7mm 08 AI Questions

WhelanLad

WhelanLad

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I was thinking , seeing as I have a 308win barrel for that Kimber montana of mine, an how much I love the 7mm 08 cartridge, an the 84m itself, how it would be a bit of a unique thing to have it Ackley Improved in the future for a Birthday or some reason.. :D when funds allow.

I was also thinking of the complications with Dies.. however I thought Fireforming Factory ammo would work.. worst case low level reloads as 7mm08..
an then I thought I would be able to get away with the 7mm 08 LEE Collet Neck sizer die.. is that correct? same as I do now.

the problem I do see is once the cases are in need off a FLS, ill be at a Cross road -
- Find / Buy 7mm08 Body die?
- Pull the top end out of a 7m08 FLS die?

at the moment I have done the Federal brass about 3-5 times some more and only Trimming and Neck sizing in that Kimber chamber ive not needed to do any more to have them cycle freely, the odd one with bit of resistance to close.... So if I could get the same result with 708ai I'd be laughing However I don't think I would, as the chamber is tight I don't think the pressure from a min book load is stressing the brass much..


just thinking out aloud here, do come round an throw a log on the fire , im all ears

WL


Edit- they actually make 708ai dies..
 
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posted by J E custom on l.r.h

I am a big fan of the 7/08 and feel it is in a leage of it's on. So when I started thinking of more
I went to the 7/08x40 (AI) and was disappointed with the amount of performance increase.

With the 140s the AI would only best the 7/08 buy 75 ft/sec and the 120 loads were only
30 to 50 ft/sec morethan the 7/08 ( The varget load with the 120gr NBT of 45.o grs achieves
3150 ft/sec average velocity in the 7/08.

I'm not knocking the 7/08x40(AI) but it was a lot of trouble to get dies and then to fire form
brass.

So I re chambered the rifle In 7mm WSM and it did what I wanted 3300+ ft/sec with a 140 gr
Accubond in the 23" barrel.

If you are planning a new build in 7mm and a short action this is what I would recommend and
you could keep the 7/08 and even Elk Hunt with the 7mm WSM and 160+gr bullets @ 3000
ft/sec .

You would have to open a standard bolt face up if that's what you have for a don-er but that's
no biggie.

And if I haven't talked you out of a 7/08x40 I have 100rds of fire formed once fired brass and a
set of dies for sale for it.

J E CUSTOM
 
I personally have not seen why to AI much of anything when like stated above if you want increases it may be time for a different chambering all together , I too am a big fan of the 7/08 and I can get it to do anything I need in a standard form.

Not much in way of performances increases for the hassle IMO.
 
Less trimming with ai's apparently. That in it self is almost worth it. I am getting 2900 with 139's so bump that up could probably get 3k with 139's nothing wrong with that.
 
WL..........7-08 AI ...........what about a 284 Win, ever thought of it? A truly useful and efficient 7mm cartridge and no messing around with fireforming and dies and the like.
 
cfmbi - do you know if that's still a standard bolt face?
would the 708 Kimber tube have enough meat left of in to have the Chamber cut a but more? or is it a total new barrel job?

ps- magazine length no good in kim for the 284!


other idea is to get funky with the 308 barrel... 308 ai :D be like a 3006 then!

nah I duno, pipe dream maybe not worth it all round..

I rekon if I do anything it will be to AI the 708, cool looking little deer smacker!!
 
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The .284 is a rebated rim design, standard bolt face with a fat body. My Nosler manual lists the c.o.l. as 2.8", the same as the 7-08, so I don't see why it wouldn't work in the Kimber. You might have to play with the feed rails to get it to function properly, but otherwise it would be just a simple rechambering job.
 
If you want something unique that gives at most 50 fps more at equal pressures and requires special dies and fireforming then 7mm-08 might be the ticket.
 
I think all you are getting out of a whole lot of pain is a poor man's 284 Winchester. The 284 Win has more reasonable case capacity (66 grains) for a 7 mm, but not gross like all the 7mm magnums. It is off the shelf, at least for a handloader...

ballard284x330.png
 
I have built many rifles on the 284 case and never once had to make any changes to get feeding properly. If it feeds a 308 family case it'll feed the 284 just ducky..............The case is also not so big that you need to worry about your barrel having enough meat on it, it's not a 7 WSM and as stated above the SAAMI COAL is the same as the 7-08. Not sure on your hesitancy, you want more than a 7-08 and you don't want to go to the WSM in a short action rifle................voila...284 Win to the rescue !!
 
I run a 7-08 Ackley. No real need for fancy dies as you can do quite well with standard dies. However, after fire forming you can use a Redding Ackley body die for bumping. If not run a FL die in so that you can just chamber easily and then fire form again (only needed when chambering gets harder after 4 firings or so). Other than that the lee collet works great with a thin washer as a spacer to engage the collet when sizing.

When fire forming you could use the false shoulder method (see 6mmbr site) if the chambering is a touch long. This will help reduce case stretch. After 4 firings you may want to anneal the brass as case hardening will make bumping and chambering harder.

As with others comments expect up to a 100 fps gain with the AI. Not much that a critter will notice.

Elky....
 
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I had a 7-08AI for a while, and shot two or three animals with it. It is not enough different from the standard 7-08 to really be worth doing.
My 7x57 made very similar velocities with the same weight bullets.
As c-fbmi suggested, the 284 would make a good step up if you wanted to go that route, and less hassels than the AI route.
Also, when the time comes to sell it, the standard chambering appeals to a broader purchase group than do the wildcats.

I do own a couple of AI chamberings, but while the 6.5x55AI is worthwhile, the 260AI I feel is probably not. Also owned a 30 Gibbs
for a while. The case forming becomes an issue with that one.

A properly cut AI chamber does NOT require any false shoulder to form brass, since it will be cut so as to give a slight crush as you
chamber the parent cartridge.

Regards, Dave.
 
Right,
I don't rekon I would go with the effort V performance point, just isn't worth it.

im goin to read up on that 284 Win, as it is a decent increase in 'Power' and I can use the Same Tube and use the Same Bolt face?? is that all correct?

its a fine point regarding the Re sale value of Wildcat V a available factory round, I don't plan on selling the rifle though and by the time im an older fulla it will wear a 308 barrel .. I have a spare*

284 Win in a Kimber Montana does sound pretty mint!

WL
 
This fall I used the 7-08 X-bolt for deer with 150gr Nos Part and it worked just fine. Although SPEED seems to be what most shooters strive for, in 99% of cases it's not needed. With the 150gr at OH say 300mtrs you hold at just below the top of the back on deer and it will put meat on the table. The money spent to go to ACKLEY version will buy you a 7WSM or 280.
enjoy.
 
im re thinking the .284 Winchester at the moment, not the AI now.

You see im hunting quite high country a lot with this Kimber on back pack hunts and such, im noticing a lot of the shot oppertunitys are from the fatter side of 200m out to 400m , further if you wish, but big valleys and crevises can really limit in how close you can get without being on their face and that can seem 'thick' , whereas it seems open from the other side...

its always pretty windy up there too, so even though shooting across a gulley, the wind thru it may be fairly 'hooking' , so I am thinking having higher velocity with a better 150 grain bullet would be more suited.

I have had a bad run of two good Deer where I stuffed up the shot, one a Ranking shot which must of been off , drew blood but even on some back up shots on the run we weren't able to hit / find the deer..
the latest was a surprise , in the moment shot on a Stag what had spooked an ran directly away, as it slowed an turned to the left I thought i'd put on right in the boiler room just behind the shouilder... I followed up after I thought it stumbled... but I had givin it too much lead and most likely 'pulled' the shot with the lightweight rifle off hand..
but no blood on running marks for almost 200m had me doubting my shots with adrenaline (as I was on the minibike for ease of travel to base camp).
the stumble was litteraly him dislodgin a rock from the earth as he made a dash..


Not that this has much to do with the Calibre / Cartridge .... its just the Deer come out of the thick into the opens, I think the 7m08 can be a bit slow of a killer, lacking hydrolic shock on the big Sambar stags, meaning they are likely to Run a distance - maybe up too 200m well hit-
so I am thinking along the lines of 2 holes for insurance.....

2800fps with a pretty stout 150gr sounds pretty good for longer-thru- wind shots and putting decent smack down on the deer..

hhhhmmmm.

I wonder if the Twist rate from 708 suits the 284 however!!
 
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