bltmonty
Member
I posted this over at 10mmtalk.com, but thought members of the High Road might be interested.
I have wanted a 10mm for a long time, but I did not want a glock, I already had a 1911, and did not trust Tanfoglio.
After some searching, I learned about the 40 super, which is a wildcat cartridge that uses common 45 acp platforms with a barrel and spring change. I did not have a Sig, and learning that the Sig 200 45 acp was one of the original platforms for the conversion, I decided to go that direction.
I bought a used West German 220 on gunbroker for $550; it was in excellent, almost new shape. I then asked www.efkfiredragon.com about conversion barrels. They keep the 400 corbon conversion barrel in stock for $190, but they used to produce the 40 super, so they agreed to prepare the 40 super for $245. Not bad for a very high quality stainless barrel. It is extended and ported. It took about 60 days for the production.
Starline makes the brass, and Redding makes the dies ($68 at Midwayusa).
The EFk Firedragon barrel dropped right in. I used the same recoil rod but used the strongest recoil spring for the 220. The magazine for the sig 200 barely fits the longer, but narrower 40 super.
It actually took a long time to work up the loads. The available information suggests using slow pistol powders such as Accurate #9 and h110, but these proved too slow. I tried HS longshot, 800x, and finally settled on HS-7, a powder no longer in production. This is the same powder that I had great success with on my other bottleneck experiments--7.62x25 and 32 NAA.
Using 165 grain fmj and Golden Sabres, I slowly worked up the loads. I used CCI small rifle primers. The HS-7 power curve or burn rate seemed just right. It did not recoil abruptly like the longshot or #9, but had a slow workup, more like the 45 acp than my other 40 s&ws.The recoil was less than my CZ 40s and slightly sharper but less perceived recoil than with the 45 acp barrel in the 220. The porting makes a big difference.
I ended up with a load of 14.2 grains with the 165 gr golden sabres. This load averaged just under 1400 fps, with a fairly low standard deviation. That makes for about 700 foot pounds of energy, lots of momentum, and a high KO number. When I pushed the load up above 1400 to 1425, I began to get some pressure signs with the primers. This performance is equal to or slightly above the 10mm. I have achieved my goal.
I have not done accuracy tests, but they should be fine.
Here are a few pictures. The first with the 40 super extended/ported barrel in place; the second, the 40 super between the 40sw and 45acp.
I have wanted a 10mm for a long time, but I did not want a glock, I already had a 1911, and did not trust Tanfoglio.
After some searching, I learned about the 40 super, which is a wildcat cartridge that uses common 45 acp platforms with a barrel and spring change. I did not have a Sig, and learning that the Sig 200 45 acp was one of the original platforms for the conversion, I decided to go that direction.
I bought a used West German 220 on gunbroker for $550; it was in excellent, almost new shape. I then asked www.efkfiredragon.com about conversion barrels. They keep the 400 corbon conversion barrel in stock for $190, but they used to produce the 40 super, so they agreed to prepare the 40 super for $245. Not bad for a very high quality stainless barrel. It is extended and ported. It took about 60 days for the production.
Starline makes the brass, and Redding makes the dies ($68 at Midwayusa).
The EFk Firedragon barrel dropped right in. I used the same recoil rod but used the strongest recoil spring for the 220. The magazine for the sig 200 barely fits the longer, but narrower 40 super.
It actually took a long time to work up the loads. The available information suggests using slow pistol powders such as Accurate #9 and h110, but these proved too slow. I tried HS longshot, 800x, and finally settled on HS-7, a powder no longer in production. This is the same powder that I had great success with on my other bottleneck experiments--7.62x25 and 32 NAA.
Using 165 grain fmj and Golden Sabres, I slowly worked up the loads. I used CCI small rifle primers. The HS-7 power curve or burn rate seemed just right. It did not recoil abruptly like the longshot or #9, but had a slow workup, more like the 45 acp than my other 40 s&ws.The recoil was less than my CZ 40s and slightly sharper but less perceived recoil than with the 45 acp barrel in the 220. The porting makes a big difference.
I ended up with a load of 14.2 grains with the 165 gr golden sabres. This load averaged just under 1400 fps, with a fairly low standard deviation. That makes for about 700 foot pounds of energy, lots of momentum, and a high KO number. When I pushed the load up above 1400 to 1425, I began to get some pressure signs with the primers. This performance is equal to or slightly above the 10mm. I have achieved my goal.
I have not done accuracy tests, but they should be fine.
Here are a few pictures. The first with the 40 super extended/ported barrel in place; the second, the 40 super between the 40sw and 45acp.
Attachments
Last edited:
