3 years of research and my final project is done! 224 minicoop

This project kept getting side tracked so I sent the first 22 X 6 Rem ala Gibbs barrel and dies to a retired officer friend in Idaho to run with for a while. He shot a deer with the 55 grain speer at 3500fps from his 16 inch barreled Striker last year. The bullet was recovered from the off side hide. The deer dropped so fast he thought he missed it. The first barrel had too steep a shoulder angle for my tastes so I had another reamer made with a 30 degree shoulder.

I was also having a terrible time smoking bullets from 12 and 14 twist barrels so just recently I received my 16 twist 3 groove 28" Benchmark barrel for testing. A new chamber and shortly it is back to Benchmark for Nitriding.
The case on the left is a 6Rem case that has been necked down prior to fire forming. Note on the next 3 cases moving right where the shoulder use to be. The next case is a 270 case and the case all the way to the right is a 280 Rem case that was sized to 338CE. Note the pre-shoulder lines on the improved case.


[img width=600 height=450]http://i311.photobucket.com/albums/kk460/emeraldislandlover/224minicooppicture.jpg[/img]

This past week I changed my powders and went faster. Using 52.5 grains of Rel 17 under the 36gr Barnes varmint Grenade and the 45gr Barnes solid as this weeks starting load I worked up to 55 grains of Rel 17 . After the past two weeks of thinking my new chony had died I purchased yet my third new Chrony to run these bullets over. My wife Lisa recorded all data yesterday. She actually commented on how excited I was when I got the first bullets past 3000fps from a 16" handgun barrel. The bottom right picture is five 36 gr barnes average 4085. Same powder charge using the 45 grain cnc brass solid from barnes I increased the velocity 100fps average. Pictured in the top left target are 3 36gr Barnes bullets with 55grains of Rel 17 @ 4300fps! The barrel is the twin to the original barrel sent to Idaho except it has been throated a bit deeper and also rechambered with the new reamer to a 30 degree shoulder. Yes that black is Nitriding.

All targets were shot at 100 yards. Can you imagine what these bullets will do to a rockchuck? Or that 45gr solid to a coyote? With the 12" longer rifle barrel at a 16 twist I have calculated 5300-5500fps. Only time will tell if it will be possible. Both the pictured gun/barrel and the new 28" rifle barrel with plenty of ammo will be at the Varmint Jamboree this year.




Neal[img width=600 height=450]http://i311.photobucket.com/albums/kk460/emeraldislandlover/224minicooptarget.jpg[/img]

The barrel,brass and die are available for testing to the right person.

That is pretty awesome. How many rounds do you expect on the barrel?

".....and my final project is done!"

I certainly hope that is just a slip of the tongue and not a prophecy.

uj

ok, just to get solid grasp, it is a 6mm rem case with a .224 bullet.

what change did you note with the angle change?

Me like!!!!

Fast 22's are hard to beat!!!!

How does this cartridge compare to the standard 22/6mm or the 224TTH?

uj

From what I can tell, it's a 6mm Rem case with the neck shortened (body blown out) and the shoulder angle changed to 30 degrees. More capacity than a 22-6mm AI and theoretically a more accurate shoulder angle.

Seriously, how many accurate rounds are you expecting?

It is intended that this is the last of a long line of wildcats. I have a 375 RUM project underway that I hope to have finished in time for the Sept moose/griz hunt.

The change in design accomplished several things.
1. Gave me a tad better efficiency. I still had case capacity when I hit pressure before so had to go to slower powders. Slower powders in handgun barrels do not equate to the velocities I require.
2. I have room for 2 more grains of powder if I so choose before I have a bullet that touches the powder.
3. There is absolutely NO sharp or restriction areas in that funneled called the neck shoulder area.

The case on the far left is much like the TTH except I ran the neck too deep into the die. The Texas Trophy Hunter if I recall is simply the 6 Rem case necked to 224 and nothing else. If you look at the shoulder ring on the improved cases you can see how I improved and increased the powder capacity. My starting load is the max load that guys are using in the TTH! Now for the cool factory. I have a 224 Weatherby sitting here. Take the belt off and shorten the case .250 and this case looks just like a Weatherby.

Case life: ?? This is a Nitrided barrel as will the 28" 16 twist. Heat burns barrels is all I can say. Nitride causes barrels to run cooler and shooting these little bitty bullets I am going to say I don't think I will have a barrel life any different than a 22-250. I am suppose to build a wolf/coyote 1000 yard shooter with an 8 twist barrel for high BC 80 grain 224 bullets. Along with my 6.5 WSM we are watching and measuring the wear. AT 250 rounds Benchmark barrels says there isn't any wear yet. ANother shooter is pushing 142's very hard in his 6.5WSM and there is minor appearance of having been shot after 900 rounds.
For those unfamilier with the barrel life of the 6.5WSM, barrel life of 900 rounds is double and more of what a typical unnitrided barrel gets.

I have hunting and fishing to do and a remote site cabin to build and haven't the time to be running metal equipment.

Neal

Very cool Neal! I think that this could give me a use for my 12 twist 22-250 LRPV barrel. The faster twist would probably work well with the mid range bullet weights at that speed.

Good luck with the 375 RUM project as well. That should make the 375 JDJ look like a child's handgun!

Andrew