Thread: Wilcats and Pressure

OK I have seen this discussion going on for a while and not being an expert I would like to make a couple of observations and ask a couple of questions.

With any cartridge, whether a known quantity or not, starting loads can be reasonably easily established from already available loading data, or sensible comparision with other cartridges of similar capacity/projectile selection.... yes?

Sound reloading practice from suitable starting loads generally shows incremental increases in pressure evidenced by case head expansion, velocity spikes, increased bolt lift, excessively flattened primers yada yada...

The main issue we face as reloaders is: - to not have excessive pressure affecting our brass, as brass failure is our primary concern?

Brass is almost always the weakest part of our system. Brass failure is something that we need to ensure that we completely avoid.

The setting back of lugs, resulting in headspace increase over time is a possibility with repeated use of hot loads and is more likely to occur with strong brass that may not show
excessive pressure signs as readily?

However if that is occuring, we should see an increase in the signs of pressure on the brass as the headspace increases. As indicated in Kirby Allens post referenced earlier..

So we are now back to the start.... I would assume that it is unlikely that catastrophic failure is going to occur with a single hot load with new brass, a correctly headspaced low use rifle if the hot load is not a complete cockup.

Every other situation we should have progressive brass pressure signs before catastrophic failure...

Repeated firings that do not result in the need to resize, would be unlikely to be setting the lugs back in a rifle..?

Is a strain gauge giving a pressure reading a reliable predictor for brass failure? I am getting the impression that it is not (relative action strength, brass strength etc)

Is a strain gauge a predictor for the potential of action degradation as a result of hot loads over time? Potentially I think it may be .. yes? Are the other indicators of pressure in terms of brass and increasing headspace sufficient without a strain gauge? .......most probably - but you are in effect waiting for the result rather than predicting it.... and that may be a useful result.....

Is a strain gauge a valid comparator across differing rifle setups? Probably not from a scientific perspective, but in broader terms, experience would give some statistical probability..?

Is a strain gauge a useful tool for the comparative establishment of sensible pressure boundaries in a single rifle, (along with other indicators) or as illustrated by KG with choices for optimal powder selections? I would think obviously the answer would be yes..

I see it as another tool, that can assist particularly in the development of new cartridges along with other existing indicators.

It is possible however to use the basics well in that process without the need for a strain gauge.. The danger in my view is reliance on data from another rifle producing x pressure with a certain load, and using that load in your own rifle without doing proper load workups.

Asking a question about pressures (from a strain gauge) because of a concern about what is seemingly a strong loading; is valid? A response should be qualified in terms of case life, pressure signs resizing requirments, action specifications etc... but that information is hardly a commercial secret?

Help me if I am not getting it....but I think that this discussion while helpful has been being argued from differing perspectives, and neither position is completely wrong or completely right?

Yes/no?