New to once fired brass....results.

[The Oregonian]

I asked about going from new to once fired brass...this is a new gun for me and I have only been reloading for a year.

I have shot maybe 300 rounds of new brass and just cleaned and sized the first batch of once fired. Results are below.

Gun - 30-06 by Darrell Holland...Borden action, Hart 24" 10 twist, Jewell, McMillan.
Load - 57.2gr of H4350, Rem primers, Nosler brass, Nosler BT 180gr
Dies - whidden custom based on fired cases

I shot 5 of new and 5 of once fired through a Magneto. I then fired 5 of each without a Magneto to get a new zero. I was at the 100 yd range today.

New brass - avg velocity 2824, ES of 18 and SD of 6. Didn't measure group but it was so-so.

Resized brass - avg velocity of 2844, ES of 15, SD of 6. Group was better...pic attached.

I didn't know what to expect but I was pleased with how it worked out. Next up is to take out to longer range and validate drops. POI shifted but moved it down .75 and left .5 and was dead on.

 

[J E Custom]

I asked about going from new to once fired brass...this is a new gun for me and I have only been reloading for a year.

I have shot maybe 300 rounds of new brass and just cleaned and sized the first batch of once fired. Results are below.

Gun - 30-06 by Darrell Holland...Borden action, Hart 24" 10 twist, Jewell, McMillan.
Load - 57.2gr of H4350, Rem primers, Nosler brass, Nosler BT 180gr
Dies - whidden custom based on fired cases

I shot 5 of new and 5 of once fired through a Magneto. I then fired 5 of each without a Magneto to get a new zero. I was at the 100 yd range today.

New brass - avg velocity 2824, ES of 18 and SD of 6. Didn't measure group but it was so-so.

Resized brass - avg velocity of 2844, ES of 15, SD of 6. Group was better...pic attached.

I didn't know what to expect but I was pleased with how it worked out. Next up is to take out to longer range and validate drops. POI shifted but moved it down .75 and left .5 and was dead on.

Normally, once fired brass is more accurate as long as you don't over size it. It fits your chamber better and the internal volume is more consistent. (One reason the SDs are lower). With slightly
more case volume there is more air space in the cartridge increasing the burn rate slightly. (The reason that velocities were slightly higher.

Accuracy can be good with fire forming or first firing but generally gets better with second firing
and with minimal sizing.

J E CUSTOM

I recommend minimum sizing, (Just enough to chamber without forcing the bolt closed). If it is for dangerous game then it should be full length sized for safety.

 

[The Oregonian]

Thanks for the explanation of what I experienced. Are you recommending only neck sizing until the bolt tells you the shoulder needs to be pushed back?

Thx.

Tom

 

[J E Custom]

Thanks for the explanation of what I experienced. Are you recommending only neck sizing until the bolt tells you the shoulder needs to be pushed back?

Thx.

Tom

Absolutely. As long as it chambers good there is no need to over work the "Precious" brass.

If you use it in a Simi Auto, you may need to do a little more sizing.

Glad It is going well.

J E CUSTOM

 

[The Oregonian]

Absolutely. As long as it chambers good there is no need to over work the "Precious" brass.

If you use it in a Simi Auto, you may need to do a little more sizing.

Glad It is going well.

J E CUSTOM

One last question (I hope)...does neck sizing and periodic full length sizing create different velocities and POI based on which sizing was done, which may require two different sets of ballistics data, or is any difference immaterial?

Thx for your help.

Tom

 

[J E Custom]

One last question (I hope)...does neck sizing and periodic full length sizing create different velocities and POI based on which sizing was done, which may require two different sets of ballistics data, or is any difference immaterial?

Thx for your help.

Tom

Re sizing and trimming is caused by the brass flowing forward. As it is sized and trimmed (Removing some brass), A volume increase is the effect (Even though very little) also the brass becomes work hardened, and after 3 to 5 loadings, an anneal is necessary.

I recommend that you shoot all the brass you have before you reload so that changes are minimal.
also this way when your primer pockets start to loosen, you know that almost all of your cases are on there way to giving you problems.

It is easy to adjust to small changes as you go, But if you mix the brass by firings you will effect
the consistency of your pet load And the potential accuracy.

J E CUSTOM

 

[The Oregonian]

I do keep them separated and segmented by number of firings. Thanks for your help.

Tom

 

[Mikecr]

One last question (I hope)...does neck sizing and periodic full length sizing create different velocities and POI based on which sizing was done, which may require two different sets of ballistics data, or is any difference immaterial?

It can and this depends on your die -vs- chamber.
I cringe at the term 'FL sizing' as I picture off the shelf dies mutating brass to pure junk.. True FL sizing also sizes the entire neck length which is a horrible thing to do.
In contrast, custom honed FL dies, matched with a good chamber/plan, provide the very best in sizing.
Personally, I bump shoulders and partial NS only. Works great for me.

I've resisted the observation that new or heavily sized(big clearance) brass produces lower pressures because in certain aspects(like initial capacity & load density) this makes no sense. But I've taken my schooling and concede that it's true.
On firing, a case that has distant expansion to meet the chamber walls is absorbing some peak energy in doing so.
Brass that is fitted with relatively tight chamber clearances will produce higher pressure(and usually velocity) for a given load -w/resp to looser brass.
While this new/loose brass energy absorption seems an actual benefit with some combinations, I am confident this wouldn't pass tests across the gamut of cartridges we shoot. Consistent dimensions mean consistent capacity and load density. This is what I want before doing any load development.
If it turns out lower pressure/MV shoots better for me, I'll find this in development as powder adjusted rather than through brass sizing.

A 30-06 is a poor cartridge reloading-wise, compared to all the improved cartridges of late. It's long for capacity, with high body taper and low shoulder angles. Brass does roll(often called flow) on firing a 30-06, so it changes with every shot and you will have to FL size it, trim it, anneal it, and replace it..
With something like a 7SAUM and control over it's chamber and a plan, you would have none of this changing. It's brass would not flow on firing, or roll on FL sizing(because you would not be heavily FL sizing), so there would be no trimming, and no annealing. Add rational load pressures(<65Kpsi) and it's cases could last in stable dimensions indefinitely w/bumping/partial NS only.
I bring up this comparison so that you'll recognize that common notions do not always apply to the circumstances at hand.

 

[The Oregonian]

Thanks for the info. The dies I am using are from Whidden and based on the chamber dimensions, so it should be doing minimal sizing.

I do have a question about the neck sizing comment in your post...how far down the neck do you recommend to size? Just enough to allow the bullet to be seated but no more?

 

[Mikecr]

how far down the neck do you recommend to size?

No more than seated bullet bearing, while distant enough from any donut.