Which is more effective: 6X45 or .223 in AR platform?

K

Karl in Phoenix

New member
I am pondering getting a 6x45mm, after reading a recent posting from a member who has a very nice one from Mike Milli @ DTech. I already have reloading dies for 6x45mm for an XP-100 (15inch) pistol that I own.

Based on your "real world experience", is the 6x45 much more effective than the .223 Rem. for a "calling rifle" for coyotes?

Many thanks, in advance, for your thoughts and ideas.

Karl in Phoenix
 
When shooting the same weight bullets the 6x45 has an endge in velocity. Frontal bullet surface area again the 6x45 has the edge. Ballastic Co-efficient the 223 has the edge for the same weight bullet. Bullet choices it is a dead heat. Brass is the exact same except you need to run virgin through the press to size it to 6x45.

When I 1st heard about this round I immediately dismissed it as something that didn't need to be done. Somebody worked up a wildcat because they had too many 6mm bullets and too much time on their hands. Then I did some research on the round and found it is really an accurate forgiving cartridge that is cheap as wildcats go and very versatile from being able to shoot 50 grain bullets up to 107 all the while exceeeding all the parameters of it's parent case except ballistic co-efficient for bullet weight.

Personal experience....
Although the 223 is a proven performer my choice is the 6x45.
It seems to hit harder, maybe due to the larger frontal area of the .243 vs .224 bullets; even when comparing the same bullet weight.
Here in eastern Colorado the wind always seem to be blowing and the 80 grain bullets really seem to buck the wind well. The 223 with a 75-80 grain bullet really looses a lot of velocity compared with the 6x45. Real world chrono numbers put the 223 velocity almost 300ft/sec slower on the AR platform.
 
Karl,

I also shoot the 6x45, it has proven to be a great predator rig and mine is, of course, an AR15. I have had a good number of runners with the 223 rounds of various weights and design but the 6mm bullets seem to do a much better job of anchoring coyotes where they stand. Lately my go to gun is my 6x45, I feel very comfortable in taking coyotes out to 300 yards with it. So far the 75 grain Hornady HP's have been been doing a terrific job.

If I were to do it again however, I would build a 6 WOA, using the 6.8SPC case and necking it down to 6mm. Main reason is velocity but more importantly, the problem of mixing up brass between the 223 and 6x45, I shoot a lot of 223 ammo.
 
CO pretty well summed it up. You do get about 30% more energy out of a 6 x 45 than you do out of a .223. The other up-side is the expansion ratio. You have the same powder capacity as the .223 but more bore area to burn it in. The 6 x 45 will do better with the shorter barrels than the .223 does because of this point.

An old gunsmith friend of mine turned me onto the round many years ago. He has been shooting deer with his for many decades. I built my first one about 15 years ago, and now have two bolt-action rifles that I built, and a couple of AR's as well. I have taken many white-tail deer, and countless long-range varmint with the 6 x 45 over the years.

The 6 x 45 is VERY easy to find loads that shoot well. It is like any other cartridge line: The less over-bore it is, the easier it is to load for. Take the .308 Winchester. Basically if you take a good bullet, and a powder that will give you the velocity that you want, you will get pretty good groups. With just a little work, you can make those groups very small. Now take the .243 Winchester. Same case, but it is over-bore compared to the .308. The .243 is very accurate, but you just have to work harder to find the right load.

Like the .308 Winchester, the 6 x 45 is not in the least fickle.
 
The 6x45 is in my opinion the ideal predator calling caliber. Brass is readily available and it is cheap to reload sense it is based on the .223 case. You get a little better velocity with the same grain bullet compared to the .223, but the .243 bullet will have more energy due to the larger diameter. Force = Pressure X Area. Considering you have the same max chamber pressure for the .223 and 6x45 then you will get more force due to the fact the .243 has more area. You get comparable energy of a 22-250 with less powder, noise and recoil. I have seen 55gr bullets do wonders on dogs, but the 70gr Blitzking or 75gr Hornady HP are just magic.
 
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Whats is the 6x45 effective range on deer with say a 85 grain partition. How fast could you push a bullet that size from 6x45.
 
While I have never had a 6x45 in a Rifle, I acquired my first one back in 1986. Mine was a custom built Remington XP-100 Handgun with a Shilen 1 in 12" twist Barrel. Man did that thing shoot. It would put5 of each 60gr. Sierra Hollow Points, 70gr. Hornady SX & 80gr. Speer Hot Core Spitzers into a 15 shot 1" group at 100 yards. That barrel was just amazing and I am still trying to figure out why I sold it.

in the 6x45 XP-100 Handgun I was pushing the 80gr. Speer Hot Core Spitzer at 2650FPS with H-322 Powder. The first Whitetail I shot with this handgun / load was a fork horn Whitetail at 300 long paces. I hit the buck high in the shoulder and he dropped in his tracks. The bullet completely penetrated the buck (passing through both shoulders and the lungs) with about a 1 1/2" exit hole.

In later years I have had a couple different T/C Contender Handguns chambered for the 6mm T/CU (an improved version of the 6x45) and have used it to take several varmints, a couple coyotes and a couple Whitetail Deer with excellent results.

The last two Coyotes I took with a 6mm T/CU was kind of a rodeo so to speak. I was perched on top of a bale pile and called in a double. Trying to be smarter than the coyotes I decided to shoot the farthest one first in hopes of getting a double with a single shot handgun. Well it worked but not quite like I planned. I shot the farthest one first but hurried the shot (concentrating on my reload) I messed up the shot and hit the coyote too far back. I then shot the second coyote aa it wsa looking at it's buddy and immediately did a few kiki's. That distracted the first Coyote and I managed to hit it in the right place on the second shot.

The first Coyote was pushing 250 yards, while the second Coyote was about 125 yards. I was using 55gr. Nosler Ballistic Tip at a muzzle velocity of 3045 FPS out of the Contender Handgun.

For the record a .22 caliber 55gr. Nosler Ballistic Tip has a BC of .267,while a 6mm 55gr. Nosler Ballistic Tip has a BC of .279. I know it doesn't make sence to me either but that is what Nosler is publishing the BC's as.

Larry
 
Quote:
Whats is the 6x45 effective range on deer with say a 85 grain partition. How fast could you push a bullet that size from 6x45.



Here is a little info that might help answer your questions.

http://www.reloadersnest.com/frontpage.asp?CaliberID=300

I have not used my 6x45 for deer as of yet but it may get used this year. The problem I have, is the distances around here can be quite long for most of my hunting and my 243WSSM usually gets the nod for antlered duty.
 
I have a Dtech 6X45 upper I am thinking of selling if anyone wants to PM for info. Just haven't used it for hunting, but I have worked up some loads.
 
From my understanding the 6 TCU has a sharper shoulder, less neck and the taper is blown out. Not enough to make a difference in my opinion to warrant the fire forming.
 
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I'm running a 6x45mm in a bolt gun and love it. It's a Rem 600 w/Pac-Nor 3 groove barrel 22". I'm using 55gr NBT's with H-335 and 55gr BK's with Benchmark both are very accurate. Both are running 3300-3350 fps.

I've also been playing with a 204 Ruger necked to 6mm. I just took it to the range for the first time last week, haven't had it over the Chrony yet but am thinking 3500 with the same bullets.

The 6x45 has put down a few coyotes with authority so this year I'll be concentrating on the 6mm-204 in the field.

AWS
 


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