280 AI SAAMI Criterion Pre-fit 22" 1:8.5 Heavy Sporter

Orezona

Beginner
Jan 23, 2020
23
2
I believe from research that 24" is ideal. However, I'd like to have the barrel in 22" to put on my 116 WW that currently sits in a B&C Medalist with a Zeiss HD5 3-15x50.

Main bullets to be used would be 150 BT's and AB's and 160 AB's (Reloads with on hand H4831SC). Will this 22" 8.5 twist allow the benefits of the AI?

Thank you in advance.
 

Nimrod84

Handloader
Feb 20, 2017
376
2
Orezona,

To better answer your question, what benefits are you after?

When reloading the main benefits of a 280 AI are reduced bolt thrust, longer brass life and ability to fire factory 280 Rem ammo.

The 280 Rem ammo and loading manuals are rated up to 60,000 PSI; the 280 AI is rated up to about 65,000 PSI. When both the 280 Rem and 280 AI are run at the same pressure and barrel length the 280 AI is usually slightly faster (50ish fps) due to the additional case capacity.

If you only use factory ammo, a 22" 280 AI should provide some extra speed vs. a 24" 280 Rem; but it probably won't be much (50-75fps) and it really comes down to the individual barrel.

Personally, I reload and have two 280 Rems with 24" barrels that are 100-150 fps faster than my 280 AI 24" barrel using 160 grain Accubonds. My 280 AI has a slow barrel, accuracy and brass life with the 280 AI has been outstanding so I'm very happy to live with a slow barrel.

I think a 8.5 twist will work just fine but I personally tend to like the 280's in a 9 twist. Historically a number of barrel manufacturer's have loose twist rate requirements, + or - 0.25 of advertised twist rate and I like to be within 8.5-9.5.
 

Orezona

Beginner
Jan 23, 2020
23
2
Nimrod, thank you for your knowledge. I'm hoping that a hand lapped Criterion match barrel won't be "slow." I have read about slow barrels but they were mainly factory Tikka rifles. I really have no idea why I'm bent on the 280 AI other than just because I can. I reload and am set up for it. I'm down to weight and length. The barrel will definitely be a Criterion pre-fit from NSS. Pure hunting rifle is what I am in for.
 

6.5_sWv

Beginner
Mar 5, 2019
145
63
Orezona,

I completely understand your point you made about being bent on a 280AI. I just recently picked up a Kimber 84 in 280AI. I didn't really have a good reason as to why I wanted one other than I just wanted one. I bought mine for strictly a hunting gun. Mine has a 24" barrel on it and every gun I had previously had a 22, but so far the 24inch has handled very well.

If I were in your shoes, Id just go ahead and get the 24'' just to have the possibility for more velocity.

If your buying virgin brass, save yourself the money and just buy the Hornady. Its just as good as the Nosler and less money. That being said, if you plan on fireforming brass, then buy whatever brand you like.
 

Orezona

Beginner
Jan 23, 2020
23
2
6.5_sWv,

I have the 280 AI bug for sure. I think if I go 24", it will be the sporter taper vs the heavy sporter. The difference in the Criterion barrel weight between the two is 2.95 lbs and 3.34 lbs.

I already have Nosler prepped brass (new), powder, dies, primers and bullets.
 

SJB358

Ballistician
Dec 24, 2006
31,355
656
I’ll throw a similar opinion as Nimrod, my idea Of a handy and somewhat rifle in an 06, 280, 270 is a 22” barrel. The velocity difference will be negligible with a great barrel like the Criterion you mentioned. I’m also a fan of more twist than others like such as 8 twists for the 7mm. With good bullets like you mentioned using there is no downside to RPMs and only more beneficial terminal effects of the increased RPMs on animals. As for taper, I like to keep them as light as possible if they are hunting rifles which will be carried more than packed by a horse or set in a scabbard on a pack. To me, there isn’t enough difference between the 280 and Ackley to mess with but if you like it, then that’s reason enough.

I’d weigh out all of your components to include optics and see what the total weight would be and that may assist you with picking a barrel contour as well.

Sounds like a sweet rifle. Great luck to you with the assembly.
 

Orezona

Beginner
Jan 23, 2020
23
2
Thank you SJB.

Are you guys good with my choice of H4831SC in both the 22" and 24"? I think I read some information on a guy getting good accurate speeds in a 22" with RL-22(?).
 

Orezona

Beginner
Jan 23, 2020
23
2
Keith1369,

Thank you sir for the information. What are your applications for your rifle?
 

SJB358

Ballistician
Dec 24, 2006
31,355
656
That’s all my brother uses in his 280 Ackley. He’s using a 150 Swift and knocking down about 3050 with his rifle. H4831 isn’t the fastest but it is consistent from low to high and is usually available. Makes it a pretty good choice in my opinion.
 

Keith1369

Beginner
Dec 20, 2019
15
3
Orezona":2yrhx8kj said:
Keith1369,

Thank you sir for the information. What are your applications for your rifle?


I shoot mostly 160 grain Partitions for hunting and 162 SSTs for off season just shooting at rocks.

Some time ago, maybe in October or so Dr Mike did a quick load work up for the 280 that was very interesting. There is very good information on that post.
Regards
Semper Fi
 

Nimrod84

Handloader
Feb 20, 2017
376
2
Orezona,

With you reloading, I won't hesitate to recommend the 280 AI and Criterion barrels are good to go in my book. 6.5_sWv and SJB358 give good insight and advice. At the end of the day, you should have a fine rifle that will hunt anything NA.

The 280 AI is my favorite cartridge to load for and a 22" or 24" works just fine as long as appropriate powders for the barrel length are used and you aren't trying to run heavy for caliber bullets (over 175 grains) at extended range (900yds+). I suspect that most of the guys running 26" barrels shoot heavy for caliber bullets at long to extended range. For the 150-160 grain bullets handiness would trump an extra 50-75 fps in my book.

My main point with the slow barrel, was to note that the 280 Rem and 280 AI can have a lot of overlap in velocity. My 280 AI is a Kimber 84L classic with a 24" barrel and I shoot it the most as I get good brass life without having to anneal. Personal best - was with the Kimber 280 AI using 160 grain Accubonds over H4831sc, CCI BR-2 and un-annealed Hornady AI brass with 5 or 6 firings at around 2700 fps - is three out of five rounds on a 3" plate at 500 yards. Last two rounds went about 1" and 2" off of the right side of the plate, I've been assuming due to a missed wind change. My point is that if you aren't going out past 600-700 yards routinely, a normal speed 22" AI barrel should get you their with velocity to spare on the 160's.

Specifically addressing your H4831 question - it is very good with the 160 grain bullets in my opinion. I have not tried it with anything lighter than the 160 grain AccuBond load noted above. I like to have two distinct loads for every rifle, that way if a powder, primer or bullet isn't available I have a known good load that is independent of the missing component.

In the 280's I tend to run, IMR4831, H4831sc and RL-22 for the 150-175 grain bullets. I've found that I get good results with IMR4831 with the 150 class bullets while H4831sc and RL-22 get used with the 160 and heavier bullets. IMR4831 and RL-22 tend to be temperature sensitive in my rifles so I favor H4831sc for my all-purpose 160 grain AccuBond loads. A couple of guys like Keith1369 run IMR7828 to good affect along with Norma MRP.
 

Orezona

Beginner
Jan 23, 2020
23
2
All great information. Thank you to everyone for taking the time to help me out.
 
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