243 ackley brass (comparison and question)

[canuckr]

So I felt like checking the H20 capacity of some of my brass today. I have a 243 Ackley that I formed brass from IVI match 308 brass. (IVI is the CDN version of Lake City) I find the IVI brass to be of pretty good quality, and it was very consistent when I weighed the H20 capacity today. Of the 10 pieces I checked the H20 capacity of 8 of them held 54.58-54.66 grs of water 2 of them were a bit higher at 54.76 grains of water. This is my AI formed brass.
This is what brings me to my questions. I compared it to some other brass I had kicking around. I have a bit of Norma STRAIGHT 243 brass that held 53.5 grains of H20, so compared to that I didn't gain much case capacity with the Ackley. The IVI brass that hadn't been fire formed to my Ackley held 51.5 grains of H20.

So my question is: Do you think I would gain much by switching to norma brass in terms of velocity? I have a pretty large pile of the IVI 308 match brass, it is already weight sorted into 2 lots of 150-200 pieces that weigh within 1 grain of each other. I might be able to get a bit of norma .308 brass for a reasonable price. Assuming I had to pay full price for Norma or Lapua brass would it be worth it?

Thanks

Derek

 

[WDL]

Have you tried PRVI brass?

 

[canuckr]

No I haven't, This is a fairly new build. I am trying to decide if its worth continuing to use the IVI brass or if I should stop being a cheap ass and buy some brass. If it will it make an actual difference on paper or velocity

 

[lancetkenyon]

I think stick to what you have and work up a load to that. It has always worked well for me. If you have 300-400 cases, that should last a long time. I shoot a lot of Remington brass, and with weight sorting it all, the accuracy is great.

I have a couple Ackley calibers, and in a recent comparison of standard .25-06 Remington brass (for fire forming loads), I found an interesting discovery with case weights. I got a bunch of once fired brass from a friend who does not reload and decided to weigh it to see what the difference was in brass content.

I shoot Remington brass, and standard .25-06 Remington, trimmed to length, chamfered, and primed with CCI 250 Mag weighs between 195.5-196.5 grains in my keepers.
All brass below was sized, trimmed, chamfered and primed with the same CCI250 Mag primers. (I checked primer weights and found not even a .1 grain difference in about 100 from different lots/boxes)

All brass weights are average and within .5 grains
Hornady=182.1
Nosler=184.3 (was the most consistent of all I weighed, all 150 within .2 grains)
Frontier=188.0
Winchester=190.1
Remington=196.0 (most inconsistent with about 10% throw outs due to out of tolerance weights)
Federal=202.5

A 20 grain difference in brass weight alone is a huge difference and could lead to some serious pressure issues if all were loaded with the same charge weight. Imagine working up a load with Hornady or Nosler brass at just under max and then loading some Federal brass with the same load!

I know that during fire form testing, my tried and true current Remington brass load was significantly slower (50fps+/-) with the new Nosler brass. Guess I get to work up a new load now with the Nosler brass since I have 150 cases.

 

[bigedp51]

Normally military 7.62 brass is thicker, I would check the capacity of your military cases vs .243 cases "BEFORE" fire forming. Military 7.62 cases normally hold 2 grains less of H2O which would defeat the purpose of being an "improved" cartridge. Quickload shows approximately 5,000 psi increase in chamber pressure using the military cases vs standard .243 cases with two grains less of case capacity and the same powder charge. I would buy cases with the most capacity to take advantage of the improved case.

243 Win Cartridge Guide within AccurateShooter.com

Case Capacities

Nosler custom brass comes pre-prepped, weight sorted and uniformed, it costs more but saves you time and work.

You will also find that your necks will be thicker using military 7.62 brass and you might need to neck turn for your chamber.

 

[canuckr]

I'm thinking I should buy some brass. Bigedp51, your right in my case about holding 2 grains less H20.
Brass I have formed to 243 holds 51.5 grains.
Norma 243 holds 53.5
my AI IVI brass holds 54.5
So looking at those numbers I have hardly gained anything over a straight 243 with commercial brass when using my mil spec brass.
Will I actually gain enough velocity to make it worth it by switching to commercial brass?
bigedp51 Can you run it through quickload for me by chance? a safe max load of Retumbo under a 115 berger in a 22" barrel 7 twist, with the 2 different case capacities. I don't know squat about quickload if that's even possible.

I do neck turn the brass.

Thanks

 

[308sako]

No it isn't worth getting the slightly larger capacity cases as you will not get significantly faster velocities.

Sort by weight and match prep the primer pockets, burn the tube out and repeat