Hey guys. My Dad just got a new X Bolt in 280 Rem. My question was sparked from a discussion on the Medium Bore forum in regards to pressures. From what I understand the 280 was introduced in auto/pump action rifles that can't be loaded to the same pressures as a bolt action can be loaded to. What is the real skinny on loading this cartridge?

Do I still start at the low end (as per usual) of the book and work up until I find an accurate load or can I start in the middle of the book loads and work up to save components.

We will be loading 160 grain bullets such as the Partition, Game King, Interbond, and Accubond. Powder we'll be trying first is RL-19 as both Nosler and Sierra claim that to be the most accurate powder they tested and I have that on hand.

Thanks much!

quote:

What is the real skinny on loading this cartridge?

Absolutely you should start loads at the recommended starting point.....however you might load a grain or so past the "max" listed.

Here's what I do.....and I'm not saying it's the right thing but it has worked for all my lower pressured rounds chambered in modern actions.

I use Hodgdon's data as it's accompanied with pressure data so you might have a hint of what you're loading....bear in mind that this is THEIR data.....and may not necessarily be yours.....but this is true in any loading scenario.....

It's a rough rule of thumb that the typical powder used in hunting loads of cases like the .30-06 size will increase pressure about 3,000 PSI or about 3,000 CUP.....and no....PSI and CUP are not the same nor are they quivalant...

What I'm presenting is very rough guidelines...

Find a load from Hodgdon's and estimate how many grains you might be able to load over their max assuming 52,000 CUP or 63,000 PSI

Set this new number of grains as max.....and bear in mind this is a flaky number and may just evaporate in front of your eyes.....similarly the same may happen with any published data.....you must learn to read your gun and it's pressure signs.

I'll post an example in a minute or two

As an example Hodgdon's lists Win-780 powder (56.7 grains) with a 160 grain bullet at 49,500 cup.

From the CUP rating of the load it might be assumed one could go 1 1/2 grains over max and still be in pressures capably of a bolt action rifle. This might add 100 FPS to the velocity bring the 160 grain bullet to possibly 2800 FPS and this is a fair estimate....but one still works up slowly looking for pressure signs and I like using a chronograph to confirm that i'm actually getting an increase in velocity for the additional powder burned.

I'd consider 58 grains as a max based on data available but remember......we did a lot of guessing to get here.....and unless you have good pressure measuring equipment.....you're guessing too.

It also helps if you have a software program like quickload.....this is another method to get estimates of prressure.

Another thing you can do is use loading data for the .280 AI.....while it's a bit much it's not a lot much and the standard 280 Rem will approach the performance of the "improved" case....but again do so cautiously.....I'd back off a half grain from any "AI" loads used in the standard 280 rem......the "AI" loads are fully loaded to modern pressures such as the .270 winchester is loaded...

One just might say that he could load two grains over the max of any published 280 Rem loads and be fairly safe.....but again it's an extimate only....prudent reloading practices must be adhered to.

Wistrapper, this is one of the reasons I bought Quickload. If I'm shooting a bolt rifle, I don't care what the max was for the lone auto-loader the rifle was chambered in. I can use it to provide guidelines above "book", but within the limits of what I would expect for the firearm the load is to be used in.

Just for fun, lets take a look at the 280, with a 26" barrel, RL22, and the 160gr Nosler AB.

Cartridge          : .280 Rem.
Bullet             : .284, 160, Nosler AccuBond 54932
Useable Case Capaci: 58.194 grain H2O = 3.778 cm³
Cartridge O.A.L. L6: 3.330 inch = 84.58 mm
Barrel Length      : 26.0 inch = 660.4 mm
Powder             : Alliant Reloder-22

Predicted data by increasing and decreasing the given charge,
incremented in steps of 0.87% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-08.7   97    52.50   2697    2585   43678   9785     96.1    1.422
-07.8   98    53.00   2724    2636   45009   9877     96.5    1.402
-07.0   99    53.50   2751    2689   46385   9966     96.8    1.383
-06.1  100    54.00   2778    2742   47807  10052     97.2    1.364
-05.2  101    54.50   2805    2795   49278  10135     97.5    1.345
-04.3  101    55.00   2832    2849   50797  10214     97.8    1.327  ! Near Maximum !
-03.5  102    55.50   2859    2903   52369  10290     98.1    1.309  ! Near Maximum !
-02.6  103    56.00   2885    2958   53995  10363     98.4    1.291  ! Near Maximum !
-01.7  104    56.50   2912    3013   55678  10432     98.6    1.274  ! Near Maximum !
-00.9  105    57.00   2939    3069   57420  10498     98.9    1.256  ! Near Maximum !
+00.0  106    57.50   2966    3125   59222  10560     99.1    1.239  !DANGEROUS LOAD-DO NOT USE!
+00.9  107    58.00   2993    3182   61089  10618     99.3    1.222  !DANGEROUS LOAD-DO NOT USE!
+01.7  108    58.50   3019    3239   63025  10672     99.4    1.206  !DANGEROUS LOAD-DO NOT USE!
+02.6  109    59.00   3046    3296   65029  10722     99.6    1.190  !DANGEROUS LOAD-DO NOT USE!
+03.5  110    59.50   3073    3354   67101  10768     99.7    1.174  !DANGEROUS LOAD-DO NOT USE!
+04.3  111    60.00   3099    3412   69241  10810     99.8    1.158  !DANGEROUS LOAD-DO NOT USE!

Book Max for this cartridge is usually around 57k PSI, so I would expect a book max of 56.5 to 57 grains.

Most Modern bolt actions rifles are rated close to 65k PSI. This would equate to 59gr of RL22.

In some cases the US Military loads up to 68K psi. That would be be slightly above 59gr of RL22...

It's also interesting to note that in the span of that 10k PSI, you only gain an estimated 100 fps.

quote:

It's also interesting to note that in the span of that 10k PSI, you only gain an estimated 100 fps.

Yup.....and it sure makes one wonder if it's worth it!

That's great guys!! Thank you both very much I truly appreciate your time shared with me.

Due to its history, the .280 Rem is one of the few cartridges I will load higher than data values in the books (bolt gun only). Ditto for getting favorite loads/recipes from other handloaders on sites like AR/24hour. For what its worth, the 7x64 Brenneke is so close to the .280 Rem my loads for each mirror one another, tho brass is NOT interchangeable.