7.62x39 improved
Posted: Sun Dec 01, 2013 1:14 pm
We have just read the following in another place and wondered if a clever ooman - ovenpaa maybe - would comment on it.
Is there a 7.62X39 Improved cartridge? This is simlpy the parent with a 30 degree shoulder matching the angle for the 22 and 6MM PPC, but not pushing the shoulder back.
The 7.62X39 is one of my favorite cartridges to reload, because the industry specs call for a max of 50,000 CUP while factory loads are held to the 40-44,000 CUP range in deference to the AK and SKS actions out there. I load mine for a CZ Carbine bolt gun with 18 inch bbl and easily generate 2000 FPE with 130 gr Hornady PSPs @ 2650 fps. That's good for 2130 fps and 1300 FPE at 200 yards and a 4.9-inch drop sighted in at 100 yards.
2800 fps is within reach of this case, improved to hold 33 grs of water with a seated 125 or 130-gr bullet. Coupled with a 1 in 14-inch twist, this is a 0.25 MOA round. Most 7.62X39 rifles are 1 in 10 or less, which is way too fast for .308 to .311 bullets less than an inch in length. Might as well design it for a .308 bbl while we are at it. Think of it as a .308 Win with a 1-inch powder column length, designed to shoot bullets less than 1 inch in length.
I also use sabots and 55-gr .224 Hornady BTs in the 7.62X39, with remarkable results. Lil'gun easily drives these to 3500 fps and delivers 1.0 MOA. Pressure is moderate. Note that this is well over a .223 and close on the heels of a 22-250. The improved version will duplicate the 22-250. However, the suggested 1 in 14 twist would limit us to .224s lighter and shorter than the 55-gr spitzers. A 45 gr BT will do 4000 fps, guaranteed.
In the end you have a neat little rifle, 5 lbs in weight with 18 inch bbl and 2.3 inch bolt throw, covering varmints through deer, that is inexpensive and fun to shoot. You win the lightweight hunter class at your range every year and your bore and shoulder last forever.
Is there a 7.62X39 Improved cartridge? This is simlpy the parent with a 30 degree shoulder matching the angle for the 22 and 6MM PPC, but not pushing the shoulder back.
The 7.62X39 is one of my favorite cartridges to reload, because the industry specs call for a max of 50,000 CUP while factory loads are held to the 40-44,000 CUP range in deference to the AK and SKS actions out there. I load mine for a CZ Carbine bolt gun with 18 inch bbl and easily generate 2000 FPE with 130 gr Hornady PSPs @ 2650 fps. That's good for 2130 fps and 1300 FPE at 200 yards and a 4.9-inch drop sighted in at 100 yards.
2800 fps is within reach of this case, improved to hold 33 grs of water with a seated 125 or 130-gr bullet. Coupled with a 1 in 14-inch twist, this is a 0.25 MOA round. Most 7.62X39 rifles are 1 in 10 or less, which is way too fast for .308 to .311 bullets less than an inch in length. Might as well design it for a .308 bbl while we are at it. Think of it as a .308 Win with a 1-inch powder column length, designed to shoot bullets less than 1 inch in length.
I also use sabots and 55-gr .224 Hornady BTs in the 7.62X39, with remarkable results. Lil'gun easily drives these to 3500 fps and delivers 1.0 MOA. Pressure is moderate. Note that this is well over a .223 and close on the heels of a 22-250. The improved version will duplicate the 22-250. However, the suggested 1 in 14 twist would limit us to .224s lighter and shorter than the 55-gr spitzers. A 45 gr BT will do 4000 fps, guaranteed.
In the end you have a neat little rifle, 5 lbs in weight with 18 inch bbl and 2.3 inch bolt throw, covering varmints through deer, that is inexpensive and fun to shoot. You win the lightweight hunter class at your range every year and your bore and shoulder last forever.
