6mm Dasher

Years ago, I ran 308 Win 40 firings with Lapua brass no annealing, with max loads of Varget and 155s. The cases start getting head separation after that from trimming, stretching, and firing cycles.
But a guy won a match with cases that had 56 firing cycles on 308 Lapua brass with his load and he did anneal, but I didn't recall how often...they didn't have the automated annealing machines back then.
 
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I just bought some Alpha, only one firing so far. But, Lapua has been my choice before the ready to shoot Alpha and Peterson were developed. Annealing each firing, I’m over 25 firings and still going strong, bumping the shoulders .002”. Occasionally, I’ll cull one out for a loose primer pocket, rare, but it does happen.
 
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.2k here

I use SAC, see below

As I said, sac alpha dasher

As per SAC advice being dasher short necked, .264
I start usually with .264 annealing every firing the I move to .263 after ten firing or so
.241 mandrel.
Loaded round is .269 for almost anybody here including myself.
Is that .269 measurement the diameter of the neck? Did SAC recommend that bushing/mandrel combo when you emailed them?
 
Thanks, I'm gonna jump on the SAC dasher die train now. ER Collet 11 will work and i must buy the short .241 mandrel. Is there anything else you wish you knew before you ordered?
Just keep your top cap reasonably tighted and you will be 100% gtg. Haven’t asked about torque spec for that.
 
Right now I am at 2850fps with 105 hybrids, with 30.1gr
I want to try the 115 VLDs. What would be the ideal and safe starting point for this?
One of the guys said 29.1gr but later I thought shouldn't it be more charge since the projectile is heavier? Unless, it's something to do with pressure?
Edit: 30.1gr Varget

Thank you
 
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Right now I am at 2850fps with 105 hybrids, with 30.1gr
I want to try the 115 VLDs. What would be the ideal and safe starting point for this?
One of the guys said 29.1gr but later I thought shouldn't it be more charge since the projectile is heavier? Unless, it's something to do with pressure?

Thank you
Whats your barrel specs???
 
Your running BR numbers... My 26" 6BR 105 Hybrid with 30.0gr Varget is 2860 and 30.2gr is 2875....

So if your shooting a 6 Dasher with 105 Hybrids out of a 30" barrel, your slow...

I have a new 28" 6 Dasher sitting here ready for testing. I have shot 6BR for many years but this is my first Dasher so I dont have numbers to tell you where you should be, but your numbers are straight BR numbers...



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Your running BR numbers... My 26" 6BR 105 Hybrid with 30.0gr Varget is 2860 and 30.2gr is 2875....

So if your shooting a 6 Dasher with 105 Hybrids out of a 30" barrel, your slow...

I have a new 28" 6 Dasher sitting here ready for testing. I have shot 6BR for many years but this is my first Dasher so I dont have numbers to tell you where you should be, but your numbers are straight BR numbers...



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The reason I didn't go above 2850 was, one I was happy with the groups I was getting and two, longer barrel life. What's the recommended fps I should be aiming at?

Don't have the image handy but it was .75MOA at 500m with me as a factor too.
I should mention that I'm fairly new to reloading.

Thank you
 
30.0gr would be safe as a starting point for 115 VLDs. Work up as always, I'd guess you could hit 2850 or so also but with mid 31gr.

Why do you want to shoot VLDs? Compared to hybrid designs they are hard to tune and have worse BC?
 
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30.0gr would be safe as a starting point for 115 VLDs. Work up as always, I'd guess you could hit 2850 or so also but with mid 31gr.

Why do you want to shoot VLDs? Compared to hybrid designs they are hard to tune and have worse BC?

I just got a hold of 115 which I wanted to try, and they happen to be VLDs. I didn't even look into the stated BC of Hybrid vs VLD. After this box, I might just go with the hybrids as you implied, but I wanted to try to 105 vs 115 ATM.

Thank you
 
I just got a hold of 115 which I wanted to try, and they happen to be VLDs. I didn't even look into the stated BC of Hybrid vs VLD. After this box, I might just go with the hybrids as you implied, but I wanted to try to 105 vs 115 ATM.

Thank you
Well, have fun trying them out and report back.

David Tubb’s 115gr DTAC is a more popular heavy-for-caliber so maybe look into those also. I haven’t tried them or the VLD so I can’t add much more here.

I’ve shot a lot of Barnes 112gr match burners and recommend them for a heavy 6mm. They are still easy to tune, work with lots of charge weights and jumps and they retain good energy at range.
 
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Right now I am at 2850fps with 105 hybrids, with 30.1gr
I want to try the 115 VLDs. What would be the ideal and safe starting point for this?

Your current 105 hybrid load with a 30" barrel is very conservative, probably around 49k PSI. "Max" load is 65k PSI.

If you want to match the same conservative case pressure with a 115 VLD the prior advice of 29.1g Varget would do it. Likely speed will be ~2725fps which is pretty slow.

If you wanted to look at running a slightly higher pressure load with the 115VLD, you could easily work up another 100fps to around 2825. Suspect it would take about 30.5 grains of Varget to do that, and would be about 55k PSI pressure. Max pressure 65k PSI should be at around 32gr of Varget.

All the above are rough numbers from Quickload, assuming COAL of 2.385" with the 105 Hybrid and 2.40" with the 115VLD.
 
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Your current 105 hybrid load with a 30" barrel is very conservative, probably around 49k PSI. "Max" load is 65k PSI.

If you want to match the same conservative case pressure with a 115 VLD the prior advice of 29.1g Varget would do it. Likely speed will be ~2725fps which is pretty slow.

If you wanted to look at running a slightly higher pressure load with the 115VLD, you could easily work up another 100fps to around 2825. Suspect it would take about 30.5 grains of Varget to do that, and would be about 55k PSI pressure. Max pressure 65k PSI should be at around 32gr of Varget.

All the above are rough numbers from Quickload, assuming COAL of 2.385" with the 105 Hybrid and 2.40" with the 115VLD.
Thank you
Since you mentioned that it's pretty conservative, is there a speed I should be aiming at, for 115 or 105? I do understand that I'll have to work that alongside the "node".
 
Thank you
Since you mentioned that it's pretty conservative, is there a speed I should be aiming at, for 115 or 105? I do understand that I'll have to work that alongside the "node".
Speed no, rotational speed yes. And 2800 with a 7.5 twist barrel and 105 hybrids are fine. If your velocity is too slow you won't have enough RPM to stabilize the round and you will need a faster twist barrel.

And if your happy with your results at 2800 then stick with it. Trust your results on target. Most Dasher shooters are looking for a touch more velocity and would typically stick with a 6;BR for lower speeds.
 
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Could someone who's shooting 105s let me know what the OAL is on their round? I'm having feeding issues in my AI and I'm starting to wonder if the freebore is too short in the used barrel I picked up. Assuming a shorter OAL might be more picky with feeding.
 
Could someone who's shooting 105s let me know what the OAL is on their round? I'm having feeding issues in my AI and I'm starting to wonder if the freebore is too short in the used barrel I picked up. Assuming a shorter OAL might be more picky with feeding.
I have 2.39 COAL on my dasher
Although, I’m finding my rifle likes a little more jump at 2.37
 
Thank you! That's pretty much exactly where I'm at for length as well. They shoot great, but just don't feed consistently. Gray Ops is looking into the issue for me.
Maybe explain the feeding issue or post a video. I have a bit of experience when it comes to tuning/feeding for Dasher. Especially after the early batches of shit MDT mags that came out.
 
Maybe explain the feeding issue or post a video. I have a bit of experience when it comes to tuning/feeding for Dasher. Especially after the early batches of shit MDT mags that came out.
Here's a picture of what's happening. It feeds perfectly until I get to the last three rounds in the magazine, then I end up with the bullet pointed slightly down and jammed. It's difficult to tell if it's running into the back of the barrel, or if the shoulder of the case is catching on the lugs (I'm guessing the later based on the case dents I'm getting). I've tried the mag catch in a variety of positions with roughly the same results, and even swapped the barrel out of the AT-X and into an AT, and the same thing happened.

Gray Ops tells me they had an AI in house when they did the mag development, and I know of at least one other person running this combo successfully. They have my mag and a couple of my dummy rounds and were able to get it to feed with their shop rifles, but no longer have access to an AI.

I'm assuming it's a spring tension or positioning issue based on the fact that it feeds well until the last rounds.

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I've had it jam in this position a few times as well.

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When you get to that 3rd-to-last round, before you go to chamber it, look down in there and see if that round is sitting in the mag ass up and nose down, or if its sitting flat, or nose up. My guess is its not nose up. Before you try to chamber it, put your hand on the bottom of the mag and push up and hold pressure on it while you run the bolt. Did it chamber properly? This can tell you if its the mag height or not. If not, lets move on to the next possible thing.....the way the round sits in the mag. You can fix this by one of two things (or a combination of the two). Id start by taking the mag apart and stretching the spring out in increments until you get more upwards pressure from it. Don't go ham on it because you can actually get too much upward tension. Id also do some tuning on the feed lips. If you don't have a tool for this, you can make one pretty easy or use a crescent wrench. This can be a tedious task as a very tiny adjustment can make a lot of difference. You might do a Youtube search on tuning feed lips on rifle mags.

Also, do all your rounds have that dented shoulder or just the rounds that jam?
 
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When you get to that 3rd-to-last round, before you go to chamber it, look down in there and see if that round is sitting in the mag ass up and nose down, or if its sitting flat, or nose up. My guess is its not nose up. Before you try to chamber it, put your hand on the bottom of the mag and push up and hold pressure on it while you run the bolt. Did it chamber properly? This can tell you if its the mag height or not. If not, lets move on to the next possible thing.....the way the round sits in the mag. You can fix this by one of two things (or a combination of the two). Id start by taking the mag apart and stretching the spring out in increments until you get more upwards pressure from it. Don't go ham on it because you can actually get too much upward tension. Id also do some tuning on the feed lips. If you don't have a tool for this, you can make one pretty easy or use a crescent wrench. This can be a tedious task as a very tiny adjustment can make a lot of difference. You might do a Youtube search on tuning feed lips on rifle mags.

Also, do all your rounds have that dented shoulder or just the rounds that jam?

Great suggestions, except that think @WillHugh said he's running GrayOps AW pattern dasher mags, which are billet aluminum and so can't really be tuned by bending the feed lips like a traditional magazine.
 
When you get to that 3rd-to-last round, before you go to chamber it, look down in there and see if that round is sitting in the mag ass up and nose down, or if its sitting flat, or nose up. My guess is its not nose up. Before you try to chamber it, put your hand on the bottom of the mag and push up and hold pressure on it while you run the bolt. Did it chamber properly? This can tell you if its the mag height or not. If not, lets move on to the next possible thing.....the way the round sits in the mag. You can fix this by one of two things (or a combination of the two). Id start by taking the mag apart and stretching the spring out in increments until you get more upwards pressure from it. Don't go ham on it because you can actually get too much upward tension. Id also do some tuning on the feed lips. If you don't have a tool for this, you can make one pretty easy or use a crescent wrench. This can be a tedious task as a very tiny adjustment can make a lot of difference. You might do a Youtube search on tuning feed lips on rifle mags.

Also, do all your rounds have that dented shoulder or just the rounds that jam?
Thanks for the suggestions. I'm not able to change the feed lips (billet mag), but this process would at least help me determine if the mag is at the correct height/spring tension.

Brass that feeds into the gun looks fine. The dents are only on the ones that hang up.

Gray Ops still has my magazine, so I'll do some testing when I have it in hand and report back here.

The feed ramp and action lugs have somewhat sharp edges. The action also has two rows of locking lugs, so there's a lot for the round to pass through in order to make it into the chamber.

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I’ve got a Stuteville 28” CBR Dasher barrel coming in this week. .130 freebore. Bought from impact precision to pair with the 737r.

Anyone shooting the same combo and care to share what their load looks like with a Berger 109? Curious what to expect with the 28”
 
Anyone shooting the same combo and care to share what their load looks like with a Berger 109? Curious what to expect with the 28”

I would load conservative at whatever charge weight of Varget gives you 2820-2880 fps, CCI 450's and 20-50 thou jump. My guess is around 31gr is a good number with Alpha brass.

There's almost no wrong answer in that range.
 
I would load conservative at whatever charge weight of Varget gives you 2820-2880 fps, CCI 450's and 20-50 thou jump. My guess is around 31gr is a good number with Alpha brass.

There's almost no wrong answer in that range.
Appreciate the response. I’ve got a good grasp on some of the general loads and sweet spots … just curious about this particular combo and if anyone had firsthand experience.
 
I just got a hold of 115 which I wanted to try, and they happen to be VLDs. I didn't even look into the stated BC of Hybrid vs VLD. After this box, I might just go with the hybrids as you implied, but I wanted to try to 105 vs 115 ATM.

Thank you
The 115 gr shoot well in the Dasher
Here are some I tried. 2800 to 3020 fps with different powders.
Also try H4895 with the 115 DTAC, or Nosler RDF at around 2800 to 2820 fps can be very accurate.
From a 28" M24 profile, 5 R, 7.5 twist Bartlein barrel.
 

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I’ve got a Stuteville 28” CBR Dasher barrel coming in this week. .130 freebore. Bought from impact precision to pair with the 737r.

Anyone shooting the same combo and care to share what their load looks like with a Berger 109? Curious what to expect with the 28”
You are using the same combo as Austin Buschman.
Have a look at his load data on Precision Rifle Blog and his interview with Phil on youtube Masterpiece Arms "The Winners Circle" - in his Impact/28" barrels he shoots 105Hybrids/Alpha/31.0gn Varget for 2880fps
He also mentions 109s where he uses H4350 for 2870fps
COAL mentioned for 105s is 2.400"

My Dasher reamer is a 140freebore and the 105Hybrids run well at 2.400' and 2.424" COAL if that helps
 
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Mine is .104" free bore. COAL IS 2.382"...no where near 2.8" or longer....that will not even be possible.
The 115 DTAC at 2.670" COAL has the some of the boat tail still outside the case neck at 2.670" COAL...
 
Settled on this load. Middle velocity node on the rifle. Of the three nodes I’ve identified, all of them shoot half or better. This load is the best across the Chrono data and vertical at 535yds (what I had to test). I’ve shot variations of this charge at multiple seating depths, approximately 30 rounds, and had nearly identical Chrono data, so I don’t expect that this is a small sample size bias - it’s just a great load for the rifle.

Impact 737R
Stuteville Precision 28” M24 6 Dasher. .130 FB

31.6 Varget. Berger 109. Virgin Alpha Dasher. CCI 450’s. 1.787 CBTO (~30thou jump)
  • MIN 2852. AVG 2857. MAX 2863.
  • ES 10.9. SD 4.8
  • 5 shots

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Latest Dasher barrel is a Proof comp contour. Struggled for 2900 with Varget and a 109 without big pressure signs. Looked around and found guys using RL16 in their Dasher. I just bought 2 8lb jugs of MP587, which is supppsed to be “like” RL16. Ran from 33gr up to 35.5gr. At 35.5grs it was sending a 109 at 3080fps……wow. But I do not want to go that damn fast. Just wanted to see where the top end may be. Crazy thing is, I was getting only cratering at that speed where with Varget, was getting the usual straight TL3 mark from the bolt face. Came back down to a more realistic 2915 at 33.8grs. Loaded up 50 of each with a KVB SRM and a 450. The kvb’s shot ok, but I really like the round groups I’m getting with the 450’s. This was the last of each 50 from today shot side by side. KVB on the left and 450 on the right. Moral of the story, if Varget isn’t doing it, you may give some RL16 a try.



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