SwampCollie

This is tough to explain and diagnose over the internet without acctually hearing you call. But I'll try to help as best I can. Maybe it will help you find the answer yourself by pointing you in the right direction...

As your mouth warms up the latex, it expands. It becomes more flexible. Over time, the frame will acctually bend a bit as well, and you'll notice the call feels more comfortable in your mouth. Diaphrams have a bit of a breaking in period, and they also have a point at which the latex has stretched so much that you can hardly make a turkeysound with them anymore.

I think a lot of it depends on precisely how you are purring. Purring, and purring well is one of the most difficult things to do on a mouth call, or heck any wind driven call for that matter in any discipline.I personally purr best, by fluttering my lips. Its a delicate flutter, and I throw in a bit of a tounge roll and a bit of vocal vibrations, but its hard to explain it. Exactly what will work best, well, its sort of up to you to figure out. I will tell you this however, some of the sorriest sounds in the forest come from the real thing. I think that rhythm, more so then pitch is the most important part of calling for turkey hunting.But even that comes after volume, and I am writing about AMOUNT, not how loud you call, which would likely be third.

As far as reeds go, it depends again on exactly how you call. The more reeds and more cuts you have, the raspier, deeper and louder a call typically is. Also, the more pressure, or wind, you are going to have to put through it. I am not going to kid you, after practicing for 30 minutes real hard on a Matt Van Cise call, I have a headache. It takes some pressure. Sort of like doing sit ups for a long time. Its not really backpressure, but it sort of is.

With regards to just having one call that does it all....I haven't seen it.(SEEEDIT!!!) Considering that in the course of hunting you sometimes have to make both hen and gobbler sounds, you are trying to find something in a mouth call that not even the turkeys themselves have. A call that does a good kee kee, will often do a so-so yelp, and often a rotten fighting purr (which I think is more important than a hen purr). Calling competitions are certainly not turkey hunting, but it is useful to hunters because it teaches you how to use a turkey call better. The more noises you can make, the better. Comp callers have an assortmentof calls they use in a routine. Usually at least 3 or 4, and each one of those does ONE certain call better than any other they have ever used. And in some competitions (most in fact) you aren't even limited to mouth calls, so why purr on a mouth call when a slate does it that much sweeter, and that much easier? But there again, we are calling turkeys, not judges.

Personally, and here is what you are probably looking for now that I have rambled on too long, I would much rather have a raspier, louder call in my mouth, if I could only have one. Something like a Van Cise Woodhaven, or a V3, or a Sadler McGraw. I can make a passing grade hen purr with just my mouth, tucking the call away in my cheek. Really though, I wouldn't worry about a hen purr too terribly much, yes it is an important call, but most hunters make it WAY WAY too loud. I would focus on yelps, cuts, and clucks. Most importantly, I would use leafing raking, or scratching to finish a bird off. In my experience, this works 10 times better than even the best hen purr I have ever heard (the real thing).

EDIT: There is in fact one call, and in effect one caller that I have seen that can effectively immitate every sound a wild turkey makes, both male and female. The caller is a gentleman from Capron, VA named Tommy Dead-Eye Barham, and the call is a Primos Snuff Tube. Tommy has been using that thing longer than I have been alive. To hear him use it is like hearing a whole flock. He can make it sing like Springstein can make a 6 string sing, which is exactly why if you should buy one, you will see Tommy with a large Gobbler he killed on the face of the package. Will Primos knows talent when he hears it no doubt, and he's no slouch himself.