MP227-65-GC

[Ian]

FWIW, I take a couple of differnt approaches to crimping. I especially like the Lee FCD but usually modify it to crimp a fairly abrupt taper and can thus put the case mouth right in a groove...or swage one.

I'm also a fan of light roll-crimping when loading semi-auto rifle ammo....but I also do that by feel of the press handle by setting the die for a much harder crimp than I want and not camming over the press handle. Touch it, rotate the case, do it again. If you aren't confident in your feel, hang weights on your press handle until you get the amount of crimp desired and gently lower the handle on each case.

I like taper crimps for manipulating "shot start initiation pressure" as I think Neco calls it.

 

[Spindrift]

Thanks for the responses!
As I loaded some .223 today, I found two different batches of NOE225-61 (the RCBS-clone). Both where sized .226, with the same GC. One batch was sized nose-first, the other base- first (as I do with all my bullets now). We have discussed this in another thread, I know. But the difference is pretty striking, don’t you think?

 

[Ian]

I remember having this conversation on another forum years ago and someone made a really good point about how tens of thousands of pounds of gas pressure will seat gas checks very effectively. That someone was a graduate-level cast bullet shooter so his point carried some weight with me even though I fundamentally disagree with leaving the check domed or partally seated before seating the bullet. My argument is that so much can go wrong if you don't put the check on tight and square from the beginning and subsequently rely on gas pressure to cram it on there.

Like so many things, this may fall into the "it only matters if it does" category where Professor Target gives the final grade. This little test should prove educational.

 

[Spindrift]

I’ve loaded bullets sized base-first only, for my next shoot. This will provide some basic data. Then, I can do a comparison between the two batches. That will be interesting!