284 Winchester in Short action

[xNF_9]

I plan on rebarreling my 308 and putting a 284 winchester on it. I am wondering why this round has not been taken into consideration more. I've researched it and found out R-17 pushes the 162 Amax up to 3k fps in some barrels. ( depending on length twist and what not) The Hornandy website has posted that the BC on the 162 Amax is .625 which is amazing. Especially if you can push it at 2800/2900 without maxing out on case volume. There will be a lot of felt recoil, but nothing a muzzle break cant help. (with a 15lb gun shooting these Amax's at 3k fps felt recoil is 11 lbs)

I am looking for a long range hunter/varminter/target/possibly tactical caliber. Would anyone chime in and tell me why this would be a bad choice or why not to go with it. Also does anyone have any experience with a short action with a 284 Winchester could say if some of this information is correct or wrong.

Let the flaming begin.

 

[cjgemm]

Re: 284 Winchester in Short action

Check this out.

http://www.6mmbr.com/gunweek095.html

 

[xNF_9]

Re: 284 Winchester in Short action

Already read up on that. Good read. That's where I got some of my information from. The problem is OAL with magazine fed bullets. 2.900 is about as AICS mags will let you (unless modified). Still confused on why this is a dead round since the 6.5-284 caught on fire.

 

[BobinNC]

Re: 284 Winchester in Short action

The problem is the 284 is a better LA cartridge than a SA one.

Case in point:

7mm-08 case length 2.035" Case Capacity 54 grains H20
.284 case length 2.170" Case capacity 66 grains H20

The .284 is .135" longer than a 7mm-08, and the good heavy 7mm bullets are long as well. So longish case + longish bullet, means very deep seating.....Normal SA COAL's are around 2.860" if your using standard AICS mags.

A better mouse trap if you want a hot 7mm on a short action, is Remington's 7mm SAUM

7mm SAUM case length 2.035" case capacity 74 grains.

IMHO and YMMV,

Bob

 

[xNF_9]

Re: 284 Winchester in Short action

The reason I wasn't looking at the 7mm SAUM is that requires a different bolt face and I'd like to stay with the 308 boltface. I'm not looking for a hot round just looking for a round that is in the same ball park as the 260 Rem and has more knockdown power at longer ranges for hunting that still fits in the short action.

 

[Jhnmdahl]

Re: 284 Winchester in Short action

I agree with Bob - I don't think you're going to get longer than about 2.85" or 2.86" in a short action AICS magazine, which imposes some limitation on OAL of a 284 round in a short action. Great round, though - may well be my next caliber after I tire of my .308 and need something new.

John

 

[xNF_9]

Re: 284 Winchester in Short action

So you're thinking about the same thing then. I understand that the seating length will effect the amount of powder that can be put into the casing. I don't need a barn burner of a bullet just looking for 2850 fps about closest to the node which would leave extra room in the case.

 

[Cegorach]

Re: 284 Winchester in Short action

One thing I have been considering is seeing if .284 would work in the Seekin's WSM dbm set up. It has a maximum COAL of 3.14. That is getting close to optimal with a bullet like the 162 a max.

 

[xNF_9]

Re: 284 Winchester in Short action

Well I'm stuck with the 308 aics system. Looks like if you'd put that on there you would be in a lot better shape, but would the case be wide enough to be held by the mag or would it spit it out. That would put the S/A with enough room in the case to get max compacity. Do you think that the OAL of 2.6 would get you a velocity of 2850 fps with a 162gr bullet?

 

[brand692]

Re: 284 Winchester in Short action

Besides what Bob said, another thing to consider is if the the case will even fit into a AICS mag. The should is a lot further forward on the 284. I had the same problem with my 300RUM. Although I could get a loaded round to fit into the length confinements of the 338LM AICS magazine, the shoulder on the 300RUM is further forward than the 338LM and it would not fit in the 338LM mag without removing the reinforcing rib, see below. I have a thread here somewhere about how to do it. I'll see if I can't find it too.

 

[BobinNC]

Re: 284 Winchester in Short action

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: (pink)MiST</div><div class="ubbcode-body">Well I'm stuck with the 308 aics system. Looks like if you'd put that on there you would be in a lot better shape, but would the case be wide enough to be held by the mag or would it spit it out. That would put the S/A with enough room in the case to get max compacity. Do you think that the OAL of 2.6 would get you a velocity of 2850 fps with a 162gr bullet? </div></div>

I don't see deep seating as a problem of case capacity, but rather one of the bullet seating below the ogive.

The 162 A-Max is 1.415" long with a bearing surface of 0.70"

284 case is 2.170" long, AICS mag length, allowing for 0.020" difference in seating depth leaves a max COAL of 2.860". So only 0.69" of the bullet is sticking out of the case, and 0.725" inside the case. With a neck of length of only .285", means a bunch of the bearing surface is below the neck. Not much bullet for the neck to hold on too.

And that's the problem, not case capacity. You should be able to reach 2850 FPS, but will the long bullet hold under rough conditions???


Have you considered a 7mm-08 AI. Should get around 2800-2825 FPS(or about 75 fps greater than vanilla 7mm-08).

Bob

 

[xNF_9]

Re: 284 Winchester in Short action

I see what you're saying. I looked at the 6mmbr and found this picture.

They are 283 Winchester casings in a 308 magazine. It looks like they fit perfectly. If they don't then I will have to modify the AICS magazine.

 

[xNF_9]

Re: 284 Winchester in Short action

There would make a big problem huh.

I have considered the 7-08ai, but haven't seen those velocities before. Normally they are lower then what I would expect from a 308 necked down to a 7mm bullet. I've seen that it can only shoot a 168gr bullet at 2700fps max.

 

[BobinNC]

Re: 284 Winchester in Short action

Mist,

Hodgdon data in a 7mm-08 calls for MAX load of 48 grains H4350 for 2714 FPS @ 49800 CUP. That CUP pressure is well below the SAMMI Max for the 7mm-08. Realistically, in a 24" barrel 2725 to 2750 FPS and 4350 is possible (check the reloads page) with the regular 7mm-08. Add another 75 FPS for AIing the case and your in your desired ballpark.

BTW my AICS mags measure 2.880" overall. COAL has to be shorter to feed right. Not sure where and how 6mm BR got 2.90"

Hodgdon lists 2766 FPS max with the 308 and 168 gr SMK, at only 58,800 PSI. Sammi Max on the 308 is 62,000 PSI. reaching 2800 FPS + in a 308 with a 168 is no great strain pressure wise.

Bob

 

[xNF_9]

Re: 284 Winchester in Short action

I see what you're saying. I measured my AICS case yesterday with a caliper and got 2.9 being brand new. I'm not sure if I am measuring wrong but went from metal to metal on my AICS mag.

Pushing a 308 that fast is doable from what I see. The highest BC is .495 which is a lot less then a 7mm bullet at .6+ I am looking into the caliber due to it's good BC bullets. The 7mm-08 is looking good. I'll look at the reloading pages for more information.

If you take the strip in the front of the AICS mag is bad for them. Does it create them less durable or anything?

 

[steve123]

Re: 284 Winchester in Short action

300sniper does pretty well with his 284.

The only downside I can see is you won't be able to fit 10 rounds in the AI mag which means a mag change during a timed 10 round stage at the tactical matches.

 

[xNF_9]

Re: 284 Winchester in Short action

I'll have to talk to 300sniper it looks like and that would be a disadvantage in that aspect I guess. Are these timed events?

 

[steve123]

Re: 284 Winchester in Short action

Pretty much all are timed but most of the stages are 5 rounds or less.

 

[FCS]

Re: 284 Winchester in Short action

Removing the front plate has not made my AICS mags any less robust or reliable.

I'd go 7-08 with free bore set up to put boat tail/bearing surface junction of chosen bullet right at neck/shoulder junction of case.

You'll be in the 2.950" OAL range. 2.980" OAL is possible with a modified AICS mag and notched feed ramp on 700.

Getting to your desired velocity shouldn't be an issue via 7-08 set up to seat bullet out.

 

[xNF_9]

Re: 284 Winchester in Short action

That's good that most of them are 5 rounds. Hopefully they have only one stage with 10 rounds timed.

For the AICS mag modification. Is there a lot of steps or is it hard to modify them. I'll have to search the forums for this answer probably. I know it's on here.

 

[brand692]

Re: 284 Winchester in Short action

Here it is for my 300 RUM:

Click Here

I can put you in touch with the guy who did mine.

 

[shoot4fun]

Re: 284 Winchester in Short action

The 284 really should be done on a long action to take full advantage. The 7MM08 is one of my all time favorites and I just bought a GAP so chambered. Sadly, I have been unable to wring it out due to these damn chemo treatments. My AICS mag for the 7MM08 has no front spacer so OAL can be longer. As Bob mentions, the 162 AMax can be a challenge to mag length.

 

[xNF_9]

Re: 284 Winchester in Short action

I saw these today. They are a new mag that Midway sells and they allow a 2.955 oal. Would this make it long enough for a short action?

Mags

 

[Wild_Bill]

Re: 284 Winchester in Short action

Hi use a WSM morta mag and you are good to go as the shoulders are in a similar position and then you can also load 10 plus into the mags you just have to bend the feed lips in slightly to allow the 284 case to feed well/.
Actualy the 284 is realy taking off here and people are dropping the 6.5 in favor of the 7mm original chambering so load it up to the max OAl for the Morta or accurate mags whatever is the correct WSM mags and you are good to go.

 

[xNF_9]

Re: 284 Winchester in Short action

Can I use a WSM mag for a dbm that uses 308 mags?

 

[Casey Simpson]

Re: 284 Winchester in Short action

Swap the small bolt for the larger bolt.
The barrel the action in 7mmRSAUM??

 

[TP4]

Re: 284 Winchester in Short action

I went through this same dilemma earlier this year. I went with 260AI. The 7mm build will be next, 7mm RSAUM or 284 Shehane.
Let us know how your build progresses.

 

[xNF_9]

Re: 284 Winchester in Short action

Build won't happen for a while, but once funds permit I'll be doing it. I've been informed by someone else that is getting a reamer made for 162 Amax's. He said he would post a thread on it. I'm hoping that it goes all well and this will make the perfect short action round.

I don't want a 7mm RSAUM because of the changing of bolts. I wanna stay with the 308 boltface.

 

[sniperaviator]

Re: 284 Winchester in Short action

On my AICS I bought an aftermarket magazine that allows longer OAL's (up to about 2.95"). But if you get longer than about 2.9" (don't remember exactly), it wont chamber becauese the Rem 700 action wont take it. Supposedly there is a mod to the action, but some smiths dont like it.

I think the solution is 7WSM.

 

[raptor99]

Re: 284 Winchester in Short action

I decided to build mine on a short action because thats all I had and couldn't find a good deal on a long action. I went through all the things your going through and in the end deicided to make a single shot out of it.

When you modify your action with a single shot fowler you will be amazed on how fast you can feed rounds through a single shot. I am not saying you can beat a clip fed but you can throw rounds down range pretty damn fast. My barrel is on the way here and then I will be sending it off to have it put on. Looking forward to getting it back.

I shoot a lot of 6.5s and I loved the 6.5x284s but they were just to hard on barrels. I hope this will be as good only with better barrel life.

 

[xNF_9]

Re: 284 Winchester in Short action

I've seen what people have done to the actions. It looks like all they did was drill a little space out of the action out so the tips can fit trough into the chamber. Why wouldn't the smiths like to do this? It doesn't look hard to do.