Home Forums Reloading Big Game Rifles 280 Rem and 150 g Partitions

Dogger,

Pretty much what .280Rem said.

It's perfectly safe to start with .270 data, since the .280 has a larger bore. I use the 4-to-1 formula to figure out where the .280 should be in comparison to the .270. The .280 has 5% more bore area than the .270, so is capable of around 1.3% more velocity with the same bullet weight (5%/3 = 1.3%).
Additionally, the .280 has slightly more powder room since the shoulder is a little further forward. Put it all together and the .280 is capable of about 2% more velocity.

Most modern data suggests the .270 is capable of at least 2900 fps from a 150-grain bullet in a 24" barrel. Nosler's manual, for instance, lists 2905 with H4831. Add 2% and the .280 should be capable of 2958. I add powder until ending up in that velocity range. In my Gentry custom rifle the charge worked out to 58.5 grains, and there was never even a hint of excessive pressure, despite an inch shorter barrel.

Since others have covered various aspects of the 280, I'll just add that in sveral 280's I've had, the 150 Partition has always worked well with 59 gr. of RL-22 for around 2950 FPS.

If you want to compare another bullet, try a 140 or 150 NBT.......they are almost always very accurate & since they are cheap, I use them in various calibers for initial load workup with different powders.

Also, although I understand that Hart did an accuracy job, I have worked with numerous MR's & in almost every single case, the guns shot best with a neutral pressure pad under the barrel near the forend tip..........I don't even attempt to shoot a MR rifle (Remington contour) as free-floated.

You might occasionally find one that will shoot best floated, but most will not.

Here's an example on a 280 Rem MR bedded with a neutral pressure pad & 4 different powder & 2 different bullets that I did recently. These are all 3 shot groups & all are under .550"

MM

Somebody may have already referred to it in the comments above, but whatever powder Federal uses in that factory loading works darn good in my .280.

I was about to get rid of my first .280, which was a MR, when I discovered this exact thing as well, via a suggestion from my dad, and can't believe I forgot to mention it.

Good point and I'm glad you posted that as I have a stainless MR on it's way to me soon. I'll have to keep an eye out for this.

I have an older .280 mountain rifle that I purchased used years ago. It was bedded and the barrel free floated by a local smith. The previous owner said it was zero'd with Federal Premium 150gr NPs and that he was getting .75 inch groups. I put a Zeiss Diavari on it, fed it the same loads to verify the claim, and have never felt the need to shoot anyting else thru it. Its perfect on whitetails and axis deer in this area.

MM, what kind of velocities were you getting with IMR 7828 and the 150? And can you explain the neutral pressure pad a little more? I have mine free floated and bedded.

Randy,

The above targets were shot with 140's & one target with 120's.

The 7828(the SSC version) with the 140's was 3040 FPS.

I've loaded 150's with 7828 in another 280 & that typically was around 2900-2950 as I recall.

As for bedding with a "neutral" pressure pad, this is a 2 step process.

I bed the action stress free per normal procedure with the barrel floated.

(As a rule, I usually will take time to shoot the rifle that way in case I get lucky.)

To add the neutral pressure pad, just add a glob of epoxy under the barrel about an inch back from the end of the stock tip.

I place the BA in the stock & just very lightly snug up the rear action screw & then screw the front action screw down until I just get a feel on it.........don't tighten.

Allow the epoxy (I use AcraGlass Gel) to completely firm up, about 4-5 hours. remove the BA, & trim the epoxy into a neat square or rectangle about 3/4" long x 1/2" wide in the bottom of the barrel channel......nothing should show on the sides.

Allow the epoxy to fully cure, replace the BA & tighten screws normally; this will generally yield a nice support pad for the barrel with very little upward pressure or barrel distortion.

Don't forget to tape the stock on both sides & use release agent on the barrel where the epoxy will be.

Instead of the pressure pad method that I use, some choose to full length bed the barrel channel using essentially the same methodology.

PM if you need more info.

I bought a new Ti in 7-08 a few years ago & when I got it, the BA touched the stock only at the rear tang & on the barrel on the nubbs in the barrel channel...........there was around .010" clearance under the action as it sat in the stock. When tightening down the action screws, you could see & feel the barrel deflect.

After the above treatment, it's a 1/2" shooter.........if you look up at the targets above, you'll see a cluster at the top of a couple of the targets labeled 7-08. There are 8 shots in the cluster with 3 different powders & the same bullet, I dropped one shot.

MM

Thanks Bill, so far it shoots well with the 150 BT's and IMR 4831, but I have about 200 Partitions I want to run when the weather cooperates and see how they do. I appreciate the info.

I've had several 280's & none were overly finicky.

Most good slow burning powders combined with a good bullet usually works just fine.

I've killed more stuff with Partitions than all else but together.

MM

Most animals I have seen hate to see the 140AB with 54-54.5 H4350 smoking after them.