7.62x39mm .310 123 Gr FMJ into full power 303 British, or 7.62x54R
- Thread starter steelgray
- Start date
You're asking about making a "Full Power Load" from an unknown powder.
First you need to define "full power" ("Safe" in a Lee Enfield? "Safe" in a Mosin?) but even then, any load data provided would only be valid for the specific lot of powder you're pulling down. You can't assume that all milsurp ammo uses the same powder.........
Here's how I do it: https://www.canadiangunnutz.com/for...5839-Developing-a-Load-without-Published-Data
None of that can be done (properly) without a Chronograph and other known powders to which you can compare it.
You probably wanted someone to suggest a certain number of grains, or something like "Use 1.5X the powder that's in the 7.62X39, and that would be the end of it. If so, I am of no help.
First you need to define "full power" ("Safe" in a Lee Enfield? "Safe" in a Mosin?) but even then, any load data provided would only be valid for the specific lot of powder you're pulling down. You can't assume that all milsurp ammo uses the same powder.........
Here's how I do it: https://www.canadiangunnutz.com/for...5839-Developing-a-Load-without-Published-Data
None of that can be done (properly) without a Chronograph and other known powders to which you can compare it.
You probably wanted someone to suggest a certain number of grains, or something like "Use 1.5X the powder that's in the 7.62X39, and that would be the end of it. If so, I am of no help.
Thanks Andy. by "full power" I added that because the first poster immediately assumed I was interested in the deal where you dump the contents of an X39 round into a 303 case, reseat the bullet and fire a "Mexican reload" - Mexican, I suppose meaning "lacking power". Personally, I think that is rude.
Anyway no, in this case "full power" is meant to signify that I have no serious drop - compared to a factory round; say a 123 projectile managing to get up to 2,550 fps. The link is useful but I've been reloading since the '80's and know the basic stuff about start below max and work-up looking for pressure signs, ... My experience reloading powders with unpublished data goes back decades too. In fact, my main powder that I have used for nearly 20 years is a LARGE quantity of SL47 that I bought off Tom Higginson back when Ammomart sold a lot of off spec powders - where (in the case of SL47) you had to work from H414 data, but adjust your loads by ...
And BTW I do have a chronograph, but I haven't used it for years. I'm not one of those old retired guys. I haven't drawn the outlines of my tools on the wall in my garage yet, either.
Closer to home (in relation to the subject of this link) I routinely shoot 303 British loads made from 54R pull down components - and figured out the loads myself. A box of 20 round of 303 British costs me $8.80 - and the stuff shoots perfectly out my Lee Enfields and my Mohawks. I have found that steel core projectiles tend to shoot better than commercial lead core stuff for me - and others have told me the same.
If the mere though of that gives anyone a panic attack, I just say "enjoy your milktoast".
My goal is to come-up with a similarly-decent 303 load from pulled down X39 stuff. There are two reasons why, even though I'm doing fine with my 54R pull downs. First, I like light 123 gr bullets that fly flatter, compared to the old fatso 174 gr stuff. Second, I have a whole bunch of X39 corrosive ammo that I'd love to part-out because I now REALLY hate shooting corrosive ammo and the non-corrosive X39 is still cheap and everywhere.
Sierra makes a 125 gr 303 bullet. I think that your lead core fmj would use roughly the same loads. I believe that 414 is too slow for that light a bullet. If you use magnum primers and a crimp you may get acceptable results. The best results should come with 748, bl-c 3031 4064 etc or powders in that range Starting loads vary from about 38 gr of 3031 to 41 gr of 4064. All starting loads produce about 2400 and the max loads about 2700 depending on the powder. This is really the time to dig out your chronograph. I have been loading for over 60 years but I am no expert.
antiqueguy
CGN Ultra frequent flyer
- Location
- windsor ontario
The Canadian match as I call it x39 load in .303 works well cheap and a great beginner shooter load that can still take deer.
Looks like I'm going to be picking up some Russian surplus. When I reloaded for x39 I had some bullets that were actually cup based 123 grain, those might work well in .312 bores due to obturation. I'll have to dig around and see if I have any left.
Re: Mexican Match - US Mil snipers and Army match shooters were prohibited from shooting BTHP's in the US, but when they shot outside the US the regulation did not apply. They pulled the bullets from Match Ball rounds and seated 168 Match King BTHP's instead. This was first done for a competition in Mexico, hence the name "Mexican Match" loads. Literally ammo for the Mexican Match. So, it isn't derogatory and if the match they were first shooting that ammo at had been North instead of South, it could have been called "Canadian Match".
Re: Mexican Match - US Mil snipers and Army match shooters were prohibited from shooting BTHP's in the US, but when they shot outside the US the regulation did not apply. They pulled the bullets from Match Ball rounds and seated 168 Match King BTHP's instead. This was first done for a competition in Mexico, hence the name "Mexican Match" loads. Literally ammo for the Mexican Match. So, it isn't derogatory and if the match they were first shooting that ammo at had been North instead of South, it could have been called "Canadian Match".
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Mini range report: Since I’m not a retired guy, my opportunities to shoot are limited. Today was Sunday and expected to be the warmest day in the next week, so I decide to drive the hour it takes to get to my range, in a blizzard. Once there, it was minus 10 with falling snow and shifting winds. Everything was unplowed and it was no surprise that I had the place to myself.
My goal was to put maybe four or five rounds of each of my loads downrange – mostly to see if I was on the right track to be able to cook-up a load for my 303 British, made from pulling down Russian surplus AK ammo, that would group as well as my commercial powder reference load. The reference load I was trying to match was made-up of 123 Gr FMJ steel core bullets (from surplus Russian AK ammo) pushed out of 303 British cases by 43.7 grains of AA2460.
The goal was really to reach a point where I could match this load with another, made-up of donor AK powder – so that the two loads had the same point of impact, and grouped the same. If I could find the right formula for a load, motivated by pulled down AK powder – that matched my 123 gr/ AA2460 load then, I’d be in a good place. This is because I’d be able to use the “free” powder from AK rounds in my 303 until the pull down powder supply ran-out – but I’d have remaining 123 grain steel core pills – that I could then load-up with AA2460.
Given the crappy weather – and the fact that I was shooting with cold hands on a blustery day … and all that I didn't expect to get to pull down Nirvana. However, things went “good”.
First of all, my reference – load made-up of pulled down AK pills, pushed by 43.7 grains of AA2460 shot 4” groups with no drama – and the ammo cycled well in my semi auto Mohawk; throwing case about 4-5 feet. Then, I tried a load using the same AK donor pills and 1.4 times the original load of AK powder. The Mohawk cycled gun more gently – and sometimes lacked enough energy to lock the action open on the last round. If anything, this AK powder-motivated load shot better than my reference AA2460 load – with a 2.5-inch group and a slight flyer taking the overall group to sub 4”.
The next test load was AK powder times 1.5. Bingo. Another 4” group and the gun locked open on the last round. I got basically the same point of impact with the AA2460 load and the AK times 1.4 and AK times 1.5 loads. Even with AK time 1.5, I wasn’t seeing any signs of pressure – and that load didn’t eject cases as far as the AA2460 reference load. I’d bet that AK times 1.55 would get my commercial powder and AK pull down powder loads producing matching results.
Just for fun, I also tried some NOS 32-20 pills – more specifically 100 gr Remington SP .311 projectiles loaded into 303 British cases, motivated by 46 grains of AA2460. They were shot in a L-E, so I don’t know if they would have cycled the Mohawk, with its current gas settings. The point of impact of these was basically the same as the loads noted above. However, even out of my super-accurate custom No.4, these commercial SP 100 grainers only showed a 10+ inch group. Too bad. I paid $50-$80 to buy 1,300 of these. I guess I’ll try those little 100 grainers next in a 7.62x39 gun.
The bottom line is you can make accurate 303 British reloaded ammo from Russian 7.62x39 surplus ammo and, when the donor AK powder supply runs out – and you still have pull down projectiles left over, just switch to AA2460 and you can have a matching load with that stuff.
My goal was to put maybe four or five rounds of each of my loads downrange – mostly to see if I was on the right track to be able to cook-up a load for my 303 British, made from pulling down Russian surplus AK ammo, that would group as well as my commercial powder reference load. The reference load I was trying to match was made-up of 123 Gr FMJ steel core bullets (from surplus Russian AK ammo) pushed out of 303 British cases by 43.7 grains of AA2460.
The goal was really to reach a point where I could match this load with another, made-up of donor AK powder – so that the two loads had the same point of impact, and grouped the same. If I could find the right formula for a load, motivated by pulled down AK powder – that matched my 123 gr/ AA2460 load then, I’d be in a good place. This is because I’d be able to use the “free” powder from AK rounds in my 303 until the pull down powder supply ran-out – but I’d have remaining 123 grain steel core pills – that I could then load-up with AA2460.
Given the crappy weather – and the fact that I was shooting with cold hands on a blustery day … and all that I didn't expect to get to pull down Nirvana. However, things went “good”.
First of all, my reference – load made-up of pulled down AK pills, pushed by 43.7 grains of AA2460 shot 4” groups with no drama – and the ammo cycled well in my semi auto Mohawk; throwing case about 4-5 feet. Then, I tried a load using the same AK donor pills and 1.4 times the original load of AK powder. The Mohawk cycled gun more gently – and sometimes lacked enough energy to lock the action open on the last round. If anything, this AK powder-motivated load shot better than my reference AA2460 load – with a 2.5-inch group and a slight flyer taking the overall group to sub 4”.
The next test load was AK powder times 1.5. Bingo. Another 4” group and the gun locked open on the last round. I got basically the same point of impact with the AA2460 load and the AK times 1.4 and AK times 1.5 loads. Even with AK time 1.5, I wasn’t seeing any signs of pressure – and that load didn’t eject cases as far as the AA2460 reference load. I’d bet that AK times 1.55 would get my commercial powder and AK pull down powder loads producing matching results.
Just for fun, I also tried some NOS 32-20 pills – more specifically 100 gr Remington SP .311 projectiles loaded into 303 British cases, motivated by 46 grains of AA2460. They were shot in a L-E, so I don’t know if they would have cycled the Mohawk, with its current gas settings. The point of impact of these was basically the same as the loads noted above. However, even out of my super-accurate custom No.4, these commercial SP 100 grainers only showed a 10+ inch group. Too bad. I paid $50-$80 to buy 1,300 of these. I guess I’ll try those little 100 grainers next in a 7.62x39 gun.
The bottom line is you can make accurate 303 British reloaded ammo from Russian 7.62x39 surplus ammo and, when the donor AK powder supply runs out – and you still have pull down projectiles left over, just switch to AA2460 and you can have a matching load with that stuff.
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We know you're not retired and don't have much time, but how much more time would it have taken to bring your chronograph along and record MV's?
Going by point of impact is by no means an accurate way to compare MV's and hence pressure.
Going by point of impact is by no means an accurate way to compare MV's and hence pressure.
Using a chronograph in that weather would have been impossible. Even shooting that day was "iffy". The Hodgdon reloading center suggest that my reference load of a 123 Gr bullet, pushed by 43.7 grain of AA2460 should have an MV of 2,800. My corresponding test load, made up-of the original AK powder load times 1.5 shot with an indistinguishable point of impact, compared to the reference load. Since the same gun was used in the same environment at the same time, and the bullet was the same, it can be inferred that both the reference load and the test load must have had the same fight time and about the same MV. That's why you use a reference load.
I achieved my goal of finding a 303 load that is made from AK powder and bullets that is accurate safe and shoots to the point of aim established for my gun (that is, matches the way the gun is sighted-in and how it shoots my reference load). I have a reasonable estimate for its speed as well - although that factoid is less important than how it actually shoots.
I may chrono the load in the Spring when weather arrives but I'm not expecting any surprises. Chronos are fine for those who care about minutia and don't mind spending half a day at the range. I find some people who use them tend to disrupt the use of the range by others - since they constantly seem to want to call time outs so they can go forward and diddle with this and that. I'm sure their are others who are careful to avoid inconveniencing other shooters. I just haven't personally seen any of them in action.
Do you know how P.O. Ackley established the relative performance of his loads in the days before chronos? You might be surprised.
You can't be sure that you're holding the rifle exactly the same for each shot, especially if shooting that day was "iffy". Even with a perfect rest and perfect shooting, you're not putting every bullet through the same hole either, so even one inch of variability in the centre of a group can be indicative of a large variation in MV. You know this of course, but a 10% increase in MV does not suggest a 10% increase in pressure - it's much more than that.
Yes I know all about Ackley and I know too that he pressure tested nothing except to note when something blew up.
I suggest you put your Chrony on the EE - if it exists it's practically unused and lots of old inconsiderate retired people might be interested!
- Location
- Nova Scotia
Should.... is like assuming. But what temp did they test it at, what elevation, what barrel length, What crimp? There is soo many factors that it's nearly a estimation.
Actually, I think it was Ackley who tried to qualify load performance by recording the sounds of his gunshots. Probably not very precise. I use the force of ejection from my autoloader as another proxy for telling me how the load is performing against other reference loads. Still not terribly precise but a useful indicator. If my test load shoots the same as my reference load and ejects cleanly and there are no pressure signs etc., then for practical purposes I'm happy with the results. That's because I'm a shooter, not a technical ballistician. I can't sell my Chrony because it was a gift. I will use it a bit anyway but not in the middle of a blizzard at minus 10 and with 6 inches of new snow on the ground.
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I'm doing pretty much the opposite of the folks here, I have a Sabatti bolt rifle in 7.62 x 39. I've tried Com-block surplus and store-bought 123 ammunition as well as several handloads and have been very disappointed with the results.
What I did find worked very well was 150 grain .311 Brit bullets over Varget.
My $100 Cabela's crony was telling me that my 9mm pistol hand loads were going 2,345 ft/second so I tossed it back in the cupboard.
What I did find worked very well was 150 grain .311 Brit bullets over Varget.
My $100 Cabela's crony was telling me that my 9mm pistol hand loads were going 2,345 ft/second so I tossed it back in the cupboard.
I think cronys are fine, but for some running a chronograph seems to be its own obsession. One guy at the range recently showed his pride and joy off. It think he said it cost $3,000.
When I've used one, it was just as one extra data point - adding to all the other indicators of how the load was doing. I don't think I've ever been told something, by a Chrony, that actually surprised me. They generally tell you what you can already discern from other indicators, but you get the fun of knowing your FPS - right down to the last digit. As for having to worry that pressure builds quicker than velocity, I have been reloading for over 40 years and don't have a blind spot for pressure signs. I tend to be pretty conservative anyway. My Mohawk is set-up to cycle best for loads that are 5% under max and that is normally the target I strive to meet, in my reloading.
I'm the guy who literally took apart 800 rounds of factory PRVI 243 WIN - with a kinetic bullet puller - because I could tell it was WAY over spec. I loaded that stuff down and still have some. I didn't need a Chrony there either.
That off spec PRVI win 243 became well known to shooters at the time. In my case, my 243 Win M14 could handle it - but just barely - throwing the cases away really hard over a great distance. Most of the recovered cases were not reloadable - with oversized primer pockets and heads so enlarged that they wouldn't fit a normal shell holder. In my BAR I, they wouldn't extract at all most of the time - but basically welded themselves in the chamber, sometimes tearing the rim off where the extractor had tried - unsuccessful to get the case out.
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