Most Accurate Mag Fed Cartridge at 100 - 300 Yards?

[Phil3]

I am building a 6mmBR single shot rifle, but wondered what might be the most accurate mag fed cartridge at 100 - 300 yards? Some can make the 6mmBR feed from a mag, but would hate to build a rifle with a mag only to find out it won't feed reliably.

Phil

 

[Toby Bradshaw]

I am building a 6mmBR single shot rifle, but wondered what might be the most accurate mag fed cartridge at 100 - 300 yards? Some can make the 6mmBR feed from a mag, but would hate to build a rifle with a mag only to find out it won't feed reliably.

Phil

I don't know that anyone has done enough competitive ultra-precision shooting with magazine-fed (as opposed to magazine-equipped, as in hunter BR) rifles to have found anything that dominates like the 6PPC does in single-shot actions. But a well-built .223 shooting 52-75gr bullets (with appropriate twist for each bullet) would likely be in the hunt -- great brass (Lapua), great barrels, great bullets all available, and billions of rounds of experience feeding them from a magazine.

 

[Zero333]

6.5x47L

 

[earlcurtis67]

243 win or the 6mm Rem.

 

[Forum Boss]

A 6mmBR Norma can be made to mag feed reliably, but with most readily-available magazines it may be easier with a longer cartridge. The most successful mid-sized cartridge in international 300m competition is the 6XC, with the 6.5x47 Lapua moving up in recent years. Those would be my suggestions, assuming you don't want to fireform Dasher brass. Go 6XC if you want a little less recoil, go 6.5x47 Lapua if you want a little more barrel life.

I wouldn't bother with a .243 Win at all. Not very efficient... hard on barrels.

 

[BoydAllen]

With some modification Mike Bryant reports that he can get the BR to feed reliably. He is a benchrest competitor and smith with an impeccable reputation. You might want to ask him.

 

[waldo1979]

http://www.6mmar.com/

 

[br1111]

http://www.6mmar.com/

I had a 30 br on a sako a2 short action and it fed great!

 

[rvn1968]

+1 for the 6AR

 

[dskogman]

Here's what the PRS crowd uses
http://precisionrifleblog.com/2015/10/12/best-rifle-caliber/
6.5 Lapua, 6 Creed, 6.5 Creed, 6 Lapua

 

[Shynloco]

Personally, I see a somewhat self defeating result in using a magazine to feed your ammo and achieve the best seating depth that improves accuracy. There is a reason why most Bench Rest competitor use a single shot rifle. And this applies to magazine fed rifles. And that is because you are restricted from going beyond a certain loaded cartridge length (oal) because of the walls of a magazine. In other words, if you find your most accurate loads are seating the bullet longer than a magazine would allow, you are having to settle for LESS than your most accurate load. Now I'm sure there are a FEW experts (such as Boyd suggested) who'd be able to figure out a way to perhaps make a magazine work. But obviously, the top winners at competitions are using single shot rifles that allow them to load/seat to where the rifle performs the best. From a personal observation standpoint, that is why I load all my Benchrest rifles one cartridge at a time because the OAL would not be achieved using a magazine, which a few of my rifles actually have. And in recently testing new custom AR built for precision and accuracy shooting, I found my best seating depth (& OAL) could not be maintained when using a magazine and the result down range was obvious in group measurement. Good enough for some..maybe. Best possible grouping for me...absolutely not. Just my .02 worth.

Alex

 

[ireload2]

The .222 Rem and 6X47 Rem (6mmX222 Rem Mag) feed well in a Remington rifle.

 

[Changeling]

460 Weatherby and 2 guys.

 

[SG4247]

6 x 47 L from a .308 magazine.

6.5 x 47 L works great in that mag too!

 

[MClark]

What is your intended use for the rifle? Target, hunting?
A 6 PPC is accurate and will feed but is low on energy at 300 yards for a deer.

Mark

 

[Phil3]

Personally, I see a somewhat self defeating result in using a magazine to feed your ammo and achieve the best seating depth that improves accuracy. There is a reason why most Bench Rest competitor use a single shot rifle. And this applies to magazine fed rifles. And that is because you are restricted from going beyond a certain loaded cartridge length (oal) because of the walls of a magazine. In other words, if you find your most accurate loads are seating the bullet longer than a magazine would allow, you are having to settle for LESS than your most accurate load. Now I'm sure there are a FEW experts (such as Boyd suggested) who'd be able to figure out a way to perhaps make a magazine work. But obviously, the top winners at competitions are using single shot rifles that allow them to load/seat to where the rifle performs the best. From a personal observation standpoint, that is why I load all my Benchrest rifles one cartridge at a time because the OAL would not be achieved using a magazine, which a few of my rifles actually have. And in recently testing new custom AR built for precision and accuracy shooting, I found my best seating depth (& OAL) could not be maintained when using a magazine and the result down range was obvious in group measurement. Good enough for some..maybe. Best possible grouping for me...absolutely not. Just my .02 worth.

Alex

Good point. I want a variety of rifle types and want one that will fire from a mag, very accurately. I built an AR-15 for target use, knowing that gun will never be super accurate, but wanted to see how accurate I could make a mag-fed gas gun. With a heavy Krieger barrel and Geiselle trigger, it does well. I also will have a single shot 6mmBR, and for a mag fed bolt gun, was asking the question I originally posted here. I think the 6.5x47 is good for me, because it will go out quite far if I have the chance to do so but since my ranges are short, a short light bullet will probably still fit in the mag, and hopefully do well. If not, and a longer seating depth is needed, I may have to single load as you noted.

Phil

 

[Phil3]

What is your intended use for the rifle? Target, hunting?
A 6 PPC is accurate and will feed but is low on energy at 300 yards for a deer.

Mark

Purpose is strictly non-competition paper punching. 6PPC is probably best accuracy, assuming reliable feed, but wanted something simpler to reload for.

 

[chevytruck_83]

I also like the old 223 for short range. Wasn't McMillan's famous 5 shot group shot using the 222 remington? Which the 223 is an improved version of.

 

[potatoe]

Hey Phil, if its just paper punching why do you want it to be a repeater? I've had many rifles and by far the most satisfying and accurate paper puncher is the PPC. You could load cat litter and shoot .5 MOA it is very simple to load for . when I was shooting informal paper it was and still is my favorite round. Never tried a repeater though.

 

[chevytruck_83]

Ppc turns barrels into cat litter pretty fast though. Depending on your build Gary Eliseo makes a chassis and magazine specifically designed for the 6mm br to be mag fed. Though I talked to a very accomplished shooter using the setup and he said the cartridges had to be aligned in the magazines just right to make sure it would feed.