I have noticed two different issues in reloading for a couple rifles.
One is my 425 Westley Richards and the other is a George Gibbs in 280 Ross. Well, actually the 280 question is about two guns, the other is a Lancaster.
In loading the 425, I have noticed that I see signs of higher pressure in brass made by HDS than Bell brass even with the same loads and bullets.
Why is this? Internal case volume?

And, I loaded some 280 Ross to the Seyfreid recommended load.
When fired in a Lancaster Mauser with a rather pitted chamber, there was no problem at all in firing, cycling or ejecting. Very surprising.
But, when the same shells were fired in my Gibbs, magnum Mauser no less, the bolt was difficult to turn and the primers were very flattened!
Question is, I guess, is there a reason for there to be such different results in two different makes of brass, or two different makes of rifle?

Reloading 1-0-1.

Never swap components and expect to start at the max load developed with different components. There are endless options of what can go wrong - e.g. varying internal brass capacity.

Never fire a max load developed for rifle A in rifle B. Load development for one rifle can not be substituted for load development in the rifle to be fired. Many reasons why - e.g. varying bore or chamber dimensions.

In a word: always work up from below.

- mike

All the pressure "sign" really tell is that
brass in that chamber with that load is begining
to yeild. That is usually beyond what is safe.
Not unlike a mild "heart event".

The load isn't near max. The 280 load is replicating the original cordite load, and factory ammunition is expected to perform in many different rifles of that chambering, then why is there a different expectation when hand loading?
I hadn't run into this before because I normally have just one rifle in each chambering except my 303s. With those, common handloads perform just fine in either but there are differences in the fired brass as far as shoulder shape.
I guess I will dial back on the 280 and shitcan the HDS 425 brass. Unless I just use the HDS for reduced plinker loads...

quote:

Originally posted by Huvius:
...shitcan the HDS 425 brass. Unless I just use the HDS for reduced plinker loads...

Try a lighter load in the HDS brass. It just might chronograph the same as a heavier charge loaded in a larger case.

- mike

With the 425 weighing the cases (trimmed to same OAL) will quickly answer the question. The heavier case will have less case volume.

In the .280 I suspect the real problem there may very well be in the bore dimensions. Many early british and european .280 bores (7x57, .280s, etc.) actually had .286 - .288 groove depths, possably what the Lancaster mauser has. The "standard" became .284 with commercial barrels in this country which may be what the Gibbs has. Suggest you slug the barrels to find out if that's the answer.

Also suggest a chamber cast as freebore in the Lancaster may be longer than in the Gibbs. This can affect psi also.

Larry Gibson

Larry gave some other things to looks at. In addition to different bore dimensions different rifling twist affect pressures to a degree. Your HDS brass also may be softer then your other brass. I find the Norma brass I have used is like that. It was also a good idea to fire a lighter load in the HDS brass and compare the velocity to the other brass. A chronograph is a good tool here and even better is pressure reader such as a strain gauge. Also make sure your bores are really clean of any jacket alloy. If you want to check your case capacities take some fired cases of each brand and fill them to the top of the case mouth with walnut cleaning media for example and then dump the media in your scale and compare the weights.

I'm with mho. I label my handloads by also identifying the rifle for which they were prepared. I work up separate loads from scratch. Ex.: I have two .270 Win'rs., one a Rem., the other a Mauser. I worked up two different loads.

The Mauser would not tolerate a max load but still gets sizzling velocity; it shows signs of high pressure before reaching max. (Has short throat.) The Rem. tolerates well max+ loads without usual signs of high pressure. (Has long throat.)

I fear the max load of my Rem. would blow up in the Mauser. IMHO too many variables to safely interchange loads with multiple rifles- even if they are supposedly equivalent to factory loads.