Re: Telling Pressure in a wildcat cartridge.

08 February 2004, 06:50

Anthony,

There is now way you can tell pressure from "pressure signs". The only thing you'll know when you begin seeing the effects of high pressure is this: you are already way deep into the danger zone. Get a Pressure Trace and don't guess.

http://www.shootingsoftware.com/pressure.htm

08 February 2004, 07:13

Savage99

Almost all of the handloading books have chapters on how to read pressure signs. Since each gun is an individual one must go by what you see.

While that pressure trace might be a nice feature it is not without the chance that it will fail, be used wrong or just go computer crazy. We all know how bad computers are.

Thus one could use it as an additional guidepost. Nothing wrong with that.

There is no way that I am going to glue stuff to my guns so I am not going to get one.

I did have a conversation with Jim at RSI over chronographs and other gun stuff and I was very impressed with his knowledge.

08 February 2004, 08:00

denton

The PressureTrace is a real good tool for wildcats.

The other thing to get is Ackley's Handbook for Shooters and Reloaders. He gives loads for a lot of wildcats, but I don't find anything on the cartridge you mentioned.

08 February 2004, 08:18

Bwana-be

Here's an idea: Start out with a cartridge that will do more than you need, then don't load it to the hilt.
Novel, I know.

08 February 2004, 09:48

Dutch

bwana has the right idea. A pressure gauge is a good idea, but a computer simulation will get you pretty darn close. Give yourself healthy safety margin, and you are good to go. JMO, Dutch.

08 February 2004, 12:56

Hot Core

Quote:

....257 STW how do you find a starting point to go from and know its a safe starting point?

Hey ANTHONY, One of the best ways to get the Starting Load for your Wildcat is to ask the Gunsmith that made it for you. He should be able to give you Starting Loads as well as a SAFE MAX Load.

Also agree with a portion of Dutch's post(no I'm not drunk). He mentioned, "a computer simulation will get you pretty darn close". If you use the Starting Loads as recommended in a program similar to "Load From A Disk", while watching for the Pressure Indicators, you will do fine.

The CHE Method mentioned in your other Thread will also work to help protect you from a Gross Over-Load.

And actually, the PRE Method will provide indications of when to STOP too. But they are very subtle and you would need experience using the Method to recognize the Indicators since you don't have the Factory Ammo to establish a Benchmark Comparison Standard.

Ask the Gunsmith about the Loads.

08 February 2004, 15:19

knobmtn

Anthony,

Hot Core is right. The gunsmith who did the chamber owned the reamer. He should have a good idea of where to start. But, I'm going to assume that for whatever reason you don't have a starting point. You just need to measure your new wildcat in grains of water and then find a standard round that has the same case capacity and is in the same bore size and play around the starting load for the standard cartridge.

If you can use an Oehler with a strain guage so much the better. But, I've usually watched the primers for any flattening or cratering, the case head for any sign of brass flowing back into the bolt(scuff marks) and also pay close attention to the bolt lift on a fired round. I've also always miked the pressure ring just above the base before and after firing. Stay conservative in the beginning. It helps to have someone who is experienced along at the range the first time you tangle with a wildcat with no data.

All this assumes, too, that the wildcat is chambered in a good barrel on a modern bolt action rifle.

If you're going to fool with wildcats a good book to try and get ahold of is "The Handloaders Manual of Cartrtidge Conversions" by John Donnelly. Mine was copyrighted in 1987 and was published by Stoeger Publishing.

knobmtn

08 February 2004, 16:06

waitaminit

First, have a look into as many reloading books as you may have acces to to find comparable cartridges.

Second, use QuickLoad or ask someone to calculate your load.

You may use LoadTech or Load from a disk as well, but my experience with LFAD is not so positive.

And finally, you may get hands on the Powley Computer which is a bit aged and for IMR powders only, but it will give you a good understanding for the matter and together with a powder quickness chart,and yield a range, where you can start with a safe load.

08 February 2004, 16:38

knobmtn

Hey waitaminit,

I didn't think there was anyone around that still knew and used a Powley Computer. That's why I never mentioned it. If anyone has one it is a great way to go.

knobmtn

09 February 2004, 00:47

waitaminit

The Powley Computer isn's that far out of reach as one may assume - it's frequently offered at eBay.