Using Russian components to load for 303 Brit?

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Fox

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I have been told that you can pull the components from the 7.62x39mm and just load that directly into a 303 Brit case for a plinking round. I have my concerns though, the case capacity would be really empty, in the area of 55%, which I know can be a problem for flash over.

I wanted to know though if anyone has taken a bunch of military surplus and bumped up the powder to make a safe load for plinking. I know that the 7.62x39mm has a very narrow powder burn rate, so with 2 loads that are both used with 303 Brit (125gr) and 7.62x39mm (125gr) I notice that the starting load is about 1.4x more in the 303 Brit.

If you took 20 7.62x39mm loaded rounds, broke them all down and used the bullets with the powder equivalent to 16 rounds for that same box or 1.25x the powder load of the 7.62x39mm, which is less than the starting load for 303 Brit.

Just thinking about ways to get components for the 303 Brit.

I know 7.62x54R bullet are closer to the military bullet for the 303 Brit but the powder range is iffy to be able to use the powder.

Thoughts?
 
You can use a reduced power load with Hogdon H4895. You use 60% of the max load stated on their website. That would give you about 325 rounds per pound of powder and it would make a nice low recoil round for your old Enfield. You might be able to use the bullets from surplus SKS ammo but you can also get gaschecked lead bullets for cheap from one of our site sponsors.
 
I use 125 gr pulled bullet from 762x39 for my 303 round.....with that I fill the case with 35.0 Grs of mystery powder from 762x39 cases.
Works well,accurate for 303,and cheeeeap!!!
 
That is what I was thinking, 2 powders that are used in both 303 Brit and 7.62x39mm with 125gr bullets are H4895 and H335. The Russian has a max weight of about 30gr, the Brit has a minimum weight of about 40gr, I would think that 35gr, as long as the case capacity is more than 60% full you should have no problem using something in the middle. I know it would be something that you would have to check the powder weight in a case and compare to known cases to get an idea of what it would be similar to.
 
i have loaded the bullet and powder charge from 7.62X39 surplus into primed and neck sized 303 cases - shoots well about 3-4 moa out of my 2 groove barrel ( at 50 yards - never went farther yet
 
Fox said:
I have been told that you can pull the components from the 7.62x39mm and just load that directly into a 303 Brit case for a plinking round. I have my concerns though, the case capacity would be really empty, in the area of 55%, which I know can be a problem for flash over.

I wanted to know though if anyone has taken a bunch of military surplus and bumped up the powder to make a safe load for plinking. I know that the 7.62x39mm has a very narrow powder burn rate, so with 2 loads that are both used with 303 Brit (125gr) and 7.62x39mm (125gr) I notice that the starting load is about 1.4x more in the 303 Brit.

If you took 20 7.62x39mm loaded rounds, broke them all down and used the bullets with the powder equivalent to 16 rounds for that same box or 1.25x the powder load of the 7.62x39mm, which is less than the starting load for 303 Brit.

Just thinking about ways to get components for the 303 Brit.

I know 7.62x54R bullet are closer to the military bullet for the 303 Brit but the powder range is iffy to be able to use the powder.

Thoughts?
Click to expand...

I don't understand what you mean. Why would the powder range be "iffy" to use the powder?
 
jethunter said:
I don't understand what you mean. Why would the powder range be "iffy" to use the powder?
Click to expand...

There are a lot of different burn rates that will work well in the 7.62x54R and they are not necessarily safe for the 303 Brit at the same weights.
I know that due to the semi and full auto firearms that the 7.62x39mm is used for the burn rater of powder does not vary that much and so can be more easily approximated.
 
Fox said:
There are a lot of different burn rates that will work well in the 7.62x54R and they are not necessarily safe for the 303 Brit at the same weights.
I know that due to the semi and full auto firearms that the 7.62x39mm is used for the burn rater of powder does not vary that much and so can be more easily approximated.
Click to expand...

I don't think that is "iffy" at all. Any powder which can be used for 7.62x54R will be usable in 303 British using the same bullet weight. The charge weight likely needs to be reduced because 303 Brit case has a smaller capacity, but the powder itself should be perfectly usable in 303 Brit. I don't see the "iffy" part.
 
jethunter said:
I don't think that is "iffy" at all. Any powder which can be used for 7.62x54R will be usable in 303 British using the same bullet weight. The charge weight likely needs to be reduced because 303 Brit case has a smaller capacity, but the powder itself should be perfectly usable in 303 Brit. I don't see the "iffy" part.
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Any thoughts, for reference material only or course, on how much of a reduction you would go with powder charge from one to the other?

I notice that the minimum loads for powder that will work in both (published) H4350 and H4895 are both 6-7gr higher in the 7.62x54R than in the 303 Brit, so would reducing my 10gr be too much?
 
If you are as scared of it as you seem to be then just don't do it. The rest of us will continue on loading with x39 and x54 components just as we have been for years...
 
It is not scared, it is a lack of knowledge of doing it. I know there can be an issue using a case that is not full enough, so it probably makes sense to bump up the 7.62x39mm powder charge a little and the 7.62x54R will be charged higher than safe for the 303 Brit, so what is a good starting point for powder percentage drop from the 7.62x54R, that is what I am asking.
 
Fox said:
Any thoughts, for reference material only or course, on how much of a reduction you would go with powder charge from one to the other?

I notice that the minimum loads for powder that will work in both (published) H4350 and H4895 are both 6-7gr higher in the 7.62x54R than in the 303 Brit, so would reducing my 10gr be too much?
Click to expand...

I think reducing 10 gr would likely be OK, but that's dependant on how much powder is actually in the 7.62x54 case to start with.
Personally I would look at it like this: Case capacity is about 15% lower for the 303. I would use that as an indication of the difference and reduce the russian load by about 20% to start, trying to stay above 70% case fill - which does not include the space taken up by the bullet.
 
B said:
If you are as scared of it as you seem to be then just don't do it. The rest of us will continue on loading with x39 and x54 components just as we have been for years...
Click to expand...

He's not scared, he's still learning. Just like everyone else did.
 
I didn't mean to sound as harsh as I did. I was commenting more on the fact that he seemed more interested second guessing everyone when it's a very common practice with (as far as I know) no one blowing up their guns. I have lots and lots of x39 into .303 and never worry about a flashover because it just isn't going to happen. Using x 54 is a lot more ideal since bullet weight is higher and you can actually load to full velocity. Start low and work up, backing off 10 grains would be a good start.
 
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This is exactly how I approached it. I had some MFS 185 gr X54 not being used and bullet dia. was .3115 or .312 IIRC. Average charge weight was around 46 grs. I believe I loaded 36 grs and they shot to POA in a full wood No4. Not knowing which powder was used, what pressure they were loaded to and the difference in case capacity and max pressure I didn't want to risk it. I think I'd rather cast for .303 but surplus components definitely work.

jethunter said:
I think reducing 10 gr would likely be OK, but that's dependant on how much powder is actually in the 7.62x54 case to start with.
Personally I would look at it like this: Case capacity is about 15% lower for the 303. I would use that as an indication of the difference and reduce the russian load by about 20% to start, trying to stay above 70% case fill - which does not include the space taken up by the bullet.
Click to expand...
 
I found that my Mosin barrels copper foul fast and heavily from using the copper wash plated steel jacket ammo. So my first thought is to not use the surplus components for anything else. And in fact I'm shifting away from shooting the milsurp ammo as a result of this.

Mind you I've only used the one SPAM can of surplus. Ammo from other sources might not be as bad as the junk I've got. But it's worth watching to see how bad it is.
 
supernova said:
This is exactly how I approached it. I had some MFS 185 gr X54 not being used and bullet dia. was .3115 or .312 IIRC. Average charge weight was around 46 grs. I believe I loaded 36 grs and they shot to POA in a full wood No4. Not knowing which powder was used, what pressure they were loaded to and the difference in case capacity and max pressure I didn't want to risk it. I think I'd rather cast for .303 but surplus components definitely work.
Click to expand...

obviously great minds think alike :)

Love your avatar - do you have a link to a website where I can get that?
 
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