Reloading 7.62x39

Started by Rumple, Sep 19, 2024, 01:00 PM

Previous topic - Next topic

Rumple

Hi All,

I've been reloading handgun and shotgun for a few years now and recently decided to start shooting IPSC rifle and acquired a Norinco Type56...My local gunshop sells steel cased, berdan primed ammo at R11.90 each, so I decided to venture down the rabbit hole of rifle reloading... I have finally been able to source all the components and equipment to reload, but have a problem with the bullets...The standard COL for 7.62x39 is 56mm, if I seat these bullets at that length I end up with less that 3mm of the bullet in the case neck, I have measured the distance to the rifling in the chamber and this appears to be correct. According to the internet the seating depth should at least be equal to the diameter of the bullet. When I seat the bullets at that depth I have a COL of 50.2mm. Granted my measuring technique is not state of the art but that seems like a big difference to the rifling of the barrel.

The bullets that I bought were Silver Rapids 123gr 7.62x39 , I have messaged them in this regard (and am waiting for a response) but I would like to know if anybody has used these bullets with a Norinco Type 56 and how deep they seat these bullets?

oafpatroll

#1
The bullet profiles differ substantially which will make up a fair bit of your shortfall. Your jacketed example is longer and pointier. Suspect that if you seat your coated bullet off a comparator, i.e. match ogive to ogive, measurement you'll be fine. Drilling a neat sub calibre hole inone of the flats of an M10 or M12 nut and filling I slot in the opposite face makes for a usable comparator add on for you vernier.




Ds J

Silver Rapid bullets are lead bullet. Your bought cartridges contain bullets with a copper alloy over a lead (or steel) centre. There is more volume for the same weight, and thus the Silver Rapid bullets are shorter.

Ask around at your club. Others should give you the correct measurements.

Tripodmvr

A jump of 6mm is nothing to be worried about. If feeding from the magazine is a problem, lengthen the COL to make sure that 80% of 7.82 = 6,25mm is seated against the case neck. That is enough to ensure a good grip.

Rumple

Quote from: oafpatroll on Sep 19, 2024, 01:11 PMThe bullet profiles differ substantially which will make up a fair bit of your shortfall. Your jacketed example is longer and pointier. Suspect that if you seat your coated bullet off a comparator, i.e. match ogive to ogive, measurement you'll be fine. Drilling a neat sub calibre hole inone of the flats of an M10 or M12 nut and filling I slot in the opposite face makes for a usable comparator add on for you vernier.





Ordered one of these :)

https://sudamix-ring.co.za/product/sudami-bullet-comparator-ogive-30/
https://sudamix-ring.co.za/product/comparator-body/

Rumple

Quote from: Tripodmvr on Sep 19, 2024, 01:47 PMA jump of 6mm is nothing to be worried about. If feeding from the magazine is a problem, lengthen the COL to make sure that 80% of 7.82 = 6,25mm is seated against the case neck. That is enough to ensure a good grip.
Thank you for the reply.

Rumple

Quote from: Ds J on Sep 19, 2024, 01:35 PMSilver Rapid bullets are lead bullet. Your bought cartridges contain bullets with a copper alloy over a lead (or steel) centre. There is more volume for the same weight, and thus the Silver Rapid bullets are shorter.

Ask around at your club. Others should give you the correct measurements.
Nobody at our club shoots 7.62x39 and I'm starting to realize why ::)

Tripodmvr

You are not reloading for ultra precision. 3 MOA might be good enough for your purposes, but I can assist with Quick Load to give safe and optimum loads. COL will be the least of your worries. Some European calibres even jump as much as 10mm.

Create a functional cartridge that goes bang every time and feeds and ejects reliably. You can then concentrate on your shooting ability.

oafpatroll

#8
Quote from: Rumple on Sep 19, 2024, 02:27 PMNobody at our club shoots 7.62x39 and I'm starting to realize why ::)

A good few at mine do and they use their own stubby round nose bullets cast from the cheapest Lee mold. I can't remember seeing one having a storing of any sort. I don't think you have even the beginning of a problem on your hands