PRS cartridge selection

[PRSDietitian]

I've had a PRS rig in mind for over a year while I save up(work wasnt going well in 2022). I have bounced around cartridge selection for majority of that time.

Initially I was leaning 6XC until I realized the different chambers, how different brass is optimized for certain chambers and you didnt always know which sizing die was for what chamber dimensions

After that I looked into the 6 GT. It was the hot new thing at the time. I was on the FB group for about a year or more now too. But it seemed like it was a solution for a problem that wasn't asked. It was in between a dasher and a 6x47 lapua but imo didn't offer any benefits over either. Not just that but you're stuck with either hornady brass which im not a fan of, or alpha brass which isnt always available.

Then I looked into 6mm creed because there's still SRP lapua brass floating around, peterson and alpha make brass, everyone makes brass. I don't need factory ammo unless SHTF but that's another story. Downside is i saw ES/SD go up with reduced charges to get slower voleocities to improve barrel life and be able to spot trace/misses easier and if you went near max charge, barrel life goes way down.

Finally I considered 6x47 lapua after talking to a few local shooters. I heard in the past that it was finnicky to load for but a few smiths told me it was likely to improper chamber dimensions from improper reamer design when compared to the 6.5x47. I know you can still get 6.5x47 lapua brass from various manufacturers like lapua, peterson, and alpha, but peterson also makes dedicated 6x47 brass which im a fan of.

I know many will say go dasher, but i would rather not have to fire or hydroform brass. i know alpha has dasher brass but like i said above, it's not always in stock. Just wanted other perspectives on cartridge selection.

 

[TheOfficeT-Rex]

6x47 and 6CM are big powder burners, with the speed and barrel life to match.

6 Dasher and 6BRA are the contenders for smaller 6's. If you're going to run 'em slow, get a BRA and a mag kit and tweak it till it runs.

 

[XLR308]

If you really like the 6CM and dont want the top end speeds to save some barrel life i would just run a slower powder.
Thats what i did in 243win with 105amax and 105scenar.
With H1000 just off of memory i was somewhere between 3050-3100.

 

[PRSDietitian]

If you really like the 6CM and dont want the top end speeds to save some barrel life i would just run a slower powder.
Thats what i did in 243win with 105amax and 105scenar.
With H1000 just off of memory i was somewhere between 3050-3100.

I heard David Tubb did that with the XC but I didn't find a lot of info on it. Is there merit to that and barrel life?

 

[XLR308]

I heard David Tubb did that with the XC but I didn't find a lot of info on it. Is there merit to that and barrel life?

I honestly cant answer that with any certainty since i dont shoot comps and burn up barrels like many around here.
From what i remeber reading is H1000 has a relatively low burn temp compared to many other powders that are more optimum like H4350.
Another that may be worth consideration would be H4831SC.

I could be ass backwards on that one since it has been awhile since looking into that and getting older isnt helping my memeory retention.

 

[CK1.0]

I have barrels in 6GT and 6CM, and if I had to pick one over the other it would be 6CM.

I load my 6CM rounds to only 2875-2900fps, and ES/SD going up as speed and charge weight goes down is mostly a fallacy... some powders are easier than others of course, but if one's brass prep is slick and they put the same amount of powder into every case down to the kernel (+/- 0.02gr), single-digit SDs and a good ES will appear.

6GT, which I also load to 2875-2900fps, works well with Varget (and/or Shooter's World Precision Rifle, which is nearly the same thing), and that alone makes things vastly easier than usual for most, but its advantages end there IMO.

One of these days I'll get around to fucking around with Varget/SWPR in the 6CM, and I won't be too surprised if I can get it to behave just like the 6GT.

 

[Mudflap621]

Just run a straight BR or Dasher around 2800-2850 and it’ll shoot tiny groups, Lapua or Alpha brass. When brass comes in stock don’t cry about the price just buy it. If u want more readily available cheap brass go 6 or 6.5 creed.

I went down the BRA route few years ago and still there. It’s a great caliber but honestly thinking of going back to BR just to eliminate one step in the process.

 

[OREGUN]

Don’t paralyze yourself with too much analysis here. 6CM will mean you can shoot factory easily if you want (saves tons of time). Barrels are expendable…whether that happens at 2000 rounds or 2500 or 3000 doesn’t mean much in the long run. If you don’t want to shoot factory, just go dasher. Buy a couple hundred pieces of dasher brass (300-500) and you won’t have to buy brass again for a long time.

Brass is never as hard to come by as bullets and powder.

 

[Dead Eye Dick]

Brass is never as hard to come by as bullets and powder.

Don’t you believe it. I am short on large rifle primers, but through diligence have amassed a good stock of small rifle primers. But, have you looked for small rifle primer brass for the 6.5? Non available for months, maybe years. Now, powder is available and bullets are an on and off thing, depending on how closely one is married to one bullet (I heard there was a myth called the Berger 6mm 105 Hybrid). Other bullets that work almost as good are easily available.

 

[OREGUN]

Don’t you believe it. I am short on large rifle primers, but through diligence have amassed a good stock of small rifle primers. But, have you looked for small rifle primer brass for the 6.5? Non available for months, maybe years. Now, powder is available and bullets are an on and off thing, depending on how closely one is married to one bullet (I heard there was a myth called the Berger 6mm 105 Hybrid). Other bullets that work almost as good are easily available.

Maybe I’ve just been lucky. Maybe I should start trying to trade brass for the various powders/bullets I can never find.

 

[Lightning8]

I had an older 6XC PRS barreled action - 115 DTACs over H4350, shot great but used a lot more powder for the required speeds. When the barrel died - I rebarreled to 6BRA. If starting from scratch (and I reloaded), I would get 6 Dasher, 6BRA, or 6BR.

 

[PRSDietitian]

I had an older 6XC PRS barreled action - 115 DTACs over H4350, shot great but used a lot more powder for the required speeds. When the barrel died - I rebarreled to 6BRA. If starting from scratch (and I reloaded), I would get 6 Dasher, 6BRA, or 6BR.

You switch to 105 or 109s?

 

[Lightning8]

You switch to 105 or 109s?

105 Berger Hybrids - Have 107 SMKs in reserve.

 

[Lightning8]

105 Berger Hybrids - Have 107 SMKs in reserve.

As stated above - 105 Hybrid at 2830-2860 fps. I also have a 6 Dasher I run at 2920 because it seems to like that speed/load. Found 105 Hybrids and never found 109s in stock.

 

[Lightning8]

105 Berger Hybrids - Have 107 SMKs in reserve.

I still have 1000 plus 115 DTACs - I may shoot those one day if no 105/107/109 available

 

[Dead Eye Dick]

Maybe I’ve just been lucky. Maybe I should start trying to trade brass for the various powders/bullets I can never find.

Problem is, I am married to the srp brass. I have another 6.5 that I use lrp brass in to differentiate. So, while large rifle primer 6.5 brass is easy to come by, the primers aren‘t so I have to hold on to those for the one rifle that uses this combination.

Oh for the days when primers were a buck-fifty per hundred, powder was less than five bucks and bullets somewhere in between with the lgs always having more than a fellow needed. (And a rifle that could put three shots into one inch was a rare jewel to be cherished.)

 

[CK1.0]

I think it's an advantage to pick a cartridge that can take both LRPs and SRPs, like 6CM (or 6.5CM). There were multiple-month-long stretches a year ago when SRPs were unattainable but LRPs could be found here and there, and now, these days LRPs are scarce and tough to find. It's nice being able to just stockpile what you can when you can and not really worry about it since they shoot the same.

Another advantage with 6CM is that it's easy to "make" cases, even if there's no 6CM brass out there: Lapua doesn't make LRP 6CM brass so I made some out of 22-250Rem brass, 22-250Rem brass makes excellent 6CM brass, all it takes is a mandrel before loading them up and firing them, they fireform on the first firing and that's it, and of course, one can always easily neck-down any 6.5CM stuff they find too.

 

[OREGUN]

The time is now!!!!!

Alpha Munitions - 6mm Dasher Brass (Qty 100) - Bullet Central

Alpha Munitions – 6mm Dasher Brass

www.bulletcentral.com

 

[PRSDietitian]

The time is now!!!!!

Alpha Munitions - 6mm Dasher Brass (Qty 100) - Bullet Central

Alpha Munitions – 6mm Dasher Brass

www.bulletcentral.com

Can you run 115's in a dasher?

 

[TheOfficeT-Rex]

Can you run 115's in a dasher?

Sure, If you've got the twist and don't mind them being slower - that's more for a x47/CM sized case. The sweet spot for the BR based cases are 103-109. Lots of options in that range both off the shelf and custom means there's really no reason to chase the heavies.

 

[PRSDietitian]

Sure, If you've got the twist and don't mind them being slower - that's more for a x47/CM sized case. The sweet spot for the BR based cases are 103-109. Lots of options in that range both off the shelf and custom means there's really no reason to chase the heavies.

The reason i ask is i have about 500-1000 DTAC's and 500 109 ELDM's on hand. I'll have a 1:7 twist barrel so that wont be a limiting factor

 

[TheOfficeT-Rex]

The reason i ask is i have about 500-1000 DTAC's and 500 109 ELDM's on hand. I'll have a 1:7 twist barrel so that wont be a limiting factor

If you've got 1500 DTACs/ELDMs that's pretty much the usable life of a 6CM so go run it like a racecar.

 

[spife7980]

Can you run 115's in a dasher?

I prefer 115s in my dasher. Youre going to run them at 2750-2850 where accuracy is regardless of if its a 105 or 115, why not max that bc with the 115? A 7 twist is prime.

 

[Taylorbok]

I'd go for a Dasher personally. BR or any of the variants is an option also.

 

[CK1.0]

If you're going to go 6mm anything... 7.5 twist, even with 112/115gr bullets IMO. DTACs kick ass.

Speed almost doesn't even matter, anything over 2750fps that shoots is fine, no reason to run hotter than ~2900fps.

 

[OREGUN]

Can you run 115's in a dasher?

Well hell yes you can. And 103s and 105s and 108s and 110s. Go nuts!

 

[PRSDietitian]

Quick question regarding twist rate. Do ya'll put a lot of emphasis on that at all? I always check the berger calculator when looking at new bullets. At say, 2800 fps on a dasher with 115 dtac with a 7.5 twist it has it at 1.47 and i always heard 1.50 and above was ideal. A 1:7 puts you at 1.68. bugholes said they never carry faster than 1:7.5 for 6mm because they mentioned overstabilizing.

 

[DeathBeforeDismount]

6gt is very hard to beat for all around. Br mag kits have closed the gap but nothing is as versatile AND easy to load for in 6mm. It's like right in the middle between the br and the xc. It's the smallest round that flawlessly feeds in unmodified mags.

6.5cm can still be competitive, especially if you want to shoot factory ammo. Good 6.5cm match ammo is much cheaper (23-25 ) a box vs 6cm (35+). The barrel will also last like 3 times as long at factory speeds.

 

[Niles Coyote]

Over the years I have used 6mm XC, 6mm CM and now 6mm GT for PRS. Of those the GT is my favorite but if I were to start over I'd likely go straight 6 BR. Four of my fellow competitors & friends have been running them with great success and our velocities are so similar (2770-2870 depending on bullet used) it would be nice to use Lapua brass and 2 grains less powder.

The mag kits where just coming out when I made the switch 3 years ago to the GT and that was the reason why I didn't go that direction. Folks were still having some feeding issues with the BR based cartridges at the matches I was attending. The feeding problems seem to have gone away now that they have been refined and shooters have learned how to tune their mags.

 

[TylerN]

Can you run 115's in a dasher?

Yes, I run 112's in a Dasher and get 2880 FPS with a medium load with Varget. 115's wouldn't be much different.

 

[beetroot]

I have barrels in 6GT and 6CM, and if I had to pick one over the other it would be 6CM.

I load my 6CM rounds to only 2875-2900fps, and ES/SD going up as speed and charge weight goes down is mostly a fallacy... some powders are easier than others of course, but if one's brass prep is slick and they put the same amount of powder into every case down to the kernel (+/- 0.02gr), single-digit SDs and a good ES will appear.

6GT, which I also load to 2875-2900fps, works well with Varget (and/or Shooter's World Precision Rifle, which is nearly the same thing), and that alone makes things vastly easier than usual for most, but its advantages end there IMO.

One of these days I'll get around to fucking around with Varget/SWPR in the 6CM, and I won't be too surprised if I can get it to behave just like the 6GT.

What powder are you using for those slower 6CM speeds?

Have you used a slower burning powder or just a smaller charge?

 

[CK1.0]

What powder are you using for those slower 6CM speeds?

Have you used a slower burning powder or just a smaller charge?

For the last couple years I’ve been using Sta-Ball 6.5 for 6CM (mostly because that’s all I could get in a larger quantity), and it’s not bad. I’m not completely sure, but it seems like it’s cooler burning or something, because my barrels have been having long lives, but it takes work to see good ES/SD numbers. I’ve stayed around 41gn the whole time.

I’d really like to try H4831 for 6CM as it should yield good case-fill but still keep one in the 2850-2900fps neighborhood…

 

[beetroot]

For the last couple years I’ve been using Sta-Ball 6.5 for 6CM (mostly because that’s all I could get in a larger quantity), and it’s not bad. I’m not completely sure, but it seems like it’s cooler burning or something, because my barrels have been having long lives, but it takes work to see good ES/SD numbers. I’ve stayed around 41gn the whole time.

I’d really like to try H4831 for 6CM as it should yield good case-fill but still keep one in the 2850-2900fps neighborhood…

What sort of barrel life have you been getting?

Did you try H4350?
That appears to have a similar burn rate to StaBall, is somewhat popular in the smaller 6mms.

 

[CK1.0]

What sort of barrel life have you been getting?

Did you try H4350?
That appears to have a similar burn rate to StaBall, is somewhat popular in the smaller 6mms.

I’ve tried and like H4350 and that was my go-to… but with the pandemic it became tough to get. Similar speeds to StaBall but far easier to achieve good ES/SD numbers IME.

No BS, I’ve got 2 6CM Proof SS prefits that I thought were dead at ~2200rds, but after cleaning them back to bare metal, they’re both still shooting 1/2MOA out to 1000yrds… one has ~3100rds on it now (which I just pulled even though it’s still shooting), and now the other one has ~2400rds on it and is hammering too… I still haven’t quite figured out why they’re lasting so long, but with both I’ve been jumping .100” and have never pushed them faster than ~2900fps, so I’m pretty sure that has a lot to do with it… If/When I figure out exactly what’s going on I’ll put the info out there lol…