- #Integrally suppressed 9mm ar upper how to
- #Integrally suppressed 9mm ar upper trial
- #Integrally suppressed 9mm ar upper free
This is the drawing I left for them with one of my 9mm uppers. I have Adco working on it now as we speak.
The suppressor would stick out about 1/2" past the tube so you can still grab it and twist it on and off. The tube would be narrow enough to fit under a hand guard but wide enough to cover the suppressor. I'll perm attach a 6" tube on the end of a 10" barrel with an adapter built into the perm attachment so I can screw on my Trident 9 under the tube. I think I'm going to go a different route. using 147gr American Eagle factory ammo.) (8" averages about 1126fps and the 16" about 912fps. In fact, side by side chronograph data on my 8" barrel and my 16" barrel show that the velocity in 16" barrels is already lower by 112fps on average. The burn rate on 147gr 9mm bullets is so fast that you have no accelleration happening at 16". The big problem I have run into is the fact that bullet drag happens. So the solution of the situation is that I can make a 16" upper integrally suppressed and then I would have no problems bringing it into Michigan. However, I still haven't gotten it in writing just yet. I've also written a letter to the ATF asking for a formal response. I discussed this ad nauseum with the ATF, and the MI State police. No requirement to bring a 5320.20, nor any need to have your Stamped Form 1 as long as it is has ONLY the 16" upper with it. I can bring the the 16" barreled upper and the lower into the state, as you would any title 1 firearm.
#Integrally suppressed 9mm ar upper free
However, if you leave the short barreled upper home in the safe, and put on a 16" upper, you have a Title 1 firearm and you are free to treat it as a Title 1 firearm. Though I already have an SBR, and I can use it in Free states, I still can't bring it into Michigan. Not even if you filled out hte ATF form for transporting an NFA item? I may call him anyway.ĭidn't know you couldn't bring a legal SBR into the state. I'm not sure if I would either, if I was in the mfg business. I know that Will at Red jacket is making suppressed uppers, but I am not sure if he will actually be willing to share any of his r&d. Worse case I ruin a 9mm AR barrel.Still less than the cost of a tax stamp! If the velocity is "acceptable" then I'll stop and wait patiently for the form 1 to come back so I can build the chamber dividers and outer tube. Then 1-2" closer to the chamber from that to measure any further effect on velocity. Then I may port again BEYOND that port 1-2" to see if that has any effect on velocity.
I plan on starting with a 2mm port, then dual 2mm ports, then 3 2mm ports to see how the number of ports effect the velocity. While I'm waiting on my form 1, I think I'll start porting the barrel at 10" and measure the velocity reduction. My 147gr bullets loaded with 5gr of Win231 meter at about 1000fps in an un-ported 16" barrel. The actual velocity with this load is lower than predicted, probably because of the bullet drag.
I'll have 6" of barrel where there is no acceleration, but the rifling will drag on the bullet slowing it down to the muzzle.
#Integrally suppressed 9mm ar upper trial
The only "problem" that's going to take some trial and error is figuring out how much velocity reduction I'll be getting because of bullet drag if I off gas too early. I think I could bring the gas pressure at exit pretty darned low. Make the ports small enough so they catch the gas expanding and slowly bleed the gas back into the bore when the bullet has already left the barrel. Catching the expanding gas in it's own chamber. So I'm thinking start the porting at 8-10" and then port every 1-2 inches beyond that. Looking at quickload data for Winchester 231 under a 147gr bullet, you get complete burn at 2" of barrel, and at 8" you only have some 1775psi behind the bullet. However, I handload all of my rounds, and 147gr aren't very hard to load for this rifle, so I think I'm going to try to keep the velocity from dropping off like that. This is how they get 115 and 125gr bullets subsonic in the HK. Some 30 2.5mm holes near the chamber of the gun. One school of thought is to port like the HK MP5's.
#Integrally suppressed 9mm ar upper how to
I've been looking at some different ideas on how to do the porting. I'll use a mid length handguard and let the shrouded barrel stick out a few inches. I think I'm going to do a more "traditional look" with this one.
0 kommentar(er)
