Load Development brass

[jaybic]

Hello,

I am getting ready to begin load development on both a 6.5x47L and a 6BRA and got to thinking about the brass used in either one. One is brand new factory Lapua in 6.5x47L and the other is brand new Lapua 6BR that has been fire formed with 30 grains of H4895(so is now once fired and annealed. My question is this:

What are some opinions/facts/suggestions/experiences with the best brass to use for load development?
1. Brand new, never fired?
2. Brand new, fired once? twice?
3. annealed? not annealed?

Any and all thoughts and input is more than welcome and greatly appreciated.

Thanks for your time, stay safe in these strange times and have a great day!

Jamie

 

[mtnhunter22]

Never thought on this much but personally don’t do load development until after 100 rds or so. So by then my brass is typically once fired and maybe annealed depending on brass.

 

[jaybic]

the 6.5x47 has about 150 rounds on it and the BRA is at 266 fire forming loads on it...if that helps at all...

 

[Rocketmandb]

What are some opinions/facts/suggestions/experiences with the best brass to use for load development?
1. Brand new, never fired?
2. Brand new, fired once? twice?
3. annealed? not annealed?

My opinion is that you want to load develop using brass that is as close as possible to what you will be using in the final form. Otherwise, you're introducing variables into the development - case volume will change, neck tension (unless prepped) will be factory, etc.

For a new rifle or barrel, I'll take 50 cases and break the barrel in with them, then do load development. If I'm not fire forming, if I have to use once-fired, it's acceptable. If I'm fire-forming (I have a 6 BRA too), then I prefer to get two firings on the cases.

For a new bullet, case, powder, or whatever else I'm playing with in an existing barrel, I definitely use existing multi-fired brass, since I'll have plenty of it.

As for annealing, I anneal every firing, so I'll anneal during load development too.

 

[Dthomas3523]

I’d use fired brass. If you have 2-3x fired, that’s prob ideal especially for brass requiring Fireforming.

You can use virgin brass, but it will typically be a little slower.

 

[hengehold]

For the 6.5-47L I would start load dev after about 50 rds have been fired in new barrel. For load development purposes, I don’t think you will see a difference between virgin brass and fired brass on an unmodified case.

6BRA is a different story. I would start load development with brass that has been once fired. I know others may suggest that the case is not fully formed until it has been shot multiple times but I just have not seen that much change after the first firing.

-TH

 

[Milo 2.5]

the 6.5x47 has about 150 rounds on it and the BRA is at 266 fire forming loads on it...if that helps at all...

On the BRA, about have to develop on fireformed brass. I hope you at least developed enough of a load that the FF load was accurate for the BRA, no use wasting rds. There are 2 philosophies of FF brass, hammer the piss out of it, or baby it in. I have had both work, so not sure which I prefer. It does pay to monitor your load after each sizing of the brass, go test 10rds, between the target and a chrono, it will be right there for you to make decisions.
For the 6.5x47, iMO, it depends on the number of pieces of brass you put into service, If you bought 100 pcs, by all means fire them first. If you have 3-500, now it doesn't make much sense to fire them all first.
I bend myself over way more when it comes to having a load and a barrel speed up wrecks it. I have a HH barrel speed up over 100fps, just had a Kreiger 25 cal barrel yield a 90fps increase, these are tougher to overcome than anything going on with a loaded rd.

 

[jaybic]

The BRA fire forming loads seem to shoot extremely good IMO At 30.0 Gr of H4895 and a 105 hy, It runs .3 so that is all good. The actual BRA loads where shot using H4895 and 105 hybrids and loaded at 30.2/30.4/30.5(a suggested sweet spot for the BRA) 30.6/30.8 and 31.0(quit shooting these as bolt lift was noticeably heavy...pressure)

The 6.5x47 and 140 hybrids were shot on twice fired brass and at 36.5, 36.7 and 36.9 and shot .145, .399 and .199 respectively. seemed slow tho. All were shot using varget and the speeds were at 2710(36.5), 2721(36.7) and 2724(36.9).

 

[jaybic]

For reference

The BRA fire forming loads seem to shoot extremely good IMO At 30.0 Gr of H4895 and a 105 hy, It runs .3 so that is all good. The actual BRA loads where shot using H4895 and 105 hybrids and loaded at 30.2/30.4/30.5(a suggested sweet spot for the BRA) 30.6/30.8 and 31.0(quit shooting these as bolt lift was noticeably heavy...pressure)

The 6.5x47 and 140 hybrids were shot on twice fired brass and at 36.5, 36.7 and 36.9 and shot .145, .399 and .199 respectively. seemed slow tho. All were shot using varget and the speeds were at 2710(36.5), 2721(36.7) and 2724(36.9).

 

[Rocketmandb]

The BRA fire forming loads seem to shoot extremely good IMO At 30.0 Gr of H4895 and a 105 hy, It runs .3 so that is all good.

I run my fire-forming loads a lot lower at 28.6 - I'm one of those guys who wants to ease in the brass during this process.

The actual BRA loads where shot using H4895 and 105 hybrids and loaded at 30.2/30.4/30.5(a suggested sweet spot for the BRA) 30.6/30.8 and 31.0(quit shooting these as bolt lift was noticeably heavy...pressure)

I'm running mine at 30.7, and will drop to 30.6 during warmer months. My bolt lift hit at 30.8.

 

[Steel head]

My new brass always gets a firsts firing with a moderate load before I get serious.

 

[jaybic]

perhaps I am running my ff load to hot???

 

[Rocketmandb]

For reference

Base on this, I'd do some more concentrated testing around 30.4, .5, .6, and .7.

On my BRA, my sweet spot with 4895 is very narrow. 30.7 shoots lights out - 30.6 just okay. As a matter of fact, I missed the node by doing groups and ladder testing at .2 gr increments. 30.6 shot okay, 30.8 was sticky bolt, and I never shot 30.7.

Then, I decided to play around 30.6 (up and down by .1, and retesting stickiness at 30.8). I discovered the sweet spot at 30.7, validated the 30.8 sticky, revalidated 30.7 with 20-round strings.

I'm thinking about playing with the 109s to see if I can find a wider node with those - just not sure I want to do that right now.

 

[Rocketmandb]

perhaps I am running my ff load to hot???

IMO there is no reason to run them hot. I use them as practice shots to work on trigger management. Who cares if they're fractions of an inch low at 100.

 

[jaybic]

I am actually following your path. I am targeting that 30.4-30.7 window and am going to test in .1 increments both at 100 and with 3 round groups at 600 to be certain of vertical. then play with seating depth and fine tune....thanks again to all for the insight...

 

[Steel head]

IMO there is no reason to run them hot. I use them as practice shots to work on trigger management. Who cares if they're fractions of an inch low at 100.

Surprisingly I often find these mild FF loads quite accurate and totally acceptable for shooting steel past even a 1000 yards.

 

[Rocketmandb]

I am actually following your path. I am targeting that 30.4-30.7 window and am going to test in .1 increments both at 100 and with 3 round groups at 600 to be certain of vertical. then play with seating depth and fine tune....thanks again to all for the insight...

I'd add in one more validation step: testing with 20ish rounds over a chrono at the "final" charge weight. You can do this at the same time you're doing the seating depth.

 

[jaybic]

I have 900 pieces of brass so I was gonna just use my ff load for some local matches. I have 300 formed so far but a buddy of mine has another BRA tube that has 2250 rds on it and was done by the same smith and same reamer that he is gonna let me use to blow out the rest of my brass with out burning up my new tube....Impact barrels...

 

[Rocketmandb]

I have 900 pieces of brass so I was gonna just use my ff load for some local matches. I have 300 formed so far but a buddy of mine has another BRA tube that has 2250 rds on it and was done by the same smith and same reamer that he is gonna let me use to blow out the rest of my brass with out burning up my new tube....Impact barrels...

I wouldn't fire form in someone else's barrel - it's not going to match yours, and depending on your resizing die vs their chamber, could cause extraction/sticky bolt issues.

Also, why are you forming so much brass all at once? I usually have 200 ready to go and use them until they are worn out or lost, then move on to the next couple hundred.

 

[jaybic]

I guess I was thinking that being that it was an Impact action and the barrels are supposed to head space identically, and that it was the exact same reamer used by the same gunsmith on the same CNC program that it would produce nearly identical brass. Now it has me second guessing myself. its not something I would do if the reamer and or smith was different but maybe it is a bad idea. As for how many to form, I was going to fire form the first 500(same lot) so that I had enough ready to for for back to back 2 day matches with a round count of 200-250. that way I dont have to do the mad reloading scramble during the week. the other 400 are a different lot that i am holding in reserve.