7mm Options in AI AT or SA AICS rifle?

[Glassaholic]

Has anyone spun up a 284 Winchester in an AT or short action with AICS no binder plate mags? Just curious what kind of speeds are realistic from the SA platform and loading within mag length for 2.95" OAL or less. I'd be looking to shoot 180 Hybrids or 184 F-Open pills so if you have experience with these heavy bullets I'd be most interested. Thanks in advance.

 

[Skunk]

Now you're talking! Been wondering this myself, though leaning more toward 6.5-284.

 

[Glassaholic]

Now you're talking! Been wondering this myself, though leaning more toward 6.5-284.

That's got to be close to a 6.5 PRC but without having to go with a magnum bolt face. Biggest question is whether or not there are seating issues (with heavy bullets) with how far forward the shoulder is on the 284 based cartridges and seating to mag length. Just hoping someone else has done it and had good results.

 

[Skunk]

Exactly.

A buddy of mine just built a 6.5SST in an American Rifle Co action (not sure which) and it's awesome. Would like to mimic that performance in a short action AX but, as you mention, without having the option of a magnum bolt face.

 

[beetroot]

I looked a lot into running a 284win in my Tikka CTR so limited to 3.000" OAL and decided it wasn't worth the effort.
It seems that you are best to run 160ish grain bullets, which unless you need the energy on target most of the heavier weight 6.5mm bullets will have a better BC and shoot very similar velocities.
I was dead set to build a 284win off my T3x CTR setup but ultimately decided I'd be better off sticking to 260/6.5CM class of cartridge.

The 284win has a fairly big fan base on the NZ Hunting Shooting forum, with guys getting impressive results from very short barrels, but it seems limiting yourself to short action and being able to use the heaviest 7mm bullets is a bridge too far.

There's few thread on the hide about the 7mm SAW cartridge, it seems like that will basically match 284win ballistics with less powder if limited to a short action.
@b6graham seems to be the man to talk to about the 7mm SAW.

 

[Glassaholic]

I looked a lot into running a 284win in my Tikka CTR so limited to 3.000" OAL and decided it wasn't worth the effort.
It seems that you are best to run 160ish grain bullets, which unless you need the energy on target most of the heavier weight 6.5mm bullets will have a better BC and shoot very similar velocities.
I was dead set to build a 284win off my T3x CTR setup but ultimately decided I'd be better off sticking to 260/6.5CM class of cartridge.

The 284win has a fairly big fan base on the NZ Hunting Shooting forum, with guys getting impressive results from very short barrels, but it seems limiting yourself to short action and being able to use the heaviest 7mm bullets is a bridge too far.

There's few thread on the hide about the 7mm SAW cartridge, it seems like that will basically match 284win ballistics with less powder if limited to a short action.
@b6graham seems to be the man to talk to about the 7mm SAW.

You're probably right beet, originally I was thinking of having trophyhunter work up a magnum bolt for the AT so I could use 7 SAUM but not sure I want to go that route just yet. This is not a hunting gun, it is a range gun so I really don't need the energy but looking for supersonic at distance and wind, when I did ballistic comparison of my existing 7 SAUM vs my buddy's 25 Creedmoor data I was shocked to see the 25 Creed with Blackjack ACE 131's staying fairly even with the SAUM out to 2000 and the 25 Creed is still supersonic past 2000 at my altitude.

As I mentioned in another thread, this is probably not the time (with all the shortages) to go investigating an entirely new cartridge, but simply stick with what works.

 

[beetroot]

You're probably right beet, originally I was thinking of having trophyhunter work up a magnum bolt for the AT so I could use 7 SAUM but not sure I want to go that route just yet. This is not a hunting gun, it is a range gun so I really don't need the energy but looking for supersonic at distance and wind, when I did ballistic comparison of my existing 7 SAUM vs my buddy's 25 Creedmoor data I was shocked to see the 25 Creed with Blackjack ACE 131's staying fairly even with the SAUM out to 2000 and the 25 Creed is still supersonic past 2000 at my altitude.

As I mentioned in another thread, this is probably not the time (with all the shortages) to go investigating an entirely new cartridge, but simply stick with what works.

I don't particularly love load development or case prep so the thought of sticking too an easy cartridge I can get Lapua brass for is what swung it for me.

The 25 Creedmore does look good on paper and if your buddy has one then atleast you know it does what it says on the tin. Unfortunately the Blackjack projectiles aren't widely available outside of the US.

I only stumbled across the 7mm SAW a few weeks ago (when again I got the 284 itch) and it does show some real promise, seems like a stupid efficient cartridge and the simple resize of 308 brass with no further prep is rather appealing.

 

[Glassaholic]

That's pretty interesting with the 7mm SAW, here's from their website:

7mm SAW barrel length and power tests – West Texas Ordnance, Inc. | Custom Rifles & Accessories

183gr Sierra MatchKing/H4350 powder, 2.978” OAL
44.5: 2670FPS
45.0: 2694FPS, primer looks great
46.0: 2751FPS, primer looks the same at 45.0
46.7: 2782FPS, max load, compression causes issues seating to 2.180”

 

[beetroot]

That's pretty interesting with the 7mm SAW, here's from their website:

7mm SAW barrel length and power tests – West Texas Ordnance, Inc. | Custom Rifles & Accessories

183gr Sierra MatchKing/H4350 powder, 2.978” OAL
44.5: 2670FPS
45.0: 2694FPS, primer looks great
46.0: 2751FPS, primer looks the same at 45.0
46.7: 2782FPS, max load, compression causes issues seating to 2.180”

Considering most 3000fps+ loads from the 284win are using RL17 (or equivalent) those are some very respectable speeds from H4350 and considerably powder.

 

[Jeremy45]

Has anyone spun up a 284 Winchester in an AT or short action with AICS no binder plate mags? Just curious what kind of speeds are realistic from the SA platform and loading within mag length for 2.95" OAL or less. I'd be looking to shoot 180 Hybrids or 184 F-Open pills so if you have experience with these heavy bullets I'd be most interested. Thanks in advance.

If you haven't read this, it may be helpful.

.284 Win Tactical Hunter

6mmBR.com is the best guide for 6mm BR Benchrest precision shooting, complete with 6BR FAQ, Reloading Data, Shooter Message Boards, Reader Polls, and Photo Gallery. Match event calendar and rifle competition accuracy training tips. Equipment reviews (.243 bullets, 30BR cartridge, 6mm Norma...

www.6mmbr.com

 

[Eostech]

People have been trying to get decent performance out of standard bolt face SA's forever.

7x47
https://www.accurateshooter.com/guns-of-week/7x47-lapua-wildcat-cartridge/

7 wssm
https://www.snipershide.com/shootin...m-switch-barrel-for-comps.179112/#post-179112

7 Creedmoor was going to be a game changer in 2012
https://www.snipershide.com/shooting/threads/7mm-creedmoor.121148/

168gr @ 2,972fps

pretending high pressure is efficiency didn't seem to catch on.

You could try a long throat and single feed the 180's with the .284, use lighter jump tolerant bullets to mag feed.
No idea how that would work.

Or 7 SAUM/SS will get you the velocity for your 180's is a SA,

 

[Heffo]

I’ve been told to steer clear of the 284 Win and that was coming from a bench rest guru Stuart Elliot. Has its issues!

 

[Simia Dei]

I’ve got two rifles chambered in 7mm SAW if you need load data.

 

[beetroot]

I’ve got two rifles chambered in 7mm SAW if you need load data.

Please share.
I've read through the SAW threads but up to date data would be appreciated.

 

[Steel head]

I’ve been told to steer clear of the 284 Win and that was coming from a bench rest guru Stuart Elliot. Has its issues!

Considering it’s popularity in f class I’m interested in it’s “issues”

 

[fdkay]

The best thing to happen to the SA 7 bore in a while in the 65staball powder.
It works very well in a standard 7-08. I got 2900 with slight pressure signs (ejector swipe) with 162 eldm and starline .308 brass necked down.
I backed off the load a little as I'm happy with 2800+ with a bc over 620.

 

[Glassaholic]

You could try a long throat and single feed the 180's with the .284, use lighter jump tolerant bullets to mag feed.

I think realistically that is the only way this cartridge would work, the case neck is simply too far forward and the longer heavy bullets have to be seated so far back that the ogive sits below the face. This was similar to some of the issues I faced with the 7 WSM and why I went to the 7 SAUM as the OAL of the case itself is shorter allowing for proper seating of longer bullets.

 

[Adam B]

I have a 7 SAUM conversion for my AI and I am very happy with it. Works great and shoot like a laser beam!

 

[Glassaholic]

The best thing to happen to the SA 7 bore in a while in the 65staball powder.

Ball powders have struggled in the past for accuracy, I'm assuming you've seen some very good results here?

 

[Glassaholic]

I have a 7 SAUM conversion for my AI and I am very happy with it. Works great and shoot like a laser beam!

Did you have trophyhunter do your bolt?

 

[Sniperwannabee]

Did you have trophyhunter do your bolt?

Yes he did

 

[Adam B]

I did and their level of service and workmanship is fantastic!

 

[Steel head]

Yes he did

When are you getting it done?

 

[fdkay]

Ball powders have struggled in the past for accuracy, I'm assuming you've seen some very good results here?

In my rifle, yes. But it is quite the laser

 

[Glassaholic]

In my rifle, yes. But it is quite the laser

I'll have to check it out, problem is where on earth to find it these days...

 

[Glassaholic]

I’ve got two rifles chambered in 7mm SAW if you need load data.

So after reading more about the 7 SAW, I'm a bit puzzled, a 7mm-08 is simply a necked down 308 is it not? This is what the 7 SAW appears to be as well, but using better brass and SRP (recommended). Am I missing something?

What bullets and accuracy nodes are you getting between your two rifles?

 

[fdkay]

I'll have to check it out, problem is where on earth to find it these days...

Forgot to add. My brass is the SRP starline

 

[Glassaholic]

I did and their level of service and workmanship is fantastic!

You make it very tempting to just pony up the $1k and go this route as I'm already loading for 7 SAUM in my other rifle...

 

[beetroot]

So after reading more about the 7 SAW, I'm a bit puzzled, a 7mm-08 is simply a necked down 308 is it not? This is what the 7 SAW appears to be as well, but using better brass and SRP (recommended). Am I missing something?

What bullets and accuracy nodes are you getting between your two rifles?

Must just be down to case shape/shoulder/etc.
Much like the 7mm08AI gives a decent performance boost the SAW is just able to do it without fire-forming.

 

[Jakerz]

So what's the different between the 7mm SAW and a 7mm-08 AI? I kinda like the 7mm idea too, might look into this!

Jake

 

[Heffo]

Considering it’s popularity in f class I’m interested in it’s “issues”

Not up on the F class game, but I think it’s a cartridge for the super experienced and very thorough handloader, to get the most out of it, or along those lines. Don’t they run a lot more improved versions now in F class?

 

[beetroot]

So what's the different between the 7mm SAW and a 7mm-08 AI? I kinda like the 7mm idea too, might look into this!

Jake

7mm08ai requires fire-forming of cases whereas the the 7mm SAW is just running 308 brass through the SAW die.

 

[beetroot]

Not up on the F class game, but I think it’s a cartridge for the super experienced and very thorough handloader, to get the most out of it, or along those lines. Don’t they run a lot more improved versions now in F class?

My mate shoots a 284win in a long action and found it super easy to load for.
Necked up 6.5-284 brass and neckturned, slapped in some RL17 and had it shooting small groups.

 

[Steel head]

My mate shoots a 284win in a long action and found it super easy to load for.
Necked up 6.5-284 brass and neckturned, slapped in some RL17 and had it shooting small groups.

^^^^This is what I generally hear.
Easy mode like 6 BR.

Not up on the F class game, but I think it’s a cartridge for the super experienced and very thorough handloader, to get the most out of it, or along those lines. Don’t they run a lot more improved versions now in F class?

Lots of shehane’s and straight 284’s and a very good reputation for both.

 

[Hondo1]

So after reading more about the 7 SAW, I'm a bit puzzled, a 7mm-08 is simply a necked down 308 is it not? This is what the 7 SAW appears to be as well, but using better brass and SRP (recommended). Am I missing something?

What bullets and accuracy nodes are you getting between your two rifles?

Think 7mm SLR

 

[Sniperwannabee]

When are you getting it done?

maybe when I get a stimulus check haha

 

[NW Valkyrie]

Dan Bertocchini won the Hornady PRC match last year shooting 284 Shehane from a short action, using Accurate Mags. Listening to the VP Precision podcast I believe he said he was getting 2800 fps from a 28" barrel with 180 Hornady's.

With Lapua announcing 284 Winchester brass in 2021 makes things even easier. (and with 6.5 PRC Lapua brass also on the way, w/ essentially identical case capacity I'm sure there will be 7/6.5 PRC barrels spun up to experiment with)

The challenge is finding a gunsmith offering prefits for 284 Winchester. I've reached out to the usual suspects and they either don't have the reamer or they have one but with a long freebore for shooting out of a long action.

If anyone knows of a source please pass along.

The 284 variants dominate F-Class. The fact Lapua is coming out with brass for it instead of relying on everyone necking up 6.5/284 to me is a good indication it's popularity will only increase.

 

[Steel head]

I always wondered why a shortened and blown out 284 wasn’t tried.
Basically a 7SS with a 308 rim.

 

[beetroot]

From left to right,
7 SAUM, 7WSM, 284W, 7-08AI, 308, 7 Creedmoor, 6.5 Creedmoor
View attachment 7516603

So the SAUM is just that much shorter to allow heavies to be seated in a SA?
Doesn't look like much in it.

What barrel life have you found 7SAUM vs 284win?

 

[Eostech]

Most of my .284W COALs with 180 grainers are well I'm excess of 3.2". I just don't see it happening in a SA

I think a mock up came out almost 3.5” for me, but that was a while ago and I can’t check it at the moment.

All you are doing is pushing the shoulder/ neck junction down to create a 300 thou long neck and a 35*(?) shoulder angle.

maybe 30 thou?
300 thou = almost 1/3 of an inch, = longest neck ever

 

[Steel head]

So the SAUM is just that much shorter to allow heavies to be seated in a SA?
Doesn't look like much in it.

What barrel life have you found 7SAUM vs 284win?

My last 7 saum barrel died just after 1900.
It shot 180’s at mag length really well.

But you'd lose your ass in diameter though, right? Wouldn't a shortened 284 just be a 7-08? I'm too lazy to measure webs and shoulders

It would easily do what 7 saw does without the pressure.
Really the gains would be minimal but it would be a fun experiment.

 

[Hondo1]

I always wondered why a shortened and blown out 284 wasn’t tried.
Basically a 7SS with a 308 rim.

I’ve pondered the same question, I hunt with a FIX and threw around the idea of shortening a .284 case to work in SR25 mags.
looks like back in the late 80’s and into the 90’s it was toyed with but nothing recent.

 

[Steel head]

I’ve pondered the same question, I hunt with a FIX and threw around the idea of shortening a .284 case to work in SR25 mags.
looks like back in the late 80’s and into the 90’s it was toyed with but nothing recent.

Yea
I remember reading about something similar years ago.
Maybe the juice wasn’t worth the squeeze.

 

[Eostech]

I always wondered why a shortened and blown out 284 wasn’t tried.
Basically a 7SS with a 308 rim.

Actually did the math for this a ages ago, can’t remember the out come but as I lost interest, probably marginal lol.

Check out posts from jedi on page two of that 7mm creedmoor thread (2012) I linked before. Some interesting stuff, mostly theory but he does have some case capacity worked out.

 

[Hondo1]

I've been thinking about doing a 7 Creedmoor for a while. For OAL reasons. But in a hunting rifle where I'm not looking for velocity

Same I started a thread about it back in 2018. Got a whole lot of opinions but no first hand information. 162’s fly great and kill very well.

 

[Hondo1]

Didn’t get that far

 

[Steel head]

I've been thinking about doing a 7 Creedmoor for a while. For OAL reasons. But in a hunting rifle where I'm not looking for velocity

I’m surprised 7CM isn’t a thing
Better concept than 7.62CM

 

[Glassaholic]

Appreciate the pictures and comments reubenski, that pretty much axes the 284 Win for me, I had a feeling it was too long of a case to seat heavies properly for SA and so many comments have confirmed this.

 

[Steel head]

Appreciate the pictures and comments reubenski, that pretty much axes the 284 Win for me, I had a feeling it was too long of a case to seat heavies properly for SA and so many comments have confirmed this.

It really would be a single feed option at best.

 

[Hondo1]

What’s the story on the short action AI mag bolt faces? Machining the existing bolt or offering a turn key solution?