Steel 7.62x39 ammo - anyone covert to Grendel

[lazyengineer]

I'm in good shape, but many right now are not. Looks like steel 7.62x39 ammo can be had for the order of .30 cents. Amd 6.5 bullets can be found. I would imagine one could pull the bullet, move the powder over to a "storage" casing, resize down to 6.5 Grendel while still primed. and put a Grendel bullet on top. It's primed and the powder is already there, I imagine a light 90 TNT or such would be fine. It'll "fireform" on the first (and last) shot, but for someone desparate that primed ammo and 6.5 bullets are readily available right now. This is essentially already being done with 6.5 Grendel Wolf Steel with great success, but obviously without thre resizing need and there being more confidence the powder and charge are correct.

Curious if anyone has tried it?

[mdram]

sgammo has steel cased grendel in stock

[m796rider]

I'm not sure you could just use the 7.62x39 powder with a light 6.5mm bullet and call it good...

I'd guess by the time you have everything figured out and working for a project like this, you'd be dangerously close to the $0.65/rd cost of Grendel steel cased.

[lazyengineer]

I'm not sure you could just use the 7.62x39 powder with a light 6.5mm bullet and call it good...

I'd guess by the time you have everything figured out and working for a project like this, you'd be dangerously close to the $0.65/rd cost of Grendel steel cased.

Yea definatly not a recommended preferred route. Your cost estimate isn't too far off, maybe break it down to 50 cents, but only with luck, and 60 cents is a more realistic floor. As noted, 75 cent steel Grendel makes more sense if you can find it (which apparently you can). That said, powder burn rates tend to be close, and I would expect this route with TNT 90's will be a more accurate and effective hunting round. But realistically, I would advise buying the wolf steel Grendel, and topping that with a 100 or less gr Grendel bullet, for the better path, as you imply.

Just a technical question more than anything - who knows what 2024 will be, so just wondering if this is a route.

[oyster]

I believe there's a thread on here about "Russian reloads" where you take a steel cased wolf FMJ, remove the bullet/ powder and either reuse said powder or change and use a better bullet.
Jay

[m796rider]

I believe there's a thread on here about "Russian reloads" where you take a steel cased wolf FMJ, remove the bullet/ powder and either reuse said powder or change and use a better bullet.
Jay

Moscow Match...

Yep, I do this fairly regularly using 100gr Match Monsters from Midsouth.

[biodsl]

I believe there's a thread on here about "Russian reloads" where you take a steel cased wolf FMJ, remove the bullet/ powder and either reuse said powder or change and use a better bullet.
Jay

Moscow Match. Here's the best I could achieve. Speer 90gr TNT.
Speer_MM_.jpg

[tdbru]

Um... I know this is a dumb question, and doesn't relate to the OP subject, but if you have steel cases 6.5 Grendel, why do Moscow Match? Why not just shoot it as is?

The OP was inquiring about some serious contortions to come up with shootable (maybe?) 6.5 Grendel ammo starting with 7.62x39 ammo.
the powder burn rate for 123gr. 7.62x39 is going to be quite different than what is needed in the 6.5 Grendel for 123gr. Grendel ammo.

Back when 6.5 Gr was just starting out I would go through the work (lot of work) to re-form brass 7.62x39 to 6.5 Grendel. It was a lot of work and as soon as I could get some genuine 6.5 Grendel brass I gladly moved to that. I am not sure how well steel would do through the reforming operations. and I did a couple neck anneals and a neck turning while getting to a fire formed case.

Many of the steel 7.62s39 cases I've examined had berdan priming, which would probably preclude doing any fireforming and then neck annealing and then reloading with a "normal" load. You'd have to go straight to the shooting part with no annealing and likely no neck turning in between. perhaps a better idea would be to acquire a couple of hundred cases when they next come available and call it good?

-tdbru

[Old Bob]

I think someone would have to be pretty desperate for Grendel fodder to be pulling bullets & necking down 7.62x39 steel cased ammo. I know most new Grendel ammo with brass cases isn't exactly bargain priced these days but it's still the better option outside of the steel cased Wolf Grendel ammo. And we all know the brass cases can be used again... more than once. Then I think about the wear & tear on my dies & press. Although they may be tough enough to handle the job, I'd rather not subject them to that kind of work.

[m796rider]

Um... I know this is a dumb question, and doesn't relate to the OP subject, but if you have steel cases 6.5 Grendel, why do Moscow Match? Why not just shoot it as is?
-tdbru

The Wolf 6.5G bullets are undersized, so you can very easily improve accuracy by swapping in an inexpensive but correctly-sized bullet.

[biodsl]

Um... I know this is a dumb question, and doesn't relate to the OP subject, but if you have steel cases 6.5 Grendel, why do Moscow Match? Why not just shoot it as is?

Not a dumb question. The 100 grain steel case bullet is undersized at .262 instead of .264. This, in part, leads to the less than stellar accuracy of the steel case. 'Moscow Match' is a play on Mexican Match.

https://www.snipercentral.com/history-m118-ammunition/

It really doesn't make a ton of sense to do Moscow Match since we're paying for the steel case, unlike the competitors who were getting the military ammo for free.

EDIT; I should add, it was a ton of fun!

[lazyengineer]

...
7.62x39 is going to be quite different than what is needed in the 6.5 Grendel for 123gr. Grendel ammo.
...-tdbru

So as it turns out, not as much as you might think, which is pretty interesting. Of course, to remind, this is a hypothetical, and only a path for the desparate. And that buying Wolf Steel 6.5 Grendel to start with is a way better route - so long as you actually have that option.

But yea, I remember this from back when you could get AA2220 as a 7.62x39 powder surpluse, and run in .223 ammo, quite similarly to AA2230. And I ran over 16lb of that 7.62 powder. So that got me thinking, maybe those powders are close between the two cartridges. As most reloaders know, the bigger the diameter the bullet (iin relation to case capacity), the faster powder it needs, to replace the large increase in reaction chamber volume as the bullet starts down the barrel (bigger hole). Which means a .30 cal will need a faster powder than a .223 or Grendel. But the lower the pressure, the lower the charge. And the heavier the bullet, the slower the powder. As it turns out, those 3 variables seem to combine to give fairly similar charges across all 3 rounds. Taking a 123 gr 7.62x39 round, necking it down to 6.5, and putting a light 90 gr bullet actually can work (but I haven't done it, hence the post and question).


So looking it up, a typical 7.62x39 123 gr reload is:
26.5 gr H4198
31.5 gr H335
etc.

A typical 90 gr TNT Grendel reload:
26.8g H4198
31.7gr H335

Pretty much the exact same load. Obviously this is uncharted territory and caution is a must, but the base though that this is a route to cheap primed (and charged) cases that with processing in a press to neck down, is a cheap and readily available route, to start firing a Grendel to those desparate without options. And only, ,for those without options.

Also, my own experience with fire-forming has been that is way higher priority for people than it needs to be. I run 7.62 casings all the time, up to 5 cycles on some now, necks are doing fine. Once you find a load appropriate for those thicker walls, it doesn't matter if it's fire-formed or not. The brass flows out to full chamber dimensions before peak pressure hits, meaning peak pressure isn't any different fireformed or not. Just run that load, and it cycles fine, velocity is the same, and accuracy is surprisingly also the same. My only 1/2 MOA group I ever got was with PMC full-load blaster 7.62x39 brass I was shooting that wasn't evenfireformed yet (i.e. still 7.62x39 body tapered). Cycled fine, shot great. I don't anneal or any of that. Just adjust the die so that a resized casing fits in the chamber, and run with it.

Again, this is a technical hypothetical conversation, not a recommendation. Just an investigation on what back-up plans there are that one can keep in their back pocket. I suspect the biggest unknown really, is the resizing and necking down of a steel casing. It's easy with brass (with a crumple failure rate of around 5%, depending). With steel, I don't really know if that works or not.

Also, as noted above, while this route is currently only marginally cheaper than just buying Wolf Steel 6.5 Grendel (if you can find such), it will amost certainly be considerably more accurate, as well as pragmatic as a hunting round, since a .264 dia TNT 90 is a way more accurate and effective bullet than a 100 gr steel jacket .262" dia Wolf Steel FMJ bullet.

Thanks for all the replies, having fun with coversation .

[plamia2]