All right here's one for the Dasher Guru's. I had a Dasher built with a .269 min. turn neck. I then fireformed 250 pcs of Lapua 6br brass into Dasher cases using the COW method found on this site. (special thanks for all of those that took the time to post their procedures and results) After fire-forming and neck-turning I loaded the brass with 107 SMKs' and proceeded to shoot them three times before trimming to a uniform length 1.545" my reamer print shows 1.555" so I figured that to be sufficient. Having not shot a 40 degree shouldered case before I was wondering if "what I deem as a heavy bolt closing" normal ?? or should / could I do something different to help alleviate this condition. Please be made aware that I let Pacific Tool know what brass I intended to use (Lapua), (this is not a critisism of their work) I'm meerly providing you all with my information in hopes that it will help aid you in answering my question. However even after three firings I feel that it takes (my perception) an excessive amount of force to close the bolt compared to my wifes 6mm BR Norma. Any suggestions or ideas would be appreciated ?? I'd like to thank all of you in advance for taking the time to answer my question.
6 Dasher cases difficult to chamber
- Thread starter BigKev
- Start date
I ran several ladder tests at 200 yds and found two accuracy nodes one at 32.2 gr. and the other was at 32.8 gr. both with Reloader 15. Right now I'm neck sizing only using a Redding die and a .266" titanium bushing, resizing just over half the neck. I've checked all of the cases after neck sizing with a Sinclair Concentricity gauge, most cases show between .0005" to .001" runout on either the neck or on the loaded bullet. Not one single round exceeded .001" in total runout. I have a Forrester full-length sizing die but I do not use it because it resizes the neck too much for what I want regarding bullet tension. I've read posts that claim that Lapua brass runs a tad larger than other brass and was wondering if that might be a contributing factor. Thanks again for taking the time to answer my question and I hope this helps in some way.
Sounds to me like you need to bump your shoulder.
I turned the necks after fire-forming, I loaded a sample and took several readingings from a dozen or so cases with my micrometer. I then turned the necks down so that I ended up with .003" clearance from a loaded round, .266" in a .269" chamber. Even after their fourth firing I'm still getting the same readings from .00025" to .003" clearance and the neck wall thickness has also remained constant (yes I measure that too with an tubing thickness micrometer). At this time I don't think its the neck or the over-all case length (checked length), reason being is that I run the same exact tolerances in both my wife's 6mm BR and in my .308 bench guns and I've never experienced the pressure that I'm feeling that's needed to close the bolt on the Dasher. I've been told that it's difficult to actually bump a 40 degree shouldered case and was wondering if this is what might be what I'm feeling.
maybe try a Redding body die.
Joe
Joe
You have given a lot of good technical info , all but how far you are bumping the shoulder back!
For a bolt gun you should be bumping the shoulder back .0015 to .0025 Inches when you FL resize. With only neck sizing, the dimension of the case from shoulder datum to base is growing and making the bolt hard to close.
Bob
For a bolt gun you should be bumping the shoulder back .0015 to .0025 Inches when you FL resize. With only neck sizing, the dimension of the case from shoulder datum to base is growing and making the bolt hard to close.
Bob
My Forster bump shoulder neck bushing die won't touch the shoulder unless it is screwed down to touch the shell holder with the ram up.From there I can get a little more buy turning it down ,so that it cams over on the stroke.The rage is aproximtely .001-.005.Explain it to Forster tech support,they don't always have the measurements right.They packaged a .228 bushing in the three bushing kit with my die.That's the size of a loaded 20cal.I kept the .224 bushing,sent the the .228 and .226 back for a swap of .225 and .223.
Hey Kev,
Just set the shoulders back once, they'll chamber just fine.
You have to set the shoulders back on a Dasher, just like anything else. The problem is that currently there aren't any full length bushing dies from a production die maker. So you'll have to either use a standard full length die or have an expensive custom die made.
Just set the shoulders back once, they'll chamber just fine.
You have to set the shoulders back on a Dasher, just like anything else. The problem is that currently there aren't any full length bushing dies from a production die maker. So you'll have to either use a standard full length die or have an expensive custom die made.
Gentlemen,
First and foremost thanks for taking the time to answer my question. I currently have a Forrester full length sizing die but I don't use it because it resizes the necks way too small. After reading all of your posts I measured several of my cases from the base to where the shoulder starts (as best I could with calipers). I then compared this to my reamer print, every case was oversized (too long). Does Redding or any one else make a body / bump die ?? if not I'm going to see if one of the local machine shops could ream out the neck area of my Forrester die so that it doesn't resize the neck at all. I'll then full size all of the brass and post my results, Thanks again for your replys.
First and foremost thanks for taking the time to answer my question. I currently have a Forrester full length sizing die but I don't use it because it resizes the necks way too small. After reading all of your posts I measured several of my cases from the base to where the shoulder starts (as best I could with calipers). I then compared this to my reamer print, every case was oversized (too long). Does Redding or any one else make a body / bump die ?? if not I'm going to see if one of the local machine shops could ream out the neck area of my Forrester die so that it doesn't resize the neck at all. I'll then full size all of the brass and post my results, Thanks again for your replys.
BigKev said:
Call Forrester, explain your situation and send your FL die in to have the neck reamed to the size that you need. Problem solved. When you get it back, dedicate a particular shellholder for that purpose only and adjust your die so that you set back the headspace about .001 to .0015.
Mark
ridgeway
Silver $$ Contributor
I would send it back to Forster to have it opened up before taking it to a local machine shop. I think its like $15 for that service and it will be straight when you get it back. JFI, the Forster neck size on their Dasher die is .261".
Redding does make a Type S FL Die.
Redding does make a Type S FL Die.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.