OP
OP
N555
Member
If I can swap a cold hammer forged barrel savage barrel for $200, don't need all the fancy stuff.
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P Flados
Member
The new 3 piece case is very likely only a small improvement over Russian made coated carbon steel case ammo (currently available in 6.72 x 51, https://www.ammunitiontogo.com/prod...0rds-308-win-red-army-standard-150gr-fmj-ammo). And once production is set up, full steel cases are cheaper than brass instead of 3 piece that are probably triple the cost of brass.
From a pressure retaining standpoint, a full carbon steel case can easily be made adequate for 80 ksi. Without the mechanical joint, I would expect slightly higher case capacity.
The only real advantage of the SIG case is probably corrosion resistance.
Because they are using my tax dollars for this boondoggle, I wish that they would produce this new round in the cheaper full steel at least for training use. Even though it makes tons of sense, they probably wont do it since it would seem to admit that the Russians "got it right" before we did.
For reloading, the SIG brass should reload just fine. With the higher yield strength of the stainless they are using, the base should not expand much if any on firing.
From a pressure retaining standpoint, a full carbon steel case can easily be made adequate for 80 ksi. Without the mechanical joint, I would expect slightly higher case capacity.
The only real advantage of the SIG case is probably corrosion resistance.
Because they are using my tax dollars for this boondoggle, I wish that they would produce this new round in the cheaper full steel at least for training use. Even though it makes tons of sense, they probably wont do it since it would seem to admit that the Russians "got it right" before we did.
For reloading, the SIG brass should reload just fine. With the higher yield strength of the stainless they are using, the base should not expand much if any on firing.
mcb
Member
I suspect the stainless steel Sig is using in their case head is more than just a little stronger than the mild steel Russians use in their ammo. A steel/stainless strong enough to seal against these high pressures probably will not release from the chamber as well hence the hybrid steel case-head and brass body.
The challenge with the 80,ooo psi for the barrel is not the pressure and the stress/strain that induces, that is straight forward to design for. It's that as the chamber pressure goes up so does the flame temperature of the propellent gases. At 80,000 psi the problem is going to be flame erosion of the barrel. Using standard 4140 steel that is common in steel barrels, barrel life is potentially going to be fairly short due to this high pressure/temperature. There are ways to mitigate that accelerate wear but those add cost commensurate to how much barrel life they add.
OP
OP
N555
Member
I think as long as most of the spent LC cases male it to DRMO and get sold to commercial reloading companies, it's tax payer money well spent. Better than handing tax payer money to the Ukrainian government.
AJC1
Member
I would not want to bear the additional cost of this new round... I shop cartridges partly by barrel life... advance ballistics may be better with the 243 than my 6mmbr but I can't afford that game...
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