I recently had my 45-70 Mauser rechamberd to 45-90. The problem is there is
no reloading data available for modern rifles in this caliber.

I thought there should be no problem because I thought I would be able to
recognize the signs of excessive pressure, such as difficult extraction
and/or flattened primers. However, I read a posting in another forum in
which the writer claimed that straight-wall cases in rifles don't exhibit
the classic signs of trouble until they blow up.

So, what is the experience of the estemed readers of this forum? Will the
45-90 let me know it is reaching its limit before it blows up?

Thanks!

"" Will the
45-90 let me know it is reaching its limit before it blows up?""

If you are using IMR7383 it may be a real gamble. There are those of this forum who know it for a fact.

Do you have a chronograph? roger

No access to a chronograph and I'm using Accurate 4350 powder for now.

Thanks for all the responses. Your answers are encouraging.

L8'er, THP

I think pressure signs are pressure signs. I shoot a relatively straight walled case in my #1, a .338x74Keith. It's a blown out, necked down 9.3x74R. I find sticky extraction & flattened promers are still a decent indicator. There may be a problem w/ early head separations w/ rimmed. straight wall cases. Keep track of your reloads & watch for early head separation. Using Norma cases I had them showing up after 5 firings. Using RWS cases I am up to 6 w/o signs.