280 Ackley vs 7mm Rem.

[Strokerace_dave]

I was wondering if a 26" 280 ackley will have a velocity about the same as a 26" 7mm remington magnum? Can I get the pretty close the same velocity out of 168 and 180 grain bergers for long distance? or should I go with the staight 7 mag?

 

[J E Custom]

I was wondering if a 26" 280 ackley will have a velocity about the same as a 26" 7mm remington magnum? Can I get the pretty close the same velocity out of 168 and 180 grain bergers for long distance? or should I go with the staight 7 mag?

Dave.

The 7 rem mag has a 8 to 10gr advantage in powder capacity over The 280 Ackley.

For 160gr and down the ackley is very close in velocity. But with heaver bullets the
7 RM has the edge.

So depending on whitch bullet you want to use this should help.

Both cartriges are very good performers so get what you like the best.

J E CUSTOM

 

[Michael Eichele]

I prefer the 280 AI, as you get close to the same velocities as the 7mm rem but with much less recoil and better barrel life. Also it is my opinion that the 280 AI is MUCH less finicky than the 7mm rem. Better accuracy potential, better life, less recoil more than makes up for a few FPS the 7mm rem may offer.

 

[Strokerace_dave]

Thanks guys for the reply, I was just thinking about getting a 280 ackley built as soon as I found a donor action. I am glad to see that I can get very close velocities from the Ackley compared to the 7mm mag.

Another quick question, I was thinking about going with a #5 contour barrel, in comparison would the barrel be about the same thickness of say a Sendero barrel? I believe specs on the barrel say .750 at the muzzle. I was just wondering if I built it with that barrel would it be too heavy to carry around? and what twist should I go with to shoot all ranges of bullets up to the 168 gr bergers.

 

[loaders_loft]

1:9

#4 contour is getting pretty heavy unless its fluted, maybe that would help. Maybe a synthetic stock would help with weight too, but it might throw off the balance.

my 7wsm is a 26" #5 pacnor supermatch, paired with a winchester classic laminate stock. It's pretty heavy to me. Definitely an open country gun not a mountain gun.

 

[mindcrime]

One vote for the 280 Ackley w/ 1-9" twist, FWIW!!!

 

[Strokerace_dave]

The rifle will be in a h-s precision stock, fluted barrel, I am guesing maybe now a #4 contour, I wanted to build a 8 to 9 lb gun with scope? Would the #4 contour still be too heavy? I stilll want a pretty ridged rifle, and a not overly shin barrel, just a little heavier than factory contour.

 

[loaders_loft]

As I understand it, flutes are for heat dissipation and weight reduction.

Flutes actually reduce rigidity compared to the same contour without flutes.

 

[Pdvdh]

The rifle will be in a h-s precision stock, fluted barrel, I am guesing maybe now a #4 contour, I wanted to build a 8 to 9 lb gun with scope? Would the #4 contour still be too heavy? I stilll want a pretty ridged rifle, and a not overly shin barrel, just a little heavier than factory contour.

I think you're to the point where you need to talk to your gunsmith to confirm which barrel contour will result in a finished rifle that meets your weight target. A #4 contour fluted barrel might get you down to 9 lb with scope, depending on the weight of your scope, base, and rings. You'll need to identify the scope for sure, because some weigh 12 oz and some weigh 30 oz or more.

To get to 8 lb for the completed rifle, I suspect you'll need to go with a lighter #3 contour barrel.

 

[Supertrucker]

My .280 Ackley has a 4/3 Krieger 24" barrel on it in a Mcmillan Mtn rifle stock with a Leupold 3.5-10. It weighs 9 pounds. So I think you'd be around 10 pounds with a #4 and HS stock.

 

[Forrest Ebert]

My 280 AI has the Pac Nor #4 Supergrade match sts 26"fluted barrel with a HS precision stock Leu 4-14 x 40 scope and it's a DBM model and it wieghs in at 8lbs.
If you need to go faster then step up to the ultra mag. as I have never seen a 7rem.mag. shoot max. loads accurately but both the standard 280 & 280AI does and very well I must say.

gun)

 

[Pdvdh]

If you need to go faster then step up to the ultra mag. as I have never seen a 7rem.mag. shoot max. loads accurately but both the standard 280 & 280AI does and very well I must say.
gun)

I've got two factory Tikka T3 7RMs. I shot one 0.36 moa 3-shot group at 990 yds with the one using Berger 168 VLDs using 74.9 gr Hodgdon Retumbo, Federal 210 primers, @ a muzzle velocity of 3080 fps out of the 24 3/8" barrel. This is a plain-Jane stock factory Tikka. Maximum loads. This rifle will pretty consistently shoot 1/2 moa and better using this load. So it must be a stretch to say that the 7mm RM can't perform at maximum loads. Both rifles easily hold 0.75 moa or less using maximum loads & Nosler 160 gr Ballistic Tips. These are the only two 7mm RM's I've ever owned or fired.

But we've got two other members voicing some concern - and I can't say with certainty that their rule of thumb is incorrect.

 

[Michael Eichele]

I've got two factory Tikka T3 7RMs. I shot one 0.36 moa 3-shot group at 990 yds with the one using Berger 168 VLDs using 74.9 gr Hodgdon Retumbo, Federal 210 primers, @ a muzzle velocity of 3080 fps out of the 24 3/8" barrel. This is a plain-Jane stock factory Tikka. Maximum loads. This rifle will pretty consistently shoot 1/2 moa and better using this load. So it must be a stretch to say that the 7mm RM can't perform at maximum loads. Both rifles easily hold 0.75 moa or less using maximum loads & Nosler 160 gr Ballistic Tips. These are the only two 7mm RM's I've ever owned or fired.

But we've got two other members voicing some concern - and I can't say with certainty that their rule of thumb is incorrect.

It is not that the 7mm rem cant be accurate at max loads. It is however that the 7mm rem is much more finicky and unforgiving than the 280 AI. Most guys will have trouble with the 7mm rem getting phenominal accuracy due to its temperment. Again, not that shes not capable, just touchy.

The 280 AI reminds me of the 308 when it comes to accuracy and user friendlyness, just with much more punch.

 

[Pdvdh]

Yeah, that's what I figured you and Forrest were implying.

I've got a 280 AI being shipped to me today. It will be interesting to see how my load development goes with this rifle. I'm pretty fanatical about my reloading. I'll be keeping your comments in mind as I put it through the paces.

Thanks for the follow-up comments.