with an ES of 35 and an SD of 9 is a pretty solid combo you can be confident with.

 

[WKR]

Without making any adjustments I would send a cold bore and a few more at that same target/POA the next time you go out, just to confirm it's going to hold together and for a more valid aggregate POI for zeroing.


Velocity is a biproduct of the load and rifle combo. There has never been documented proof of a statistically valid "node" where the velocity was more consistent than it was at a different charge weight or seating depth, without changing something. I would define what you consider good or no good, and shoot a decent sample size (this is where the magnetospeed sucks) and determine your results.

The truth is it does take a valid sample size to see what's going on. Just 2 weeks ago I recorded 10 and 14 shots each on 2 different rifles, they went from an ES of 8 and 20 something @ 4 shots, to 30's and 75 at the 10 and 14 shot sample size. Once you understand how sample size will effect the dispersion of a rifle systems capability, or the velocity numbers, a .8 rifle with an ES of 35 and an SD of 9 is a pretty solid combo you can be confident with.

My plan was to now load up ten rounds at the same charge weight, strap on the bayonet and shoot a ten shot string with a cool down break between every 3 shots.

Elaborate on what you mean when you said "this is where the magnetospeed sucks"

 

[Harvey_NW]

Elaborate on what you mean when you said "this is where the magnetospeed sucks"

What you said about barrel harmonics and POI shift. Sucks to burn 10 rounds for just velocity data, that's why I ditched the magneto.

 

[WKR]

What you said about barrel harmonics and POI shift. Sucks to burn 10 rounds for just velocity data, that's why I ditched the magneto.

Yeah your exactly right because thats what I just did with the previous load I thought had potential, come to think of it, if I go and shoot another 10 shot string with this load and the numbers aren't good that will be 20 rounds down plus the initial 8-10 for grouping. That kinda hurts with the scarcity and price of components nowadays.

Did you go with a labradar?

 

[Harvey_NW]

Did you go with a labradar?

No, I was going to but I went cheap because of budget at the time and honestly have been completely satisfied with the ProChrono DLX. It was repeatedly parallel to the magneto when I tested them together, obviously the optical being min 12' in front of muzzle will be a bit slower. A little more work to setup on a range but for the cost it's worked great. Bluetooth is convenient and app is super user friendly as well.

Examples from the app

 

[Vedauvoo]

I've been loading for the 280 AI for going on 30 years. I loaded 150 gr Barnes TTSX over RL-22, but didn't like the temp sensitivity. Lately I've been loading the same bullet over RL-16. I am very pleased with this combo. /Good accuracy and not temp sensitive.

I think H4350 would be a good bet as well.

 

[Petwa]

What kind of velocity are you getting out of the RL 16 and that 150gr Barnes bullet?

 

[Vedauvoo]

I have clocked these up to 3120 ft/sec. This was a little warm in my rifle. I backed off a bit to about 3050 ft/sec. Really happy with the accuracy and low SD's.

RL-16 has become a favorite. I load it in a 6mm Creedmoor as well.

 

[.270]

I tried the 145 lrx in my .280ai with H4831sc, RL17 and RL26. Rifle didn't like the bullet I guess. Tried the 143 hammers with rl26 and the groups tightened up real quick. Out of a 24" barrel I am going 3075 fps, never found pressure but the accuracy was there and I am happy with that load.

 

[wind gypsy]

I'm assuming the velocity climbed as shot numbers went up? If not, temp sensitivity probably isn't your problem.

IMO you'd be better off shooting the 10 rounds at near your max hunting range to see how it groups than burning 10 more just for chrono readings. If it has a ton of vertical, then worry about your velocity spread. Otherwise it seems like you're going to chase your tail and still have no idea what the real impact on hit % at distance would be.

Unless you have smaller case capacity than most with your brass, your charge weight is quite mild.