7.62x39 to 6.5 Grendel

[molar]

I have some new IMI 7.62x39 brass and some once fired PMC and Fiocchi.

I think I would lose too much case capacity with the thick walls of the IMI brass, but the PMC and Fiocchi should work fine for making 6.5 Grendel brass.

Is it worthwhile to do this, considering the cases will have to be fireformed? Hornady 6.5 Grendel brass is expensive at 70 cents each and in my experience with it, a lot of cases are lost after only one or two firings due to loose primer pockets. Lapua brass will last forever, but at over $1 each, it gets kind of expensive.

On the other hand, I figure I will have at least 32 cents in powder, primers, and the bullet to fireform, plus the 17 cents or so I could sell the 7.62 brass for. That puts me at 49 cents for twice fired grendel brass.

I know the Fiocchi 223 brass lasts forever, but what about the 7.62x39 brass? If I would get several firings out of it, I would definitely go to the trouble of converting it.

So what should I do? Sell the 7.62 brass and buy Lapua 6.5 grendel brass or convert the Fiocchi 7.62 brass?

[GRUMPA]

I've converted a few into the 6.5 but as far as head stamps I can't remember what they were. Forming is real simple, just use a case gauge. Although I never used them if you anneal after forming the fire forming part is moot.

[bruce drake]

I've done this for my 6.5Grendel and yes, its a simple reform to 6.5x39 and then a fireformed (18gr of RL19 with a 100gr 257100 that are paperpatched to .268") to blow the shoulder out to 6.5 Grendel dimensions. I figure my converted cases lose about 2-3gr of powder space with the conversion but I also don't make hotrod loads for my 6.5 Grendel AR15 (26.5gr IMR 8208XBR with 100gr Hornady A-max (2400fps) for NRA Rifle Matches).

Most 7.62x39 cases use Large Rifle primers while I believe 6.5 Grendel cases are setup to be primed with Small Rifle primers as they were originally made with 220 Russian/6PPC cases.

[Jake70]

Interesting. I'm wanting to get a 6.5 Grendel soon, and I didn't know you could form it from 7.62x39mm.

[reed1911]

I'm curious to know what pressures you are running to loosen primer pockets up that quickly. I'm firmly in the mind that while Hornady brass is not the best it is not total junk either. You must be running hot to get them loose that quickly. No offense intended here just asking questions.

@ Jake,
Yep. The .220 Russian started it all, it was later formed to the PPC variation as well as the 7.62x39 and then 9x39, and the 7.62x39 later necked back down and blown forward to be the 6.5 Grendel as well as a wise array of other wildcats.

[rockrat]

I form my 6.5 brass from x39 and load using a charge about 4gr less than 6.5 data shows, and go shoot. The fireformed brass I load about 2 grains less because of the thicker brass. I usually shoot the 95gr vmax

[molar]

I'm not hotrodding it. Most of my loads are .5-1 gr below book max using CFE 223, AR Comp, XBR 8208, or BLC-2. Hornady brass is just too soft. I've had issues in other calibers with primer pockets loosening after a couple of firings.

[molar]

I wish there was a source for cheap 6.5 bullets moulds. I could cast cheap bullets to fireform with. I'm hesitant to fire form using the 123 AMAX's I have 25 cents each in. Seems like a waste.

[xacex]

I wish there was a source for cheap 6.5 bullets moulds. I could cast cheap bullets to fireform with. I'm hesitant to fire form using the 123 AMAX's I have 25 cents each in. Seems like a waste.
One of our members here designed a great 125 grain bullet for the grendel max that works well with the grendel. You can get one at NOE. That is what I am using for fire forming. NOE also has a bushing sizer die in the size you need, and .264 gas checks. I am finding the shoulders are a little rounded on the first fire form, but sharpen up with a moderate load after the initial forming.

[molar]

One of our members here designed a great 125 grain bullet for the grendel max that works well with the grendel. You can get one at NOE. That is what I am using for fire forming. NOE also has a bushing sizer die in the size you need, and .264 gas checks. I am finding the shoulders are a little rounded on the first fire form, but sharpen up with a moderate load after the initial forming.

Do you think I could use coated .258 bullets to fireform. I know accuracy would suck, but should not lead with coated bullets. Using those and some unique would allow me to fireform cheap.

[bruce drake]

I used paper-patched .258 lead bullets to fireform my x39 brass to 6.5 Grendel. accuracy was bad but they stayed on the target frame at 50 yards.

the 7.62x39 brass actually was the parent case of the 220 Russian... The Russians designed the 220 Russian as a deer round for its citizens that didn't use a military cartridge in the 1950s. The 7.62x39 was developed in 1944 and was actually used during WWII in combat against the Germans.

[Sur-shot]

I only use Win 7.62x39 brass with LR primers to make my Grendel brass. The Win brass is quite a bit tougher than the Hornady which I have found to be soft, it blows primer pockets quite easily. I also only use 120 SMKs for my sonic stuff and the .267 Hornady 160gr for my subsonic loads to get full function and .5 inches at 50.
Ed

[dtknowles]

I only use Win 7.62x39 brass with LR primers to make my Grendel brass. The Win brass is quite a bit tougher than the Hornady which I have found to be soft, it blows primer pockets quite easily. I also only use 120 SMKs for my sonic stuff and the .267 Hornady 160gr for my subsonic loads to get full function and .5 inches at 50.
Ed

This is the second post in two days about primer pocket problems. Am I the only one who never has this problem? I don't have a rifle that operates at over 60ksi but 6.5 Grendel is only 52Ksi and 7.62x39 is only 45Ksi so that could be a clue. I have not pushed the limits much but I have used RP small primer 7.62x39 brass to make some 6mm PPC brass and fired it with pretty hot loads and have a couple reloads on the brass without primer pocket problems.

Tim

[Houndog]

IF you are lucky enough to find them, Remington 7.62/39 brass has small primer pockets. I used them to make 6PPC cases when we had a shortage of Lapua and Norma cases years ago. They worked fine, but remember they won't handle the pressure like Lapua brass although they are better than Norma for pressure!

[Preacher Jim]

That 8208 and 107 smk groups great from my 24" 6.5 Grendel barrel brass needs to be annealed after forming

[paul edward]

I'm wanting to get a 6.5 Grendel soon, and I didn't know you could form it from 7.62x39mm.

You can also form 6.5 Grendel from 6.5 Carcano although the necks may need to be reamed.