How a 280 AI Compares to 7mm RSAUM

[Tatty 4578]

Have a build about happen on my new Toy F- open rifle .Was going to be chambered at 7mm RSAUM ,but spoke to my gunsmith today and suggested chambering it possibly at 280AI
Just wondering if any of you guys have had any experience with the 280 AI that you might like to share ??
How it compares to the 7mm RSAUM etc, preferences, any Loading information or performance Data etc.
Would really be appreciative input on this subject

[IanP]

I see you live in Qld and that really makes a big difference in selecting which case to go with for your project. Basically the Saum is wasted in Qld as the state has range restrictions in place that limit muzzle energy. If memory serves me correctly Qld shooters using 180gr bullets, (best choice for 7mm F-Open) are restricted to approx 2960fps.

The Saum is capable of driving the 180gr bullets to 3100+fps and some F-Open shooters in other states launch them at those velocities. The Saum is especially good for use in Long Range F-Class where the extra velocity can give a shooter a ballistic advantage.

My choice would be, (and I have the reamer waiting to be used) the 280AI as it can deliver upto 3000+fps, with the 180gr bullets and easily accommodate the Qld restricted velocity of 2960fps. At 3000+fps case life would be longer with the Saum but at 2960fps the 280AI will have long case life as well. Saum cases are expensive and sometimes hard to come by whereas the 280AI has formed Nosler cases available or if you want to fire form your own then you have a choice of cases to pick from.

The Saum is a very accurate case with the 180gr bullets but the 280AI is just as accurate but unable to deliver long case life at 3000+fps. Its your choice and both cases are excellent so you really cant go wrong with either one of them.

One point to keep in mind is that case life for the 284 Lapua brass is limited when velocities go above 2900fps, so the 280AI and the Saum offer reliable case use above the 284 brass limits.

Ian

PS JohnK any word on whats happening with the QRA negotiations for lifting the muzzle energy restriction?

[Tatty 4578]

Thank you for the information Ian,
It has had me thinking hard and long today on the subject of Caliber, case life , velocity restrictions ,etc that have been placed upon us
I was also wondering about Barrel life and throat erosion as well Ian?
I think I can remember reading somewhere ages back ,that the 280AI can be hard on Barrel life. Wondering if you may be able to shed some light on this subject as well.
Cheers,

[Matt P]

BJ
I use a 280 AI and I really like it, case life is great, pretty easy to live with and does everything a 284 does without the stress on cases, I have run mine up to about 3000 FPS but I chose to run at 2870 ish and cases live forever and is very accurate, I have shot a few 60.10's with it so it is accurate, will work with 2209, 2213 and 2217, in my current barrel I'm using 59 grn of 17 with 180 VLD's for about 2870.

Matt P

[Tatty 4578]

Thanks Matt,
It appears to be pluses all around for this caliber Matt ,It certainly sounds like it has definite advantages in a lot of areas , and capable of staying very competitive with the 284,s and Saums

[BATattack]

I've got several saum barrels on the go and it's a great caliber but brass is hard to get and it's hard on barrels.

You won't be loosing much performance going to the 280ai and you'll still be well in front of the 284s and accuracy should still be very good. Also you don't need a magnum boltface.

[macguru]

If you have a SAUM, you could load it down to the 2950 node and get great case and barrel life, and try hotter loads if that interests you. But if you switch calibers, you will need a standard boltface ... i guess it depends on what you already own and what interests you. You could get a really good load in either with great vertical, but until you test them i am not sure you can pick the best accuracy wise....

[DaveMc]

I run the Saum at 2950 with 2209 (around 56 grains depending on barrel length and powder batch etc) and it is an extremely accurate cartridge. This is mild on cases and barrel life seems very good (haven't actually burnt one out yet). Pushing it harder killed the cases but I see no need (Just as I ran the Shehane at the 2820-40 area). I would argue emphatically that the SAUM case is not wasted in Qld but rather this is one spot it really "hums". The US 1000 yard F class record was set with this load (200.15 equivalent to 120.15) and just before the worlds last year I had two barrels holding amazing 1000 yard vertical with this load and achieving almost the same sort of scores (Just the shooter holding it back ). Most of the US team settled with 4350 (2209) and between 2950-3000 fps after extensive testing. Mark Fairbairns load is basically identical (bit more powder but with Molly for same velocity)

WASTED????? W.T.??????? - Running the SAUM at this speed has proven to be one of (if not "the") best 1000 yd F class combination in the world??????
IMHO the right balance of ballistics, long range elevation and mild recoil. - plus a load proven to perform in many varying conditions around the world. (altitude, heat, cool etc). Reasonable barrel life and good case life - it is where the SAUM "LOVES" to run.

But - in saying that the 284 at 2800-2900 was also up there and the 280ai should achieve a similar result and I would be happy going down that path too... This balance of 7mm accuracy and ballistic performance with "usable" recoil has proved itself over and over.

[Brad Y]

It seems alot of people havent got the concept of accuracy trumps velocity any day. Theres no prizes for getting to the target first in this sport. Thats why not many people push their 284 and shehanes up over 2900fps. Accuracy is world class at 2750-2850 and cases last and barrels last.

Ive only seen one SAUM here and that is Bob K's. I believe he has run it fairly hot in the past. I think he has been having alot of trouble sourcing cases for it recently and he has been getting somewhere around 1000 shots before barrels are starting to let go- not 100% on that but its what Ive heard. Yes it shot well- and it was great to have it in tassie, but without new cases its a caliber that I feel is probably best left for big matches and not used for week to week shooting.

If your new to FO I would go down the path of the 280AI out of the choice of these two cals purely for the amount of rounds you will get out of the barrel and for being able to get brass. If you develop your wind reading skills it has the potential to be a very competitive combination.

[BATattack]

Hi Dave, what is your max amount of rounds you've put through a barrel so far without seeing any loss in accuracy?

[Tatty 4578]

Really enjoying and taking on board the feed back you guys are giving me on this subject , think i will definitely leaning toward building the .280AI this time this Cal sounds quite flexible and user friendly
Thanks for the input Guys appreciated.

[Rifletalks]

Has anyone tried the 280AI with 190berger from a34inch barrel?

According to quickload with n565 and 3.430 COAL 280AI from a 34inch barrel can deliver 2995 ftswith 190 berger.
Anyone tried it?

Tnks

Rod@rifletalks.com

[ben_g]

I’m going to guess no one is running the 190 near 3000fps.

I think most SAUM shooters run the 180 between 2920 and 2970fps

[GSells]

Hi , I came very close to winning Qld Queens last year with a 280 ai( needed a little
More luck lol) against another 280ai of K Hills . I believe they are a poor mans Saum ! Easy to get 30/06 brass and fire form . Actually I started a thread 280 ai blog and 280 ai cream of wheat fire forming . It loves 2213sc and fed primers , internal chamfer of the flash hole has seen ten shots SD’s below 5 , running 180’s happily from 2900-2960 FPS . It has a great low speed node which I used in Qld teams ( which helped us as a team along with the other team members get third after shooting the final 700 m . We were coming last I believe before that !) and and Qld Queens for the fabled 58.9 at 600 yds. Load is 2209 at 2780 FPS and cci primers ( can’t remember the amount haven’t shot it since Perth teams . ) I also used it last Nats for the last day to pull myself from 17 th to 14 th on the last range .
So it can be downloaded for the shorts and be extremely accurate and then beefed up to mix it with the best at the longs .
Great budget cal that punches well above its weight ! Pseco chambered mine and it’s a Lilja 9 twist .
My Saum is gathering dust at the moment! Not shooting much at this time . Building a turbo Barra instead .
Regards Graham.

[GSells]

Very accurate, forgiving, long barrel life , budget cal ! Poor Mans saum!
Forgot to add . I started doing testing of 2225 about 62 gr with 180’s and was giving me 3030 FPS and was wanting more speed ! I believe I could have pinned a reliable load into the 3100 FPS but abandoned testing when my scope broke !!