Some 284Win / 7mm projectile findings

[BrettSass844]

While anxiously awaiting the end of this project (SA 284Win) I just got all my loading supplies in and decided to do a little measuring tonight. Found out some interesting info and figured I would pass it along, maybee it will be of use.
Following data is assuming 284 brass at 2.170" and a cartridge OAL of 2.950 (safe Aplha mag length just to crunch numbers). Bullets I ordered to test are the 162 Amax, 162 BTHP, 175 SMK and 168 VLD. Here are the bullet specs:
162 Amax
OAL-1.431
Ogive to tip-.696
ogive to base-.735
162 BTHP
OAL-1.424
Ogive to tip-.670
Ogive to base-.754
175 SMK
OAL-1.450
Ogive to tip-.642
Ogive to base-.808
168 VLD
OAL-1.424
Ogive to tip-.693
Ogive to base-.731

I started all this because I was curious how much case capacity I would be robbing with this on a short action and limited COAL. While I am fully aware the 284 will perform better on a LA I am still confident I will achieve good velocities. Here is lost/available case capacity data:
162 Amax
0.651" (total length of projectile in case)
-.2846" (case neck length)
=.3364" (total usable space lost)
remaining capacity until load is compressed = 1.3702"

162 BTHP
0.644" (total length of projectile in case)
-.2846" (case neck length)
=.3594" (total usable space lost)
remaining capacity until load is compressed = 1.3772"

175 SMK
0.67" (total length of projectile in case)
-.2846" (case neck length)
=.3854" (total usable space lost)
remaining capacity until load is compressed = 1.3512"

168 VLD
0.644" (total length of projectile in case)
-.2846" (case neck length)
=.3594" (total usable space lost)
remaining capacity until load is compressed = 1.3772"

I will update the thread as I begin load development and begin to get some results.

 

[turbo54]

Re: Some 284Win / 7mm projectile findings

Brett, you've got a typo for the OAL on the 162bthp. I think you meant OAL of 1.424, not 1.242...

That said, I think these SA 284s will have plenty of capacity, even with the bullets seated so deep. I can jam 59gr of H4831sc under a 168 Berger @ 2.950 COAL. Note, I have NOT fired one of these, but that much will fit, very compressed.

 

[BrettSass844]

Re: Some 284Win / 7mm projectile findings

You are right. I fixed it. It was a long day and I was half asleep typing last night. I am hopeful! Ready to get some testing done. Make sure you update me when you get around to development.

 

[wburke2010]

Re: Some 284Win / 7mm projectile findings

I am also running a 284 on a SA running alpha mags with overall at 2.95, with the 162 amax over 45 grains of powder which is slightly compressed and it is running 2700 fps.

Walter

 

[BrettSass844]

Re: Some 284Win / 7mm projectile findings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wburke2010</div><div class="ubbcode-body">I am also running a 284 on a SA running alpha mags with overall at 2.95, with the 162 amax over 45 grains of powder which is slightly compressed and it is running 2700 fps.

Walter </div></div>

That is not promising for my build. I have seen some guys getting around 3,000fps with the 162 Amax in a SA. RL17 is one of the powders that comes to mind. What are the specs of your rifle? I have a 25" barrel and have a goal of 2,950 with the 162s. I also plan to try 2000MR as I was able to get the velocity of my 175SMKs in my 308 to over 2,800 with it. What all powders have you tried or info can you share if you dont mind?

 

[turbo54]

Re: Some 284Win / 7mm projectile findings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wburke2010</div><div class="ubbcode-body">I am also running a 284 on a SA running alpha mags with overall at 2.95, with the 162 amax over 45 grains of powder which is slightly compressed and it is running 2700 fps.

Walter </div></div>

What powder are you using and what workup technique did you use? I'm very surprised by your post for a couple reasons:

1. I have yet to fire a round out of mine (will this weekend, rifle is READY!!), but have spent hours at my bench tinkering with different powders and bullets, and haven't experienced any powder yet that would be compressed at 45gr @ 2.950" COAL. These include RL17, H4350, H4831, H4831SC, 2000MR.

2. 2700fps is rather slow, even for a 7-08 with 162amax

3. If you meant 54gr instead of 45gr, it seems very slow for that heavy a charge of any powder. Again, 7-08 will achieve 2800+ with that bullet and ~43gr @ 2.850 COAL

Please elaborate!

 

[mwroseberry]

Re: Some 284Win / 7mm projectile findings

My 7-08 using the 162bthp, 47.2g H4350 and a 2.870 OAL and I get 2780. So if you're running that slow something isn't right.

Good luck,
Merritt

 

[trailrider121]

Re: Some 284Win / 7mm projectile findings

Same here with 7mm-08 24" barrel 168 Vld's with 46.6grs H4350. Runs 2740 fps.

 

[wburke2010]

Re: Some 284Win / 7mm projectile findings

Sorry for that It was a typo and supposed to be 54 grains, but I just looked at my book and I am actually running 55 Grains of H4831sc, In a Winchester case with Winchester primers. Shooting the 162 AMAX, Seated at mag length which is 2.85 OAL. Being shot out of a 26 inch ER Shaw barrel. I shot five rounds through the chrony last weekend and they were around 2740ish, The weather was around the 50's. And this is not a max load I can still go a few grains higher then I start to get a little bit of a sticky bolt lift but even at 57 grains there is only still a sticky bolt lift, but no flat primers or any other signs of over pressure. and the sticky bolt lift is hardly there.
Sorry for the typo the first time.
Walter

 

[BrettSass844]

Re: Some 284Win / 7mm projectile findings

Yea I will be dissapointed beyond belief if I cant get mid 2800s let alone 2700s. I would like to know a little more detail on his load, rifle and more. That seems way to slow. Or wrong powder selection. I have high hopes for 2000MR in the 284!

 

[wburke2010]

Re: Some 284Win / 7mm projectile findings

Forgot to add that it is a 284 and not a 7-08.

Brettsass844, I have only tried this one powder and it is run at mag length because I do not want to single feed them, also it is backed off max and I didn't try to push it or even hit max because I do not want to run near max so I can save barrel life and case wear.

Walter

 

[turbo54]

Re: Some 284Win / 7mm projectile findings

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: wburke2010</div><div class="ubbcode-body">Forgot to add that it is a 284 and not a 7-08.

Brettsass844, I have only tried this one powder and it is run at mag length because I do not want to single feed them, also it is backed off max and I didn't try to push it or even hit max because I do not want to run near max so I can save barrel life and case wear.

Walter </div></div>

Thanks for the data point Walter. Looking back over other information I've got, your info looks to be right on.

4831SC is a good powder choice for 284, at least when its on a long action, but seems to underperform in the Short Action.

If you are interested in more speed, you may wanna look into trying H4350 - the same(ish) charge weight should gain you 100-150fps.

 

[wburke2010]

Re: Some 284Win / 7mm projectile findings

Turbo54, Thanks for the info on that. As of right now I think that around 2700is fine for me and personally I don't see the benefit of pushing it any faster, But that is still noted as I'm also open to suggestion and can be proved wrong.

Walter

 

[fireguyty]

Re: Some 284Win / 7mm projectile findings

I have a custom lightweight McRee SA chassis, and a 7mm Rock #4 blank OTW. I had intended to build a SA 7 SUAM for a light weight hunting rig. However, when that little chassis showed up, it was so cool that I'm now considering a light weight backup comp gun. Was gonna go 7-08, but I'll definitely hold off to see how your SA 284 goes.

Looking forward to this.
Ty