280 AI Velocity problems!?

[Darktimber]

Hi guys. I use rl23 in my 280ai and im running 180 eld m at 2900 so would have thought 3100 with 140s would have been achievable

30" barrel?

 

[Brtrout2]

I use RL17 with 168 Berger's at 3025 have tried RL 26 also with great results

 

[Swiftkill]

There are so many factors. If you are getting extractor marks and no other pressure signs, .... believe it or not, the chamber may be TOO polished. If the case doesn't grip the chamber when the case expands it puts all the thrust on the bolt face. I had a brand new Remington 5r and my bolt lift was sticking with brand new factory ammo. All brands. My friend who was a great benchrest shooter said all his friends used to roughen up the chambers. A little steel wool on a wooden dowel. Took me 10-20 minutes. Can't even really see the difference, microscopic cross hatching. No more problem at all. See if your gunsmith is aware of this. Also, make sure your chamber is free of oil, because that will prevent gripping as well. You could just try that first, degrease the chamber with 91% alcohol on a clean chamber swab, I usually put a patch over the swab to keep it cleaner, or use a brush with a patch over it, same difference. Good luck. Let me know if that works. Also, your cases should be free of resizing oil!

 

[Priley]

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 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..

 

[Swiftkill]

Lots of opinions. !!!! The easiest thing to try is to clean your chamber free of oil and make sure your brass is clean of lube and oil. That's about as free and painless as possible. Look at #3 link below. Butch said he polishes with 240 grit sandpaper!!! That's not polishing to me! That's rough. 600 starts polishing. Shoot, I used 000 Steel wool and I was worried, but that did the trick for me. That may have cleaned the oil out of my chamber. !!! LOL.

http://forum.accurateshooter.com/threads/can-you-overpolish-a-rifle-chamber.3786859/#post-36069966

http://forum.accurateshooter.com/th...n-in-a-friend’s-6-br.2819797/#post-27161406

http://forum.accurateshooter.com/threads/chambering-and-polishing.2738350/#post-26463127

 

[CCAguns]

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 a 21" bbl and can get close to 3100fps with 4831. I believe your problem is Norma brass. Good brass, but thinner wall in my opinion. I get higher speeds with Remington brass after trying Norma brass. Also found Norma ammunition to be slower than advertised. I use RL-19 with 160gr NPs to 2900 FPS. Can't imagine you'd want to use a slower powder with a lighter bullet. Good luck!

 

[James Todd]

I have used IMR7828SSC with my 280AI with great results.

 

[JRanum]

In 2 kimbers, 24 inch barrels, 63 gr. of RL22 hit 3300 fps at 70 degrees with 140 Ballistic tips. Cold weather they're down to 3240.

 

[Lefty G-gear]

I think maybe I need to get a hold of the gunsmith. This is the 3rd rifle he's built for me and all except for this one have been great.

I could not find a .280 AI case gauge.
Found this:
https://www.brownells.com/reloading...kly-improved-instant-indicator-prod95396.aspx

Case gauge.
Put a fired case in it to see how it is.


Headspace gauges.

 

[newmexkid]

I wonder what Nosler 280AI cases would do here?

I have a 21" bbl and can get close to 3100fps with 4831. I believe your problem is Norma brass. Good brass, but thinner wall in my opinion. I get higher speeds with Remington brass after trying Norma brass. Also found Norma ammunition to be slower than advertised. I use RL-19 with 160gr NPs to 2900 FPS. Can't imagine you'd want to use a slower powder with a lighter bullet. Good luck!

 

[Bob Wright]

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 went thru 100 rounds of Factory Nosler 140 BTs before I even put a Labradar on it. You have a great barrel, but my smith and many others here have said to "just shoot it". You should see a velocity change at 100 rounds that may move you off of an accuracy node if you find one too early.
Now that your brass is fire formed and reload it at 100+ rounds you should be in a more settled place to get true data. My rifle did not shoot well with IMR 4350.
With that said, RE23 is stable and easily outran H4831 and RE17 and provided a wide flat spot in velocity towards the higher end of published data for similar cartridges. I went as far as compressed powder but no pressure signs whatsoever, using a 145 Barnes LRX, Nosler brass and CCI BR 2 primers.
Mine is a standard SAAMI chamber and longer monos are consuming powder space when seated at .050 off lands.
I'm not a ballistics expert, but I'm getting great accuracy at 3100 fps, and never hit pressure as a compressed load. Thinking it is the smaller powder volume and a smoother pressure curve of RE23?
Re23 in my 7mm RM pushes a 175 ABLR at 2920 fps and no pressure either. Brass lives a lot longer life. RE23 is very good powder and I am still a Hodgdon fan in many chamberings.

 

[Calamity]

NEWMEXKID, In your opening you said you used IMR-4831 powder, and Dmagna responded that he used H4831sc. In my experience, IMR powders are a bit hotter than Hogden powders. I think Hogden should have used a different designator for their powder, which was meant to copy the older IMR 4831 WWll military powder, which was very popular with early reloaders. Your problem-It's the powder you are using.

 

[GonzoK34]

Remove the elevation knob. This will expose the top of the turret. There is a small hole on the top. You should have received two allen wrenches with the scope. Stick the smaller wrench in the hole and back off the set screw. This will unlock the Zero Stop allowing you to adjust the elevation so you can zero the scope. THERE IS NOTHING WRONG WITH THE SCOPE.
You just learned something from an OLE Marine and 73 year old Jarhead Infantrymen 0311. Disabled Vietnam Combat Veteran.
SEMPER FIDELIS

 

[Tikka300man]

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 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