Breaking in 284 win barrel with 6.5x284 Lapua brass

[Eddie Vializ]

Hey guys, while waiting for a delivery of new Lapua brass I necked up some older 6.5x284 Lapua that had been shot 8 times in a different rifle. I used a Sinclair expander mandrel and sized the brass in new 284 win dies bumping the shoulder back .003. While breaking in the barrel with "lite" rounds (53 gr H4831sc) they chambered smoothly and closing the bolt was easy. Upon firing and opening the bolt, the bolt opened two thirds of the way and required the old grab the scope with your thumb to open the rest of the way. There were no pressure signs. The primers were nice and round and no ejector marks. Today I did a ladder test 53-56 in 1/2 gr increments, two shots each. Again no pressure signs other than slight sticky bolt. If I put a fired piece of brass back in to chamber it was tight bolt. What can it be and should I just wait for brand new brass and not sweat it? Peace

 

[Eddie Vializ]

By the way, Bat model M multiflat, Kreiger 31 1/2", oal to lands 3.300 with 180 Berger hybrids.

 

[Shynloco]

Eddie,
I use RCBS precision mics to measure every piece of brass so I know exactly how many thousands to bump. As you probably know, you need to FL resize any brass fired in another chamber.

Alex

 

[DJSBRS]

Did you anneal before sizing up and after sizing before you FL resize for proper fit for your chamber? Being fired 8 times leave them with memory from the last chamber fired.

DJ

DJ's Brass Service
205-461-4680

 

[jr600yd]

What size neck does your new 284 have? What's the neck size of your loaded 284? Most 284's like .004 or more neck clearance. Did you neck turn into the shoulder to avoid a donut?

 

[Eddie Vializ]

The chamber neck size is .314. I did turn the necks for concentricity to .014 walls. The loaded rounds are .311. I used a .309 titanium bushing. I don't have an annealer. It is going to be my next "thing". I was getting 2930 fps with 56 grains. If the new brass coming in tomorrow makes the sticky bolt go away I will be very pleased.

 

[dskogman]

56g/2930 is a the very top for a straight 284. You probably will only get a couple of firings before the primer pockets are gone. Long strings can easily push it over the top. 2800-2850 if you want long brass life and consistent performance.

 

[NA Woody]

The chamber neck size is .314. I did turn the necks for concentricity to .014 walls. The loaded rounds are .311. I used a .309 titanium bushing. I don't have an annealer. It is going to be my next "thing". I was getting 2930 fps with 56 grains. If the new brass coming in tomorrow makes the sticky bolt go away I will be very pleased.

I bet annealing will take care of the issue. There are a bunch of options for annealers...my annealeze works great and was "reasonably" priced.
Good luck with your .284 Eddie...I agree with Dskogman....try to keep it around 2830ish.
Take care,
Woody

 

[Eddie Vializ]

Thanks much guys. I am more keen on low SD and ES than on raw speed. With new brass, powder and CCI BR2s coming in today I should see if the sticky bolt goes away. I will post the results. Peace

 

[JasonT]

If your case necks are around 14 thou (like in my 308), you can always spin the case in the flame of one of those cheap brass pencil torches for 8-9 seconds, dunk it in water to stop the heat transfer, and call it good. That always softens up my necks pretty well.

 

[Eddie Vializ]

Prepped up 20 new Lapua cases and did a ladder test for pressure signs. The bolt closed and opened easily upon firing and showed no pressure signs up to 56.5 gr H4831sc. at 2910fps. So it was the old brass giving me the sticky bolt with all loads all along.
I may load a couple at 56.8- 57.3 just for reference.