Crimping

[Byrnesy]

I am after experiences on bullet crimping with compressed loads.

I am working up loads for a new Stalking rifle, 8X57Mauser and both 2208 and 2209 go to 100% case capacity and beyond. Firstly I noticed a difference in seating depth across the different loads, obviously due to the different amount of compression. This was adjusted for.

But I don't want the pills jacking out over time. And this is likely to get worse as the cases are re-used and neck tension lessen.

So I am thinking about crimping but this would mean applying a cannelure to the pills (and buying a tool) as I am using Nosler 200 grain Accubonds.

Loads haven't been tested yet and the problem may lessen to disappear once cases are fire formed. But it doesnt hurt to give this some forward thought.

 

[MagnumManiac]

IMHO, you would have to be well above 110% capacity for there to be any real danger of the bullets backing out over time. Your best bet is to 'swirl' the powder charge into the case by pouring the charge with a funnel held at an angle so the powder swirls around the axis of the funnel, it should look like water going down a drain plug and be one continuous stream of powder.
If you compare an as dumped charge against one poured like this you will see a substantial difference in the height of the powder, no need for a long drop tube or tapping of the case.
I can guarantee that this technique will also give you low ES and SD numbers because the packing scheme will be uniform betwwen rounds, unlike as dumped charges where the packing scheme varies, as you found out with your differing seating heights.

Hope this eases your anxiety about compressed charges, I have beenndoing this for quite a few years in my comp guns with some dense powders and it works a treat.

Cheers.
gun)

 

[RT2506]

If you want to put a crimp on those Nosler bullets just get you a Lee Factory Crimp Die in 8X57. This die does not need a cannelure on the bullet. It makes it's own. The die has fingers in it that compresses the case neck into the bullet. I have used them a lot. In my experience it does not hurt the accuracy of even match bullets. I have found that the use of the crimp die in many of the old military rifles I have increases accuracy. These rifles usually have long throats and if you try to seat the bullet so it is anywhere close to the lands it is too long to work through the action. I load my COAL so it will work through the actions and use the Lee Factory Crimp Die and get great accuracy.
I don't know what the powders you described are but Varget and IMR 4064 have done well for me with 200 gr bullets in 8X57 JS Mauser.