Handloading a .280 AI

[Brian in Montana]

Using a rear bag to support the stock in my shoulder pocket. I'm certain it's not my shooting platform.

I did not bed the recoil lug. Like you were saying, I do remember thinking the space for the recoil lug was big, but it seemed to fit in snuggly enough, and it's a thick lug although I can't remember it's thickness off hand (I oddly can remember songs and entire movie scripts but brain can't retain numbers at all. I have to write everything down, not kidding). But the big space for the lug as well as the barrel nut is one reason I was thinking that. But I'd think as long as the action screws are tightened down adequately in the aluminum pillars that really shouldn't be a problem, at least not enough to through a shot that far.

Anyway. I'm really not convinced it isn't just the load. Different powder/bullet/primer combos can do some funny things.

 

[ImBillT]

Using a rear bag to support the stock in my shoulder pocket. I'm certain it's not my shooting platform.

I did not bed the recoil lug. Like you were saying, I do remember thinking the space for the recoil lug was big, but it seemed to fit in snuggly enough, and it's a thick lug although I can't remember it's thickness off hand (I oddly can remember songs and entire movie scripts but brain can't retain numbers at all. I have to write everything down, not kidding). But the big space for the lug as well as the barrel nut is one reason I was thinking that. But I'd think as long as the action screws are tightened down adequately in the aluminum pillars that really shouldn't be a problem, at least not enough to through a shot that far.

Anyway. I'm really not convinced it isn't just the load. Different powder/bullet/primer combos can do some funny things.

I’ve never seen a load result in that much vertical on random shots outside of trying to compress ball powders, and that’s not what you’re doing. I suspect it’s something else.

If you’re on a bench and not prone it’s possible that after a few shots you’ve wondered toward the pistol grip with the bag, and are having the butt drop as it slides off the bag. If you’re shooting prone, or monitoring bag position, then that’s not it either.

Still, changing seating depth and powder charge are unlikely to cure that issue. If you cure the issue somehow, you can probably return to that exact load and not make it repeat.

 

[Dan O]

Two questions,
Is it the same shot that goes high ex: 3rd shot
Are you using the same pressure on the bipod, forward or downward?

 

[ImBillT]

Is the flyer high everytime?

That’s a very good question. If the answer is “yes” then it really sounds to me like it’s related to the way the gun is riding the bags. Being on a bipod though, it seems less likely.

 

[Brian in Montana]

Two questions,
Is it the same shot that goes high ex: 3rd shot
Are you using the same pressure on the bipod, forward or downward?

1. No, but usually it was the 2nd shot in a 3 shot string.
2. Yes. Forward.

 

[Brian in Montana]

Is the flyer high everytime?

Not necessarily. Ill add more info.

7 three-shot strings. RL22 / 150gn ABLR / F210M

1. 59.8gn. Just not a very good grouping. Sort of a flyer to the right.

2. 60gn. Again, not great in general but here's where the pattern starts - flyer is about 1.5" high.

3. 60.4gn. shots one and three are touching; shot 2 is a little over 2" high.

4. 60.6gn. all shots were a little high, with a flyer about 1.25" right.

5. 60.8gn. shots one and three .25" apart, shot two is nearly 2" high. (A little right as well).

6. 61.2gn. Shots one and two are touching, shot 3 is about 2" high.

7. 61.4gn. just bad. About a 2" group.

So it wasn't entirely consistent. Just enough of the time to make me wonder. According to Nosler loads are compressed past 59.5gn.

 

[Brian in Montana]

I realize every load in this batch is a little over case capacity. I was going for speed. I have a different load with the 150gn ABLR that is very accurate, but doing about 2880fps at the muzzle. Nothing wrong with that, of course, but I do like speed.

 

[brockel]

I’d throw on the magneto and load 5 of those up and shoot a 5 shot group. In my experience your POI will shift with the magneto but the group size stays the same.

 

[VikingsGuy]

Not necessarily. Ill add more info.

7 three-shot strings. RL22 / 150gn ABLR / F210M

1. 59.8gn. Just not a very good grouping. Sort of a flyer to the right.

2. 60gn. Again, not great in general but here's where the pattern starts - flyer is about 1.5" high.

3. 60.4gn. shots one and three are touching; shot 2 is a little over 2" high.

4. 60.6gn. all shots were a little high, with a flyer about 1.25" right.

5. 60.8gn. shots one and three .25" apart, shot two is nearly 2" high. (A little right as well).

6. 61.2gn. Shots one and two are touching, shot 3 is about 2" high.

7. 61.4gn. just bad. About a 2" group.

So it wasn't entirely consistent. Just enough of the time to make me wonder. According to Nosler loads are compressed past 59.5gn.

Overlay all 21 shots and see if they still look like flyers or if it looks like random distribution. 3 shot “groups” can create a perception of “flyers” that are really just normal distribution of a very imprecise load(s).

 

[Brian in Montana]

Actually I just did that, pulled out the targets, including the ladder test, and considered them with that regard. When you look at it in the bigger picture, it does look less like flyers more like a shotgun pattern. I'm probably just going to move on from this combo unless I try some lower charges.

 

[Brian in Montana]

I really want to get those ABLRs zipping out there accurately at about 3000fps, or nearly. I have a pound of IMR7828ssc. I might try that next.

 

[ImBillT]

I realize every load in this batch is a little over case capacity. I was going for speed. I have a different load with the 150gn ABLR that is very accurate, but doing about 2880fps at the muzzle. Nothing wrong with that, of course, but I do like speed.

2880fps with a 150? You can do that with a 7-08.

Compressed loads are usually a good thing with stick powders, so I wouldn’t worry about that.

What twist? High rpms from a tight twist can exacerbate imperfect jacket concentricity. I don’t shoot enough Noslers to say anything with certainty, but the types of jackets they manufacture are almost impossible to make perfectly. Nonetheless, if the fliers are only vertical, I lean toward it not being related to the bullet or powder charge. If fliers are all over the place, than perhaps it is

I don’t know why you shouldn’t be able to get 150’s in excess of 3100fps unless you have a short barrel.

 

[Brian in Montana]

My higher charges in that group were up around 3070fps. I like speed, but the operative word in this endeavor is, of course, accurately.

 

[VikingsGuy]

Seems like it is time to try Hammers at 3100+ fps.

 

[ImBillT]

My higher charges in that group were up around 3070fps. I like speed, but the operative word in this endeavor is, of course, accurately.

I’m all for accuracy, but there’s no point in having a .280AI if you’re going to shoot at 7-08 velocities. If 3070 is between nodes then I would kick it up till I hit the next node up. If you’re getting pressure signs then there are ways to handle that. Lapua 30-06 brass will take more pressure. WS2 or HBN lower pressure and are usually good for another 100-150fps once you increase your powder charge to get back to max pressure. RL-22 may be a little on the slow side for a 150. It should be just right for 180+. Are you getting pressure signs with RL-22 and a 150?

 

[N2TRKYS]

Don't know. I wasn't using a chrono. I have a Magnetospeed and generally only chronograph the loads that group well.

That’s a shame and a loss of good data. If you had great es/sd numbers, then you might want to work with seating depth. If they were terrible, then a powder change maybe in order. I’ve had a simple primer change tighten groups.

This is assuming the barrel is free floating. Fwiw, I’ve never bedded any of my B&C stocks and never had issues getting them to shoot.

 

[ImBillT]

Did you brush the barrel between shooting 4831 and RL-22?

Your 60.3gr load with H4831sc was giving you 2949fps. If you adjust your charge of RL-22 to give 2949fps, you’ll get the same accuracy unless something else changes. Lots of powders don’t play well together though. It’s best to brush your barrel when you change powders.

 

[Brian in Montana]

I always start a new load development with a good barrel cleaning. So no, powders not mixing.

At some I will probably back off the RL22 to bring the MV down to where the accuracy node was with H4831, but I'm waiting bro push it faster presently.

 

[brockel]

Not sure if it matters or not to you but I’ve had horrible luck with RL22 being temp sensitive

 

[mtmuley]

Not sure if it matters or not to you but I’ve had horrible luck with RL22 being temp sensitive

This has been said about RL-25 too. Been shooting it for over 20 years. Hunting ranges won't show any problem. mtmuley