6.5x284 Norma

[PaLuke]

Hello, I have a CA Ridgeline in 6.5x284. I'm bumping the shoulder back about .002 measuring with the Hornady headspace comparator kit. The initial stretch is about .005. After 5 reloads I'm seeing signs of case head separation and with using a piece of wire I can feel a little dip in the inside of the brass. I'm using Lapua brass and have no pressure signs with the reloads. I guess my question is that is 5 reloads a decent amount before I see issues? The rifle is scary accurate with 147 ELDM's. As a side note I had a 30-378 that I'd be lucky reaching 5 reloads and my Creedmoor has 7 reloads with no issues. Thank you for your replies.

 

[338 dude]

I get 10 to 15 reloads and try new brass, I've never had a case of separation or a neck crack I anneal

after every firing and only size .001 to .002shoulder bump

 

[PaLuke]

Thanks for your help. I don't anneal which is probably the reason for my issue. Which annealer would you recommend? Thanks again.

 

[338 dude]

Thanks for your help. I don't anneal which is probably the reason for my issue. Which annealer would you recommend? Thanks again.

In my opinion the best but unfortunately also the most expensive the amp annealer. This load has worked well for me for a long time,as with any new load start lower and work your way up with my rifle in a 26 inch barrel it's running about 2980 ft./s.

 

[PaLuke]

Thanks again for the reply. I'll take a look at the annealers and check out out the AMP. What velocity are you getting with the 140 VLD's? I'm getting 2850 with the 147 ELDM's.

 

[338 dude]

Thanks again for the reply. I'll take a look at the annealers and check out out the AMP. What velocity are you getting with the 140 VLD's? I'm getting 2850 with the 147 ELDM's.

2980 With the 140s I've been going to work up a new load with the 156s but haven't got it dialed in yet

 

[dok7mm]

@338 dude has made a positive point on the effect of early case head separation when using annealing prior to resizing.

Another cause is bumping .002" (or more) after first firing of brass. It often doesn't fully expand to true headspace until after 2nd firing. If you set up your resizing die for .002 bump after one firing, you can actually be bumping a lot more than you realize, which causes the early separation.

After first firing, I always set up my resizing die a bit high, so that there is sizing of case, but no bump. I'll size 5 cases like this, wipe them clean and measure base to datum, mark those cases and chamber them with my stripped bolt (firing pin & ejector removed). If they chamber, I know not to bump shoulders until after 2nd firing.

I will then resize all my once fired brass and run them thru my chamber. Any that won't chamber, I set aside until 2nd resize. It can be a pita, but beats early case separation.

 

[PaLuke]

Thanks for the reply. I understand what you're saying in that I'm measuring the brass after 1 firing and I might be getting a false reading as far as chamber length. I have 5 new brass ready to go. I'll back off my die a turn or so and get a reading after a second firing. I think I'm bumping the shoulder back .002 but in reality it might be more causing the problem. . Take care.

 

[338 dude]

Thanks for the reply. I understand what you're saying in that I'm measuring the brass after 1 firing and I might be getting a false reading as far as chamber length. I have 5 new brass ready to go. I'll back off my die a turn or so and get a reading after a second firing. I think I'm bumping the shoulder back .002 but in reality it might be more causing the problem. . Take care.

I never explained it that closely but i neck size for at least three firings or until I feel resistance when closing the bolt that's when I will bump it back and full size from there on out.

 

[GLTaylor]

Above are correct. You can't get an accurate case/shoulder length until brass is completely formed to your chamber dimensions. Don't "bump" at all for at least 2 firings. Then measure and set up your shoulder bump. Annealing helps necks. It doesn't do anything for case walls.

 

[memtb]

Thanks for your help. I don't anneal which is probably the reason for my issue. Which annealer would you recommend? Thanks again.

It may be more than or something other than annealing!

I run my AI pretty hot and get 10 firings before tossing the brass. I do not anneal, probably should, and barely "kiss" the shoulder when resizing! I do get some resistance when closing the bolt!

Maybe I'm just lucky! memtb

 

[338 dude]

The OP commented on getting .005 stretch i usually get about .004 stretch on new brass so other than annealing or his sizing methods I don't know what else it could be?

 

[PaLuke]

I'll be able to shoot Tuesday and Wednesday and then I'll measure again. I know I measured after 1 firing to get .005. Understanding you replies maybe it's more after 2-3 firings. Thanks for your replies. I'll post after shooting.

 

[nksmfamjp]

The OP commented on getting .005 stretch i usually get about .004 stretch on new brass so other than annealing or his sizing methods I don't know what else it could be?

COW fireforming would eliminate that initial stretch.