• This Forum is for adults 18 years of age or over. By continuing to use this Forum you are confirming that you are 18 or older. No content shall be viewed by any person under 18 in California.

6BR-Dasher, trim case to ??

After fire forming several hundred Lupua 6mm BR Norma cases to 6BR-dasher, I checked the over all case length. (base to top of neck). The drawing of the 6BR dasher shows a max length of 1.560 inches.
The problem I have, in checking the length is I have cases that are from 1.535" to 1.552".
SO.... Asking all of you Dasher shooters out there. What length do I trim all the cases to ??
Much thanks..
Gina
 
For mine, I want the neck as long as possible. With that, there are usually a few that are outside the average, either shorter or longer. You can trim the longer down. I'd say measure, sort into 0.001" groups. If most are above 1.540" for example, then trim to that. You can then trim the remainder of the short ones to 1.535" and use them for foulers.

I was getting a formed length of around 1.545; on my last rifle, but am seeing a consistent 1.538" on my new one.
 
Gina

I trim mine to either 1.542 or 1.540. Both shoot well. I've never been able to get brass formed consistently over 1.548.

Interested to see how the new Norma stuff works out.

Good shooting

Rich
 
Thank you for all the advice. The majority of the cases, over 80% were under 1.540 (1.539-1.535) a very few were over 1.550. Since I can't trim them longer, I guess my target trim is going to 1.536" and see how they group. (ladder time)...again (powder and seating depth)
Gina
 
Thank you for all the advice. The majority of the cases, over 80% were under 1.540 (1.539-1.535) a very few were over 1.550. Since I can't trim them longer, I guess my target trim is going to 1.536" and see how they group. (ladder time)...again (powder and seating depth)
Gina

Your short necks will not hurt accuracy in any way. My hydro brass all forms to 1.539-1.540. It shoots great, and I dont sort it. I highly recommend hydro forming, your brass will be short but extremely consistent in length because it pulls the neck down into the shoulder rather than stretching the case body which seems to be rather inconsistent as your results show.
 
Thank you for all the advice. The majority of the cases, over 80% were under 1.540 (1.539-1.535) a very few were over 1.550. Since I can't trim them longer, I guess my target trim is going to 1.536" and see how they group. (ladder time)...again (powder and seating depth)
Gina


Are you resizing them prior to the measurements you're stating? If not, measure a few, resize them and measure again. I usually gain one or two thousandths after resizing.
 
My Dasher brass at the 2011 nationals was 1.500. A MAJOR screw up/brain fart during brass prep on my part was the cause!!!

It did ok!!

Tod
 
What is a safe chamber length if your Dasher brass is 1.550.
In other words how much longer should the chamber be than the brass?

Gary C.
 
What is a safe chamber length if your Dasher brass is 1.550.
In other words how much longer should the chamber be than the brass?

Gary C.
I always trim .005 to .010 shorter then chamber. You have to what chamber is in the gun. I have seen reamers vary from 1.550 to 1.570. Matt
 
Thanks. Are there techniques in fireforming to maximize blow length (or minimize shortening) without incurring other problems?
-
Absolutely. Lots of trial and error involved too. That is something you need to experiment with. Some techniques work for me, other techniques work for others, and some people can't get long blow lengths no matter what method they use...
 
Absolutely. Lots of trial and error involved too. That is something you need to experiment with. Some techniques work for me, other techniques work for others, and some people can't get long blow lengths no matter what method they use...
Flat base bullets help . Larry
 
I would segregate them by blow length, then trim to whatever length you choose. Inconsistent blow length is most likely inconsistent volume thereafter.

Tom

^^^ +1
Consistent blow lengths is a must for consistent volume's, in my experience.
Try to keep mine with in 0.004" and cue out the others (I use them for test/waste brass).
Also find the ones that blow short are more "sluggish" to stretch & growth then ones that blow long.
Donovan
 
I think you ask what is the trim lingth !
To me that would be dermined by the chamber reamer used when chambering. Case lingth should 5 to 10 thousand short of the reamer spec.
Any thing less then that is safe. Larry
 

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.

Forum statistics

Threads
165,869
Messages
2,205,085
Members
79,175
Latest member
rlk99
Back
Top