6 Dasher to 6 Creedmoor

[shoot4fun]

I am not a whiz at reading prints so I have to ask. Thinking about bumping a chamber from 6 Dasher to 6 Creedmoor and was wondering if everything will clean up without having to cut the barrel threads off?

 

[dkhunt14]

I think that would depend on what the throat looked like. Matt

 

[Grimstod]

Why not a 6x47Lapua. Bumping it up to a 6CM seams like a downgrade. The Lapua would clean up better. I beleive it has less taper like the dasher.

 

[shoot4fun]

I think that would depend on what the throat looked like. Matt

I don't understand this comment. The 6 Creedmoor is a much longer case than Dasher so the existing throat would be turned into chips on the floor.

 

[shoot4fun]

Why not a 6x47Lapua. Bumping it up to a 6CM seams like a downgrade. The Lapua would clean up better. I beleive it has less taper like the dasher.

I already have a 6CM and a reamer. I do not consider it a "downgrade" as my 26" 6CM barrel can (but I usually don't) launch 105 Hybrids at 3200 FPS. I have proven it a solid performer all the way to 1000 yards with a 6.6 mil elevation change from 10 yards. Plus (big consideration) I already have brass and dies for the 6CM.
Now, to the last part of your reply, the taper is why I was wondering if it would just clean up or threads would need redone.
This is just an "inquiring minds want to know" kind of project. Managing to keep the barrel at current 28" will be key to the project's execution.

 

[Carolina Man]

I don't understand this comment. The 6 Creedmoor is a much longer case than Dasher so the existing throat would be turned into chips on the floor.

It not only needs to be longer it has to be larger through the body as well. The Dasher has most of the body taper removed so what ever case is rechambered will have to be as great in diameter and longer.

George

 

[shoot4fun]

It not only needs to be longer it has to be larger through the body as well. The Dasher has most of the body taper removed so what ever case is rechambered will have to be as great in diameter and longer.

George

Thanks for the input. I have 6 Creedmoor prints that came with my reamer but no print for 6 Dasher (on hand). The whole point of my thread is to find an experienced answer to whether or not the 6CM reamer can clean up the Dasher chamber. If you know that then give me the answer.

 

[Carolina Man]

Thanks for the input. I have 6 Creedmoor prints that came with my reamer but no print for 6 Dasher (on hand). The whole point of my thread is to find an experienced answer to whether or not the 6CM reamer can clean up the Dasher chamber. If you know that then give me the answer.

There are Dasher diagrams under Cartridge Diagrams on the home page and also a pretty good write up under 6 MM Br Improved that has more info. Even though the diagrams are not in detail enough for making a reamer that will suffice to do what you need.

 

[shoot4fun]

OK. The taper talk got me thinking. I went down to the shop and found a fired 6 Dasher and a fired 6 Creedmoor for measuring. Sometimes it's dangerous for me to think but I decided I could just measure the point of the 6CM case that is at the same height as the junction of neck/shoulder on the Dasher case. I got a reading that was slightly larger on the CM case there. Then I measured both at the juncture and the 6 CM is larger at that point as well (.460 on my Dasher and .463 on the CM IIRC).
All that tells me that the Dasher will totally clean up by the CM reamer. Agreed?

 

[shoot4fun]

And looking at the brass, it is easy to see that, while still tapered, a lot has been taken out of the Creedmoor to add volume as well.

 

[Terry Altom]

Here's a relatively standard Dasher reamer print. Typical adjustments are made regarding the neck size and freebore.

 

[shoot4fun]

Yes. the .460 at shoulder juncture if what I got on my calipers too. The 6CM brass I measured was larger there. Should work out.

 

[dkhunt14]

I don't understand this comment. The 6 Creedmoor is a much longer case than Dasher so the existing throat would be turned into chips on the floor.

That means if the throat is firecracked and worn out it might not clean up. The cracking can run inches out in front and not clean up. Matt

 

[shoot4fun]

That means if the throat is firecracked and worn out it might not clean up. The cracking can run inches out in front and not clean up. Matt

Now that makes your previous statement make sense.
It has unknown rounds fired, exhibits some throat wear and a little cracking. Will do a hard look at that before we start making chips.

 

[AckleymanII]

Don't get a mind block on 28", Accuracy is probably at the top of your WANT LIST? Eh?

 

[birdog]

I have had a few Dasher No Taper barrels cut at 26 in. to make weight with insignificant loss in velocity

 

[shoot4fun]

Don't get a mind block on 28", Accuracy is probably at the top of your WANT LIST? Eh?

That goes without saying. If I need to cut off the shank to clear fire cracking it won't be a deal breaker.

 

[Loggins J]

Dasher win more then any 6mm out now in bench rest.

 

[shoot4fun]

I agree that the 6 Dasher is a great design and has taken a lot of wins. I have Dasher barrels and just had an itch to try the 6Creedmoor in a long range BR format.
Now I have my chance. The chamber was done today on an older Dasher barrel. It came out nice and I can't wait to get some rounds down range.

 

[lbran]

OK. The taper talk got me thinking. I went down to the shop and found a fired 6 Dasher and a fired 6 Creedmoor for measuring. Sometimes it's dangerous for me to think but I decided I could just measure the point of the 6CM case that is at the same height as the junction of neck/shoulder on the Dasher case. I got a reading that was slightly larger on the CM case there. Then I measured both at the juncture and the 6 CM is larger at that point as well (.460 on my Dasher and .463 on the CM IIRC).
All that tells me that the Dasher will totally clean up by the CM reamer. Agreed?

if your cm reamer is larger, then most of your dasher chamber will have to be cut off ,so the pilot on the cm reamer can contact the rifling and stay centered in the bore! hope this helps