How much crimp to use?

[daroccot]

I'm new to reloading and have a couple questions about crimping for the .44mag.

I am working on two loads, one for plinking the other for the "bush". My plinking load will consist of 240gr LSWC with 6.5 gr of Unique as per Speer#13 manual. The bush load will carry a 300gr FN (not sure if it will be Hard-cast or jacketed yet) with up to 22.5 gr of 296 also as per Speer. The question then becomes how much crimp do I need on the plinking loads to prevent squibs and how much for the bush loads to prevent unseating. My manual says to use a heavy crimp for slow burning powders (Unique is a medium? Correct?) It also states light crimps on "target" loads except when used in large cases...

Some may see why I'm a little confused. Is the .44mag considered a 'large' case? I would think Yes. Is 6.5gr of Unique light? Yes. Ergo I should use a heavy crimp. The adjustment proceedure that came with my dies (RCBS) are quite clear on how to adjust to increase crimp.

So my question is how many fractions of a turn of the seater die do I need for this "Heavy" crimp.

 

[ben hunchak]

I usually crimp in a separate operation and I turn the die a quarter turn after contact between crimp and mouth of the case. That is usually enough to turn the case into crimp groove with out distorting the case. I find it easier to crimp into a cast bullet's crimp groove than the cannelure on a jacketed bullet.

 

[ElmerFudd]

... with up to 22.5 gr of 296 also as per Speer.

Be aware that Winchester 296 is not a powder that you can reduce much if at all. Keep that in mind.

The question then becomes how much crimp do I need on the plinking loads to prevent squibs

Don't know how you will get a "squib" as long as there is powder.

... how much for the bush loads to prevent unseating.

Unseating, yes. If there is not enough crimp the bullets can unseat during recoil.

For both light and heavy loads you should adjust the crimp so you can see it turn into the cannelure. And test them at the range and see if they unseat during recoil by checking the 6th round before firing. If it is still in the cannelure your good to go. Check a few. If there is no cannelure you can take your calipers and check.

If you have a hammer type bullet puller you could even test a dummy round in that. It shouldn't come apart or bullet move out with a single light hit.

As for what is a slow powder and what is fast, they are talking about in that cartridge. So if you look through the powder for that cartridge you will see faster powder with the lighter bullets and slower powders listed with the heavy bullets and a mix in between.


Fudd