280 AI FT +P vs 7mm PRC

[Paladin300]

So I am have a Terminus Zeus switch barrel rifle built. So I don't have to change the bolt I went 22-250 AI fast twist, 308, and 280 AI fast twist with some free bore so I can load the bullets out and push the heavies. The 22-250 and 280 have 27" barrels. The 308 is 20". Tell me why I should consider a 7mm PRC over the 280 AI FT +P. The negative for me is brass and a $400+ bolt change. What does the 7 PRC give you the 280 in the above configuration won't? Just a curiosity at this point?

 

[Jud96]

They're going to be very close to each other performance wise. If you're already setup for the 280 AI then I'd just stick with that. The $400 for a bolt will buy you a lot of brass and components for the 280 AI. If you were starting out fresh, I'd vote 7PRC because support for that cartridge is going to be awesome just like it is for the other PRCs and the Creedmoors. There will be lots of brass available for the PRC by the end of the year and it will have long term support. But in your case, I'd just buy 200-300 more pieces of 280 Ackley and settle in with that cartridge and continue on with what you're doing.

 

[dogz]

what the heck is a 280 AI FT +P.............?

 

[Paladin300]

what the heck is a 280 AI FT +P.............?

280 AI fast twist 1/7 with free bore

 

[Paladin300]

what the heck is a 280 AI FT +P.............?

280 Ackley Improved fast twist with .25 of free bore. 195 Berger @ 2900, 175 ABLR @ 3000 - 3050 fps. Coal is 3.30 - 3.75.

 

[dogz]

280 Ai gotcha thx

 

[Paladin300]

what the heck is a 280 AI FT +P.............?

The free bore allows you to load more powder with less pressure but you have to load long heavy bullets, 175 and up.

 

[dogz]

speed equals pressure and pressure equals speed

but I'm following what your doing

best of luck to ya in your build!

 

[logman48]

No clickers with 280AI

 

[dougduey]

I own a 280AI and a 7STW. My personal opinion is the AI works best with 140-168 gr bullets and you're really pushing its limits if you want to run the heavier bullets. I shoot 175gr and higher bullets in the 7 STW without issues and I feel those bullets are better suited for a magnum cartridge. There are plenty of guys running the heavies in the 280AI with RL23 and great velocity, so I'm not saying it can't be done and done well, because guys are doing it
I don't think you can go wrong with either cartridge, but the PRC will give you more versatility especially with heavier bullets

 

[Shane Lindsey]

Curious to see if you can get there with a 280AI+P.

I ran a uni-throater in my 7RM to gain freebore. 190s with N570 and I am at 2835 FPS. Just under 3.6" COAL.

That said, I would agree with Doug Dewey, a little lighter pills may be the way.

 

[Shane Lindsey]

280 Ackley Improved fast twist with .25 of free bore. 195 Berger @ 2900, 175 ABLR @ 3000 - 3050 fps. Coal is 3.30 - 3.75.

Do you know of someone with one that is getting these numbers? There is (1) load in the Sherman data for the 280 Sherman with a 180 and RL26 getting over 3000. Would say that is being hotrodded though.

 

[Paladin300]

Do you know of someone with one that is getting these numbers? There is (1) load in the Sherman data for the 280 Sherman with a 180 and RL26 getting over 3000. Would say that is being hotrodded though.

RL 23 58-58.5 gr with 190s should be right at 2900. Remember we are running .25 of free bore and a 27" barrel. That load should be okay on pressure. I suspect the rifle is going to settle in around 2820 to 2850 with 190s and 195s. I have a 338 RUM +P we can push to 2900 with 300s running H1000 with no pressure signs, it will group about an inch at a 100. When we drop it back to 91g we are at 2775fps and it groups inside a half inch. Sometimes it just makes ragged holes. I suspect this barrel will be the same. We are picking up about 75 to 100 fps by adding 3-4" to the barrel.

 

[Shane Lindsey]

RL23 with 190 LRHT at 3.597" COAL in Peterson cases in mine with a 26" tube with 59gr got me 2756 FPS for best accuracy. Got up to 61gr but it trashed cases and accuracy wasn't there.

Good luck, hope it can get you there.