Thread: . 284 Winchester

School me on this cartridge. I'm considering putting a Criterion Pre fit onto my long action Sako 75. I understand you can get pretty good speed with these chopped back short? I'd be looking at cutting to 16" and running 140-150gr bullets. Anything need to be considered? Do you need to mod the magazine to get them to feed?

Check out this guys experience with a short 7mm, not a Sako I know but will help you see where you are going

https://youtu.be/Vs_neOvEiLE

No feeding issues or mods needed on my tikka, it's a fat case but not saum level fat.

Mine is at like 18. 5 inches and runs the 162 eld m at 2750 over win 760 without pushing hard. I have some rl16 coming that I think I will be able to hit 2800 with.

It's been a hammer on everything I've shot with it out to 600 odd meters.

Recoil is there but not uncomfortable, does tend to hop around when shooting from a bipod so requires good technique to spot shots.

I personally wouldn't go lighter than 150's in it, should still be able to push them over 2700 in the 16 inch barrel

excellent choice of calibre. With LA Sako you should have no issues with seating depth and mag fit. As stated above the 284 cartridge has very little taper ("fat") and this can cause feeding issues in some mags. Not sure about the Sako 75? you might have to open up the lips slightly if you find feed issues. Personally I would not go shorter than 18in as I like to retain as many fps as possible.
I'd also suggest running a bigger pill, like 160 TMK's or 162 ELDM's for everything - up close to way out there.

@GWH has a few 284s built on Tikkas and has had great success.

Originally Posted by Nick-D

No feeding issues or mods needed on my tikka, it's a fat case but not saum level fat.

Mine is at like 18. 5 inches and runs the 162 eld m at 2750 over win 760 without pushing hard. I have some rl16 coming that I think I will be able to hit 2800 with.

It's been a hammer on everything I've shot with it out to 600 odd meters.

Recoil is there but not uncomfortable, does tend to hop around when shooting from a bipod so requires good technique to spot shots.

I personally wouldn't go lighter than 150's in it, should still be able to push them over 2700 in the 16 inch barrel

I take it you are using it as a long action rather than short action (I know tikkas are only one action length)?
I'm thinking of building a 284 on a short action Tikka (to use CTR magazines) but it seems a short barrel and short action seems to limit the performance and may be better off going 7mm08.

Originally Posted by Beetroot

@GWH has a few 284s built on Tikkas and has had great success.



I take it you are using it as a long action rather than short action (I know tikkas are only one action length)?
I'm thinking of building a 284 on a short action Tikka (to use CTR magazines) but it seems a short barrel and short action seems to limit the performance and may be better off going 7mm08.

What's the internal length of the ctr mags? Throated and seated a bit deaper it will still piss all over 7mm08 velocities. Could run a la bolt stop still and open up the mags a bit?

My eldm coal is about 3.1 at 20 thou jump

Sent from my CLT-L09 using Tapatalk

https://www.youtube.com/watch?v=RuNgM6LRjgo&t=3s

check out @stagstalker

Originally Posted by Nick-D

What's the internal length of the ctr mags? Throated and seated a bit deaper it will still piss all over 7mm08 velocities. Could run a la bolt stop still and open up the mags a bit?

My eldm coal is about 3.1 at 20 thou jump

Sent from my CLT-L09 using Tapatalk

2.980" from memory, just under 3".

284 is the tits. I had a 19" one running 150gr sgks doing 2770 with a mild load of 2209 and shot deer out to 460yds. Knocked it off its feet still and bugger all recoil and noise with the dpt suppressor. When I ran the 162 eldms the gun was lethal out to 800+ but if I kept the rifle I would've kept the gameking load as it was so good.

If you are using a long action why not just rebarrel it in .280 Remington and avoid all the magazine hassles, after all, the .284 Winchester was developed to duplicate the .280 performance in a short action. I suspect that the .280 might well be a tad better than the .284 with modern powders. Of course that difference would only be of interest to deer that can read a ballistics chart!

Originally Posted by Beetroot

2.980" from memory, just under 3".

Go for it man, will still be a super usefull round, just get it throated accordingly

Originally Posted by Nick-D

Go for it man, will still be a super usefull round, just get it throated accordingly

Thats just what I wanted to hear.

I think sticking to 162gr would be the way to go rather than trying to stuff a 180gr into the short magazine.

Mine is in a Remington Short action with a 19" barrel. At the moment I shoot the 150gn Nosler ballistic tips doing 2860.

Although Nick personally would not go lighter than 150gn, I would. My favourite load was using the Berger 140gn VLD with RL 17. They were going at 3040 fps and were a bloody lethal load. I only stopped using that as I could not get hold of any more RL 17.

Originally Posted by gundoc

I suspect that the .280 might well be a tad better than the .284 with modern powders.

Recently I plugged in some numbers to see what difference QuickLOAD calculated in muzzle velocities between the .280AI and the .284Win, as I'm also thinking of making a change, from the one to the other.

The inputs kept constant were: 162gr Hornady Amax, AR2209, 24" barrel, 6mm of shank engagement with the neck, the powder weight set for a simulated 60kPSI peak in both cases.

The .280AI required 59.9gr of powder for a 2920 ft/sec MV.
The .284Win took 55.0gr for 2870 ft/sec.

Close on a 5 grain difference for 50 ft/sec then. With the simulation tweaked to shorten the barrel to 16", then the predicted velocities were 2600 ft/sec and 2580 ft/sec respectively; the difference between the two cases was predicted to have dropped to only 20 ft/sec, while overall the loss of 8 inches had knocked the MVs back by around 300 ft/sec.

If the powder is changed to AR2213sc - a powder that might be considered as having a more suitable burn rate for the case capacities and bullet weight being simulated - then with the 24" barrel, and still 60kPSI peak, the predicted velocities are both slightly more, but not by much:

The .280AI required 62.9gr for 2960 ft/sec.
The .284Win took 57.6gr for 2900 ft/sec.

The difference between them for both charge weight and predicted muzzle velocity with the slower AR2213sc powder remains much the same as with AR2209. A shortened 16" barrel then gave the predicted velocities of 2630 ft/sec and 2600 ft/sec, again the Bush Pig length of barrel cuts what little velocity advantage there was with the larger .280AI case over the .284Win in half.


Having run a number of barrels in 280AI over the years I thought the larger case would be streets ahead, but if QuickLOAD's predictions bear out, this may not be observed. At this stage I haven't cross-checked against our .284Win data.

As far as the suitability of receiver and magazine lengths, the 6mm of shank in the necks for the old Amax used in this simulation gave CoLs of 89.3mm (3.52") for the .280AI, and 79.9mm (3.15") for the .284Win. While that may well be a representative CoL for a good match to many .280AI chambers, reamers for the .284Win can often be found throated long for 180gr Bergers (intended for competition use), and the resulting CoL for bullets positioned anywhere near the rifling may be quite a bit longer than this 3.15" figure, meaning single loading for short actions.
A common second problem arises if the intention was to use lighter bullets, in that there will be no option other than huge jumps on these for the necks to have any sort of reasonable grip on the shanks. We've also had neck clearance problems - again there appears to be considerable variation between reamers, and in the neck thickness for the different sources for brass. I think it can be safely stated, and without fear of contradiction, that the .284Win is a cartridges where it pays to check the reamer for suitability for the intended application before spinning the lathe.

Interesting comps @Puffin on 284 vs 280ai - my real word experience aligns closely with the QL model data but with different powders needed to get optimal results. I did a lot of background research into 284 vs 280ai and initially went with 280ai as an “alpine tops rifle”. Partly due to higher top end potential in fps & that partly due to fact that published load data on 284 is scant and very conservative. Anyhooo 1st built a 280ai 24in bbl on REM700 action – load dev eventually ended up with N560 pushing 162 AMAX at 2980 fps. Have also built several 284’s - 2 with 20in bbls giving 2830 – 2850 fps with 160 TMK’s using RL17 or Superformance. And a 284 with 22in bbl that runs 2930 fps with RL17 pushing 162 AMAX’s.
In all cases these loads were not at pressure “max”, but at safe loads giving sub 0.5moa grps – generally a smidge under where pressure signs started showing up.
Yes, the 280ai has the edge but not by much and you really need to stay with a 24in or longer bbl to ring the max out of them, imo.
The 284 cartridge is inherently very efficient and certainly punches above its weight. If you’re after a shorter bbl 7mm for bush bashing then its ticks all the boxes, just be realistic about the drop in speed potential once you chop the bbl