Neck Sizing 6 Dasher
-
Klicker
- .17 HMR
- Posts: 245
- Joined: Tue Jul 03, 2007 5:55 pm
- Favourite Cartridge: 223,6BR, 6.5x55, 7RM
- Location: Bonnells Bay, NSW
Neck Sizing 6 Dasher
I'm planning on setting up my new barrel for F-Class with 6 Dasher. I'm interested in how neck sizing is done, I'm guessing its done using a neck bushing die? Can someone fill me in on this process, I'm new to improved and non standard calibres and am used to using the lee neck collet dies which work great for me.
-
Ackley Improved
- 6mm Dasher
- Posts: 1898
- Joined: Wed Aug 09, 2006 12:24 pm
- Location: Albury
-
woob614271
- 17Rem
- Posts: 1123
- Joined: Mon Jan 29, 2007 8:49 pm
- Favourite Cartridge: 17Rem, 22.250AI, 308
- Location: townsville qld
Either get a specialised neck die, preferably with the bushings, or as a second but I reckon, less satisfactory alternative, shotr stroke your FLS die.
The first proposal is by far the best. Talk to your gunsmith to ascertain the chamber neck dimension, and size to .002" less than that.
Some of the better reloaders among us will put you right if I have stuffed it up.
The first proposal is by far the best. Talk to your gunsmith to ascertain the chamber neck dimension, and size to .002" less than that.
Some of the better reloaders among us will put you right if I have stuffed it up.
-
Ackley Improved
- 6mm Dasher
- Posts: 1898
- Joined: Wed Aug 09, 2006 12:24 pm
- Location: Albury
OK, here we go!!!
Firstly, is it a tight necked chamber, i.e are you neck turning?
Either way I would use a Redding Type S NK die, choosing the appropriate neck bushing.
If you are going for a no turn chamber, then the chamber size will be either 0.271 or 0.272. New Lapua BR cases are around the 0.268.
So the bushing you will use will most likely be a 0.266.
For the first to lot of cases I fireformed, I used the false shoulder method. What you do is expand the neck to 25cal, and then neck it back to 6mm, only sizing so that the cases headspaces off the false shoulder you create.
For the next lots of cases I do, which will be for both my Dashers I am going to give the false shoulder method a miss. What I will do is use a Redding bushing 6mmBR die and use a bushing which is a lot tighter than you would usually use. This will give a high degree of neck tension. The plan is to then jam the projectile hard into the lands and headspace off that to fireform. So going on the chamber dimension above, I would use either a 0.263 or a 0.264 bushing for fireforming. After fireforming then I would the 0.266 bushing for loading.
The dies I would use then would be
A Forster Ultra seater (have ordered one to try as I am using a redding comp. one at the moment)
A Redding Type S Neck die
A Redding Body die, and also
A Redding Type S standard 6mmBR neck die for fireforming (could get away using the Type S Dasher neck die though)
One of my rifles uses a 0.265 tight chamber, and the other a 0.271 no turn chamber. I will be very curious as to how well the no turn chamber shoots. I am predicitng as well as the tight neck chamber.
My fireforming load is 28grains of RL15 using 107MK's.
Match load 32.9grains of RL15 seated into the lands. Obviously work up to these in you own rifle.
If I were to do anything any different, I would most likely get a custom FL die to suit my chamber.
You will be pleasantly surprised with the Dasher. It is more rifle than I would have every expected from such a small case!
I have just finished nightshift, so hope it is understandable.
Cheers
AI
Firstly, is it a tight necked chamber, i.e are you neck turning?
Either way I would use a Redding Type S NK die, choosing the appropriate neck bushing.
If you are going for a no turn chamber, then the chamber size will be either 0.271 or 0.272. New Lapua BR cases are around the 0.268.
So the bushing you will use will most likely be a 0.266.
For the first to lot of cases I fireformed, I used the false shoulder method. What you do is expand the neck to 25cal, and then neck it back to 6mm, only sizing so that the cases headspaces off the false shoulder you create.
For the next lots of cases I do, which will be for both my Dashers I am going to give the false shoulder method a miss. What I will do is use a Redding bushing 6mmBR die and use a bushing which is a lot tighter than you would usually use. This will give a high degree of neck tension. The plan is to then jam the projectile hard into the lands and headspace off that to fireform. So going on the chamber dimension above, I would use either a 0.263 or a 0.264 bushing for fireforming. After fireforming then I would the 0.266 bushing for loading.
The dies I would use then would be
A Forster Ultra seater (have ordered one to try as I am using a redding comp. one at the moment)
A Redding Type S Neck die
A Redding Body die, and also
A Redding Type S standard 6mmBR neck die for fireforming (could get away using the Type S Dasher neck die though)
One of my rifles uses a 0.265 tight chamber, and the other a 0.271 no turn chamber. I will be very curious as to how well the no turn chamber shoots. I am predicitng as well as the tight neck chamber.
My fireforming load is 28grains of RL15 using 107MK's.
Match load 32.9grains of RL15 seated into the lands. Obviously work up to these in you own rifle.
If I were to do anything any different, I would most likely get a custom FL die to suit my chamber.
You will be pleasantly surprised with the Dasher. It is more rifle than I would have every expected from such a small case!
I have just finished nightshift, so hope it is understandable.
Cheers
AI
-
Klicker
- .17 HMR
- Posts: 245
- Joined: Tue Jul 03, 2007 5:55 pm
- Favourite Cartridge: 223,6BR, 6.5x55, 7RM
- Location: Bonnells Bay, NSW
Thanks AI, I was planning on going for a no turn neck, so guessing the bushing I will need is a .266? I also will be interested to see how your dasher "no turn" goes.
I did noticed that forster had a die set for dasher, will be keen to here your thoughts on that as well.
You pretty much convinced me that the 6 dasher was the way to go as I was looking\thinking about 6BR or BRX (in a previous post about rebarreling my savage) and the extra push for the 1000yards is a good thing. I guess I was more a bit apprehensive about adding complications to reloading but it sounds very straight forward if its as simple as using a bushing die.
A question on fireforming, do you use a surrogate rifle\barrel for this process?
I did noticed that forster had a die set for dasher, will be keen to here your thoughts on that as well.
You pretty much convinced me that the 6 dasher was the way to go as I was looking\thinking about 6BR or BRX (in a previous post about rebarreling my savage) and the extra push for the 1000yards is a good thing. I guess I was more a bit apprehensive about adding complications to reloading but it sounds very straight forward if its as simple as using a bushing die.
A question on fireforming, do you use a surrogate rifle\barrel for this process?
-
Ackley Improved
- 6mm Dasher
- Posts: 1898
- Joined: Wed Aug 09, 2006 12:24 pm
- Location: Albury
Mate
No I use my rifle to fireform. The fireforming loads are accurate enough to use in a club match. You would be very surprised!
Rinso has got a good point. The 6X47L is a easier solution.
I still do not know if I would go that way over the Dasher though, but that is my own opinion. Lapua brass is cheaper for the 6mmBR... and relly the performance between the two is very similar. The Dashers shoot very well around the 3030-3050fps... and this is where people seem to be running the 6X47L. The 6X47L can run a higher velocity, but the 3050 mark seems to be the accuracy node for the 105/107grain projectiles.
I have read though that the 105/107 shoot well at 3250-3300fps... which is out of both cases league.
Where I would think the 6X47L would shine is if Sierra brought out a 115 or 117grain Matchking with a BC around the 0.600. I think this would be the perfect case for this weight projectile. I do know that there is this weight ranges in Match projectiles, but it would be good if Sierra released them under their own name, and made them easily accessable to us.
All in all, your choice. I am very happy with the performance the little Dasher obtains, enough so to have a second rifle built in the same caliber. The second Dasher will shoot 87Vmax's for varmints, but is a 8 twist and throated so it can still shoot the 107's.
The Forster Ultra seater is a nice die. I have bought one for my 308, and if the Dasher one is the same I will have no problem.
I will let you know how I go with fireforming using a high tension and hard jam. Two very well known Dasher shooters, both have held world records, fireform this way saying that the results are the same as the false shoulder method. False shoulder method sucks!!!
Rinso, I have forgotten to call you again.... have put a note on the bench to call you today! Memory like %*^&%*(!!!!
Cheers
AI
No I use my rifle to fireform. The fireforming loads are accurate enough to use in a club match. You would be very surprised!
Rinso has got a good point. The 6X47L is a easier solution.
I still do not know if I would go that way over the Dasher though, but that is my own opinion. Lapua brass is cheaper for the 6mmBR... and relly the performance between the two is very similar. The Dashers shoot very well around the 3030-3050fps... and this is where people seem to be running the 6X47L. The 6X47L can run a higher velocity, but the 3050 mark seems to be the accuracy node for the 105/107grain projectiles.
I have read though that the 105/107 shoot well at 3250-3300fps... which is out of both cases league.
Where I would think the 6X47L would shine is if Sierra brought out a 115 or 117grain Matchking with a BC around the 0.600. I think this would be the perfect case for this weight projectile. I do know that there is this weight ranges in Match projectiles, but it would be good if Sierra released them under their own name, and made them easily accessable to us.
All in all, your choice. I am very happy with the performance the little Dasher obtains, enough so to have a second rifle built in the same caliber. The second Dasher will shoot 87Vmax's for varmints, but is a 8 twist and throated so it can still shoot the 107's.
The Forster Ultra seater is a nice die. I have bought one for my 308, and if the Dasher one is the same I will have no problem.
I will let you know how I go with fireforming using a high tension and hard jam. Two very well known Dasher shooters, both have held world records, fireform this way saying that the results are the same as the false shoulder method. False shoulder method sucks!!!
Rinso, I have forgotten to call you again.... have put a note on the bench to call you today! Memory like %*^&%*(!!!!
Cheers
AI
-
chris.tyne
- .270 Winchester
- Posts: 1440
- Joined: Thu Jun 07, 2007 9:56 pm
- Favourite Cartridge: 6BR
- Location: Usually underneath
-
Ackley Improved
- 6mm Dasher
- Posts: 1898
- Joined: Wed Aug 09, 2006 12:24 pm
- Location: Albury
I am just going on what the smith has told me. time will soon tell. I may give him a call and confirm the size of 0.271 then.
I definitely want it a no turn chamer!
Just found this on 6mmbr.com
Tight Neck or No-Turn Neck -- What's Best?
The collective wisdom is evolving on this issue. Originally, 6BR shooters emulated what works for the 6PPC--tight .262" necks with a .009" or so neck wall thickness. Now the trend is in the other direction. Many shooters have had great success with .268-.269" necks that allow full neck uniforming with a cut up into the shoulder to block the formation of doughnuts. That said, we are now seeing very accurate rifles being built with .271-.272" and even .274" chambers that allow Lapua 6mm BR brass to be loaded and shot with no neck-turning. The results have been encouraging to say the least. Richard Schatz recently set a 1000-yard world record with a .271"-necked 6mm Dasher. And there is evidence that the longer VLD bullets work best with the greater neck tension allowed by unturned or minimally-turned brass. One well-known shooter says he has seen no loss of accuracy since changing to no-turn necks, and that's how he will chamber all his future barrels. However, most top smiths still recommend turning necks, but not down to .262". A .269" chamber appears to be a good compromise, allowing a quick, easy one-pass turn without sacrificing beneficial neck tension. For a varmint or tactical rifle, the choice is clear, however--go with a no-turn neck so you can spend more time shooting and less time reloading. Both the Lapua and the Norma brass are good enough that you will give up very little accuracy.
Cheers
AI
I definitely want it a no turn chamer!
Just found this on 6mmbr.com
Tight Neck or No-Turn Neck -- What's Best?
The collective wisdom is evolving on this issue. Originally, 6BR shooters emulated what works for the 6PPC--tight .262" necks with a .009" or so neck wall thickness. Now the trend is in the other direction. Many shooters have had great success with .268-.269" necks that allow full neck uniforming with a cut up into the shoulder to block the formation of doughnuts. That said, we are now seeing very accurate rifles being built with .271-.272" and even .274" chambers that allow Lapua 6mm BR brass to be loaded and shot with no neck-turning. The results have been encouraging to say the least. Richard Schatz recently set a 1000-yard world record with a .271"-necked 6mm Dasher. And there is evidence that the longer VLD bullets work best with the greater neck tension allowed by unturned or minimally-turned brass. One well-known shooter says he has seen no loss of accuracy since changing to no-turn necks, and that's how he will chamber all his future barrels. However, most top smiths still recommend turning necks, but not down to .262". A .269" chamber appears to be a good compromise, allowing a quick, easy one-pass turn without sacrificing beneficial neck tension. For a varmint or tactical rifle, the choice is clear, however--go with a no-turn neck so you can spend more time shooting and less time reloading. Both the Lapua and the Norma brass are good enough that you will give up very little accuracy.
Cheers
AI
-
chris.tyne
- .270 Winchester
- Posts: 1440
- Joined: Thu Jun 07, 2007 9:56 pm
- Favourite Cartridge: 6BR
- Location: Usually underneath
AI,I measured a couple of pieces of brass,going on the measurement I have I would need a .274 chamber to have .0019 clearance on a loaded round,that's using 7 ogive pro cals which measure .2435 on the base.I imagine that the neck thickness on the brass would differ slightly from batch # to batch # so probably not a problem as long as you measure everything whilst going along.
Anyway I reckon that I would rather have a bit to much clearance as against not enough for sure,have turned some cases so that I had .0048 clearance and could not tell the differance on the target as against having .0015 clearance.
Anyway I reckon that I would rather have a bit to much clearance as against not enough for sure,have turned some cases so that I had .0048 clearance and could not tell the differance on the target as against having .0015 clearance.
