280 AI Range Report

[JD338]

Guys,

I got my M700 in 280 AI back from the gunsmith. I had the action blueprinted and installed a Hart 24" #5 Flutted barrel 1-9 twist and Tubb recoil lug. For now I am using a Leupold VXIII 2.5x8 but will change to a VXIII 4.5x14.
Started load development with the 160 gr AccuBond and RL22. After 75 rounds, (50 fire forming) I have the following results:

60.0 grs RL22
GM210M
R-P Case
COL 3.495", .015" off the lands
3 shot groups of .295", 218"
moving up to 61.0 grs.

58.0 grs RL22
GM215M
R-P Case
COL 3.495"
3 shot group of .575" ( first 2 shots were .161")


59.0 grs RL22
GM215M
R-P Case
COL 3.495"
3 shot group of .510" (first and third shots measure .153")

moving up to 60.0 grs and 61.0 grs.

I am happy with the way this rifle is shooting, considering I am using R-P brass and I haven't squared up the primer pockets or turned the case necks. I may be pushing the limits of the 8x scope while trying to achive sub 1/4 MOA. My goal is to hit 3000 fps with the 160 gr AB. This would be a great long range deer, antelope, and caribou load that will buck the wind and take out the vitals from any angle.

If anyone is interested, I will keep you posted with future results.

Regards,

JD338

 

[Michael Eichele]

That is good info. I have been thinking of having a 280 improved put together for my LR sheep rifle. 308 accuracy with near 7mm mag performance. I like that idea.

Are you going to try the 162 AMAX??

 

[4ked Horn]

I'm interested.

Somewhere down the line I'm going to own a .280AI and all this load info will be helpful I"m sure.

 

[JD338]

I am happy to share my results, hope it will help you guys out in the future.
I am a Nosler fan so I will stick stick with the AccuBond. Once I get the 160 gr set, I will work up a load for the 140 gr.

BTW, my fire forming load was 140 gr Nosler BT with 57.0 grs of RL19 and a Fed GM210M primer. This is a proven load in my 280 Remington.
20 shot group was around 1.5" but I wasn't very serious about the group. I was pressed for time, wanted fire formed cases. I will shoot for group the next time I FF cases.

Regards,

JD338

 

[jab22]

DJ, would you mind telling what these types of improvements costs? Ballpark is good enough, I have no idea what we are talking about. Im assuming this included the AI conversion since you mentioned fire forming your cases.

Red Dog

 

[JD338]

red dog,

The cost was around $1000.00 for materials and labor. It was a little more than I expected but the results are well worth the investment.
I have settled on the 160 gr AB with 62.0 grs RL22.
Consistantly shoots in the .2's at 100 yds.

Regards,

JD338

 

[jab22]

Thanks, Who did your project?

 

[jb1000br]

velocities??

JB

 

[JustC]

H4831sc edges out RL22 in mine by a tiny bit. If you are the experimental type, try a ladder with that powder. It is the preferred propellant in both my 280AI and 6.5-06AI

sounds like your barrel is a good one, nice groups.

 

[hvy barrel]

I am interested in seeing your results. I have a 280 AI also that I have just started testing with. So far I have tried IMR4350 with 140gr Ballistic tips. I did not like the results so I have moved on to IMR4831. There seems to be a big improvement but, it is early yet.

 

[sewwhat89]

Seeing posts like this keep me in trouble. In the not so distant future, I want to have a "series" built on either the 308 or 30-06 case. In other words, either .243 AI, 260 AI and 708 AI or .25-06 AI, 6.5 AI and 280 AI. With the 308 cases, I have been toying with the idea of building a short range hog/brush gun to meet my hunting demands in East TX (and AK and Africa someday). I've been leaning towards a 9.3-08 or .375-08 for that purpose.

I don't know of any advantage the '06 family has over the 308-based rounds other than velocity and LA instead of SA. I want to set them all up identical, with the exception of the big-bore. It will be based on a 20-22" Model 7 clone, only better. /ubbthreads/images/graemlins/grin.gif

Anyone care to offer advantages/disadvantages to either class based on experience. About 75% of the gun's rounds would be shot at LR paper due to my schedule. They would all see some time afield, but that would be a secondary function.

 

[jab22]

JD, any new results to report. Am considering a similar project. I wonder how your rig would shoot the 162 gr. Amax or 175 gr SMK. Thanks in advance.

 

[JD338]

red dog,

I am a Nosler guy so I can't help you with the Hornady or Seirra bullets. My guess is that they would shoot fine.
I settled on a load for the 160 gr AB with 62.0 grs of RL22, R-P case, and Federal GM215M primers. This load consistantly shoots in the .2's with the smallest group measuring .218" center to center.
I plan on finding a load for the 140 gr AB. With 64.0 grs RL22, I am getting groups in the .6"-.7" range. I want to try RL19 and H4831sc to see if I can get smaller groups.
I did try the 120 gr BT just for grins and hit paydirt with the very first load I tryed! Using 62.0 grs of RL19, I had a 3 shot group of .277" @ 100 yds. The first 2 shots measured .100". The COL is 3.387". Keep in mind that the scope is a Leupold VXIII 2.5x8. I am planning on getting a 4.5x14 and am leaning towards the B&C reticle.
This is my first custom barreled rifle and I must say that I am very pleased with the accuracy I am getting. I would strongly urge you to look at Hart barrels. I was told that they are the most consistant and based on accuracy, it must be somewhat true. Cleaning is a snap. A few patched with Sweets and MC7 and I'm done.

As for velocity, I can't tell you because I do not own a chronograph. My smith told me that my 160 gr AB load should be right around 3000 fps but this is only a guess. I plan on getting a Oehler 35 by spring and will be able to post figures then.
Hope this helps you out.

Regards,

JD338

 

[jab22]

Thanks, sounds like you have a good shooter there.