Whisper Reload Help, Crimping?

[Dvol]

Hi Guys,

New guy with a 300 whisper checking in.

I just got an SSK AR-15 upper in 300 whisper. Also just started reloading for the first time. Reading past posts from people have been very helpful. I have brass all prepped and ready to charge with powder and seat bullet but have a question.

I have some 220gn and 240gn SMK's that I will be loading but none of the bullets have a crimp ring on them, the manuals I have read says that the bullets should be crimped when running in a semi-auto rifle but not to crimp unless there is a crimp ring.

Can anyone tell me how I should handle this?

Thanks for your help.

Also have my form 4 pending since Sept 1 for the suppressor, cant wait until it arrives.

[Hoser]

There should be more than enough neck tension to hold on to the bullets. Dont worry about it.

[RobRat]

As was said previously, you don't absolutley "need" it.

If you "want" a crimp die, send a seated case to Lee, along with $29 (I think- -the instructions are on the Lee Precision website), and in a couple weeks they will send you back a custom 300/221 Lee Factory Crimp Die. Mine works great.

[buffetdestroyer]

Ditto above...

You can crimp bullets that don't have the cannelure groove, but you don't have to.

The reason they state that you have to crimp rounds for semi-autos is because light neck tension can cause the bullet to move when it is seated into the chamber by the cycling of the action by either compacting when feeding or the bullet being forced forward out of the case mouth when case impacts the chamber.

If you have proper neck tension from your resizing die, this isn't typically an issue. I personally don't crimp any of my AR loads.

Crimping can help consistency and help keep out moisture if you are storing the loads indefinitely or are in wet, submerged, or rainy environments. But crimping can also increase the pressure of the load so be wary with near maximum loads.
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Ferrari F399 Specifications

[Dvol]

Thanks for your help guys. I really appreciate it.

[AlcoholicusMaximus]

I have been having 125gr ballistic tip supersonic loads setting back. Reading the specs on my Redding dies, they are supposed to have a taper crimp built in.

[robrob]

On the redding dies you can crimp or not, depending how you adjust the bullet seating die. I might try a light crimp.

[N310toN170]

For the ultimate in accuracy neck thickness is the primary concern. Once that's ironed out I don't recommend crimping subsonic rounds but do recommend it for hypersonics. The hyper rounds are usually shorter in bullet length and are prone to setback due in part to a more violent recoil and cycling.