Softest Feel in a Limited Major .40

[earlbob]

In my opinion, the softest loads are those that have low charge weights and high pressures. The key is to be able to make major and keep pressures under 35,000 psi without having weird pressure spikes and case head seperations. The slower burning powders look good on paper but tend to be louder and pushier than the faster powders. I have also noticed that flake powders seem to feel a bit softer than ball or extruded powders in the same burn range. It all comes down to picking a good safe load and getting used to it by lots and lots of practice.

I figured it might have something to do with the perceived recoil impulse, the noise or the powder was a dirty burner. I noticed that the powders that seemed to be chosen the most had some of the worse numbers, lowest velocities highest pressures. My thought was the higher pressures would have little bearing in compless Limited so there must be another reason people are going that way.

Two questions: 1. Why does the decibel level of the load enter in as a factor for its choice?

2. Since the perception of 'pushier' is subjective to multiple variables I wonder is there an actual effect (which could only be determined after one had become used to the timing of the new load) on ones shooting split-times etc. or is it more a mental thing we are unnecessarily bowing to?

thinking again,

earl

[ebg3]

Sorry for the delay in response...I'm using 4.5grs of a very fast burning powder and it is making a 170pf with a 180 jhp. If I went to a slower burning powder like VV340, I'd have to use a little more than 5.5grs to make the same power factor. That is close to 25% more powder, I think that is why the slower powder will be louder, there is more of it to burn.

As to the pushier feel, my theory is that the faster burning powder has a quicker impulse and the burn is over faster than a slower powder making the recoil feel less. The amount of ejecta(ie,burning powder) leaving the case could also add to the perceived amount of additional recoil with the slower powder. When figuring felt recoil in a rifle or shotgun, the weight of powder is figured into the equation so it must make a difference.

I have also noticed a difference in felt recoil between extruded powder and flake powder of similar burn rate and charge. The flake powder feels softer to me. It seems that the flake may ignite and burn faster than the extruded powder making it feel softer.? I'm not sure about that one but I can tell a difference in my trials. These are just my opinions on what I've experienced over the years reloading for USPSA.

So all that said, I choose to use a fast burning flake powder for my loads in .40 and 9mm. The one I have settled on is e3 by Alliant, it is fast and clean and the charge weights are low for both calibers. Hope this helps.

Eddie