Another caliber selection post

[_Thor_]

Hi all,
I'm planning my first custom build after running a 6.5 CM Tikka/Xray setup for a couple of years and a number of PRS-style club matches (400-1300 yards). I've settled on the ARC CDG for an action but frankly I'm at a loss for what caliber to go with. I've been very happy with my 6.5 CM, but I figure if I'm spending the money on a custom, I should get every competitive advantage I can for match performance. Going by what's popular , it seems like 6 dasher is far and away the most popular cartridge in PRS. My understanding is the benefit over a 140 6.5 CM ELDM is essentially less recoil, in exchange for worse performance in the wind (correct me if I'm wrong). I've also read here and there about 6 dasher having mag/feeding issues more than other choices.

Am I correct in assuming that choosing any 6mm other than 6 CM, I'd basically be required to reload 100% of the time? I believe there's 1 or 2 "boutique" services out there that will basically reload for you, but no real factory ammo options on the horizon, and I'm not spending $2.50+ per shot. I've got a basic reloading setup for 6.5 but I'm a novice with it, and more than that I'm concerned that I won't shoot as often if I have to reload for it all the time. For me, cranking out 20-30 takes around an hour. I suspect that's pretty slow, but I paranoidly trickle all of my powder charges up to they "just" tick up to the tenth-grain I want on the powder scale (Maybe someone with more experience could tell me if that's a pointless endeaver, even when it comes to precision).

In short, I'm wondering if it's possible I could improve the time spent reloading by adjusting my process, but at the same time I'm also wondering if the difference between 6.5 CM and 6 dasher is "worth it". Beyond that, I'm open to opinions about other cartridges as well; I suspect they will all hinge on the same reloading question.

One other question - I'm assuming worst case, if I pick a caliber I don't shoot as often what whatever reason, I'd just be a quick prefit swap away from switching calibers. Is my logic sound, or am I forgetting something else that might keep me from switching calibers without too much fuss?

 

[dcmdon]

I'll chime in with the results of some of my research, but zero actual personal experience.

The 6 GT is a tweaked version of the Dasher that has a slightly longer overall length. The goal in doing this was to correct the feeding issue. Essentially, the cartridge is now long enough so that the bullet is in the mouth of the chamber by the time the mag lets go of the base.

Ballistically, the GT and Dasher are pretty much the same with the GT having slightly more powder capacity. Both seem to be very easy to achieve great accuracy out of. Your assessment of less recoil and less cross wind performance is pretty much also what I have read. Especially compared to the 6 CM. They can shoot the same bullets, so the real difference is how fast you send the bullet out.

6mm GT or 6GT, the New 6 on the Block. - LoadDevelopment.com

The GT in 6mm GT, stands for George Gardner and Tom Jacobs , the two guys who developed the cartridge, out of the need to have a better competition 6mm cartridge.

www.loaddevelopment.com

 

[spife7980]

I’d say the dasher is less recoil for equal performance in reasonable winds.

If you have to have factory ammo then stick with the creeds, everything else would count on loading for, just do to periodic unavailability.

But I would leave the tikka a 6.5 and make the custom a dasher. You’re gonna like it.

 

[sidetoss20]

Going from 6.5 to 6, you will have a decrease in felt recoil, roughly even wind performance, and your rounds downrange will have less of a splash to spot misses with. That’s the big tradeoff, but, you’ll have an easier time staying in your optic and “recovering” from the recoil to actually spot anything around your target at all. However there is a reason 6mms are used by a ridiculous percentage of top shooters - chances are they find that tradeoff to be worth it.

6 creedmoor and 6 GT have probably the most factory available ammo (someone can correct me if i’m wrong) in the “popular” class of PRSy 6mms.

It sounds like you would do well to invest in an electronic thrower/scale combo like the RCBS chargemaster. It greatly improved my reloading experience, and that might make you less apprehensive on the dasher. Yes, you may run into magazine issues that you wouldn’t with a 6 creed or GT, but kits for mags exist to increase reliability with 6 dasher.

Ultimately yes you could buy a 6mm something (with a 308 boltface) barrel for your Tikka and swap that on whenever you feel like shooting 6mm, and swap the 6.5mm back. However tikkas are notoriously difficult to spin a barrel off of the first time, due to high factory torque specs. This is documented on this site.

 

[psharon78]

I'd still go with a 6.5 creedmoor. I'm shooting the 260 with 140gr ELDMs at 2700. You could do the same with the 6.5 creedmoor. You'll get less recoil while also have really great barrel life.

 

[_Thor_]

Going from 6.5 to 6, you will have a decrease in felt recoil, roughly even wind performance, and your rounds downrange will have less of a splash to spot misses with. That’s the big tradeoff, but, you’ll have an easier time staying in your optic and “recovering” from the recoil to actually spot anything around your target at all. However there is a reason 6mms are used by a ridiculous percentage of top shooters - chances are they find that tradeoff to be worth it.

6 creedmoor and 6 GT have probably the most factory available ammo (someone can correct me if i’m wrong) in the “popular” class of PRSy 6mms.

It sounds like you would do well to invest in an electronic thrower/scale combo like the RCBS chargemaster. It greatly improved my reloading experience, and that might make you less apprehensive on the dasher. Yes, you may run into magazine issues that you wouldn’t with a 6 creed or GT, but kits for mags exist to increase reliability with 6 dasher.

Ultimately yes you could buy a 6mm something (with a 308 boltface) barrel for your Tikka and swap that on whenever you feel like shooting 6mm, and swap the 6.5mm back. However tikkas are notoriously difficult to spin a barrel off of the first time, due to high factory torque specs. This is documented on this site.

Sorry for the confusion - I don't want to swap barrels on the Tikka and I do intend to leave it a 6.5; it's the custom I'm debating swapping barrels around on if I find myself not wanting to load for 6 dasher/GT. That said, the Chargemaster is a good suggestion; maybe the $300 is worth it given that it would make loading up 100 rounds for a match a lot faster and less tedious.

Recoil is definitely my weak spot right now, hence the 6mm questions. My personal goals right now involve getting better at recoil management with the 6.5, and moving to a 6 would help that I'm sure. @dcmdon brings up an interesting point though about 6 GT as it seems generally superior to 6 dasher? I'm not sure what the tradeoffs are.

I'm also curious what the benefits of a dasher or GT are over 6 creed, given that I can buy 6 CM ELDMs factory easily. But from what I read, it seems 6 CM is falling out of favor over the other 6s - not really sure why that is though.

 

[spife7980]

Recoil and barrel life. 6creed is pretty cool too though. Just expect 1800 rounds instead of 2500 vs a dasher. Slot the gt in at 2200.

 

[sidetoss20]

Sorry for the confusion - I don't want to swap barrels on the Tikka and I do intend to leave it a 6.5; it's the custom I'm debating swapping barrels around on if I find myself not wanting to load for 6 dasher/GT. That said, the Chargemaster is a good suggestion; maybe the $300 is worth it given that it would make loading up 100 rounds for a match a lot faster and less tedious.

Recoil is definitely my weak spot right now, hence the 6mm questions. My personal goals right now involve getting better at recoil management with the 6.5, and moving to a 6 would help that I'm sure. @dcmdon brings up an interesting point though about 6 GT as it seems generally superior to 6 dasher? I'm not sure what the tradeoffs are.

I'm also curious what the benefits of a dasher or GT are over 6 creed, given that I can buy 6 CM ELDMs factory easily. But from what I read, it seems 6 CM is falling out of favor over the other 6s - not really sure why that is though.

You can find chargemasters or similar scales in the PX for 150-200. It’s well worth it.

6GT vs 6Dasher

Why are top shooters all switching back from 6GT to 6Dasher? Is it because 6Dasher is easier to tune and has lower velocity (to see the trace)? Thank you

www.snipershide.com

Comparing some numbers from Hodgdon: (Dasher vs. GT, Varget, 107 Sierra MatchKing)

Dasher:

31.8 gn Varget

2,916 fps

51,900 CUP

GT:

34.0 gn Varget

2,909 fps

61,800 CUP

So, dasher gets you to the same velocity using less powder and at lower pressures.

The main marketing point for 6gt was the lack of a need to modify standard mags to get it to run reliably. There are guys who change their setups for the new thing for a competitive edge more quickly than others, who stick with what they already know works. Dasher is very very popular, but requires investment (reloading, buying specific magazines, etc)

I would try to get the opportunity to shoot a 6.5 and 6mm side by side to understand the difference, and make the decision for yourself.

 

[dcmdon]

@dcmdon brings up an interesting point though about 6 GT as it seems generally superior to 6 dasher? I'm not sure what the tradeoffs are.

I'm also curious what the benefits of a dasher or GT are over 6 creed, given that I can buy 6 CM ELDMs factory easily. But from what I read, it seems 6 CM is falling out of favor over the other 6s - not really sure why that is though.

6 GT definitely seems to be superior to Dasher in repeating guns and by extension PRS. Dasher was designed to be used in single shot guns, so feeding wasn't considered. The 6 GT was designed by GA precision, a maker of mostly repeating bolt action guns, for use in PRS style games.

The benefits of Dasher or GT over Creedmoor is simply that they are less powerful. This means
1) longer barrel life
2) less recoil
3) less powder usage.

Why not just fill a Creedmoor cartridge with less powder until it mimics the external ballistics of the Dasher/GT? Because then you have a partially empty cartridge that tends to increase muzzle velocity standard deviation.

Well if Dasher/GT is just as good, why does 6 Creedmoor even exist?

It's better than Dasher/GT for the same reasons it's inferior to them. It's more powerful. That means
1) better terminal ballistics if you are shooting at something other than steel or paper. (a better hunting round)
2) better external ballistics if you are shooting at things at a distance that exceeds PRS style shooting.

The Dasher/GT are pretty well optimized for PRS. They are powerful enough to run these courses accurately, but no more powerful than necessary. If you are shooting a longer course, then the extra MV of the 6 Creedmoor could be of use.

I hope this helps.

 

[Matt_3479]

I can tell you this, chambering for a gt over something like a dasher or bra for the sole purpose of avoiding feeding issues by using regular mags would be incorrect. I have seen more feeding issues with the gt then either the bra or dasher combined once the gen 2 version of mdt mags were released.

I’ve been shooting bra in prs for a few years now and started shooting the bra shortly before the gen 2 mags were dropped. I had 3 gen 1 mags and 2 of thr 3 feed fine. Mdt swapped all parts to the gen 2 and I now have 1300 rounds of 6br, 650 rounds of 22bra and 4200 rounds of bra and I’ve never experienced a feeding issue. While I have a few buddies who went for the gt for the enhanced feeding and all of them have experienced feeding issues in one form or another from different chassis or mags.

I think you’ll see this year a lot of shooters switching to 25 or 6.5 for the added performance in the wind and the added energry/splash delivered on target as well as a miss. The 6mm’s can get swallowed up sometimes. The lower recoil of a 6 is a lot more forgiving then a 6.5 for recoil management as well as poor positions, but this also can create bad habits. The 6.5 creed is a very capable cartridge, with some added benefits as well. The longer barrel life for starters especially being a newer shooter. Dryfire works wonders but you still need to get out and shoot.

I have shot 6.5’s, 260’s, 25 creed, 6 creed, 6br, 6bra just for references. I love my 6bra/br’s without a doubt but will be giving the 25x47 a go this upcoming season as a change. A 6bra will forever be in my lineup and will most likely be my main match rifle. Just want to try a 25x47.

A 135 25 cal bullet at 2750 for shouldn’t be too harsh on recoil for spotting, while delivering roughly 2/10’s less elevation (not that it matters), 1/2 mil less wind and almost double the energy and 30gr more lead to hopefully spot more splash/miss/trace on those hard to see and recover on targets.

 

[R_A_W]

I suspect that's pretty slow, but I paranoidly trickle all of my powder charges up to they "just" tick up to the tenth-grain I want on the powder scale (Maybe someone with more experience could tell me if that's a pointless endeaver, even when it comes to precision).

That said, the Chargemaster is a good suggestion; maybe the $300 is worth it given that it would make loading up 100 rounds for a match a lot faster and less tedious.

If you shoot more than 100 rounds a month, an electronic powder dispenser is the biggest individual improvement you can make to a basic reloading set up.

You've already got a 6.5cm set up well enough to run in PRS matches and you'll be able to keep shooting/practicing with it as is. I suggest you buy a FX-120i & nice thrower (ATv4, STg2, IP, etc) over a second barrel for your custom build.

e: removing IP system... I shouldn't be recommending something that hasn't shipped & keeps getting delayed

 

[Dead Eye Dick]

One of the nicest shooting rifles, I ever owned was a 6.5 Creedmoor. It was dead reliable in hitting targets a long ways a way. I rebarreled it to 6GT, and it shoots good but not as good as my other GT which in itself is not quite as accurate as the 6.5. Now, in practice, I find hitting PRS style targets much easier with the GT. But seeing hits and misses on targets past 600 yards, is difficult unless the targets are well marked and the background/berm is such that spotting misses is going to send up a slash of dirt. (Top Shot and Prince don’t, Altus and Arena do)

If competition is your goal, unless your custom is going to be in the 25 pound class, go with a GT or possible a 6mmCM. It is easier to stay on target. If weight is no object or your are not in it for the win, stay with the Creedmoor. There will not be enough gain the a Dasher or GT over the big 6.5.

I shot my Creedmoor with 130 Bergers and Sierra’s and both showed great splash and fairly light recoil.

Caveat. In my day I was a pretty good hand with a shooting iron. Today, I’m a shaky, weak old timer who loves to send .22LR down range. Take my advice as you will.

 

[Harman117]

My vote: 6 Creedmoor

Won't have to worry about feeding issues (use AW mags with your CDG, not AICS) and you can walk into most any big gun store and find factory ammo for it.

Buy 6 CM in bulk online and focus on the important stuff like fundamentals and actually shooting the thing! You can always easily re-barrel it later down the road.

Once you get more experienced at reloading and have a more adapt setup, you might be more inclined to going to something a little more specialized.

 

[_Thor_]

I can tell you this, chambering for a gt over something like a dasher or bra for the sole purpose of avoiding feeding issues by using regular mags would be incorrect. I have seen more feeding issues with the gt then either the bra or dasher combined once the gen 2 version of mdt mags were released.

I’ve been shooting bra in prs for a few years now and started shooting the bra shortly before the gen 2 mags were dropped. I had 3 gen 1 mags and 2 of thr 3 feed fine. Mdt swapped all parts to the gen 2 and I now have 1300 rounds of 6br, 650 rounds of 22bra and 4200 rounds of bra and I’ve never experienced a feeding issue. While I have a few buddies who went for the gt for the enhanced feeding and all of them have experienced feeding issues in one form or another from different chassis or mags.

I think you’ll see this year a lot of shooters switching to 25 or 6.5 for the added performance in the wind and the added energry/splash delivered on target as well as a miss. The 6mm’s can get swallowed up sometimes. The lower recoil of a 6 is a lot more forgiving then a 6.5 for recoil management as well as poor positions, but this also can create bad habits. The 6.5 creed is a very capable cartridge, with some added benefits as well. The longer barrel life for starters especially being a newer shooter. Dryfire works wonders but you still need to get out and shoot.

I have shot 6.5’s, 260’s, 25 creed, 6 creed, 6br, 6bra just for references. I love my 6bra/br’s without a doubt but will be giving the 25x47 a go this upcoming season as a change. A 6bra will forever be in my lineup and will most likely be my main match rifle. Just want to try a 25x47.

A 135 25 cal bullet at 2750 for shouldn’t be too harsh on recoil for spotting, while delivering roughly 2/10’s less elevation (not that it matters), 1/2 mil less wind and almost double the energy and 30gr more lead to hopefully spot more splash/miss/trace on those hard to see and recover on targets.

Interesting - you think the trend is going to swing back towards 6.5? My understanding was that it was very much moving towards the the 6mm variants. I am partly trying to guess what the trend will be a few years down the road, because I don't intend to change calibers every year if I can help it. Others in the thread have made some good arguments for 6 dasher or GT, and I am leaning in that direction at this particular moment. I've sent a couple of others' nice custom 6s before, but I think I'd need more time behind one to determine how it really compares subjectively. At the same time, I'd hate to go with a 6, have an easier time staying on target, but still miss out on spotting my misses due to the smaller splash.

If you shoot more than 100 rounds a month, an electronic powder dispenser is the biggest individual improvement you can make to a basic reloading set up.

You've already got a 6.5cm set up well enough to run in PRS matches and you'll be able to keep shooting/practicing with it as is. I suggest you buy a FX-120i & nice thrower (ATv4, STg2, IP, etc) over a second barrel for your custom build.

e: removing IP system... I shouldn't be recommending something that hasn't shipped & keeps getting delayed

From what I just Googled, the FX-120i is $700 and looks like it's just more precise scale but without any throwing/measuring capability. I think that's out of my price range, but the RCBS Chargemaster might be a good option for me. A bit benefit would be increasing my speed with charging my reloads, since that's the bulk of what makes it a PITA.

Maybe something for another thread, but I'm not super solid on what is truly required for good precision reloads. I have the RCBS MatchMaster FL dies currently, I do a basic tumble of once-fired brass (which I have tons of), and I hand prime. I don't trim cases, anneal, shoulder bump, or sort bullets. If I understand it correctly, shoulder bump is useful for getting the max # of firings of your brass and is less accurate (?) than FL sizing, but better than neck sizing. Trimming and annealing too seem to be good for brass with repeated firings. In my case at least with 6.5 since I have enough brass to last quite a while, the way I see it is my current process is just as good accuracy-wise if I don't care as much about maxing brass life. Maybe someone could correct me though. On the other side of it though, if I went with a "reload-only" cartridge, I might suddenly be more concerned with brass life since I'd likely be buying brass to start with.

My vote: 6 Creedmoor

Won't have to worry about feeding issues (use AW mags with your CDG, not AICS) and you can walk into most any big gun store and find factory ammo for it.

Buy 6 CM in bulk online and focus on the important stuff like fundamentals and actually shooting the thing! You can always easily re-barrel it later down the road.

Once you get more experienced at reloading and have a more adapt setup, you might be more inclined to going to something a little more specialized.

That's something to consider. The way I read it, 6 CM should be lighter recoil than 6.5 but still heavier than 6 dasher/GT, right? Being able to buy factory ammo is a benefit, but I'm also debating if, I go to a 6, if I should just go all the way so I'll have a perspective from the opposite end of the spectrum. Part of this build, I think, is a valuable chance to try different stuff from what I've got already - hence why I'll likely be chasing a different brand chassis, different trigger, etc.

 

[R_A_W]

you think the trend is going to swing back towards 6.5? My understanding was that it was very much moving towards the the 6mm variants.

The huge switch to 6mm is anything but recent. It's true that some some people have gone back to 6.5cm or 6.5x47, while others are now trying out some .25 variant. You should ignore any current or emerging trend and only consider 6 dasher, 6gt, 6cm, or 6.5cm

From what I just Googled, the FX-120i is $700 and looks like it's just more precise scale but without any throwing/measuring capability. I think that's out of my price range, but the RCBS Chargemaster might be a good option for me.

FX-120i should be about $540 new from CE Products. You have to add a thrower on top, like the AutoThrow v4 for $500. If you don't want to spend that much, just start with a Chargemaster Lite & use that for a year & then revisit the issue if you feel like it. Don't buy a Matchmaster dispenser.

If I understand it correctly, shoulder bump is useful for getting the max # of firings of your brass and is less accurate (?) than FL sizing, but better than neck sizing.

No, FL sizing is bumping the shoulders. The best way to get precision ammo is to use a FL sizer with neck bushing. You'll need to do more research here.

 

[Harman117]

That's something to consider. The way I read it, 6 CM should be lighter recoil than 6.5 but still heavier than 6 dasher/GT, right? Being able to buy factory ammo is a benefit, but I'm also debating if, I go to a 6, if I should just go all the way so I'll have a perspective from the opposite end of the spectrum. Part of this build, I think, is a valuable chance to try different stuff from what I've got already - hence why I'll likely be chasing a different brand chassis, different trigger, etc.

Yes 6 CM will have more recoil than the 6 Dasher/GT, simple physics. Same bullet being pushed faster via more powder = more recoil. Should be a little softer than 6.5 CM depending on load.

Honestly the PRB link you have in your first post spells it out... Any of these calibers will be competitive. The fact that 2nd and 3rd place were taken by guys with 6.5 CM should tell you something. (Your skill is the weakest link in the system)

Correct me if I'm wrong, but it seems like you don't really want to spend all the additional money and time at the reloading bench for a specialized cartridge. That's why I say 6 CM.

The BR/Dasher/GT stuff is cool though. Just be prepared to expand your current reloading equipment, time, knowledge, etc. (which is half the fun, if you can afford it)

 

[dcmdon]

The BR/Dasher/GT stuff is cool though. Just be prepared to expand you're current reloading equipment, time, knowledge, etc. (which is half the fun, if you can afford it)

This is key.

I started reloading in college with a Lee turret clamped to a Black and Decker workmate. I originally did it because I was a poor college kid and wanted to be able to shoot more. (I didn't want to spend less. I wanted to spend the same but shoot more)

I quickly realized that I really enjoyed reloading. It became a hobby unto itself.

As I got older and entered the professional world, I had friends who made good solid incomes say "I want to reload to save money". I've always cautioned against that.

IMHO. If you aren't willing to have reloading become a hobby in and of itself. Or if you think you will see it as drudgery, then don't do it.

 

[R_A_W]

"I want to reload to save money"

 

[Matt_3479]

Interesting - you think the trend is going to swing back towards 6.5? My understanding was that it was very much moving towards the the 6mm variants. I am partly trying to guess what the trend will be a few years down the road, because I don't intend to change calibers every year if I can help it. Others in the thread have made some good arguments for 6 dasher or GT, and I am leaning in that direction at this particular moment. I've sent a couple of others' nice custom 6s before, but I think I'd need more time behind one to determine how it really compares subjectively. At the same time, I'd hate to go with a 6, have an easier time staying on target, but still miss out on spotting my misses due to the smaller splash.

The switch to 6mm has been dominate for quite a few years and isn’t a new thing. Even if the trend is moving back to 6.5 I don’t see a need to necessarily follow. I think the 6’s and 6.5’s will fluctuate and bounce back and forth over the years. The low recoil, reduced powder, ability to spot impacts and trace is a huge plus for smaller 6’s.

The faster 6’s make it extremely different to spot trace as it’s just fast enough to miss the trace sometimes, slightly added recoil, and hard on throats.

The 6.5’s are much easier to spot trace with a larger slower bullet, significantly easier to spot impacts on those further/larger/heavier targets, significantly easier to spot misses with the splash and yet still not too much recoil. It causes you to have slightly better fundamentals to be able to track behind the rifle and manage recoil.

This year and next I believe the 25 will be a big thing but still the 6’s will be predominant. The 6.5’s I think you’ll see make a big come Back as well. The added wind deflection on those windy matches and ability to spot trace has already started to turn people back to 6.5’s