I have a case of Czech 7.62x25 that has hard primers. They go bang in a TT but not a Norinco NP762. I've though of throwing the projectiles and powder into boxer/ brass 7.62x25 cases but then thought - "What about a one-to one dump of powder and projectiles into 30 carbine cases?" Anybody tried that?
Anybody tried dumping 7.62x25 surplus pulled bullets and 1:1 powder into 30 carbine?
- Thread starter steelgray
- Start date
Do a couple and find out.
That bullet is a few thou larger than what 30M1 Carbine barrels are made for, but shouldn't give you any issues.
The load used for those cartridges is quite stiff and will easily operate an M1 Carbine action. I converted an M1 Carbine to shoot those bullets and it worked very well. The Chinese military also rechambered captured M1 Carbines for the cartridge.
So, yes, it's been done and your loads should be worked up carefully.
That bullet is a few thou larger than what 30M1 Carbine barrels are made for, but shouldn't give you any issues.
The load used for those cartridges is quite stiff and will easily operate an M1 Carbine action. I converted an M1 Carbine to shoot those bullets and it worked very well. The Chinese military also rechambered captured M1 Carbines for the cartridge.
So, yes, it's been done and your loads should be worked up carefully.
.30/06 FTW
CGN Ultra frequent flyer
- Location
- Thunder Bay, Ontario
Without knowing what powder was used there's no way I'd ever do that.
Like bearhunter says, one can start below and work up - but the Chinese military did rechambered captured M1 Carbines for 7.62x25 - which as we know has a lower FPE number. I suppose the only issue is using a powder that was intended for a bottleneck case in one with straight walls. Normally that wouldn't be a problem, unlike potentially the reverse.
.30/06 FTW
CGN Ultra frequent flyer
- Location
- Thunder Bay, Ontario
Start below what though, you have no frame of reference and no idea how the powder is going to behave.
I would do it.
Comparing the same bullet and powder for the two calibers, one sees that the Carbine takes more powder. The Carbine typically takes 1 to 3 grains more powder. So the lighter charge from the 7.62 should be just fine 1:1.
It would be like dumping 308 powder into a 3006 and using the same bullet.
Comparing the same bullet and powder for the two calibers, one sees that the Carbine takes more powder. The Carbine typically takes 1 to 3 grains more powder. So the lighter charge from the 7.62 should be just fine 1:1.
It would be like dumping 308 powder into a 3006 and using the same bullet.
Umm why NOT? You can bet an M1 Carbine action is a lot stronger than a Tokarev pistol.
Good Grief, the case capacities are almost identical. Do some due diligence.
- Location
- Nova Scotia
30 carbine uses 308 bullets, 762x25 uses .312 might be a little more pressure. But should work.
Okay issue I see is 30 carbine headspacing on the neck, so might not fully chamber.
Okay issue I see is 30 carbine headspacing on the neck, so might not fully chamber.
Last edited:
It works just fine, unless you happen to have a rifle with a custom chamber.
7.62x25 bullets are anywhere from .309-.310 diameter on any surplus bullets I've measured.
You have raised a very good point. This may not be safe in some rifles.
When the round fires the neck has to expand to release the bullet. The Tok bullet is fatter, so the OD of the loaded round will be bigger and the chamber may be too tight and not let the neck expand.
Measure the neck of a fired carbine round and the neck dia of a loaded round. If the loaded round is smaller, you are good to go.
When the round fires the neck has to expand to release the bullet. The Tok bullet is fatter, so the OD of the loaded round will be bigger and the chamber may be too tight and not let the neck expand.
Measure the neck of a fired carbine round and the neck dia of a loaded round. If the loaded round is smaller, you are good to go.
This is really good advice. Most of the Carbine chambers I've measured will be just fine. However, the chambers cut with my reamer are "tight" because the chances of chambering dirty or out of spec ammo in them are almost nil.
With Czech bxn/aym surplus I had to bump the charge to 11.5grns for reliable cycling. The shorter copper washed FMJ seen with older brass cased surplus will require more powder. I actually noticed a big difference and don't recommend the bullets with straight lead cores.
I saw a lot of scary stuff quickly while experimenting so be careful. In the end I gave up and used most of the bullets in my .300BLK. They are a bit short but with a decent charge of H110 they fly fast and hit hard.
A side note... I have never measured a x25 bullet bigger than .309 across pretty well every common brand/make of surplus there is. Many are actually undersized, up to .365.
I saw a lot of scary stuff quickly while experimenting so be careful. In the end I gave up and used most of the bullets in my .300BLK. They are a bit short but with a decent charge of H110 they fly fast and hit hard.
A side note... I have never measured a x25 bullet bigger than .309 across pretty well every common brand/make of surplus there is. Many are actually undersized, up to .365.
Last edited:
I don't know if this helps, but in my M1 carbine the inside neck of fired brass measures 0.314". This would indicate that the chamber is large enough to accomodate 0.312 bullets without excessive pressure. To be sure, measure the fired brass in YOUR M1 before going this route. Another quick check, in my fired cases a 0.303 bullet easily slips in.
I have an Auto Ordnance Paratrooper POS. Great looking gun but I have replaced the entire trigger housing and other parts to get it running without a stoppage or two every 5round mag... I wouldn't be surprised if most surplus carbines ran just fine with a straight swap.
Assuming you have the "long" FMJs I load them to 1.78" (the crimp ring left on certain batches). Reliability is 100% from 7.5" and 10.5" barrels. I do use Magpul .300 mags but I would expect 5.56 mags to perform well enough. I never bothered trying the shorter lead core FMJs.
Last edited:
Here is my Labradar data in case you choose to go ahead with it.
Series 228-
.300BLK 85grn Czech FMJ
23grns CFEBLK 1.84"
RP/CCI 450
1678fps ES 53 SD 11.6 (crappy load)
Series 229-
.300BLK 85 Czech FMJ
19grns H110 1.80"
CJ95/CCI450
2107fps ES 29 SD 14.6
Series 230- .300BLK 85 Czech FMJ
20H110 1.80"
CJ95/CCI450
2194fps ES 38 SD 13.2
They ran and shot very well with enough H110 under them. CFEBLK was not much good. The limiting factor for accuracy seemed to be my 3moa Red Dot. Also felt there was plenty of room for more speed but 2200fps from a 7.5" barrel was enough for me at the time.
I also found velocities for my swap, I didn't write down much for comments unfortunately. The beginning info was likely carried on.
Series 115- .30C 85 FMJ 10.2 (straight swap) Czech powder 1.680" 1658fps ES 131 SD 58.5
Series 116- .30C 85 FMJ 11 Czech powder 1.670" WSR 2139fps ES 33 SD 11.7
Series 117- .30C 85 FMJ 11.2 Czech powder 2189fps ES 43 SD 11.3
Series 118- .30C 85 FMJ 11.2 Czech powder 2210fps ES 22 SD 8.8
As you can see when I bumped the charge speed and consistency increased dramatically. I just cast 120grn bullets to load plinking ammo for my M1 now so I don't see much value in this myself any more.
Last edited:
