I've had my Robinson XCR 7.62x39 conversion for a couple of months now and have shot a few hundred rounds of S&B ammo through it, mainly to collect the brass for reloading. So, I finally did some reloading and here are some results.
Using S&B brass, CCI large rifle primers and H4895 powder. I loaded 16 rounds with 29.0 gr and used Hornady 123gr .310 bullets loaded to a COL of 2.185.
I also loaded 16 rounds of 28.0 gr using Hornady 150 gr .308 bullets at a COL of 2.220.
(why the odd number ? It was the number of primers left in the package, heh)
The chronograph showed the average velocity for the 123gr bullets at 1980 fps, while the average for the 150gr was at 1935.
This seems a little slow to me, for reasons I'll mention later, but that was the load data recommended from the Hodgden website.
I tested these loads by shooting at both 50m and 100 m. My scope on the XCR is only a 1.5-5 power, with a 2 MOA dot in the center, so trying to do precision shooting at 100m is difficult, but not impossible. I shot three 3 round groups at 50m with both loads. I shot the remaining at the 100m target..
My conclusion was that the 150gr .308 bullets shot just as precisely as the 123gr .310 bullets, which are the specified size for 7.62x39, according to many. In fact, I would say the 150gr bullets were doing a slightly better job at 100m, though again, I was limited by my scope. At 50m, I could reliably get 1/2 MOA groups with both bullets; at 100m, while the groups opened up, both groups were very close to equal size, with 150gr doing slightly better.
The Hornady reloading manual has, in it's 7.62x39 section, listings for bullets anywhere from 110 to 150-155 gr. The only bullets that are .310 are the 123gr bullets, all the rest are .308. I suspect these folks might.have some credibility when they suggest bullets that you can use for a specific caliber.
Conclusion, use up those .308 bullets you have laying around in your XCR, or even in your SKS if you want to hunt with it.
Now, for the surprise part. I tested some of the surplus ammo too. I had some of the old Czech ammo that comes in the blue paper packages. This stuff went over the chrono at 2300 fps on average . Then I tried some surplus that I just bought in the 1200 round crates.. This stuff came packaged in plastic, in 300 round battle packs, with each 10 round stripper clip individually packaged in plastic.
This surplus ammo, made in 1984 according to the paper that came with it, went over the chrono at 2500 fps !! And, it groups very well.
So, I'm thinking that maybe the reloading data is somewhat more conservative than it needs to be, and, if you are going to buy that Czech surplus, you might want to consider the larger 1200 or 1500 round crates.
Using S&B brass, CCI large rifle primers and H4895 powder. I loaded 16 rounds with 29.0 gr and used Hornady 123gr .310 bullets loaded to a COL of 2.185.
I also loaded 16 rounds of 28.0 gr using Hornady 150 gr .308 bullets at a COL of 2.220.
(why the odd number ? It was the number of primers left in the package, heh)
The chronograph showed the average velocity for the 123gr bullets at 1980 fps, while the average for the 150gr was at 1935.
This seems a little slow to me, for reasons I'll mention later, but that was the load data recommended from the Hodgden website.
I tested these loads by shooting at both 50m and 100 m. My scope on the XCR is only a 1.5-5 power, with a 2 MOA dot in the center, so trying to do precision shooting at 100m is difficult, but not impossible. I shot three 3 round groups at 50m with both loads. I shot the remaining at the 100m target..
My conclusion was that the 150gr .308 bullets shot just as precisely as the 123gr .310 bullets, which are the specified size for 7.62x39, according to many. In fact, I would say the 150gr bullets were doing a slightly better job at 100m, though again, I was limited by my scope. At 50m, I could reliably get 1/2 MOA groups with both bullets; at 100m, while the groups opened up, both groups were very close to equal size, with 150gr doing slightly better.
The Hornady reloading manual has, in it's 7.62x39 section, listings for bullets anywhere from 110 to 150-155 gr. The only bullets that are .310 are the 123gr bullets, all the rest are .308. I suspect these folks might.have some credibility when they suggest bullets that you can use for a specific caliber.
Conclusion, use up those .308 bullets you have laying around in your XCR, or even in your SKS if you want to hunt with it.
Now, for the surprise part. I tested some of the surplus ammo too. I had some of the old Czech ammo that comes in the blue paper packages. This stuff went over the chrono at 2300 fps on average . Then I tried some surplus that I just bought in the 1200 round crates.. This stuff came packaged in plastic, in 300 round battle packs, with each 10 round stripper clip individually packaged in plastic.
This surplus ammo, made in 1984 according to the paper that came with it, went over the chrono at 2500 fps !! And, it groups very well.
So, I'm thinking that maybe the reloading data is somewhat more conservative than it needs to be, and, if you are going to buy that Czech surplus, you might want to consider the larger 1200 or 1500 round crates.
