Handloading a .280 AI

[brockel]

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

Meant more for working up a max load in 30-40 degree Montana weather and then practicing through summer might see some excess pressure

 

[mtmuley]

Meant more for working up a max load in 30-40 degree Montana weather and then practicing through summer might see some excess pressure

Yep. Gotta pay attention. mtmuley

 

[ThunderNocked]

Man I am going back through trying to catch up! Lots of info!!!

 

[Brian in Montana]

Definitely going to do some follow-up with this one. Ladder test using RL19 and 160gn Accubonds. I haven't looked at the data yet, but seemed to have a flat spot around 2920fps.

 

[ImBillT]

Definitely going to do some follow-up with this one. Ladder test using RL19 and 160gn Accubonds. I haven't looked at the data yet, but seemed to have a flat spot around 2920fps.

View attachment 177018

You have 4-5 shots in the flat spot there. You probably have two nodes on that target.

When I do a ladder, I draw a target on a note pad, and put a spotting scope on the bench with me. Then I draw the bullet hole on the drawn target after every shot, and number each bullet hole. Below that I log the velocity and powder charge of each shot. When I’m done, I use the drawn target to number the actual target, and write the velocity and powder charge data at the bottom. When going from a book starting load, all the way up to your first pressure sign, you’ll usually cross at least two nodes. The nodes are equally well at dampening velocity variation, so usually you just shoot the high node. If you’re chasing the absolute maximum accuracy, then you can load up a ten shots at the middle powder charge of each node, and shoot two 5-shot groups with each load over the chrono. Statistically the accuracy data will not usually be meaningful, but the velocity spread will often show a statistically significant difference in SD/ES between the two loads, and over the long haul, the better of the two give you a smaller average group size.

 

[Brian in Montana]

I shot some 3-shot strings this afternoon based off the ladder test; 6 of them. Every group was less than 1". My worst group was .85". The best was 57.8gn at .4". 59gn and 58.6gn were basically identical at .58". I felt I flinched a little on the 3rd shot of 58.6gn, so that might have effected the group a little. It's a good problem to have when you're having more than one charge weight that groups, so I have some more shooting to do.

I'm estimating the MVs to be about:

59gn - 2938fps
58.6gn - 2907fps
57.8gn - 2860fps

This combination could be a toss-up with the load I worked up using H4831sc and 154gn Interbonds. Whichever winds up the most accurate and consistent, I'm going to hold off on more experimentation for now and load them up for spring bear.

 

[Jbotto]

I shot some 3-shot strings this afternoon based off the ladder test; 6 of them. Every group was less than 1". My worst group was .85". The best was 57.8gn at .4". 59gn and 58.6gn were basically identical at .58". I felt I flinched a little on the 3rd shot of 58.6gn, so that might have effected the group a little. It's a good problem to have when you're having more than one charge weight that groups, so I have some more shooting to do.

I'm estimating the MVs to be about:

59gn - 2938fps
58.6gn - 2907fps
57.8gn - 2860fps

This combination could be a toss-up with the load I worked up using H4831sc and 154gn Interbonds. Whichever winds up the most accurate and consistent, I'm going to hold off on more experimentation for now and load them up for spring bear.

What powder/bullet combination was this? I may have missed a few posts so I’ll go back and read.

 

[Brian in Montana]

This was Reloader 19 and 160gn Accubonds.

 

[ImBillT]

So your node appears to include from 2907fps to 2949fps.

 

[cahunter805]

I shot some 3-shot strings this afternoon based off the ladder test; 6 of them. Every group was less than 1". My worst group was .85". The best was 57.8gn at .4". 59gn and 58.6gn were basically identical at .58". I felt I flinched a little on the 3rd shot of 58.6gn, so that might have effected the group a little. It's a good problem to have when you're having more than one charge weight that groups, so I have some more shooting to do.

I'm estimating the MVs to be about:

59gn - 2938fps
58.6gn - 2907fps
57.8gn - 2860fps

This combination could be a toss-up with the load I worked up using H4831sc and 154gn Interbonds. Whichever winds up the most accurate and consistent, I'm going to hold off on more experimentation for now and load them up for spring bear.

Brian what was 58.2gr? Do you have any pictures of the target/groups? Seems you may have found a nice powder node.

 

[Brian in Montana]

I don't have any pics this time. When a grouping shows promise I always take some scissors and cut it out of the target, and tape it into my notes with the load data next to it, sometimes notes on the weather conditions. I cut out the 3 I posted earlier. The problem always seems to be time. Just getting more test groups loaded and range time in between work and getting kids to school and various activities. I wish I could shoot everyday, but sometimes it's hard to squeeze it in. Getting into the time of year again where the kids are all doing 20 different things. I'm not sure I'll make it to the range again this week.

 

[cahunter805]

I don't have any pics this time. When a grouping shows promise I always take some scissors and cut it out of the target, and tape it into my notes with the load data next to it, sometimes notes on the weather conditions. I cut out the 3 I posted earlier. The problem always seems to be time. Just getting more test groups loaded and range time in between work and getting kids to school and various activities. I wish I could shoot everyday, but sometimes it's hard to squeeze it in. Getting into the time of year again where the kids are all doing 20 different things. I'm not sure I'll make it to the range again this week.

Totally understand man. Life always seems to get in the way of range time sometimes.
The reason I asked about 58.2 is because if it grouped close to what 57.8,58.6 and 59 did I would recommend fine tuning around 58.2-58.6. Reason being is Your powder node would be very good there and usually less affected by inconsistencies.

 

[ImBillT]

I don't have any pics this time. When a grouping shows promise I always take some scissors and cut it out of the target, and tape it into my notes with the load data next to it, sometimes notes on the weather conditions. I cut out the 3 I posted earlier. The problem always seems to be time. Just getting more test groups loaded and range time in between work and getting kids to school and various activities. I wish I could shoot everyday, but sometimes it's hard to squeeze it in. Getting into the time of year again where the kids are all doing 20 different things. I'm not sure I'll make it to the range again this week.

I think you’re making this too complicated.

You already know a velocity node.

Pick the bullet you want to hit an animal with.

Pick a powder that you can get your hands on that should completely fill your case and produce a velocity inside your node.

Shoot over the chrono till you know your exact powder charge to be inside the node.

If you want to tinker with seating depth, do that now, but you don’t need to do tons of test.

Now you’re all done. Enjoy your rifle and load.

Guys that try 50 different bullet/powder combinations and think they found the magic load usually just happened to eventually land on a velocity node on accident, and often did 3-5 times during the process, but didn’t recognize that those 3-5 loads were not statistically different.

I usually only shoot 1-2 bullets per gun, and the only reason for more than one bullet would be if I thought I might shoot drastically different sized animals with that gun.

 

[ThunderNocked]

Took my 280AI out - first time to the range. Guy who worked on it gave me an extensive break-in so I ran through that. Took me about 1.5 hours - but I was very pleasantly surprised with recoil, shooting, etc.
I'm hoping to get back out provided that it will stay warmer. Yesterday warmed up to 12*F (yes positive 12 was warm) but by the time I was done at 7 i couldn't feel my fingers and toes. I'm excited to shoot through this factory stuff and then start reloading a little bit. I'm enjoying this thread as it is definitely giving me some inspiration. Hoping to be sighted in and have shot out to 300 yards by Saturday!

 

[Brian in Montana]

The winner for that powder/bullet combination was 58.6gn. I shot grouped it 3 times, never quite came out with the holes touching, but each group was a little under .75". That's kind of my benchmark for a handload. I got an average MV of 2903fps. My ES was 27, which could be better. I'm thinking this load may be worth playing with a little more once I have some better brass. A 160gn Accubond hitting the air at 2900fps is going to be pretty formidable on the receiving end.

 

[Brian in Montana]

So I decided I'm going to try one more combo before bear season. I still have a bunch of 150gn ABLRs and I want to get them moving faster without sacrificing accuracy. I'm going to push them with RL19.

 

[Brian in Montana]

Loading for bear. Going with the second combination I tried: 60.3 grains of H4831sc pushing a 154gn Hornady Interbond, F210M primers. I'm only loading 30 at this point because I have some Peterson brass on backorder and I don't want to over-commit to this re-purposed, fire-formed 280 Remington brass. This will get me through spring bear.

 

[BenInMT]

The winner for that powder/bullet combination was 58.6gn. I shot grouped it 3 times, never quite came out with the holes touching, but each group was a little under .75". That's kind of my benchmark for a handload. I got an average MV of 2903fps. My ES was 27, which could be better. I'm thinking this load may be worth playing with a little more once I have some better brass. A 160gn Accubond hitting the air at 2900fps is going to be pretty formidable on the receiving end.

I would take this .75” velocity node that you like for speed and ES and do a seating depth test. I would be willing to bet that by jumping the bullets possibly even a great distance you will be able to pull your groups in. I shoot 280AI though I have never tried the 160AB in my 280AI but in other cartridges and in my case the ABLR liked a considerable jump.

Don’t forget that when you go to better brass you’re going to have different case capacity which will mess all this up. In my somewhat extensive experience with 280AI once I find a velocity that it shoots well at I can change any component as long as I can get a bullet of the same weight moving the same speed I have seen the accuracy.

And dude, ES of 27... I don’t know how many rounds that’s over but that’s pretty good and I would take that any day. How freaking far do you have to shoot before 27FPS could cause a miss?

 

[Brian in Montana]

The one I'm going with had an ES of 29fps over 8 shots, and all in less than .7". It's a good load. I'm going to come back to the RL19 / 160gn Accubond load at some point, you certainly could be right about the seating depth test, but I'm feeling like settling for the time being until after bear season.

Accubonds do seem to like a little jump in my 7mm-08.