To crimp or not to crimp

[oneof79]

AR-15, 1 in 7 twist, stainless
69 gr Sie Matchkings
loaded mag length
no cannelure on bullet

Any one worry about setback when not crimping bullets?

 

[bettingpython]

I haven't started loading for 5.56 ammo yet so I haven't researched everything yet but my understanding is crimp them puppies to avoid bullet setback and a possible KB. Hopefully one of our experienced relaoders will be along shortly.

 

[Bobrob]

I don't crimp or worry. I see a setback if there is a mis-feed that jams the bullet tip into the front of the mag. That seldom happens though.

The only down side to crimping is you will work-harden the case lip potentially causing cracks to develop. If you keep your cases trimmed that may never be a problem.

Crimp or don't whatever makes you happy.

Best regards

PS I am loading Varget and the cases are near compressed (not max but full) so it would take a lot to push the bullet back.

 

[oneof79]

I don't crimp or worry. I see a setback if there is a mis-feed that jams the bullet tip into the front of the mag. That seldom happens though.

The only down side to crimping is you will work-harden the case lip potentially causing cracks to develop. If you keep your cases trimmed that may never be a problem.

Crimp or don't whatever makes you happy.

Best regards

PS I am loading Varget and the cases are near compressed (not max but full) so it would take a lot to push the bullet back.

I am using Varget also. I am going to try Reloader 15 soon. Anyway here is a page I found with some interesting stuff on it.

http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm

 

[Woodcutter]

If the bullet does not have a cannelure ( and Match Kings do not), then you should not try to crimp it unless you are using the Lee Factory Crimp die. Even then, Sierra probably would not recommend crimping the bullet. Crimping might destroy the accuracy of this precision made bullet. The bullet was made for the AR15 type semi-auto rifles and if they thought you needed to crimp it Sierra would have put one on it. Many thousands of rounds of Match Kings are fired each year out of AR-15 rifles at Service Rifle matches, and like was said already, if you load them right you should not have to worry about setback. Just make sure the expander ball in your sizer is the correct size and you use good brass, you should be good to go. If you want a little extra insurance against bullet setback, use a slower powder that fills the case and is slightly compressed.

 

[Bobrob]

I am using Varget also. I am going to try Reloader 15 soon. Anyway here is a page I found with some interesting stuff on it.

http://www.exteriorballistics.com/reloadbasics/gasgunreload.cfm

I bookmarked that link, that's some good info in there. Thanks

 

[MilitaryBolt]

If you are wanting accuracy then don't crimp but if you want 100 percent reliability then do crimp.