Brass Question

[MOA or bust]

New 7mm PRC (Defiant Classic, Proof CF 22”, Element Mg chassis). I have 100 new Peterson cases. I can probably find an accurate hunting reload before I shoot 50 rounds, certainly before I fire 100. After “seasoning” the barrel with a dozen or so rounds, wouldn’t it be reasonable to go ahead and work up a load on virgin brass?
I realize I would have to reassess the load after I start using once or twice fired brass, but I don’t think I’ll need or want to wait until I’ve shot all 100 pieces before developing a load.
Rifle elk hunt this Fall, but this will be my back up rifle (behind 28 Nos).
Please advise.

 

[K.E.C.]

I work with 50 pieces of brass at a time.
I have done what you are thinking.
Like you said you have to tweak your load for 1st fired. Go for it.

 

[FEENIX]

New 7mm PRC (Defiant Classic, Proof CF 22”, Element Mg chassis). I have 100 new Peterson cases. I can probably find an accurate hunting reload before I shoot 50 rounds, certainly before I fire 100. After “seasoning” the barrel with a dozen or so rounds, wouldn’t it be reasonable to go ahead and work up a load on virgin brass?
I realize I would have to reassess the load after I start using once or twice fired brass, but I don’t think I’ll need or want to wait until I’ve shot all 100 pieces before developing a load.
Rifle elk hunt this Fall, but this will be my back up rifle (behind 28 Nos).
Please advise.

Sometimes, you get lucky, but "I" do not usually do load development until it has been fired off the chamber at least once. However, this is the perfect time to try different powders (pressure test).

 

[Chesterrose79]

It would be good to work up a load with virgin brass but definitely keep in mind that a load that’s near pressure max on virgin brass will most likely be over pressure on once fired brass because fire forming your virgin brass takes some of the energy out of the load. I’d do another pressure test on once fired brass. If you don’t want to do all 100 pieces now work with 20 of them and keep good track of the data between the different firings so you have a good idea what to expect from the other 80 once you get around to it.

 

[Beluebow]

My vote is to work up a load immediately on new barrel/brass, no sense in wasting barrel life or brass life IMO.....Just know that there is a big possibility you will have to jerk powder out to stay in tune as the barrel speeds up. And or retune fired brass.

 

[MOA or bust]

^^^ That’s my plan.

 

[bmnkbrandon]

Literally just did this two weekends ago with a new 7prc I put together on a savage action. The build was a savage action, 28 inch McGowen number 4 spiral fluted barrel. Action trued and machined recoil lug. Grayboe phoenix 2 stock on this one. I bought 150 new same lot adg and 100 gunwerks brass (to compare). Btw if anyone is curious, pretty sure adg and gunwerks 7prc brass is the exact same thing with a different head stamp. Anyway I picked 50 pieces of brass and started with full length sizing them and started load development right away. I loaded 20 rounds for barrel break in and fouling rounds. Then loaded 3 rounds of 13 different powder charges (Staball hd and N165 with 195 bergers 20 thou back from jam). Found my nodes roughly and loaded 20 rounds of each top 2 performers (64.2 grains N165 and 69 grains Staball hd). Found with the once fired brass I was 75 fps higher but group size was even better and I’m calling it good enough for a 10 lb scoped hunting rifle. Groups were 3/8 to 1/2 inch at 101 yards. I plan to use these 50 pieces of brass until they are wore out then start over with another 50 pieces. Not sure if the brass sped up that much from being once fired or from going from Sami spec on brass to 2 thou shoulder bump for second firing. Anyway hope it helps and I strongly recommend N165 if you don’t mind losing 50 fps

 

[YZ-80]

I typically work with 30-35 pieces to start, loading some check charges down low up to the “rung” of the ladder I choose to start with (5 shots each) increasing in .3 grain increments. This is for chamberings that are not exotic and where I can find a good consensus on what is working best for most guys with a given powder/bullet/twist combination. Typically, I have things figured out after the second range trip with fire formed brass. My personal standard is .5 MOA at 300 yards. I had my last two Tikka T3X rifles figured out pretty quick. They basically shot themselves into half a minute within 40 rounds. Anyway, in my situation, yes, that leaves me 65-70 pieces of unfired brass to use after the first batch wears out. I don’t sweat it and just load the virgin stuff up with my pet load and fire away. I’m not shooting that far so there really is not a discernible difference. All that said, I totally get the merits of annealing, keeping very detailed records on brass cycles, etc., it’s just not necessary for me. All the best, -YZ

 

[can1010]

20 rounds barrel brake in, six sets of 3 for seating depth test. use 20 once fired for load development and put rest once fired in bucket. every time you go to range take a handful of virgin brass to foul the barrel before load development and by the time you finalize and verify your load you will have about 100 rounds down the barrel and it should have speed up and settled down and you should have about 40 once fired pieces without wasting any time or components by just shooting to fireform virgin brass or developing and finalizing a load on virgin brass or until the barrel starts to settle down.

 

[josh_127]

I shoot all of my barrels, until they speed up and stabilize, with new brass and a medium load...I work on bullet seating depths till then to find the sweet spot. I do this to fireform my new brass. Once it's broke in I run a ladder test with powder charges and find the low and high nodes...my bartlein 7mm stw barrel took 120 shots to stabilize...my proof on my 25 saum is still speeding up and I have 80+ down it...my hawk hill 6mm barrel took 150 to stabilize.

 

[josh_127]

My bartlein sped up 80fps...the proof so far is up 70 over new. Hawkhill went up almost 100.

 

[SheepShapeAK]

What bullet are you planning on shooting? Not sure if it was mentioned.

 

[lancetkenyon]

I am not waiting on a barrel to speed up. I have a Bartlein 400MODBB on a 25CM that took 300+ rounds to finally speed up. Still shooting the same load as it did when it had 30 rounds down the barrel.

I think it is shooting "good enough". This was 3 weeks ago. 3 shots after swapping the scope to another rifle and back. Dialed down .7MIL, shot 1 to confirm, reset the zero and called it good.

I start load development on virgin brass and a brand new barrel. Usually takes me anywhere between 18-45 rounds depending on how picky the rifle is. Then load and go.
I rarely have to tweak a load unless it is a belted magnum. But I rarely run at max.

 

[Rosebud]

That is my method of loading. Find a load with the Virgin brass and sight in. Hunt with it until 85% is used up. Then tweak the new load. components cost to much to shoot up for me. Plus I can get excellent loads using Virgin brass.