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mil-surp 762x54R diameter
gotstolefrom
Member Posts: 1,479 ✭✭✭✭✭
I have some bulk mil-surp 7.62 x 54R ammo, 50's vintage I believe.
I was pulling a few bullets, dumping propellant, and punching the primers to make 'snap caps' to go in the Christmas package of an M44 to my God-child.
I looked at the base of the bullet, and it had a conical cavity to the lead core (the jacket wrapped around about 1mm). My thoughts wandered,,,,, is this for expansion to the bore, or...what ?
I took two bullets to mic, and both were between .300 and .305.
This brought an old thought to mind, that .310 or .311 was the usual bullet size.
Am I mis-remembering this bullet or bore dimension from the 7.62 x 39 rounds of 'AK type' weapons ? That the 'AK' bullets / bore are of .310 - .311 and not the Mosin's ?
Thank You for Thinking. All replies appreciated.
I was pulling a few bullets, dumping propellant, and punching the primers to make 'snap caps' to go in the Christmas package of an M44 to my God-child.
I looked at the base of the bullet, and it had a conical cavity to the lead core (the jacket wrapped around about 1mm). My thoughts wandered,,,,, is this for expansion to the bore, or...what ?
I took two bullets to mic, and both were between .300 and .305.
This brought an old thought to mind, that .310 or .311 was the usual bullet size.
Am I mis-remembering this bullet or bore dimension from the 7.62 x 39 rounds of 'AK type' weapons ? That the 'AK' bullets / bore are of .310 - .311 and not the Mosin's ?
Thank You for Thinking. All replies appreciated.
Comments
The under size bullets your seeing are not uncommon in military ammo (it's even worse on wartime production rounds), and yes the bullet will "slug up" when fired.
When the core is inserted, the jacket heel was rolled under to keep it in place, also the Russians liked a weight forward bullet design so having the base of the core further inside the jacket didn't bother them a bit.
Good questions.
The Mosin Nagant is problematic to pin down as far as bore or bullet diameter is concerned because of wide manufacturing tolerances.
The nominal bore diameter is 7.62mm = 0.300 inches. Although the nominal bore diameter on some Mosin Nagants is 0.300 inches the groove to groove diameter can be anywhere from 0.311 inches to 0.314 inches or more. I know this sounds confusing but the manufacturing tolerances on the Mosins were sometimes outrageously out of specification and it makes a difference if referring to bore diameter (land to land) or groove diameter (groove to groove). I have read of Mosin bores measuring from 0.306 (groove to groove) to 0.316 (groove to groove) inches diameter which is a large variance.
Please read the attached link:
http://7.62x54r.net/MosinID/MosinSlug.htm
Because of the manufacturing tolerances, the only way to get a Mosin to shoot sometimes is to slug the bore because accuracy problems can sometimes be linked to bullet-bore diameter. Most mil surplus bullets I have measured have been 0.3105 to 0.311 inches diameter.
My Mosin M-44 shoots horrible with mil surplus nominally sized bullets which are usually 0.310 to 0.311 inches. Wolf bullets are normally 0.311. If reloading and substituting 0.308 inch bullets in the below rifle the accuracy is ridiculously bad.
Therefore, I slugged the barrel on my M-44 and found the groove to groove diameter was 0.3135 inches. No wonder it performed like a dog with 0.308 bullets. I reload 7.62x54mm and after determining the real bore diameter of the rifle, opted to reload with Hornady .303 British bullets which measure 0.312 inches diameter. This leaves the bullet 0.001 inches less than bore diameter. After fitting the bullet to the bore, the rife has consistently fired approximately 1.0 inch groups at 100 yards.
Hope this helps.
Heavyiron