photo of Kimber barrel - re rechamber

WhelanLad

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IMG_4428barrel.jpg


That's a .270 Win Top
.308 Win Bottom.

Chambered for short action ATM, rekon it would be suitable for .284win?

WL
 
I see a 270Win (.277") beside a 308Win (.308") beside an unmarked bbl. and you want to chamber in 284Win. (.284").

I don't get it.
 
If you're asking if there's enough meat in the barrel to accommodate a .284 chamber, then I would say yes.
Yeah mate, that's what im wondering.
its a 308 Winchester chambered, Kimber Montana barrel in the picture, But the one on the Gun now (708) is what I will proberly get rechambered into the .284win , and keep this for later use.
as we discussed in the other thread, the 7mm is most accesable to re chamber to..
my worry is with the 'throat' an stuff, where the main explosion occurs an if its strong enough!?
 
I see a 270Win (.277") beside a 308Win (.308") beside an unmarked bbl. and you want to chamber in 284Win. (.284").

I don't get it.

Good observations Captain, They are comparison Examples of a Long Action Case and a Short Action Case, as you would be aware, these cases are the parent figure of many 'calibres'.

Specifically, its a Kimber Montana .308 Winchester chambered 22 inch tube.. but not the one I will be having Work done too.. shes a mock up pick for comparisions.

good night
WL
 
I would be more concerned if you were going .280

.284 should be fine as case is not much different than .308 (less than 4 MM in case length)
 
WL...........that's lots of shank for a rechamber to anything you want. That barrel has plenty of meat for even a 7mm RM or 7WSM or 28 Nosler...........not the slightest worry going to 284 Win, mate.
 
Yeah mate, that's what im wondering.
its a 308 Winchester chambered, Kimber Montana barrel in the picture, But the one on the Gun now (708) is what I will proberly get rechambered into the .284win , and keep this for later use.
as we discussed in the other thread, the 7mm is most accesable to re chamber to..
my worry is with the 'throat' an stuff, where the main explosion occurs an if its strong enough!?

You have me a little puzzled. Yes, the .284 would be fine as far as pressure goes, and length. And the .284 is a rebated rim with a fatter body, so the chamber will clean up. However, you have a .308 bore, and that is not going to work well with a .284 bullet. You have to replace the barrel to go smaller in bore. You could go to a 30-284 I guess, and you would gain about 10 grains of case capacity over the .308.

As far as putting a new barrel on, the action should be fine for any short action cartridge with the standard .473 bolt face.
 
He is rechambering a 7mm-08 barrel. The 308 is there for reference.

I missed that. If it is, then it certainly makes it doable. The .284 is a fatter cartridge at about 0.030" bigger near the rim, and 0.020" bigger at the shoulder. The feed rails will need to be relieved some to get it to feed smoothly. The other issue to think about is the required freebore and ensuring the bullets you want to shoot will fit the magazine. The .284 was designed for a short action, but it works better in a long action.
 
I don't know about the Montana, but I have never had to touch the rails on any of the dozen or so Rem 700s I have made up using a 284 case in 224, 234, 6mm or 6.5. Right now my 23-284 is on a Marlin action and I never had to touch the feed rails or follower on that action either. As stated above, the case is only .030 bigger and as far as I have found no modern action requires feed rail work.......they feed flawlessly as is. Old military 98s do for sure, but it is a 5 minute job to open the gap between the feed rails a touch with a file, and the followers have way more than .030" tolerances in the magazine......never had to touch them.
All this crap about 284s not feeding from standard actions comes from the magazines of the old 88 and 100 Wins which are not interchangeable with the 308/243 mags. They can be made to work, but are a PITA and one is better off to get the correct magazine.

Another fallacy is the LA/SA debate, the 284 was designed to be used in a 2.8" magazine action and even though one must seat the bullets to magazine constraints, it is still a far superior cartridge than the 7-08 in the same length action. How many 30-06s, 270s, 280s etc have been made on military 98s without mods to the mag length? The same applies here, but nobody even mentions this same scenario..........All cartridges designed for short action will do better in a longer action, except maybe the 22-250 and the like. However unless one must use ULD/VLD bullets for long range target work the bullet seating just isn't an issue in a hunting rifle, and yes you do get greater powder capacity with the 284 case and the attendant increase in exterior ballistics. It may not be a 7mmRM but it is a step up from the 7-08 and a significant one at that.
 
I don't know about the Montana,
All cartridges designed for short action will do better in a longer action, except maybe the 22-250 and the like. However unless one must use ULD/VLD bullets for long range target work the bullet seating just isn't an issue in a hunting rifle, and yes you do get greater powder capacity with the 284 case and the attendant increase in exterior ballistics. It may not be a 7mmRM but it is a step up from the 7-08 and a significant one at that.
Thanks for your previous comment too mate, an the above is what I am after!
 
Good post c-fbmi. I believe the M70 action, which kimber basically is, you can seat the bullets out a little longer than 2.800. There will still be plenty of powder capacity even for the heavier bullets. I would be more concerned with seating the bullets past the ogive than case capacity. I got a model 70 EW 7-08 that Im going to rebarrel to 284 win. I want to go with a 24" barrel rather than 22" to gain as much velocity as I can. The 284 win is my favourite cartridge. I will be using 140 - 150gr bullets. I wouldn't bother rechambering a standard action to 284 win, I would simply go 280 rem. The 284 is a perfect cartridge for a light weight rifle imho.
 
pete, that is good, I too want to use 140-150gr bullets , just a bit faster than I can now.

I think the magazine room should be fine for the 284 an seating depths
 
pete, that is good, I too want to use 140-150gr bullets , just a bit faster than I can now.

I think the magazine room should be fine for the 284 an seating depths
Yes it will be. I have a browning Abolt with a clip so I have to stick with 2.800 length and with 139 gr hornady, I load 57gr of h4831 no problem. For velocity RL17 is a good powder. I loaded 154 gr hornady with 54 gr of RL 17 and got 2900 fps with a 20" barrel. I have also loaded up 162 gr seated out long and feed them singly. My rifle has a lot of free bore so it allows for it. It was a tack driver with those bullets.
 
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