What's The Correct Procedure?

[SPECTRE66]

I just purchased 2K of Win 7.62X39 once-fired brass from Top Brass, and went thru the annealing process with them.
I attempted to run them thru my 6.5 first stage die, and the first couple crumbled.
This once fired brass has the primer punched, but doesn't show evidence of having been thru a first-stage 7.62X39 die, as the neck of the brass is slightly dented from ejection from an AK or similar gun.
Thinking I need uniform pressure on the neck as I go thru the 'squish' to 6.5, I ran several of my dented cases thru the first stage 7.62X39 die. THEN, I put it thru my 6.5 first stage die, and everybody came out good.
I wanted to confirm that this is the process I need to go thru for all my brass initially.
Thanks.

[Clarence]

Not Grendel specific, but I've found that, when necking down any cartridge, the end of the neck must be perfectly round, either by running through a larger sizing die, as you did, or a suitably large expander plug that does the same thing.

Clarence

[LR1955]

SP66.

Sure sounds like everything is going just fine.

Didn't work one way but works the other. Guess that is a process that works.

Make sure it is bumped down enough to chamber.

Make sure the primer pockets will take a primer without it falling out.

Expect three or four shots before your primer pockets open up too much for safety.

Expect velocities that are about 100 fps slower than if shot using Grendel brass.

Your 7.62 X 39 brass has less internal volume than Grendel brass so do start with the low end of the load data. It has even less volume before you blow it out so load accordingly.

There is no ideal powder, charge, or bullet for blowing out the AK brass. Use what ever is safe but also something you don't really care about. Cream of wheat and other fillers will not be sufficient to blow the brass out.

The topic of forming and using 7.62 X 39 brass is pretty extensively covered on the Forum. Run a search and you will probably end up knowing more than you ever wanted to know about it.

LR55

[Bwild97]

Hmmm....I don't remember having any issues necking down 7.62x39 brass using my Grendel dies. I do remember that the Win brass that I have is quite soft when compared to all the other brands of x39 brass I have. The best x39 brass to find is Rem, it uses small primers, the next best is Lapua, Fiocchi, Fed (fc), any russian boxer primed, PMC, and Win. In that order. I have never annealed any brass for the Grendel not even after 12-13 loadings. As far as procedure goes I just run the 1xfired x39 brass straight through the Grendel sizing die. If you are crushing the brass, you may be pushing the shoulders to far back? Have you tried lubing the necks first?

[LRRPF52]

Welcome aboard.

Is this mixed brass?

There are so many sources of Grendel brass now, there is no reason to mess with 7.62x39 brass, and load data will not be the same for reasons LR1955 mentioned.

[VASCAR2]

I use Dillon case lube and it made sizing 7.62 X 39 brass much easier to lube the inside the case mouth. I put a couple of drops of case lube on a Q-tip and put lube on the inside of the case mouth/neck. I run a lubed case neck about every 5-10 pieces of brass.

[Djgrendel]

Back when I did some fire forming for grendel, I didn't have any issues. Had 500 new winchester x39 I found at a gun show for 10 dollars a bag. Couldn't resist. The once fired brass I had was used in my sks and ak. Seemed to size ok as well. I lubed necks and went to work checking multiple times for fit. I used 95gr. Vmax and 100 gr ballistic tips. Used my fireforming loads on the prairie dog towns. Worked, but with all the good grendel stuff around I don't bother with x39 forming these days. My notes show that I used 25.1 gr of benchmark, and seated about .010" off lands. Primer was cci 200. Be safe and have fun. This data is for my rifles. Use at your own risk.

[LR1955]

I use Dillon case lube and it made sizing 7.62 X 39 brass much easier to lube the inside the case mouth. I put a couple of drops of case lube on a Q-tip and put lube on the inside of the case mouth/neck. I run a lubed case neck about every 5-10 pieces of brass.

VC:

How come you didn't just toss the AK brass into a plastic bin, spray a couple of sprays of the Dillon lube and shake the bin for twenty or so seconds then let sit for a minute?

At first I thought it wouldn't get the lube inside the necks but was proven wrong. Out of about 100 pieces of brass, I may have had two or three that were a bit harder to pull through a sizing button. Saved a huge amount of time and didn't change anything in terms of function or performance.

LR55

[VASCAR2]

I'll have to try that LR1955, I always laid my brass on a cookie sheet and sprayed them and rolled them around.

[LR1955]

I'll have to try that LR1955, I always laid my brass on a cookie sheet and sprayed them and rolled them around.

I did the same thing until I tried the toss, spray, and shake technique that Dillon recommended with the spray lube. Just have a lid on the container when you shake.

Laying the stuff out and carefully spraying did a slightly better job but takes quite a bit longer.

[Texas]

I have sized a number of 7.62X39 down to 6.5 Grendel and only lost the first couple of brass because I was bumping the shoulder too far back. Once I had the dies set properly, no problems. Have been Hornady waxs that I use on my .50 BMG when sizing.

On another note, I am getting higher velocities out of the 7.62X39 brass using 30.0 gr of CFE and 123 gr amax than I do with Hornady 6.5 Grendel brass and no signs of pressure which is what I would expect from a case with less volume.

I AM NOT RECOMMENDING THIS LOAD FOR ANYONE ELSE, but it works well in my rife.

[LR1955]

I have sized a number of 7.62X39 down to 6.5 Grendel and only lost the first couple of brass because I was bumping the shoulder too far back. Once I had the dies set properly, no problems. Have been Hornady was that I use on my .50 BMG when sizing.

On another note, I am getting higher velocities out of the 7.62X39 brass using 30.0 gr of CFE and 123 gr amax than I do with Hornady 6.5 Grendel brass and no signs of pressure which is what I would expect from a case with less volume.

I AM NOT RECOMMENDING THIS LOAD FOR ANYONE ELSE, but it works well in my rife.

Tex:

Roger. I got higher speeds with Varget too. Brass went two shots and the primer pocket opened up too much. However, speeds were about 50 fps higher. Am sure I could get higher speeds with other powders if I wanted to blow primers. This was before CFE or Leverloution which I understand seem to have lower signs of pressures with decent velocities.

None the less, it is still easier and more cost efficient to buy Grendel brass instead of trying to get 7.62 X 39 brass to be of any more value than brass one doesn't care if they lose.

LR55

[LRRPF52]

I have sized a number of 7.62X39 down to 6.5 Grendel and only lost the first couple of brass because I was bumping the shoulder too far back. Once I had the dies set properly, no problems. Have been Hornady was that I use on my .50 BMG when sizing.

On another note, I am getting higher velocities out of the 7.62X39 brass using 30.0 gr of CFE and 123 gr amax than I do with Hornady 6.5 Grendel brass and no signs of pressure which is what I would expect from a case with less volume.

I AM NOT RECOMMENDING THIS LOAD FOR ANYONE ELSE, but it works well in my rife.

Reduced case volume with the same charge from a Grendel case will increase the pressure.

The number one pressure sign to look at is muzzle velocity. Then attempt to read your brass/primers.

Bill A. said he has seen many proof loads that are at 67,000psi with nicely dimpled primers, no signs of anything wrong on the brass.

What barrel length and speed are you getting with 123gr AMAX with 30.0gr CFE in 7.62x39 brass?

[Texas]

Reduced case volume with the same charge from a Grendel case will increase the pressure.

The number one pressure sign to look at is muzzle velocity. Then attempt to read your brass/primers.

Bill A. said he has seen many proof loads that are at 67,000psi with nicely dimpled primers, no signs of anything wrong on the brass.

What barrel length and speed are you getting with 123gr AMAX with 30.0gr CFE in 7.62x39 brass?

I am using the 7.62X39 brass when we are out pig hunting because I do not like having a brass catcher on my rifle and do not want to leave any Lapua or Hornady brass in the field.

I bought 1000 range pickup brass for 130.00

Out of my 20 in the chrono is about 2560 fps. Hornady factory AMAX is about 100 FPS slower.

Just as an aside, we had to pressure test every M2 bolt we manufactured. We proofed a couple of thousand with the same barrel. I am of the opinion that proof testing probably should not be done because I have not seen a failure, and it can create micro fractures which may cause a failure in the field.