Thanks for all your posts. Most have very valid points and good recommendations on cartridges.
Reason I am going away from the 222-223 class rounds is velocity, I want more then these can offer with 50-55 gr bullet weights. I will be using one of the tipped bullets in 6mm in the 55 to 58 gr range or one of Richards Wildcat 60 gr pills.
Catshooter, I am not sure what you mean when you say your case for the 6mm-223 is very flawed.
A 223 Rem will hit 3300 fps easily with a 55 gr pill in 24" barrel with more powders then I care to list.
The 6mmx47 which is simply a 222 Rem Mag necked up to 6mm will easily push 3400 fps in a 26" barrel and one I have developed loads for with a 27" Lilja averaged 3530 fps with a 58 gr Hornady V-Max bullet.
Remember in my post I said standard 22-250 loads. Factory loads in the 22-250 will be listed at 3600 fps with a 55 gr pill. In reality most factory loads are in the 3500-3550 fps range with this bullet weight. This is what I was comparing it to, not full throttle handloads which will add a couple hundred more FPS to this level.
I have not tested the 55 gr 6mm blitzking yet but I have tested the 55 gr V-Max in the 223 and the 58 gr V-Max in the 6-47 and in those two rifles 3350 fps and 3530 fps were comfortable top end velocity averages for each chambering respectively.
Comparing those two rounds, out to 400 yards with a 250 gr zero and a 10 mph crosswind here are the numbers:
Drop at 400 yards:
223 Rem............-16.1"
6mm-47.............-14.4"
Retained velocity at 400 yards:
223 Rem............1926 fps
6mm-47.............2029 fps
Retained energy at 400 yards:
223 Rem............453 ft/lbs
6mm-47.............503 ft/lbs
Wind drift at 400 yards:
223 Rem............20.4"
6mm-47.............19.3"
Now these are not imagined numbers, these are actual loads I have tested and developed in customers rifles so I have already proven that these numbers are possible, not projections.
Again, I am not looking to invent a new wildcat. There have been so many 6mm wildcats based on the 222, 223 and 222 Rem Mag case that it would be impossible to list all of them. All are basically very similiar in performance.
The plain vanilla 223 WILL NOT fly flatter, hit faster or hit harder then the 6mm-223. Quite the opposite in fact is the truth.
Plus being a custom rifle builder I care very little about being able to buy the rifle off the rack and as an accuracy minded shooter, I could give a rip about factory ammo as well.
I know full well how large the investment in time and money there is into designing your own wildcats, have a couple of them out there. That is not what I am doing here. Again, my goals for the project are:
-Enough ballistic potential to allow consistant hits out to 400 yards.
-No case fireforming required
-Extreme case barrel life
-Very low barrel heat
In every one of these aspects the 6mm-223 would outperform the 223 Rem. In every case no question.
If that is not believable, then look at the 223 loaded with a 55 gr V-Max compared to a 6-223 loaded with a 65 gr V-Max. both will easily be able to top out in the 3350 fps range with these two bullet weights. THe 65 gr has a BC of .280 listed compared to the 22 cal 55 gr version with a BC if .255.
Again, there are examples all over that prove the 6mm-223 will outperform the 223 in every ballistic area out to 400 yards with similiar bullet weights.
Just not sure where your getting your data from, what load are you using in your 6-223?
Thanks for the response, no flame intended in my response to you but I believe your facts are not quite that!!
Kirby Allen(50)
