Forbes 280AI Load Development

Hi all,

Have a bit of time on my hands at moment so thought I'd put this up for a) those who are interested and b) for those who might have any ideas to offer etc.

As above, I've got a new Forbes in 280AI with a VX6 on top & a mate & I are working up some loads for it - ok, he is working up loads for it. Cheers Phil.

I'm taking a gamble on the new (& unproven?) ELD-Xs having good terminal performance. ADI2217 gave the highest velocity on their website so we started with that.

57 Grains
Attachment 61600

58.0 Grains - sorry not sure what happened to this target but the velocities were 2704, 2645, 2666.

58.5 Grains
Attachment 61601

59 Grains
Attachment 61602

59.5 Grains
Attachment 61603

60 Grains
Attachment 61604

60.5 Grains
Attachment 61605

61 Grains
Attachment 61606

So, 61 Grains is looking like the clear winner ;). Next trip is to shoot two 3 shot groups of 61grains to validate it - these are the top two groups on the next target.

Also, of interest is ADI2225 which Phil uses in his 7mmRM which gives him around 3050fps with the 162ELD-x. We were a bit surprised to see the 280AI 250fps behind the 7mmRM so were interested to see what 2225 would deliver. So, we loaded 1 round at each increment with 2225 to test for pressure & velocity. Not sure which shots are what powder charge.

Attachment 61607


So, 61grain looks like it'll do the job at around 2800fps BUT 2225 looks like it'll deliver higher velocities. Our next step is to load up groups of 63.5g, 64g & 64.5g of 2225 & see what happens. It's fair to say this is a full case.

Will post those results when they're in.

Reflections so far....
- The Forbes is a shooter. The Timney trigger is awesome.
- Seems to shoot most combinations well. Might be less fussy than other rifles.
- Interesting to see that the 2225 ladder shot so tightly given the varying powder charges.
- Recoil is lively but noticeably less than Phils 7mmRM Sako Finlite which weighs nearly 1kg more. We were surprised by this.
- The barrel is probably still wearing in & settling down so things may tighten up further yet.

Cheers all. Hope this is useful to someone. Anyone else fiddling with a Forbes &/or a 280AI?

Whats the length of barrel mate, seems pretty slow. Mates 280AI could run the 162 Amax at over 2900 no problem with a 24" barrel. Think he was up closer to 3k at one point, but 2900 gave better accuracy.

He wasnt using either of those powders tho.

Yeh I'd agree as I had a Kimber and had the 150 AB at 3150 and the 162 up to 2960-2990. No pressure but plenty of boot and some of the powders I was using were too temperate sensitive and on one day would be 40 fps slower and the next the same but faster so I settled with ADI 2217.


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What's the rifle weigh ready to roll with the VX6 on it?

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Originally Posted by GWH

Whats the length of barrel mate, seems pretty slow. Mates 280AI could run the 162 Amax at over 2900 no problem with a 24" barrel. Think he was up closer to 3k at one point, but 2900 gave better accuracy.

He wasnt using either of those powders tho.

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Its got a 24" barrel too. I agree that 2800 does seem slow & that I was hoping to get around 2900.

Any idea what powder your mate was using? I'm going to stick with ADI because of availability.

I'll ask him

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Quote:

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Originally Posted by Danny

Yeh I'd agree as I had a Kimber and had the 150 AB at 3150 and the 162 up to 2960-2990. No pressure but plenty of boot and some of the powders I was using were too temperate sensitive and on one day would be 40 fps slower and the next the same but faster so I settled with ADI 2217.


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That's some impressive speeds. I hear what you're saying about temp stability - thats the other reason I'm keen to stick with ADI as they seem more consistent. Do you mind sharing what load of 2217 you settled on & what velocity you were getting?

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Originally Posted by Ryan_Songhurst

What's the rifle weigh ready to roll with the VX6 on it?

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Cant answer at the moment as Phils got it. But from memory its around 3.1-3.2kg with the 3-18x44.

N560 is best for speed and accuracy in 280
2900 easily achievable in a standard 280 with 24 inch barrel and 59 gns

@Feebz I'd have to have a look around for details but I know it wasn't pushed into the high 2900's but more 2920 but it was a hell of a lot better for availability, consistency and my safety [emoji57]
Can you put up a photo of the Forbes? An interesting proposition but I'd like one in a younger calibre.


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Quote:

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Originally Posted by Echo

N560 is best for speed and accuracy in 280
2900 easily achievable in a standard 280 with 24 inch barrel and 59 gns

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Thanks for that. I've done some googling and it appears you're quite right. I'll try & get my hands on some. Cheers

Quote:

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Originally Posted by Danny

@Feebz I'd have to have a look around for details but I know it wasn't pushed into the high 2900's but more 2920 but it was a hell of a lot better for availability, consistency and my safety [emoji57]
Can you put up a photo of the Forbes? An interesting proposition but I'd like one in a younger calibre.


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Thanks for having a look. We've loaded up some higher charges of 2217 so we'll see if it'll get us to 2900 (safely).

The proposition was a lightweight rifle for multi-day trips that sits just under magnum capability that could be (somewhat comfortably) shot without a suppressor or brake. You wouldn't want a scope that is any larger - I might look at taking my 2-12 off another rifle (if i find a cheaper substitute to put on that).

Attachment 61912

Nice rifle, a perfect setup.


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So, 2225 isn't a goer. The 63g group was poor & then it showed pressure at 63.5g.

As mentioned, we'll explore higher loads of 2217 & look into n560.

Quote:

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Originally Posted by Feebz

Its got a 24" barrel too. I agree that 2800 does seem slow & that I was hoping to get around 2900.

Any idea what powder your mate was using? I'm going to stick with ADI because of availability.

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59gr of 2213sc for 2900 from 24" 280AI, near max so work up

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Originally Posted by GWH

59gr of 2213sc for 2900 from 24" 280AI, near max so work up

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Well over adi book max?

This isn't a 162 load but I finally sorted a load yesterday for mine with 150LRABs which are pretty slippery for their weight.

Despite what the ADI and Nosler load data suggest, I could get good vels and good accuracy with 2209. Although well above book max, vel is 3130 average (27" bbl) with no base expansion measurable at 1/2gr above what I settled on so that'll do me. No point wringing its neck any further.

I would suggest that if intending to load the 162gr for 60kPSI peak or over - as seems to be the practice in the endless quest to equal 7mmRM performance - then 2213sc may be the limit for burn rate as the case is not large enough for the slower ADI powders to generate this figure. N560 has also produced top velocities for me, followed by Re-22, but I wouldn't be dogmatic with any claim about best accuracy and in the 280AI prefer the ADI single-base powders in this regard along with the added benefit of better temperature stability.

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Originally Posted by Puffin

I would suggest that if intending to load the 162gr for 60kPSI peak or over - as seems to be the practice in the endless quest to equal 7mmRM performance - then 2213sc may be the limit for burn rate as the case is not large enough for the slower ADI powders to generate this figure. N560 has also produced top velocities for me, followed by Re-22, but I wouldn't be dogmatic with any claim about best accuracy and in the 280AI prefer the ADI single-base powders in this regard along with the added benefit of better temperature stability.

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Useful comment Puffin. I currnetly jam about as much 2217 in my 7x64 as will fit, but still a pretty moderate load. About to start playing with some bulk 4831 I acquired, to look for a little more speed.

I do wonder though, if people want 7mmRM performance it's probably safer to just start with one. I don't understand the fascination in trying to make cartridges something they're not. I wouldn't want to stand in front of my "slow" load (and it shoots better than I do)!

That's true, a .280AI will never truly reach 7RM performance even if you wring its neck.

Equally, no point buying a 300 WSM and loading it like a weak .308 as does one guy I know. "It boots too much if you don't back it off.."

Further to the previous post and some more info specifically for @Feebz' Forbes in case he is interested, putting his results into QuickLoad along with the other powders being mentioned. This identifies that the slower powders do produce more velocity at a fixed moderate peak pressure which may be what the book data was indicating. Predicted for 50kPSI peak:

2225, 66.5gr, 2850 ft/sec, 10% compressed (if achievable)
2217, 61gr, 2800 ft/sec, 2% compressed
2213sc, 58gr, 2725 ft/sec, 95% fill

If loading for 60kPSI peak then the following is predicted, the double-based N560 also included:

2217, 64gr, 2950 ft/sec, 7% compressed (if achievable)
2213sc, 61.5gr 2900 ft/sec, 1% compressed
N560, 62.5gr 2980 ft/sec 1% compressed

So if wanting to try for more velocity than the 61gr of 2217, then 2213sc, N560, or similar burn rate powders are recommended, bearing in mind that the above figures are from a simulation and come with no guarantees. If preferring to stay with 2217 and happy to work with heavily compressed loads and accuracy remains, then the prediction is that there is still quite a bit of room to move.

Thanks guys. I appreciate it all, even though I don't understand it all. Though the last paragraph seems to sum it all up & gives me something to move forward with. Thanks Quickload owners (esp @Puffin ) for sharing the paid-for info.

Definitely not trying for 7RM performance, just trying for higher 280AI performance.

I've used RL22 & 162 AMAX with really great results in my 280AI 24 in Truflite UM barrel. Up to 2950 fps before hitting pressure signs. But the accuracy sweet point (0.3 moa) was back at a more modest 2850 fps - still plenty for 800 yds which is what I built it for. Beyond that you really need to go to a magnum.

Hi Feebz,

Good post mate, and some really good info to read. Have a 280 AI as well. Was a Tikka 708 so barrel is 22". From memory running 55.5gr of 2209 on 150gr LRAB. This was 1gn over book max. Gives about 2835fps. Has claimed one victim at about 325yds and was good clean boom flop! Have some heavier projectiles and 2213sc loaded up to have a go with. Once have had time to do this will report back.

Cheers,

Hi All,

Just an add/ressurection of this post by Feebz. Finally got some 168gr LRAB's down range. 58.7gr 2213sc and gave 2750fps for sub moa.(note 1gn over book max).This on 22" barrel, 1:9.5 twist. Will do some verification in the next while.

Cheers

N560 in this Forbes with 162gn ELDMs:

59.0gn=2787fps
60.0gn=2955fps
61.0gn=3019fps
61.5gn=3051fps
62.0gn=3061fps
62.5gn=3099fps (hard extraction)

Cluster is 61.5, 62, 62.5 top to bottom. Water capacity is 75.3gn, OAL 3.333". Calibrating with QL I the last 2 twp are definitely over pressure. 61gn didn't group spectacularly (1") so will try 60.5gn and 61.5gn. Also 60.5gn in 168gnVLDs.https://uploads.tapatalk-cdn.com/201...c388360ad8.jpghttps://uploads.tapatalk-cdn.com/201...c0f71323fe.jpghttps://uploads.tapatalk-cdn.com/201...6ebd06389b.jpghttps://uploads.tapatalk-cdn.com/201...a5d67ccc6a.jpg

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Impressive velocities. Nice to see it's in good hands.

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Originally Posted by Feebz

Impressive velocities. Nice to see it's in good hands.

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N560 does well... not sure how temp stable it is...which is where ADI powders are good. Just carried this thread on to build on your good posts.

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Group is around 0.25MOA. Very cold morning. Easy bolt lift and sticky extraction...even with milder loads. Brass might be past use by? https://uploads.tapatalk-cdn.com/201...51acbb460a.jpghttps://uploads.tapatalk-cdn.com/201...7e0fdd1549.jpg

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Haven't played with mine for awhile, settled on R22 with 150grn swift's around the 3100fps.

160gn TMK 3050fps 61.5gn N560.https://uploads.tapatalk-cdn.com/201...5e3b948db5.jpg

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Looks decent mate and looks like the low talleys worked well?

I had a few sticky extractions on hotter loads, may have been the brass but I borrowed a small base die and it seemed to solve problem

Hey Jock...yep just fits. Will looks into that die, not familiar with those.https://uploads.tapatalk-cdn.com/201...8b5293d7cb.jpg

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A-Tec Forward 45 QD suppressor added. 61gn RE26 and 162gn ELDM.


https://uploads.tapatalk-cdn.com/202...c65cee13aa.jpghttps://uploads.tapatalk-cdn.com/202...3ac8472bf5.jpghttps://uploads.tapatalk-cdn.com/202...a4fe65d6de.jpg

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@Tikka7mm08 what length barrel? Have just bought 162 eldms and n560

24" - N560 is good but RE26 is more temp stable. First 2 shots are the right, third went left. Around 0.3MOA.

Quote:

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Originally Posted by GWH

Whats the length of barrel mate, seems pretty slow. Mates 280AI could run the 162 Amax at over 2900 no problem with a 24" barrel. Think he was up closer to 3k at one point, but 2900 gave better accuracy.

He wasnt using either of those powders tho.

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Been using Reloder 23 in my Kimber Hunter .280 AI (24 inch barrel) with 160gr Sierra TMK's and 58.5 grs gets me to 2958fps without pressure signs and consistent 3/4 MOA. Just got rifle back from Gunsmith who bedded / threaded so be interesting to see if it shoots any tighter. Also have 2kg of N560 to try as well.