Need advice on AR build .204 Ruger or 6 X 45????

[Jm32526]

See.... This is why I love this site!!! Outstanding input from everyone.

my wife loves the 6x45 the only problem is I cant reload fast enough

HA!!! I hope I don't run into that same problem, but if I did that would be fine with me!!!

 

[Jm32526]

Ive not shot a 204, but did build 2 20 Practicals for p-dogs & coyotes on a bolt & AR15 actions few years back. After dismal effects the wind (15-23MPH) had on the 20 calibers I got rid of them. I have shot tons of p-dogs with the 6x45 with 55g bullets in the range you want. One still needs to dial/hold for drift when the winds are blowing. The 6x45 is also very nice for deer sized game with a 80g bullet. I have 11 6x45s builds under my belt. I use 1/10" twist, heavy sporter bbls, 20" on AR15s and 22"-24" on bolt builds. I stopped using heavy varmint bbls since the heavy sporter is as accurate and carry weight is a bit less. If its going to be a bench type rig then yes Id go with a varmint bbl.

Well.....It's tough to argue with someone who has 11 6x45 builds under their belt. 6X45 it is!! That is interesting about just going with a heavy sporter. I did plan on mostly bench rest but I like the idea of it being a little lighter to carry. I will most likely do at least a muzzle break if not a suppressor so I would suspect recoil would be minimal either way.

 

[Jm32526]

I use a 6x45 with a 20" barrel length. Sierra 80grn Varminter #1515 bullets with a full load of 8208XBR. Look at the knock down power of 1166 ft./lbs. of energy at 100yds. & 940 ft./lbs. of energy at 200yds with this load. That's 25% more energy than my 204R AR-15 with a 20" barrel shooting factory Hornady Superformance 40grn V-Max bullets. I'm getting 892 ft./lbs. of energy at 100yds. & 708 ft./lbs. of energy at 200yds. With the factory Hornady 32grn V-Max bullets in my 204R AR-15 the energy at 100yds. is 747 ft./lbs. and at 200yds. 552 ft./lbs. of energy.
The 204R will work however, the 6x45 will do it better.

Thank you for the load data. Seems like you also have pretty good luck with a 20" inch barrel. Do you mind if I ask the twist rate?

 

[Jm32526]

Lots of different input so far, all hunt varmints much differently than I do. So without know if you are going to walk, or shoot from a table, how many rounds per year you expect to fire, distances you want to shoot at, etc. - you may get vastly different answers.

I shoot a lot of PD's each year (over 5,000 this year), so barrel life and recoil is important to me. I shoot by myself and have to spot my own rounds. So I shoot a 20P in a 10T 24" WOA varmint barrel. Always off a shooting table. I use an A2 stock with the butt stock weight in it. Balance is terrible, but it doesn't move when I fire it. I can spot hits with the scope on 24 power. When the pups come out in May, it is carnage. But you may hunt vast differently than I do.

5000 this year..... I don't suppose you'll save some for the rest of us??? I will be lucky if we go varmint hunting more then twice a year, hopefully more if I can peak my wife's interest enough. I just want to make sure I put a build together that increases her level of success and confidence.

 

[Jm32526]

just build 2 uppers and shoot what you are in the mood for. that is what I did for a while

It's funny you say that. That is actually my plan, but it will be a while before I scrape enough funds together to build another upper. I just want to make sure I start off on the right foot so to speak...

 

[RussellJ]

Thank you for the load data. Seems like you also have pretty good luck with a 20" inch barrel. Do you mind if I ask the twist rate?

1 in 9 inch twist.

 

[fredo]

Listen to “5 spd”
He probably shot more 6x45 Rifles
Than anyone on Earth!

I know the first 6x45 he ever shot, was one of mine...LOL

If p-dogs are your main game, a .20cal. 39Blitzking offers as much, or more 'splattericity' than a 6x45 with a 70Blitzking...out to about 350yds. Past that, they're about equal in p-dog Jell-O production.

 

[fyrewall]

For a AR type rifle I would go for the 6X45. I once had a 6X47 (6mmX.222 Mag). My bullets of choice were the 60? and 75 grain Sierra with H335 powder. It shot real well and had extremely good barrel life and could be fired over 100 times without cleaning. Availability of cheap .223 or 5.56X45 brass should provide a good pile of cases for volume shooting. Provided, I am not shooting in tall grass, weeds, or snow my recovery rate for cases fired from semi auto weapons is about 85%. I have 2 .204 Rugers - flatter trajectory, slightly less recoil but much more expensive brass. Having a AR rifle means a person can really hammer away on the varmints, most likely rodents, without working a bolt and loading rounds - this enables shooting without the distraction of loading. A common ordinary .223 loaded with a bullet like the 53 grain VMax would probably be a more practical choice.

 

[Jm32526]

For a AR type rifle I would go for the 6X45. I once had a 6X47 (6mmX.222 Mag). My bullets of choice were the 60? and 75 grain Sierra with H335 powder. It shot real well and had extremely good barrel life and could be fired over 100 times without cleaning. Availability of cheap .223 or 5.56X45 brass should provide a good pile of cases for volume shooting. Provided, I am not shooting in tall grass, weeds, or snow my recovery rate for cases fired from semi auto weapons is about 85%. I have 2 .204 Rugers - flatter trajectory, slightly less recoil but much more expensive brass. Having a AR rifle means a person can really hammer away on the varmints, most likely rodents, without working a bolt and loading rounds - this enables shooting without the distraction of loading. A common ordinary .223 loaded with a bullet like the 53 grain VMax would probably be a more practical choice.

You make a lot of great points. I really agree with you on the .223 brass angle. I have enough of that to keep me happy. I am definitely going to start with a 6x45 upper. If I really like the results I will probably leave it alone. If not, I can always build another upper. That’s the benefit of AR’s. By the way... Thank you for the load data!

 

[fyrewall]

In the old days the 6mmX47 (6mm - .222mag) was touted as the bench rest cartridge then the 6mmX45 (6mm-.223). Better ballistic properties than comparable .224 bullets were the apparent reason. I liked my 6X47 and used it for rockchucks and targets but now getting a large supply of .222 mag brass would be a problem. If I had to do a 6mmX45 (6mm-.223) project I would try out the 55 to 65 grain 6mm bullets to get higher velocites. All sorts of powders would work. My Berger manual has data for the 6X45. Using the lighter bullets loaded rounds should fit into an AR magazine.

 

[GrocMax]

If you want to wildcat, the 6TCU is what I am building my bolt gun on. 6x45 Ackley.

Be aware the 6TCU and 6x45AI are not the same, don't ream for one and buy dies for the other, ain't gonna work. TCU has a longer neck.

 

[Hotshot]

I have had both in ar-15. I currently have 3 6mm rifles, 5
20cal rifles and a couple 22cal. I started shooting prairie dogs with my dad when I was 7, that's 60 years ago. I've shot hundreds of thousands various rounds at prairie dogs over those sixty years in several states. I can't imagine what circumstances would possess me to choose 6x45 over the 204R. Not even close in my opinion!