280 Ackley Improved anyone?

[DrThunder88]

You guys gotta quit bring this up! So far I've been able to resist! But that won't last forever if I keep getting tempted. :-))

I know the feeling. A shockingly good deal from SPG on a .300 Blackout AR barrel is why I now have a .300 Blackout AR pistol. And the real kicker is that I haven't even gotten the barrel yet!

[Armed in Utah]

Who would have thunk...Sportsman Guide selling Savage tubes......?

[Rooster 50]

Shot mine today 140gr ballistic tips with 62gr of H4350SC....1/2 in groups. My load development is done. I love this gun and with the muzzle brake I have under 500 in it.

I will verify the load with my accubonds now and load up 50. Cant wait for deer and Antelope season to start.

[Rooster 50]

Shot mine today with 140gr Ballistic tips 62gr of H4350SC and it shot great. 1/2 in group. I am done messing with it. I'm gonna hunt with it just like it is. ugly and accurate.

I do want to try the same load with the accubonds but I feel good that it will perform the same as the ballistic tip. Cool thing is it is a %100 load. I got a great case fill and super accuracy.

[scooterf79]

Thanks for the update, I just got mine built (used a Criterion) but im still glancing at this one from Sportsmans guide. I broke my barrel in and now im gonna try and shoot Saturday, going to try 168gr bergers with imr 7828, and ive got 140 ballistic tips laying out but im torn between powders, H4831, re22 (temp sensitive tho), and ive been thinking Imr4350. Dont have any H4350 handy so thanks for adding to it lol. Did you try any other combos?
Thanks
Scooter

[Dewey7271]

Scooter,
I ran Norma MRP. Supposed to be very similar to RL22 without the temp sensitivity.
Worked really well and chrono'd right where Quickload said it would.

[Rooster 50]

I tried IMR 4831 and it shot well but not as well as the H4831 and the H is less temp sensitive. Measured the group this morning .531. I am still gonna bump it up 1/2 gr to max and see if that makes any difference but the 62gr load was great.

[Dewey7271]

Definitely can't complain about 1/2" groups.
Nice shooting.

[scooterf79]

Thanks for the response guys,
Dewey, thanks for the info I couldnt tell ya the last time I saw any Norma MRP around here, but ill definitely pick up some when I find to give it a try
Rooster, thanks for the info too. Ill load up some with the H4831 and see how it does.
Thanks again for the info, ill let ya know how it goes
BTW....half in groups....NICE!
Scooter

[FW Conch]

Rooster 50, you said you shot 140grn Ballistic Tips with 62grns of H4350"SC"? Never heard of it? I think you meant 62grns of H4831SC?

Quite a difference!.........Just Sayin :-))

[scooterf79]

Finally got out this weekend to shoot some groups with my 280AI.
I loaded some 140gr B-tips with H4831. Went up in .5gr increments up to 61.5gr. Heres some pics of my groups (3 shot groups)
http://i1287.photobucket.com/albums/a631/scooterf79/Mobile%20Uploads/20140901_013129_zpsc5vg8qdt.jpg (http://s1287.photobucket.com/user/scooterf79/media/Mobile%20Uploads/20140901_013129_zpsc5vg8qdt.jpg.html)
http://i1287.photobucket.com/albums/a631/scooterf79/Mobile%20Uploads/20140901_013217_zpscpgwm2ow.jpg (http://s1287.photobucket.com/user/scooterf79/media/Mobile%20Uploads/20140901_013217_zpscpgwm2ow.jpg.html)
http://i1287.photobucket.com/albums/a631/scooterf79/Mobile%20Uploads/20140901_013158_zpsysyfbxtx.jpg (http://s1287.photobucket.com/user/scooterf79/media/Mobile%20Uploads/20140901_013158_zpsysyfbxtx.jpg.html)
http://i1287.photobucket.com/albums/a631/scooterf79/Mobile%20Uploads/20140901_013141_zpsvigggtcq.jpg (http://s1287.photobucket.com/user/scooterf79/media/Mobile%20Uploads/20140901_013141_zpsvigggtcq.jpg.html)
I shot 6 different groups with this combo, and the average of 5(I left out 1 because I shot it while the barrel was pretty hot and it started stringing) was right at 1/2in.
My velocities arent quite where I want them but my best group was with the highest charge so Im gonna work up from there and see if I can break 3000fps and keep the accuracy. My 61.5gr charge just barely broke 2900.
This is my first build and I'm thrilled with the results.
I've got some 168gr Bergers loaded but didnt have time to shoot them. Im gonna go out on a limb and say theyll have a hard time beating these 140s B-tips
Scooter

[drybean]

great shooting

[Rooster 50]

I want top be VERY CLEAR. My load was 62gr of H4831sc with the 140gr ballistic tips. Like the previous poster I am not real thrilled with the speed based on the downrange performance. I was looking for around 3100 with that load especially at this altitude(7500ft). I am headed out again Thursday with the same load and the 140gr Accubonds. I will probably drag out the chrony for that deal.

Sorry for the confusion.

[scooterf79]

Be sure and give us an update Rooster, im curious as to what ya get. Im gonna try to get back out this weekend with some increases in powder and see how mine goes
Thanks
Scooter

[Dewey7271]

Rooster,
Here's where Quickload says that should be if that helps at all.
Cartridge : .280 Ack Imp
Bullet : .284, 140, Nosler AccuBond 59992
Useable Case Capaci: 66.192 grain H2O = 4.298 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length : 23.0 inch = 584.2 mm
Powder : Hodgdon H4831 SC

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 80 49.35 2330 1687 28306 9036 82.1 1.525
-18.0 82 50.59 2391 1776 30204 9377 83.6 1.485
-16.0 84 51.82 2452 1869 32235 9713 85.1 1.446
-14.0 86 53.05 2513 1964 34406 10045 86.5 1.408
-12.0 88 54.29 2576 2062 36731 10371 87.9 1.370
-10.0 90 55.52 2638 2164 39222 10689 89.2 1.328
-08.0 92 56.75 2701 2268 41893 10999 90.5 1.287
-06.0 94 57.99 2765 2376 44757 11298 91.7 1.247
-04.0 96 59.22 2828 2487 47836 11587 92.8 1.209
-02.0 98 60.46 2892 2601 51147 11862 93.9 1.172
+00.0 100 61.69 2957 2718 54710 12124 94.8 1.136
+02.0 102 62.92 3021 2838 58551 12370 95.8 1.101 ! Near Maximum !
+04.0 104 64.16 3086 2960 62698 12600 96.6 1.068 ! Near Maximum !
+06.0 106 65.39 3151 3086 67179 12812 97.3 1.035 !DANGEROUS LOAD-DO NOT USE!
+08.0 108 66.63 3216 3215 72025 13003 98.0 1.004 !DANGEROUS LOAD-DO NOT USE!
+10.0 110 67.86 3281 3347 77245 13175 98.6 0.973 !DANGEROUS LOAD-DO NOT USE!