I’m not entirely sure I followed what you were saying, but a 115gr 9mm load typically has more powder than a 147gr load, assuming the two are using the same powder, are loaded to similar pressure, etc. For example, Hodgdon’s Titegroup data has about a 33% higher powder charge for 115gr than 147gr. The 150-165gr “hush” type loads use even less powder. This is another reason why subs are quieter.Completely unscientic explanation:
If 147 has the same powder charge as 115, the heavier bullet will travel slower, but think of newtons law about action reaction.
It’s pushing a heavier bullet and the bolt is reacting rearward more so
Now it all depends but I’d suggest that a 147 subsonic prob has a little more powder than your typical 115, bc it’s 27% heavier but only 12% slower (I know it’s not a direct correlation - but just for illustrative purposes) to get it to 1050fps or so. (115 is typically 1190)
If you want more power and faster shots, go with 124 NATO
It’s pushing 124 at 1200. So heavier bullet near same speed as typical 115
Caliber Multi: 9mm NATO
Muzzle Energy: 396 lb/ft
Muzzle Velocity: 1200 fps
Compare to 124 lawman 1090 and 124 federal 1160
Wwb115 is 1190
362 lb
So nato is about same speed w heavier bullet so see the energy rating.
Energy won’t necessarily mean what you feel but when comparing similar loads it’s probably a good proxy
Yes. It was for comparison purposes re velocity.9mm NATO is +P, the last thing you want to use if you're trying to be quiet.
I’m not entirely sure I followed what you were saying, but a 115gr 9mm load typically has more powder than a 147gr load, assuming the two are using the same powder, are loaded to similar pressure, etc. For example, Hodgdon’s Titegroup data has about a 33% higher powder charge for 115gr than 147gr. The 150-165gr “hush” type loads use even less powder. This is another reason why subs are quieter.
If a typical 147gr bullet is hitting 1050 and a 124gr lawman is hitting 1090, then the 147 has MORE powder charge.
I can assure you that the 124 lawman is much slower RPM than the 147.
It’s a lot heavier bullet doing about the same speed. Ergo…
When we drop to 115gr bullets they go about 1190.
I have no idea whether most of the subsonic capabilities are due to the heavier bullet or a lighter charge bc I don’t reload, but I’d suggest that it’s probably a very similar charge and the weight of the bullet is what slows it down. Otherwise why not just use a 115 w reduced charge.
Reloading Data Center – Hodgdon Reloading Data Center
hodgdonreloading.com
115g loaded to 1167fps is 5.1grains of 231 powder = pressure of 28,100 CUP
Having trouble getting 147gr to 1050…
4.1grains of xxx gets to 947fps and 32,200 CUP
Ramshot Sillouette powder
147gr take 4.6grains to get to 981fps
115gr take 5.3grains to get to 1147fps
So it’s a little of both
I was also assuming subs were 1050fps so to get the 147 up to that speed would take a little more.
Edit: 124gr take 5.4 to get to 1082fps
My experience is that lawman 124 is basically subsonic probably due to short barrel and open bolt.
Short answer. Know-one! LolThere have been so many threads about a SD barrel and suppressor for a Mac style upper here. But the SD ports would be inside a standard upper where the bolt needs to go. I know there are some that have looked into 9mm for the Lage Max/15 uppers. I think that it would be cool to combine the HK SD ported barrel and suppressor with the Lage upper.
This is something that I would like to do with my Tenko 10-16. Funds have been very short, so I have not done it yet. But I have the SD style suppressor which would be the biggest hurdle. So who will be the first to have a SD Mac? There is the recent FW video about an AR style SD upper.
Scott
It's not the length of the barrel, it's the energy of the projectile.An integrally suppressed barrel for M10 doesn't sound all that difficult. Little machine time and some research into how to build integral cans and I could probably slap one together. As long as I started with enough barrel!
Uhh, one affects the other since smokeless powder does not explode but burns rapidly.It's not the length of the barrel, it's the energy of the projectile.
Totally went over my head!Sorry was trying to make a joke ala motion of the ocean ;-)
The correct answer was... "that's what she said."Uhh, one affects the other since smokeless powder does not explode but burns rapidly.
I'm not known to not be oblivious.The correct answer was... "that's what she said."
That won’t work on a MAC. The barrel/trunnion/bolt on an M10/11 is a totally different setup than an M16I think an integral suppressor like this would work with the Mac without modifying the receiver.