Changing cases in .223 Rem. load

[uncle-buck]

Have worked up a nice .223 load using LC cases, Rem. 7 1/2 primers, Hornady 55 gr. FMJ bullets, and 25.0 gr. of IMR-4064 powder.

To obtain the same muzzle velocity using a case with slightly less capacity (such as Geco), I understand that slightly less powder will be required.

But loading to the same MV doesn't necessarily mean the same level of precision will be achieved, does it?

 

[dolek]

Have worked up a nice .223 load using LC cases, Rem. 7 1/2 primers, Hornady 55 gr. FMJ bullets, and 25.0 gr. of IMR-4064 powder.

To obtain the same muzzle velocity using a case with slightly less capacity (such as Geco), I understand that slightly less powder will be required.

But loading to the same MV doesn't necessarily mean the same level of precision will be achieved, does it?

You never know until you try...sometimes switching things up works just fine,other times it can take some tweaking.

 

[CharlieNC]

At 300yd I have not found any difference for LC vs Lapua on fclass targets. LC has a little more capacity and the neck as are thinner. Did not check velocity.

 

[Uncle Ed]

5.56 and 7.62 Case Capacities - Load Data

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=2ahUKEwjrrpK42cXdAhUqxVkKHRjUA8kQFjAAegQIBxAC&url=https://loaddata.com/articles/PDF/BenchTopics%2087.pdf&usg=AOvVaw0xLr_ztHf3891W52sUpyY1

 

[55fairlane]

Uncle buck,

While I am not 100% certain what your asking, hopefully this will help......

I am a service rifle shooter (sling and iron sights) , most of the guys I know hold LC brass as thee standard, so one afternoon I loaded up 20 LC 2011 cases ( 69 SMK & 8208XBR) and 20 mixed range brass ( wolf gold, IMI, federal, geco) and went to the range with my MN and my clock.....

I found the average muzzle velocity and the average SD and ES to be soooooo close to each other, I don't bother to sort cases anymore, in fact the match I shot this weekend, was mixed range brass and I picked several X's and got a medal for my shooting

 

[Jacob.A]

Nodes are based on velocity. As long as the new load matches velocity it should be the same results on target. Of course there's always weird stuff that can happen so I wouldn't load up a few hundred for a big match to start - do a little testing to make sure you're at the same node, then shoot a 10 shot group to make sure it performs the way you expect it to.