280 AI information Blog

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GSells
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Re: 280 AI information Blog

#31 Postby GSells » Fri Nov 30, 2018 10:52 pm

KHGS wrote:
GSells wrote:
KHGS wrote:
Have you heard of "detonation"??? I suggest you research it if you haven't heard about it!!!!! Oh & watch the carbon with loads on the "light" side with slow powders.
Keith H.

Thanks Keith, we are I believe no where near that . There is no smoke . But I’ll keep an eye on carbon . I saw your cleaning series on Fb !


I don't think you are near it yet either......just a word of caution is all. Detonation has never been replicated in a laboratory test & only theories as to how it happens are available to us. However it is widely accepted among ballistic experts (I am not one) that it mostly occurs with lighter loads (lower pressure) of slow burning powder, it happens without warning & is catastrophic. I would not be relying on "smoke" alone as an indicator.I have seen the results of what was most likely a detonation, not pretty to be sure!!!
From a safety prospective I am of the belief that it is better to approach a velocity goal with a powder that yields that velocity within the "normal" pressure range for the cartridge. One must always remember it is not velocity that yields accuracy it is chamber pressure that yields accuracy, velocity with the correct powder choice is only an "indicator" of the correct chamber pressure.
This is not to say that powders that would be considered not ideal for a certain caliber will not work well, but there are checks & balances that must be followed when working outside the square (& inside it too). The 7mm calibers are remarkably flexible as are ADI powders & while this is a good thing it can also lead to disaster if we forget proper practices.
As an example, I have developed a highly accurate load for my 280HI's using lighter (162 to 168 grn bullets) with AR2208 powder. I use this load for fireforming & often shoot match winning scores whilst fireforming with this load. It is much safer to use a light load of faster burning powder than to use a light load of slow burning powder. Remember no matter what powder is in use chamber pressures must be kept within the safe range or the load will be unsafe (read possibly dangerous), meaning that the pressure can be too low just as it can be too high, go out of the range & one is playing with matches in a pine forrest on a hot & windy day. Please proceed with caution!!!!
Keith H.

As per usual Kieth some good advice there . Thanks for sharing your knowledge!

mike H
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Location: JUNEE NSW

Re: 280 AI information Blog

#32 Postby mike H » Sat Dec 01, 2018 6:49 pm

GSells wrote:Sorry , but I guess my strategy for a Queens will be shoot my .284 up to 800 yds or 900 yds then switch barrels to the 280 ai for 1000 yds . Switching barrels during a comp is something I’ve been practicing.
And I still need more practicing . It did cost me a opm just recently. But you will never grow just playing it safely. So I may never when a Queens lol!
Seriously, I’ll keep practicing switching barrels , I will get it down pat !

Graham,
Every time you post I know that It will be entertaining and challenging so keep it up,if you will excuse an old have been I would suggest that you forget this barrel changing competition nonsence and have two rifles,one for the shorter ranges and one for the longs.There is,as far as I know, no prizes for speedy barrel changing and if you can change a barrel,get the scope zero perfect and then drop the next longer range shots into the middle,you are a champion,far easier to either use one rifle or two,both correctly zeroed.
Mike.

GSells
Posts: 417
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Re: 280 AI information Blog

#33 Postby GSells » Sat Dec 01, 2018 8:01 pm

mike H wrote:
GSells wrote:Sorry , but I guess my strategy for a Queens will be shoot my .284 up to 800 yds or 900 yds then switch barrels to the 280 ai for 1000 yds . Switching barrels during a comp is something I’ve been practicing.
And I still need more practicing . It did cost me a opm just recently. But you will never grow just playing it safely. So I may never when a Queens lol!
Seriously, I’ll keep practicing switching barrels , I will get it down pat !

Graham,
Every time you post I know that It will be entertaining and challenging so keep it up,if you will excuse an old have been I would suggest that you forget this barrel changing competition nonsence and have two rifles,one for the shorter ranges and one for the longs.There is,as far as I know, no prizes for speedy barrel changing and if you can change a barrel,get the scope zero perfect and then drop the next longer range shots into the middle,you are a champion,far easier to either use one rifle or two,both correctly zeroed.
Mike.

Yes it’s been a little boring on here of late lol! Thanks for the advice too! :D

Wal86
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Location: Kilmore, VIC

Re: 280 AI information Blog

#34 Postby Wal86 » Sat Dec 01, 2018 8:38 pm

Graham,

If your going to switch out barrels, just run two scopes, one sighted in for each barrel, run on a pic rail job done.. Ive done this many of times after taking down rifle to recrown barrel, put back together and had no point of impact shift what so ever...

GSells
Posts: 417
Joined: Sun Aug 13, 2017 11:04 pm

Re: 280 AI information Blog

#35 Postby GSells » Sat Dec 01, 2018 10:19 pm

Ok , I don’t know how to say at the risk of sounding like an arogant so and so !! In the flesh, I am really am a nice person lol! Being half Finnish , I guess my Viking comes out on these forums sometimes [-X . So I am flattered that fellow shooters are concerned about switching barrels and holding a perfect zero . I must say there are others up here in Qld too ( eg my Captain ) .

I’ll qualify my description of “ costing me a opm ( Northarm!) “ . Well I hadn’t competed at opm level on Au ground since last year Vic Pol and Vra Opms last year ! And hadn’t competed in F class except a little at Crowsnest and Dalby which was back in July ish! So I was rusty . The lil 7-08 was just cracking on !! And I was in contention after the 2 Nd day 500 yds .

Everyone’s jaw dropped when I said that I had to change out to 280 ai ( well the lil 7-08 ai was very capable to finish. But no guts , no glory !)
I changed out to my Lilja 280 ai . I adjusted the turrets to where I know I have a near perfect or perfect zero .
I got down and fired first shot with close elevation 3/4 moa high . Correct . Second sighter from memory was a 6 !!

One thing I didn’t do and this is just poor form from lack shooting was..... I didn’t adjust the parrelex!! Also I had no confidence in the 280 ai and it beat me mentally!! U can look up the scores , but that was 55.2 ! ???
Next 600 was better with a 58.5or 6 .
So more to do with a looong absence and poor form . But the Windage was perfect and I’ve adjusted for the elevation correction for next time .

I have one datum barrel that all the other barrels are corrected on . Under my turrets is a datum mark of the datum barrel ( Wilddog’s old Saum barrel , now .284 w) and I know the corrections from there .

I must admit, no gasbagging when this process is going on.
But it can be done , I’ve been practicing it before Bundy opm last year . And yes it’s not easy and very easy to stuff it up ! I did it at NZ Queens leadup with my .284 and 7/08 ai . Hopefully I’ll show ya at a Queens next year . You might see me CRAsH AND BURN HAHA! :lol:

But hopefully it will work out . The idea is to prolong barrel life with these fast 7’s . If I can make this Lilja .280 ai which looking at old and new plot charts seems to be in super tune ( eg general conditions, 50% x ring ) . Technically I should gain an edge in not having to start from near scratch with a new barrel . As if when ones shoots a Saum or 7 wsm from 300 yds to 1000 yds more often.

That’s the theory anyway . In practice there are many pitfalls . Fortune favours the brave ( or foolish lol) . :shock: regards Sellsy.

GSells
Posts: 417
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Re: 280 AI information Blog

#36 Postby GSells » Sun Dec 02, 2018 8:36 am

Actually just recalling, Trans Tasman and NZ Queens , barrel changing behaviour lol!
Friday practice started with 7/08 ai then changed to Bart pink bits .284 and tuned load. That change was at 900 yds .
Saturday practice and first time the team got together, was pink bits Bart .284 for the longs .

Sunday the Wellington was changed back to the 7-08 ai and changed to blue Brux barrel .284 w
Monday, Game day Tran Tasman teams . Changed back to Bart .284 pink bits zero perfect and we gave the lovely or Pesky Kiwis ( hey I still luvs ya all!) bit of a hiding with 41 points and 27 supers .
Tuesday leadup . Changed back to 7-08 ai came 3 rd in the Mids changed back to .284 blue barrel Brux

Wednesday the NZ Queens changes back to .284 Bart pink bits .
All of my rifles were on zero . It was very hard to take , I was at my best and so were the rifles and I walked away a little broken hearted, being Trenthamed pretty good at 300, 600 and 900 which pretty well did me in ! At least I didn’t get rained on during one of my ranges !! A few more Trentham Ladders instead of slippery slides ( snakes and ladders ) would have been handy! Just not my meet or time . One wanders , will it ever be! At the end of it , I was very happy to shoot at my best and really that’s all I look for !
Still hurts though! :roll:

KHGS
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Re: 280 AI information Blog

#37 Postby KHGS » Sun Dec 02, 2018 9:40 am

mike H wrote:
GSells wrote:Sorry , but I guess my strategy for a Queens will be shoot my .284 up to 800 yds or 900 yds then switch barrels to the 280 ai for 1000 yds . Switching barrels during a comp is something I’ve been practicing.
And I still need more practicing . It did cost me a opm just recently. But you will never grow just playing it safely. So I may never when a Queens lol!
Seriously, I’ll keep practicing switching barrels , I will get it down pat !

Graham,
Every time you post I know that It will be entertaining and challenging so keep it up,if you will excuse an old have been I would suggest that you forget this barrel changing competition nonsence and have two rifles,one for the shorter ranges and one for the longs.There is,as far as I know, no prizes for speedy barrel changing and if you can change a barrel,get the scope zero perfect and then drop the next longer range shots into the middle,you are a champion,far easier to either use one rifle or two,both correctly zeroed.
Mike.


Be worried, very worried about a "one gun" man..........more often than not he will know how to use it!!!!
Keith H.

ben_g
Posts: 117
Joined: Sun Apr 24, 2016 7:37 pm

Re: 280 AI information Blog

#38 Postby ben_g » Sun Dec 02, 2018 3:32 pm

I swap barrels on and off my barnard, sometimes between ranges.

I just keep good records of elevation for each barrel at the various ranges.

As for windage. I keep records of how far from the bottom of the wind turret the zero is for each barrel. No need to have a second scope and zero is always spot on. However it would be easy enough to forget to reset wind zero after a barrel change, and agree a full second rifle is a preferable option.

When I have more funds I will be having a second full rifle built, but with a young family I am on a budget and when I acquire extra funds it is usually invested in fresh barrels.

I actually changed out my Dasher barrel for a 284 just before the first range on day two of ACT queens before realising I had left the 284ammo at home!!! So had to quickly change back, idiot I know!!

GSells
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Re: 280 AI information Blog

#39 Postby GSells » Tue Dec 18, 2018 9:27 pm

Just a heads up . Don’t use 2225 ! Was good till now the barrel has run in a bit . It now has some erratic extreme spreads with the above powder . So back to 2213 sc .

Steve N
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Location: Gippsland Victoria.

Re: 280 AI information Blog

#40 Postby Steve N » Wed Dec 19, 2018 5:57 am

Graham I heard that AR2225 can have pressure "spikes" when loaded up to maximum pressure but would have thought your place were pretty moderate? Have you tried AR2217?

GSells
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Re: 280 AI information Blog

#41 Postby GSells » Wed Dec 19, 2018 8:29 am

Steve N wrote:Graham I heard that AR2225 can have pressure "spikes" when loaded up to maximum pressure but would have thought your place were pretty moderate? Have you tried AR2217?


I had the opposite, Steve . I had huge pressure drops which threw me into the 4 ring and then would be back into the 6/x ring .
2217 is a bit hard to come by where I am . I just did a quick test yesterday at home with 2213 sc .
Now the barrel is run in , I’m nearly back to my starting load at 59.8 2213 sc at 2920 FPS and and indicated sd of 6 FPS with br 2’s . More work needs to be done!
2225 did work for a while but not reliable . But I sure could get some speed out of it ! It did test well but now has fallen on itself.
9A923FB5-73E9-442A-9484-04AB61CB2C2D.jpeg

Ps , I’ll redact my statement about Saums !! I could be wrong lol!
You do not have the required permissions to view the files attached to this post.

GSells
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Re: 280 AI information Blog

#42 Postby GSells » Wed Dec 19, 2018 9:46 pm

Actually does anyone have a load for 2209 and cci br2 pushing 180’s at about 2830-2860 FPS 30” barrel
For club fire forming , that I can give a whirl at ?

KHGS
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Re: 280 AI information Blog

#43 Postby KHGS » Thu Dec 20, 2018 7:42 am

GSells wrote:Actually does anyone have a load for 2209 and cci br2 pushing 180’s at about 2830-2860 FPS 30” barrel
For club fire forming , that I can give a whirl at ?


I use a load of 2208 & 162/168 grain bullets for all my 280 HI fireforming. For 99% of the time my fireforming load will shoot well inside the 6 ring with the odd fireforming flyer. The load I use will shoot just over X ring groups in fireformed cases & I have shot numerous 15 shot double possibles in club shoots with this load. This load will deliver velocities in the 2750 fps range and is competitive to 600 yards, I have shot it to 800 yards with good groups out to that range.
Keith H.

willow
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Re: 280 AI information Blog

#44 Postby willow » Thu Dec 20, 2018 1:49 pm

GSells wrote:Actually does anyone have a load for 2209 and cci br2 pushing 180’s at about 2830-2860 FPS 30” barrel
For club fire forming , that I can give a whirl at ?


52gr of 2209 gave me good accuracy at 2815fps with single digit ES and SD.

GSells
Posts: 417
Joined: Sun Aug 13, 2017 11:04 pm

Re: 280 AI information Blog

#45 Postby GSells » Thu Dec 20, 2018 4:46 pm

willow wrote:
GSells wrote:Actually does anyone have a load for 2209 and cci br2 pushing 180’s at about 2830-2860 FPS 30” barrel
For club fire forming , that I can give a whirl at ?


52gr of 2209 gave me good accuracy at 2815fps with single digit ES and SD.

Awesome. I’ll work up to that and see how it goes . I’m trying to find a good slow load for short to mids and for fireforming etc .
No use throwing full strength loads up close !!

Thanks Willow ! I’ll let u know how I go ?
Regards and Merry Christmas Graham .


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