So many 6mm calibers to pick. Which one for PRS and why?

[bross412]

Hey everyone,
I shot my first PRS match over the weekend and I am officially hooked. I am looking to build a PRS gun. I am new to the whole precision rifle scene, and I am looking for some advice on a 6mm. I looked at the options and there are many. I am looking to get an Impact Precision 737r action. Any advice on which 6mm to get and why? Currently, I am thinking 6BR, but I've heard there are feeding issues? Is that true?

 

[Mordamer]

There are not feeding issues with 6 BR if you get the correct mags. Lots of top shooters use 6 BR in an Impact 737R.

Do you reload?
Do you mind fire forming brass and shooting a wildcat cartridge?

If you don't want to always reload then 6 Creedmoor is the no brainer choice.

If you do reload but don't want to fire form then 6 BR is a great option. 6 Dasher with factory Alpha, Peterson, or Hydroformed lapua is also a great option.

If you do reload and you don't mind fire forming then that opens up 6 BRA as an option.

My advice if you aren't deep into reloading is to get a regular 6 BR and use it. With a 105 Berger Hybrid or 110 A-Tip going about 2,800 FPS there probably isn't a match out there you couldn't win if you did everything else right. This is the easy button and there is no drama on loading for the cartridge.

 

[BrienM]

I’m pretty stuck on my next one being a 6br .. low recoil, great efficient cartridge and barrel should last several shots. No fire form fuss for me.. but I also have a 6cdm.. pick one and go.. they all work good.

 

[bross412]

I just got all the items to reload except the dies. So yes, I plan on reloading. That is all great advice. Thank you.

 

[Mordamer]

I just got all the items to reload except the dies. So yes, I plan on reloading. That is all great advice. Thank you.

If you are just getting into reloading then 6 BR makes more sense than anything. Load it nice and mild and it will treat you right.

 

[bross412]

thanks @Mordamer and @BrienM I think 6BR is the round for me.

 

[Krob95]

+1 on a 6BR. I have an Impact 737R with a kreiger barrel chambered in 6BR. I use the MDT 6BR 12RD mags and haven’t had one single issue in the last 700 rounds I’ve put through the rifle.

 

[hereinaz]

Consider 6bra or 6brx if a straight 6br is on the menu. Fireforming loads in either of them from 6 br brass are plenty accurate for a local match. Then you get a little bit more velocity on second loads. I am building a 6bra now, its not for competition, but I did ALOT of reading on them.

Hope you have some small rifle primers or start looking for them now... I am glad I have a few hundred laying around.

 

[Sheldon N]

Hard to argue with a straight 6BR for someone getting started in PRS and wanting an easy, accurate shooting round. Feeding with the straight 6BR is going to be pretty much the same as any of the the other BR based 6mm cartridges. Lots of guys go with 28" barrel to get a bit of speed back.

FWIW I shoot a 6BRA and am very happy with it. Once you get the brass fireformed it will last you a long long time.

 

[PracticalTactical]

I find 6mms to be a bit of a trick. If we think about popular over the counter options, we have the 6BR, 6PPC, 6XC, 6 Creed, 243, 6x47 Swiss, maybe a few others and besides these, the rest are hand loaded wildcats.

What throws me off is the powder capacity gap between the 6BR/6PPC and all the others.

I know of no over the counter cartridge with a powder capacity in between... and that's why so many popular home brew rounds are in the middle.

I'm a huge fan of the 6x47 Lapua but only with large primers and even that is truthfully a little hot. The 6 Dasher is sweet but a royal PITA to form brass.

When is someone going to mass produce a suitable round in between the 6BR and everything else?

The manufacturers keep taking the cheat and necking down a larger cartridge and passing it off to us without having the decency to reduce the powder capacity proportionally to the smaller bullet.

 

[spife7980]

Making dasher is as hard as jamming a bullet over 30 grains of Varget and pulling the trigger

 

[bross412]

So i think im going to go with the 6BR, any idea on the twist rate? 7 or 7.5?

 

[sleeplz]

Go lone peak, impact is great but I played with both and decided to pick up the peaker. Go 6br, fireforming is an extra step and burns more of your powder/primer. It also takes away time from what you really wanna shoot and time is mas importante to me.

 

[Krob95]

So i think im going to go with the 6BR, any idea on the twist rate? 7 or 7.5?

I run a 7.5tw and it stabilized the 115dtacs. I shoot 105 berger hybrids tho and have zero issues.

 

[BrienM]

I think my next 6br barrel will be a 7.5 twist. 8 will do but we get some cold weather and I feel like the 7.5 would treat me better.
Something else I learned recently, Borden actions has their own version of AICS style magazine built for 6br (Borden-Accurate mag 10round Dasher/BR mag. That may be something worth looking into for us wanting to run shorties. They're on page 3 of the attachment https://bordenrifles.com/wp-content/uploads/2019/Borden actionretail pricelist_2019.pdf ... That borden super short 6 action would be awesome too!!!

 

[Wheres-Waldo]

For the purposes of PRS style competition and accuracy expectations, what is a reasonable barrel life range for a mild 6BR?

I’m near the death of my current 6Creedmoor barrel and the 6BR has my attention just due to barrel life potential.

 

[hereinaz]

I find 6mms to be a bit of a trick. If we think about popular over the counter options, we have the 6BR, 6PPC, 6XC, 6 Creed, 243, 6x47 Swiss, maybe a few others and besides these, the rest are hand loaded wildcats.

What throws me off is the powder capacity gap between the 6BR/6PPC and all the others.

I know of no over the counter cartridge with a powder capacity in between... and that's why so many popular home brew rounds are in the middle.

I'm a huge fan of the 6x47 Lapua but only with large primers and even that is truthfully a little hot. The 6 Dasher is sweet but a royal PITA to form brass.

When is someone going to mass produce a suitable round in between the 6BR and everything else?

The manufacturers keep taking the cheat and necking down a larger cartridge and passing it off to us without having the decency to reduce the powder capacity proportionally to the smaller bullet.

6 GT?

 

[Mordamer]

For the purposes of PRS style competition and accuracy expectations, what is a reasonable barrel life range for a mild 6BR?

I’m near the death of my current 6Creedmoor barrel and the 6BR has my attention just due to barrel life potential.

3,000 rounds

 

[BrienM]

I agree with 3000. Lots of things can affect that number (Cleaning/lack of, heat stress, how hot you run it,etc)

 

[bross412]

@BrienM how often do you clean your barrel?

 

[BrienM]

I clean after every match.. Some are 40+/-.. some are 100+/-.. That being said.. I have only participated in 5 PRS matches.. there are some on here that are really good and probably better references for information. My wife has a bartlein 6br 8"twist.. been shot near/over 1K. had for 3 summers. It looks same as the day we brought it home. It hasn't been ran in PRS..

 

[Ledzep]

Mild 6's are fun. I've been running a 6mm ARC for the last few matches and it's killer. Effectively mimics my old 6.5 Creedmoor trajectories (110 @ 2940fps, 28" barrel), minimal recoil, minimal barrel heat, 3000+ barrel life. Feeding is a non-issue with un-modified MDT BR mags. The only thing that's a pain for the 6 ARC specifically is bolt faces. I have ~1000 rounds on the barrel and bore scoped it last night and there's the beginning hints of heat checking for about 0.25" in the throat, the rest of the barrel is clean/polished. It looks like a 6 creed that has like 200 rounds on it.

6 BR is in the same realm with a standard bolt face. If I was going to mess with a variant on the BR I'd try BRX, but I have a hard time talking myself into fire forming.

I've also run a 6mm Competition match, and was not a fan. It's the reason I hate fire forming (PITA, waste of barrel life, time, etc.. Not for me), and the barrel life suffers running 49gr of powder. Hell, stuffing 49gr of powder into the case was a PITA in itself. I also tried a 6mm Creedmoor and the short barrel life is a turn off. I found the 6.5 Creedmoor to be more forgiving, better barrel life, etc... But the little mild 6's I can get along with.

One bummer, though... Don't expect to see much splash on plates past 800. If the match doesn't have hit indicators on the long shots you might be in trouble. I have lost points where R.O.s couldn't see it and didn't hear it with all the other shots going off. Especially on the 1000+ targets with any mirage.

 

[bross412]

Mild 6's are fun. I've been running a 6mm ARC for the last few matches and it's killer. Effectively mimics my old 6.5 Creedmoor trajectories (110 @ 2940fps, 28" barrel), minimal recoil, minimal barrel heat, 3000+ barrel life. Feeding is a non-issue with un-modified MDT BR mags. The only thing that's a pain for the 6 ARC specifically is bolt faces. I have ~1000 rounds on the barrel and bore scoped it last night and there's the beginning hints of heat checking for about 0.25" in the throat, the rest of the barrel is clean/polished. It looks like a 6 creed that has like 200 rounds on it.

6 BR is in the same realm with a standard bolt face. If I was going to mess with a variant on the BR I'd try BRX, but I have a hard time talking myself into fire forming.

I've also run a 6mm Competition match, and was not a fan. It's the reason I hate fire forming (PITA, waste of barrel life, time, etc.. Not for me), and the barrel life suffers running 49gr of powder. Hell, stuffing 49gr of powder into the case was a PITA in itself. I also tried a 6mm Creedmoor and the short barrel life is a turn off. I found the 6.5 Creedmoor to be more forgiving, better barrel life, etc... But the little mild 6's I can get along with.

One bummer, though... Don't expect to see much splash on plates past 800. If the match doesn't have hit indicators on the long shots you might be in trouble. I have lost points where R.O.s couldn't see it and didn't hear it with all the other shots going off. Especially on the 1000+ targets with any mirage.

Thanks for the info. I never thought about the splash at distance. First, I have to worry about hitting the target before I worry about getting docked points

 

[Krob95]

I clean my barrel about every 200rounds with just CLR to break up any carbon in the throat. I expect to get 3k out of the barrel as I run a pretty standard load and it doesn’t get super hot when I shoot.

 

[BrienM]

Ledzep said : "One bummer, though... Don't expect to see much splash on plates past 800. If the match doesn't have hit indicators on the long shots you might be in trouble. I have lost points where R.O.s couldn't see it and didn't hear it with all the other shots going off. Especially on the 1000+ targets with any mirage."


That is one reason some people like the 115's in 6mm calibers.. I'm with you @bross412 I'm still trying to figure out how to hit them too.. lol.. Man is it fun though!!!

 

[hereinaz]

Go lone peak, impact is great but I played with both and decided to pick up the peaker. Go 6br, fireforming is an extra step and burns more of your powder/primer. It also takes away time from what you really wanna shoot and time is mas importante to me.

You were doing fireforming wrong, imo...

 

[kthomas]

6BR or 6BRA.

6BR is simple, time proven and with the right equipment is really easy to get running in our PRS rifles.

6BRA is what I've converted to. Original firing is essentially 6BR, and after that you have the extra capacity to load up a bit faster if you choose (~80-100 fps). If you want you can still load to 6BR specs, and leave more room in the tank for a huge pressure tolerance window, or you can step it up if needed. Fireforming is really easy, no need to jam bullets or create a false shoulder, and FF rounds have proven to be super accurate for me.

Lot's of great 6mm rounds these days, with their own subtleties and nuances. I've settled on to the 6BRA as I appreciate the ease of FF, the little extra velocity over straight 6BR, the precision potential (it's slaying on the 1,000 yard BR circuit right now) and the ease of loading.

 

[sleeplz]

You were doing fireforming wrong, imo...

How so?

 

[b6graham]

How so?

fireforming is basically just shooting a 6BR. fireform loads hammer and are just a little slower. definitely useful rounds and not a waste. plus if its new brass on a new barrel you get through the speedup fireforming

fireform in local matches at 2850. BRA/dasher at 2900-2950 for bigger matches or once you're through all your brass

 

[B-P-UU]

Lots of good advice so far.. you are on the right track with BR-based cartridge.

BRA definitely has some advantages and FF is stupid simple with great accuracy and performance. Straight-BR is easy button and you won't outgrow it.

Lapua brass is king

 

[kindabitey]

Any of them, the easiest way to choose is to write the cartridge name on a small piece of paper, attach to wall, and throw a dart
at them with your eyes closed
Honestly, I've gone from BR to Dasher and now at GT. Not much difference in any of them.

 

[spife7980]

I think my next 6br barrel will be a 7.5 twist. 8 will do but we get some cold weather and I feel like the 7.5 would treat me better.
Something else I learned recently, Borden actions has their own version of AICS style magazine built for 6br (Borden-Accurate mag 10round Dasher/BR mag. That may be something worth looking into for us wanting to run shorties. They're on page 3 of the attachment https://bordenrifles.com/wp-content/uploads/2019/Borden actionretail pricelist_2019.pdf ... That borden super short 6 action would be awesome too!!!

I would go 7 twist, especially at br speeds the extra twist wont hurt and only help if you want to run 115s.


Ive heard some not great things about the borden super short 6 action or whatever its called but I cant find the thread on it now.
Id be hesitent of their mag situation as it was sort of the inverse of what people found to work best in a normal rem700 short action foot print. Normally we use a spacer at the back of the mag to keep the rounds up on the feed ramp at the front. The borden action pushed the bullets to the back of the mag and then extended the tennon to bring the feedramp back to it I believe meaning that the mag would have a huge gap to overcome when used in a normal rem700 footprint. I reserve the right to be wrong since I cant find the old thread. All of the links on Bordens website have been scrubbed of it as well.

Edit: I see on their facebook that they are still working on followers etc to get it to feed

 

[kthomas]

The Borden super 6 short action seemed like a cool concept, but in practice has some quirks that need to be worked out. Borden makes a great action, but I think this action needs a little bit of re-work before it becomes a more practical option to recommend to the mainstream.

Lot's of other great actions out there to choose from, that are capable and proven of running the BR family of cartridges. I'm using a Mausingfield for my 6BRA, and my wife's 6BRA is on a LP Fuzion. Both work great, both have their own nuances and features that may or may not be to your specific liking, but I can wholeheartedly recommend either action.

 

[Brandon05_88]

.243 Win

 

[S3th]

6BR w/ 95gr TSMK for 600 yards and in matches
Matches with most targets over 600 yards, I would run a 6GT

 

[FCrifles]

Pick your poison, really no bad choice and any of the calibers can/do win. Worry more about building a stable position and breaking good shots with follow through. You get that mastered and you will quickly realize cartridge choice is pretty low on the list.

 

[BrienM]

We have a primal rights kit in an AI mag as well as an MDT 6BR mag.. Can't think of a hiccup with either one.. the MDT mag is my daughter's. I agree with FCrifles.... no perfect round out there..

 

[1moaoff]

And this question is why I have rifles in
243
6 creed
6mm comp match

 

[1moaoff]

Don't ask about 6.5 calibers... similar answer

 

[hereinaz]

And this question is why I have rifles in
243
6 creed
6mm comp match

Hahahaha, 6xc, 6cm, .243, and soon a 6bra for me. I almost ended up with a 6 grendel too...

 

[bross412]

Hahahaha, 6xc, 6cm, .243, and soon a 6bra for me. I almost ended up with a 6 grendel too...

Can you guys give me the GPS location for this infinite money tree?

 

[Wheres-Waldo]

Apparently everyone and their mailman is shooting a BR, I’m having a hard time finding a FL Bushing die or HS gauge anywhere in stock... not to mention Varget

 

[Winny94]

Consider 6bra or 6brx if a straight 6br is on the menu. Fireforming loads in either of them from 6 br brass are plenty accurate for a local match. Then you get a little bit more velocity on second loads. I am building a 6bra now, its not for competition, but I did ALOT of reading on them.

Hope you have some small rifle primers or start looking for them now... I am glad I have a few hundred laying around.

I would second this.
If you are shooting where you need a bit more velocity than a straight BR, the BRA is the ticket (not even why anyone does a Dasher anymore, but to each their own haha).
I have a 6BR in an ARC Nuke that feeds great from the MDT mags and its a lot of fun.

 

[hereinaz]

Can you guys give me the GPS location for this infinite money tree?

I should say I have barrels in most for one rifle and swap depending on purpose. My 6 bra is gonna be on a Howa Mini Action. So, only 2 rifles really.

 

[ddridan]

Another vote for the 6BR. I couldn’t be bothered forming or paying Alpha brass prices (crazy high in Australia) for Dasher so a buddy and I decided to go with the BR even getting our own reamers. His BR is an Impact 737 with an IBI 8T, I got impatient waiting for my Defiance Ruckus so I spun an IBI 7.5T on a spare Howa 1500 action I had. Stupid easy to load for and extremely consistent even with virgin Lap brass. Ive been running Hornady 105 BTHPs for practise and to once fire all my brass (2810fps, ES:14, SD:5.6) but going to the range today to find a load for the 107SMKs.

 

[bgavin]

Got a Curtis axiom in a mpa chassis. Heard the 6 br can be tricky to run smooth in a 3 lug.

Anybody running one on a axiom? What mag and kit are you using?

thanks

 

[kthomas]

Got a Curtis axiom in a mpa chassis. Heard the 6 br can be tricky to run smooth in a 3 lug.

Anybody running one on a axiom? What mag and kit are you using?

thanks

I think plenty are running 6BR type cases in a Curtis with no problem. Jon Pynch has ran a bunch of 6 Dasher, and Jake Vibbert (@JC Steel) a bunch of 6BRX.

I can't speak for them specifically on what they had to do to make it work, but I doubt it was that much trouble if any at all.

 

[1fliride]

dasher or bra. If you want to run heavier faster bullets, go dasher.
If you are fine with lighter slower bullets, go BRA

 

[chevy_man]

Pick the one that fits a barrel life you're comfortable with.


6br will be on the longer side, 6 Creed/243 etc. on the shorter side. I am comfortable putting a new pre-fit on my 243AI every year. You may not be.

Faster can give you some cheat room in the wind, but it's all a balancing act that you have to choose how to balance.

 

[steve123]

I bounce back and forth! A friend and I were shooting at 785Y on a 1 foot wide steel with me/6mmBR, and him/6mmBRX, both 105's. Darned if we didn't have that 308 thing going on where we'd be hitting on both sides of the steel(back and forth) due to slight changes in the wind, we didn't have wind flags. But our rifles put down small vertical, I can hit the 4" head often in low wind, and my load gave 6 fps ES over the chrono.

I don't remember having that "WIND"problem with my 6x47L sending those same bullets at 3175 fps. SD was 6-7 and was still accurate enough to hit normal sized steel.

I wonder how much the recoil would be for a 25 cal based off 6mmBRX using those .69BC 131gr Blackjacks? Gotta be a lot less than 6.5 Creed, right?