Small rifle Primer hardness

[Mikemontminy]

I’m fireforming for a 6 mm Dasher out of Lapua 6mm brass using 88 grain Bergers with a flat base. I figured they had more bearing surface and would slip less in the case than boattails. My problem is if I use CCI 450’s with the bullet jammed 5 thousands only half of them go off. I also tried Win small rifle primers which all go off but half of those pierce the primer. This is for a no turn neck chamber. Which primer would possibly fall between these two in hardness or easier ignition without piercing. Wasn’t sure if CCI 400’s may work or would they pierce as well.

 

[centershot]

Remington 7 1/2.

 

[Richard Coody]

you might try the false shoulder method. just size part of the neck down to 6mm and leave the rest 6.5. your reamer diagram should give you the proper dimension for the false shoulder.

 

[Dusty Stevens]

No primer will be soft enough for a dasher forming with the jammed bullet method. The cases will be all over the map lengthwise. The false shoulder method works best for me if im not hydroforming

 

[Mikemontminy]

you might try the false shoulder method. just size part of the neck down to 6mm and leave the rest 6.5. your reamer diagram should give you the proper dimension for the false shoulder.

I already have a Dasher die setup to push the shoulder back one thousand as this is my second batch of brass that I am fireforming for this barrel. First batch only lasted six firings and some of the primers are falling out. I guess I should pick up a 6.5 mm mandrel to open up the necks to create a false shoulder. If I use a bushing die to bring the neck back down to 6 mm to create a false shoulder do I have to do it in steps with larger bushings or is the shoulder / neck junction going to start squeezing the neck down anyway before a larger bushing would make contact. By the way the ones that did go off are all within four thousands in length.

 

[Nature Boy]

My problem is if I use CCI 450’s with the bullet jammed 5 thousands only half of them go off.

I was having exactly the same problem fire forming 6BRA rounds with the #450 primer. 50% failure rate.

However, the #400, 205M, 7 1/2....all worked 100%

 

[243winxb]

First batch only lasted six firings and some of the primers are falling out.

High pressure. Reduce the powder charge, is what i would do.

Is it possible to get the extractor to hold the brass while fire forming? Blowing the shoulder forward? Light neck tension, with a jam may retard the firing pin blow, as the bullet is pushed deeper into the case.

Just asking, as a Savage 223 will fire the primer when there is no shoulder to stop forward movement. I cut the shoulder off.

 

[Shaggy357]

Open the brass up to .277 or .284. I have 7BR dies that would work for me. A 270 Win sizer would work as well. Once the brass is opened up, set your full length die to size the neck down until the action on your rifle just closes on the brass. Firm bolt close will give you max headspace.

Use Rem 7 1/2 primer and 28.0-29.0gr of Varget. Seat bullet up to touching, but NOT into the lands. Mild load, but should form your brass perfectly. Some folks don't like the tight fit of the Rem primer in Lapua brass. It works for me....WSR should work in this load also, but will be a little milder.

This is similar to my competition load in 6BR. My brass has been loaded at least 10 times each and I have lost 1 out of 400 brass due to reloader (me, not the press) error. I neck size about 3-4 times then full length size the brass to fit the chamber. If I am shooting outside in real hot weather, I have to full length size after the third firing. The brass swells just that little extra if it is hot outside.

Good luck. Hope this helps.

 

[Stan Taylor]

I have shot at least a 1000 rounds of dasher brass fire formed with 205 federal hard jam with 29.0 grains of r15 haven't lost over a dozen case's without a false shoulder.

 

[Richard Coody]

I have shot at least a 1000 rounds of dasher brass fire formed with 205 federal hard jam with 29.0 grains of r15 haven't lost over a dozen case's without a false shoulder.

hard jam works too. basically headspacing off the bullet. that will hold the base of the case tight to the bolt face. shouldn't have any problems with light strikes with that method.

 

[Bc'z]

Open the brass up to .277 or .284. I have 7BR dies that would work for me. A 270 Win sizer would work as well. Once the brass is opened up, set your full length die to size the neck down until the action on your rifle just closes on the brass. Firm bolt close will give you max headspace.

Use Rem 7 1/2 primer and 28.0-29.0gr of Varget. Seat bullet up to touching, but NOT into the lands. Mild load, but should form your brass perfectly. Some folks don't like the tight fit of the Rem primer in Lapua brass. It works for me....WSR should work in this load also, but will be a little milder.

This is similar to my competition load in 6BR. My brass has been loaded at least 10 times each and I have lost 1 out of 400 brass due to reloader (me, not the press) error. I neck size about 3-4 times then full length size the brass to fit the chamber. If I am shooting outside in real hot weather, I have to full length size after the third firing. The brass swells just that little extra if it is hot outside.

Good luck. Hope this helps.

Curious if you back off on powder charge when you do the full length size?
I too am a neck sizer.
Just got compairitor, so don't know if I need to completely full length or try and go for the .02 set back.

 

[1lnbrdg]

Curious if you back off on powder charge when you do the full length size?
I too am a neck sizer.
Just got compairitor, so don't know if I need to completely full length or try and go for the .02 set back.

Readings off the comparator can be misleading if not used in conjunction with measuring what the bolt actually closes on.

I just went thru an issue with a 6X45 where the fired cases were coming back to what I measured the case before firing but having case head separations. When I started working with what the bolt actually closed on, realized that I had a major issue with excessive headspace. The measurements of the fired brass wasn't telling me that though.

Simple test: as you start full length sizing, start with the die backed out. Testing the bolt closing as you work the die down, it makes the case grow in length. The bolt should close then grow in length to where it doesn't close. Keep working it down until the bolt just closes on it.

Measure with the comparator when you get the bolt to close.

 

[Bc'z]

^^^^^ copy^^^^^^
You answered another question also.
Die set up for bump!!
Thanks

 

[Richard Coody]

Readings off the comparator can be misleading if not used in conjunction with measuring what the bolt actually closes on.

I just went thru an issue with a 6X45 where the fired cases were coming back to what I measured the case before firing but having case head separations. When I started working with what the bolt actually closed on, realized that I had a major issue with excessive headspace. The measurements of the fired brass wasn't telling me that though.

Simple test: as you start full length sizing, start with the die backed out. Testing the bolt closing as you work the die down, it makes the case grow in length. The bolt should close then grow in length to where it doesn't close. Keep working it down until the bolt just closes on it.

Measure with the comparator when you get the bolt to close.

yeap

many start setting up the shoulder bump on their brass way before it is fully fireformed. until a fired case chambers tight you brass is in no need of a shoulder bump. just set it up to size the neck until then.

 

[Dusty Stevens]

yeap

many start setting up the shoulder bump on their brass way before it is fully fireformed. until a fired case chambers tight you brass is in no need of a shoulder bump. just set it up to size the neck until then.

I witnessed a guy bumping his brass back .024 at the east west from doing that exact thing.

 

[Mikemontminy]

No primer will be soft enough for a dasher forming with the jammed bullet method. The cases will be all over the map lengthwise. The false shoulder method works best for me if im not hydroforming

Picked up a .25 cal mandrel to create a false shoulder. I chambered one round with a CCI 450 primer. No powder or bullet. Pulled the trigger and it went off. I think this will work in my .272 chamber. The bulge at the false shoulder measures .281 so it keeps the case from sliding forward.

 

[Dusty Stevens]

View attachment 1056529
Picked up a .25 cal mandrel to create a false shoulder. I chambered one round with a CCI 450 primer. No powder or bullet. Pulled the trigger and it went off. I think this will work in my .272 chamber. The bulge at the false shoulder measures .281 so it keeps the case from sliding forward.

Looks good

 

[Richard Coody]

just like it should look

 

[spife7980]

Curious if you back off on powder charge when you do the full length size?
I too am a neck sizer.
Just got compairitor, so don't know if I need to completely full length or try and go for the .02 set back.

Im sure you meant it but: .002" set back, .020 is 10x too much.

 

[Bc'z]

Im sure you meant it but: .002" set back, .020 is 10x too much.

Yes