280 AI Velocity problems!?

[AggieHunter]

Now that the weather has cooled off I have started searching for a load for my new 280AI. While contemplating the build, I was hoping for at least 3100 FPS with a 140 gr. Nosler Accubond. My barrel is a Brux finished at 26". So far I have tried H-4831SC-IMR4350-IMR4831. All with Norma fire formed cases with CCI primers. This morning I got a velocity of 3018 FPS with a max load, (for the rifle) of IMR4831. The Nosler book shows IMR 4831 as their accuracy powder at 58.5 grs. I got extractor marks at 57.5 so I won't go any higher.A guy at the range said I should try RL 26 for more speed. Is that correct?

I have had a custom built 280AI for over 10 years. I use 140 grain Accubond. I use 7828ssc at 62.5 grain and I get 3200 FPS w/tremendous accuracy

 

[newmexkid]

I do not see where you specify if you're using standard or magnum primers. With that said, Hodgdon shows a maximum of 58.0 gr of IMR 4831 with a 140-gr Ballistic Tip using the WLR primer. They got top velocity using a maximum of 57.0 gr of Hybrid 100V. Both of these were loaded to 3.330" OAL, using the standard Winchester large rifle primer. If you're getting extractor marks at 57.5 gr of IMR 4831 then you might have a tight chamber. If you can find it, Reloder 26 is an awesome powder and should probably give you the best velocity; although don't overlook RL 22. I've seen people go as high as 63.0 gr with RL 22 but that might be too hot for your rifle. Good luck

I'm using standard primers. I have 13 lbs. of RL 26. Rounds already loaded with it, have to wait until Monday.

 

[BigSky112]

Now that the weather has cooled off I have started searching for a load for my new 280AI. While contemplating the build, I was hoping for at least 3100 FPS with a 140 gr. Nosler Accubond. My barrel is a Brux finished at 26". So far I have tried H-4831SC-IMR4350-IMR4831. All with Norma fire formed cases with CCI primers. This morning I got a velocity of 3018 FPS with a max load, (for the rifle) of IMR4831. The Nosler book shows IMR 4831 as their accuracy powder at 58.5 grs. I got extractor marks at 57.5 so I won't go any higher.A guy at the range said I should try RL 26 for more speed. Is that correct?

The book is close to worthless, attorney liability issue.

 

[Bob Wright]

The book is close to worthless, attorney liability issue.

Well, at least you found out where pressure affects your chambering. Load data is subjective. That's why we always, always, start low and work up till you find something that works. Never trust data until you back off from max and run a speed test. Unless you know a powder/primer/bullet combo that shows consistent pressure ramps. The 280AI is very forgiving IMHO, and easy to load for if you take care to study options and similar loads. I just can't believe how successful so many handloaders found quick load development for so many different combinations. Go back to basics ... you'll find it.

 

[Roughwater]

I ran into this problem and figured it out to be the Norma brass has less capacity so it spikes your pressure.. Cannot believe anyone else hasn't talked about this problem..

I use Norma brass a lot. In my experience with several different calibers Norma brass is lighter in weight than Remington brass. That said, all else being equal it will have greater capacity, not less. However due to the heavier, thicker Remington brass, with the same powder/primer charge the Remington will net higher velocity because you actually have less capacity in the Rem case which causes higher pressure thus higher velocity. That's been my experience anyway.

 

[Priley]

I use Norma brass a lot. In my experience with several different calibers Norma brass is lighter in weight than Remington brass. That said, all else being equal it will have greater capacity, not less. However due to the heavier, thicker Remington brass, with the same powder/primer charge the Remington will net higher velocity because you actually have less capacity in the Rem case which causes higher pressure thus higher velocity. That's been my experience anyway.

If I load Norma brass to the same load as my Hornady or Remington brass I get a sticky bolt and ejector prints. Norma brass doesn't have the capacity of other brass and I only use it for lighter loads to stay away from pressure problems.

 

[Huntz]

I had good luck using Ramshot Magnum with CCI LR Mag primers and 140 grain NBT`s.No problem getting 3150 out of a converted 24" 280 barrel rechambered to 280AI.Very accurate.

 

[RockyMtnMT]

We have two 280ai saami chambered rifles. One with a 22" barrel and one with 27" barrel. Both are 8" twist. We are running the 143g Hammer Hunter in both. In the 22" barrel we tried rl26, rl23, and rl16. It didn't have enough barrel to burn the rl26, stopped gaining vel at 64g. Rl16 we hit the highest vel of the 3 at 3230 fps but felt that pressure was too much. Tried the rl23 and settled on a load of 63g and a vel of 3130. COAL is at 3.48" and using Fed215M primers.

The 27" barreled rifle we tried H4350, H4831sc, and rl16. 4350 we abandoned right away. Didn't note why, I think it was a case capacity issue. H4831 we worked up to 61g and a vel of 3176 fps and ran out of case. rl16 we worked up to 58g and a vel of 3300fps. Too much pressure and backed down to 56g and a vel of 3213 fps. COAL of 3.373" and wlrm primers. We will revisit this rifle as I am pretty sure that if we run with rl26 we can get another 100fps out of it. The longer barrel should be able to take advantage of the slower powder.

To the OP: Give the 143g Hammer Hunters a go. If you don't like them I will refund your money. I am sure they will give you the vel you want and the accuracy you need.

 

[newmexkid]

We have two 280ai saami chambered rifles. One with a 22" barrel and one with 27" barrel. Both are 8" twist. We are running the 143g Hammer Hunter in both. In the 22" barrel we tried rl26, rl23, and rl16. It didn't have enough barrel to burn the rl26, stopped gaining vel at 64g. Rl16 we hit the highest vel of the 3 at 3230 fps but felt that pressure was too much. Tried the rl23 and settled on a load of 63g and a vel of 3130. COAL is at 3.48" and using Fed215M primers.

The 27" barreled rifle we tried H4350, H4831sc, and rl16. 4350 we abandoned right away. Didn't note why, I think it was a case capacity issue. H4831 we worked up to 61g and a vel of 3176 fps and ran out of case. rl16 we worked up to 58g and a vel of 3300fps. Too much pressure and backed down to 56g and a vel of 3213 fps. COAL of 3.373" and wlrm primers. We will revisit this rifle as I am pretty sure that if we run with rl26 we can get another 100fps out of it. The longer barrel should be able to take advantage of the slower powder.

To the OP: Give the 143g Hammer Hunters a go. If you don't like them I will refund your money. I am sure they will give you the vel you want and the accuracy you need.

Sounds like I got nothing to lose.

 

[.300 Dakota]

I, too, have had substandard velocity over what I expected with my custom 280 AI with 26" Criterion barrel. To put it in perspective, I have a 284 Winchester with long leade in a McGowen barrel that shoots Berger 180s at 2945 f/s. My 280 AI with the same bullets only get around 2800 and change. It also has a long leade, but maybe not quite as long as the McGowen. Accuracy outperforms the 284, however, with groups well under 1/2 MOA, while the 284 hovers right at 1/2 MOA and just above.

First of all, 4831 is one of the SLOWEST powders you can shoot. No, I don't mean slow burning. It is what I would consider moderate-slow burn rate. I mean with the velocities it generates. It is more pronounced in some cartridges than others. I don'tbthink you need Reloader 26 with 140 grain bullet. If you want SPEED, try IMR 4955. It is almost interchangeable with 4831and will produce speeds far exceeding the 4831 loads of comparable weight. Accuracy may suffer...or not. Other good alternatives I have found for more speed is Vihta Vuori N560, Norma MRP, and Alliant's 4000MR. One of these will cure your speed issue. And besides...good luck finding Reloader 26, even if you switch to 180 grain bullets where it might be beneficial.

 

[Clark]

All 3 of my 280AI rifles get the same handloads:

140 gr Accubond moly coated
Nosler 280AI brass
56.2 gr IMR-4166
3.34" OAL
3100 fps

 

[newmexkid]

Well, I just got home from the gun range. The answer for velocity was...RL 26. I loaded up 5 rounds each at 63.0-63.5-64.0.
63.0 avg.---3220 fps
63.5 avg.---3230 fps
64.0 avg.---3280 fps
No pressure signs on any of the loads.
So, today I will load up some rounds at 63.0 and see how they group. I will not be adjusting anything else until I see how they group. By the way, I shot all rounds using just a front rest. Not counting my first shot, all the rest of the rounds from the 3 loads were fired at the same target. I got one large group at 1.725" at 100 yds. I think I'm on my way, (finally). A big thanks for all the help.

 

[codym]

Where are you at NM kid? I'm in Cruces. I've been playing with a new 280AI with a 24' proof carbon barrel. Running the 175 eol at 2950 with RL23, 165 game changers at 2975 with h-1000.

ive has great luck with other 280 AI's with h4831 with the 160-168 class bullets, no issue hitting 2900 plus out of 26' tubes. If your local hit me up and I can let you try a few other combos.

 

[newmexkid]

Where are you at NM kid? I'm in Cruces. I've been playing with a new 280AI with a 24' proof carbon barrel. Running the 175 eol at 2950 with RL23, 165 game changers at 2975 with h-1000.

ive has great luck with other 280 AI's with h4831 with the 160-168 class bullets, no issue hitting 2900 plus out of 26' tubes. If your local hit me up and I can let you try a few other combos.

Well, I used to live in Rio Rancho but, currently living just outside of Richmond, VA.