243/6mm rifle build...thoughts?

[lancetkenyon]

Cheap button. .243 Win
Only a sizing die swap and some fire forming. .243AI
Best brass options. 6CM (Lapua, Alpha, Peterson)
New kid on the block. 6GT But I think you will lose a bit of performance, but also loading less powder/recoil and better barrel life.

I have a 24" 6CM. The "Mr Confidence" nickname was given to it by my shooting buddies.
I have taken pronghorn, and a ton of coyotes out to 921 yards, and about a thousand rounds on steel. Not sure how much more life I will get out of the barrel, but I will shoot it until it gives up the ghost. 105 Hyb @ 3188fps is no slouch. It is my truck gun on scouting trips, because it annihilates coyotes. Can't wait for July 1st to go smoke some prairie dogs with it too.

 

[lancetkenyon]

Go 30 inch and ackley might get 3100 plus fps.

I get 3188fps w. 105 Hybs in my 24" 6CM.
I get 3050fps w. 130 OTMs in my 24" .260AI.

A 30" .243AI better get 3400+ with a 105.

 

[Deleted member 8840]

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If you need more than 26" to get your velocity, you are really running the wrong cartridge in most cases. Ignore if you are shooting past 1,000 yards regularly or if you are shooting PRS competitively.

I run a 30 inch barrel in a 28 nosler that pushes a 190 atip at 3330. Its sonic to 2650 and shoots 4 mils at 1000 and shows 1000 lbs of energy at 2000 yards. I quess thats the wrong one also.

 

[JAYgs8163]

Do a 7 twist 6CM and don't look back. I built mine after a long discussion with Berger tech and a Krieger smith and some load help with @lancetkenyon. 7 twist will stabilize the heavies (Krieger and Berger recommended). I built mine with a 22" Krieger 7twist cut rifle barrel for hunting. I like that rifle so much I built another for target and varmint hunting. Pet load is a 115 Berger, running around 3045 FPS with H4350. Super accurate. Easy to find components, so easy to tune a load for. My smith throated to run 105-115 Bergers.

 

[mdmiller]

I just built a 243 on a Savage target action with a 30 inch 1 in 7 twist barrel. I'm pushing the 115 nosler rdf and the 112 barnes matchburners burners at 3050 fps. The bc on both are close to .643 on both. I have shot it out to 1500 and still been very accurate. With the 30 inch barrel no ackley is needed. It may be the most accurate rifle I've owned out to 1500. Shooting the highest bc and heaviest bullets for the caliber. I'm using lapua brass superperformance powder and like I said accurate accurate accurate!!!

What's your COAL for these bullets?

 

[SSG Graybush]

I have a 243 and a 6XC. Both are great. 6XC is right in between the 6cm and 6x47 for case capacity. For hunting the GT would limit your effective range the most. No matter what you get get a 7T barrel.
The 6XC is pretty turn key with a 112 to 115 gr bullets. 39.5 grs of H4350, play with jump and bam, .5 moa or less. Criterion makes good remage barrels for the 6XC. For target shooting I'd definitely do a 6XC again, and it will carry 1000 #'s of energy to 800 yards at a attitude of 7200 ft, for hunting. If you want more range a 243, 243 AI or 6CM would be in order. Especially if you want to make long shots at lower attitudes when hunting. Or want to play around at 1 mile with it.

 

[Bang4theBuck]

Well, since I've had both of the cartridges referenced as well as a 6x284, and 6 dasher, and 6CM. I rechambered the 243 win to a 6 dasher and it shoots very well after thousands of rounds, and I sold the 6CM because both the 6GT and the Dasher out performed it from an accuracy standpoint (not due to cartridge). I can say that my 243 was lights out with 105 Hybrids, in an 8 twist barrel. This simply comes down to choice. 6GT brass is readily available, don't let anyone tell you differently. CCI 450s have been much more available than other large rifle primers, like you would have to use in a 243 case. And yes, there is no doubt that the 6GT is more efficient. You will cover the cost of the additional brass and dies in a jiffy based on the reduced powder charge, and the extended barrel/case life that you get. If you go really rogue and sell your 243 Win stuff, the economics of look even better. There is no wrong decision, as far as I am concerned.

 

[Sid Post]

I run a 30 inch barrel in a 28 nosler that pushes a 190 atip at 3330. Its sonic to 2650 and shoots 4 mils at 1000 and shows 1000 lbs of energy at 2000 yards. I quess thats the wrong one also.

For the OP, and what he is doing and what I think he wants, a more 'standard' 6mm/243 is probably the best fit since he is 'married' to his "pet Remington 700 in 243 Winchester".

Sticking with the same action and similar cartridges to me suggests things like the 243AI, 6GT, 6XC, etc. are more appropriate.

No offense intended but, my 358 Norma Mag replacement wouldn't be a 338 Lapua or modern Norma. They are just too different in use to be comparable to me. If I rebarrel my 338 Lapua, I'll do the new 338 Norma. If I rebarrel my 358 Norma Mag it will be with another 358 Norma Mag barrel!

All this being said, most of what is being discussed beyond the obvious, is not a big factor for most of us in practical uses of our rifles/cartridges. I may prefer a 6XC but, if I was given a 6GT I doubt there would be enough difference to me to cause me any heartburn or regret. Same with a 338 Lapua and 338 Norma. At some point were are splitting hairs with no practical difference to 99% of the people building rifles and even less to those actually running them hard!

I shot good generic AR-15's for ~20 years until I realized I would benefit from a better rifle. That KAC SR-15 LPR has been a real eye-opener for me in skill development! That being said, any good AR-15 inside 200~400 yards will serve me well. The OP is essentially there so, an appropriate cut 243Win barrel will likely exceed his expectations by a big margin but, personally, I think one of the PRS targeted 6mm cartridges is where he would see the best "value". In my case, I am thinking about a 6ARC for my AR-15 needs when my 5.56 isn't enough because I need more payload for feral hogs and less drop helps when shooting running feral hogs and wanting less recoil recovery time than my other rifles.

 

[Allen Lone wolf]

Based on everything thing you said your 243 fits you perfectly. I would rebarrel in a twist to accommodate those heavier bullets you want to shoot and call it a day. If it ain't broke and you love it don't fix it.

 

[Airedale56]

Check out the Weatherby 307 rifle with an updated twist rate for the .243.
I'll be buying the Magpul version.

I've run a .243 since 1999 in a Weatherby Accumark ULW / Leupold 4.5-14x50 with either Hornady 58 VMax or Barnes 85 TSX on coyotes and antelope.

Great combination.

I'm moving to the WBY 307 .243 to replace it solely because I'm going to screw in a factory takeoff WBY ULW .338-06 A-square barrel in my ULW for big game here.

The 307 is a Rem 700 style action with some updates and the reason I'm passing it along is because it may not be much more $$ than a re-barrel job. Something to consider.

Good luck with your project.

 

[big7fan]

I would also look at the xc. I have three of them, all on short actions. One each 7, 7.5, and 8 twist. All longer throats
Shoot bergers out of all of them and all will shoot 1/2 moa at distance. I shoot these out to 1K

115 Vlds out of the 7 T at 2960 fps
105 vld out of the 7.5 T at 3070 fps
105 vld out of the 8 T at 3150 fps
Every thing Ive killed with these have been one shot kills ...mule deer, whitetail and a 400 lb black bear at 150yds. Bear dropped and didn,t even twitch.
I could shoot 115s out of all of them but ended with a bunch of 105s and really like how they perform

 

[Nomad8961]

I say stay with a 243 or the Ackley version in the twist and chamber for bullets you plan on shooting. I just picked up a McWhorter custom 243 with a rem model 7 action at a pawn shop for 800.00$ and it shot a .3 three shot group with factory ammo! Needles to say its my new favorite rifle.

 

[300 Driver]

Hello everyone! I'm thinking ahead a bit, but I'm considering a 6mm build in the next couple of years. I will preface this discussion with the fact that I will be building the rifle on a Remington 700 action in 243 Win. I have shot thousands of rounds out of this rifle, and it is my favorite gun. Period. I've killed prairie dogs, varmints, coyotes, deer, and antelope with it. Shot paper, steel, shotgun shell hulls, and coins with it. The thing has always been a tack driver, and I it!

Anyway, my only complaint about the gun, being a factory rifle in 1-9.5 twist, is that I could not stabilize anything heavier than 95 gr pills out of it. Groing in the long range game, I've found myself leaving the gun in the cabinet in favor of my 7mm Rem mag and 308 Win.

I'm torn about what cartridge to focus on for a new build. All would have a 28 inch barrel with a 1-7" twist.

243
Pros - I already have a love for the chambering, I have the dies, brass, etc.
Cons - you cannot let the heavier bullets out as much (COL) as I might want to.

6CM
Pros - There are components, specifically brass, available. There is more room to seat bullets out in the short action mags.
Cons - I'd have to buy new brass and dies. I will also be honest that I don't want to become part of the CM fan Boyz I like my older cartridges.

6 GT
Pros - From everything I've read, you get more for less. The same velocity, less powder, less recoil. The chambering looks exceptionally efficient! I can let my seating depth out even more than the CM.
Cons - finding brass looks to be a pain in the ***, and again I'd have to get new dies. It doesn't hurt my pride as much as becoming a fan boy, but switching still hurts my pride a bit.

Those are my thoughts. I'd love to hear what y'all think. Thanks in advance!

I was in your shoes a couple years ago with a factory 243 Win and a 10 twist. Savage 10. I went with a 1:8, 25"(just because I could) barrel. I have no regrets launching my stockpile of 105Amax at 3100fps. The largest game I have shot with it is whitetail and axis at 50 to 550yds. Now that my barrel is nearing replacement, I have been thinking about this lately as well. My conclusion is that I am going to get a 22", 7 twist barrel next, but throat it long to take advantage of the extra space in my magazines.

My opinion, stay with 243 Win. You already have components and it will do anything the AI, CM, GT or any other 6mm can do to a game animal. Spend the money saved on RL26 when you find it!

 

[billywreid]

Hello everyone! I'm thinking ahead a bit, but I'm considering a 6mm build in the next couple of years. I will preface this discussion with the fact that I will be building the rifle on a Remington 700 action in 243 Win. I have shot thousands of rounds out of this rifle, and it is my favorite gun. Period. I've killed prairie dogs, varmints, coyotes, deer, and antelope with it. Shot paper, steel, shotgun shell hulls, and coins with it. The thing has always been a tack driver, and I it!

Anyway, my only complaint about the gun, being a factory rifle in 1-9.5 twist, is that I could not stabilize anything heavier than 95 gr pills out of it. Groing in the long range game, I've found myself leaving the gun in the cabinet in favor of my 7mm Rem mag and 308 Win.

I'm torn about what cartridge to focus on for a new build. All would have a 28 inch barrel with a 1-7" twist.

243
Pros - I already have a love for the chambering, I have the dies, brass, etc.
Cons - you cannot let the heavier bullets out as much (COL) as I might want to.

6CM
Pros - There are components, specifically brass, available. There is more room to seat bullets out in the short action mags.
Cons - I'd have to buy new brass and dies. I will also be honest that I don't want to become part of the CM fan Boyz I like my older cartridges.

6 GT
Pros - From everything I've read, you get more for less. The same velocity, less powder, less recoil. The chambering looks exceptionally efficient! I can let my seating depth out even more than the CM.
Cons - finding brass looks to be a pain in the ***, and again I'd have to get new dies. It doesn't hurt my pride as much as becoming a fan boy, but switching still hurts my pride a bit.

Those are my thoughts. I'd love to hear what y'all think. Thanks in advance!

Try out a 243 Ackley. Old school round that is friendly on saving brass to last 2-3 times longer than normal 243. Until you shoot a few rounds to fireform, you can use regular 243 rounds. Better performance than the 243 win. I have 2, a Remington 700 & a CZ 550, both with set triggers. My Remington with a 26" Shilen 1-7" barrel is my go to almost every time. After a little time and effort, I finally found the perfect powder bullet combination using Berger 115 VLD for hunting and H4350 powder pushing it just under 3200. Amazing round.