Variable
OK guys, I'm speed posting so this is a cut and paste from another board(silencer talk). I'll post updates and pics when I get time. :D
PASTE:
OK, I finally got to shoot my 762-SD on my Grendels!
I went over to a friends house and we shot the SD on two different Grendels I have: A 10.5" SBR, and a 14.5" SBR...
We used two types of ammo:
Wolf Gold 120g MPT
My own homemade 160g subsonic ammo. (My subsonic load is a 6.5mm Hornady 160g jacketed RN loaded with 7.6 grains of Trailboss powder in a Wolf Gold case and a CCI LR magnum primer. It chronos at 1050 fps. out of my 10.5" barrel. I haven't chronoed it yet in the 14.5", but it is also subsonic in it as well. This load will not cycle my rifles, but it will probably be a tall order to get any subsonic load to cycle in a Grendel, I'll have to try that later. These loads are stable in my 1-7.5" twist barrels, but I haven't tried them in my 1-8" twist 19.5" barrel yet- so beware and test first!
The 10.5" Grendel:
We started out shooting the SD on my shorty with the Wolf Gold 120g MPT ammo. We compared it side by side with my Colt 11.5" "Commando" and my older M4-2000 (pre '07 model). We fired 62 grain Federal AE junk through the Colt.
The Colt was noticeably quieter than the Grendel, but not by a whole lot. I couldn't say how much obviously, but reasonably close to my ears.
The shorty cycled perfectly on full auto, and gobbled up mag after mag. I picked the SD for use on my Grendels because I figured it would keep the back pressure down, and it did seem to do a good job of that. While the SD is longer than my M4-2000 can, it actually weighs noticeably less. Even in the hand you can tell the difference! The longer length wasn't too much of an issue in my book compared to the volume you get and less weight than the old M4-2000...
I didn't try accuracy, as I only had an Aimpoint on the shorty, and we were mostly just goofing and shooting 2 liter bottles.
Now the best part: The subsonic loads!!! Oh my god that rocked! I had hoped that maybe my subsonic loads would be as quiet as my SWR Trident on my G34, but I way overshot the mark on that one! Both Grendels sounded like a BB (or weak pellet) gun when fired. There was a weird "Ptink" sound, and that was pretty much it. My friend (who can hear better than me) said he could clearly hear the bullet in flight while I was firing. We giggled like maniacs, and fired up the 80 rounds I had loaded through both guns. The bullets appeared to stay stable, because I was able to hit a couple 2 liter bottles at 200 yds. using the mildot reticle on my 14.5" for hold-over. There was no expansion of course, but lots of penetration! This load easily penetrated 2 liter bottles placed end to end lengthwise, rectangular 2+ gallon detergent jugs placed lengthwise, and 8" into a hardwood log we fired into.
The 14.5" Grendel:
It also fired perfect on full-auto, accuracy appeared great, and the shift didn't seem to be much. We didn't have time to shoot paper targets and be formal and all, so I can't say the exact shift. Firing at the jugs (starting at 250yds with the Wolf 120's) required one moa of windage adjustment to the right, and I couldn't say for elevation because I haven't worked that load in that gun at range. We just used the mildots, and it was easy to hit 2 liter pop bottles out to our max-available range of 450 yds. This can kicks ass on an M4 Grendel carbine! I really look forward to trying serious handloads at longer distances with this setup!!!
P.S.-- Is there any way to get an 18 tooth Blackout mount in a 3/4X28 TPI thread???? I have a 19.5" Grendel that I want to use this suppressor on also, and I would hate to change anything on it because it shoots like gangbusters!!!
PASTE:
OK, I finally got to shoot my 762-SD on my Grendels!
I went over to a friends house and we shot the SD on two different Grendels I have: A 10.5" SBR, and a 14.5" SBR...
We used two types of ammo:
Wolf Gold 120g MPT
My own homemade 160g subsonic ammo. (My subsonic load is a 6.5mm Hornady 160g jacketed RN loaded with 7.6 grains of Trailboss powder in a Wolf Gold case and a CCI LR magnum primer. It chronos at 1050 fps. out of my 10.5" barrel. I haven't chronoed it yet in the 14.5", but it is also subsonic in it as well. This load will not cycle my rifles, but it will probably be a tall order to get any subsonic load to cycle in a Grendel, I'll have to try that later. These loads are stable in my 1-7.5" twist barrels, but I haven't tried them in my 1-8" twist 19.5" barrel yet- so beware and test first!
The 10.5" Grendel:
We started out shooting the SD on my shorty with the Wolf Gold 120g MPT ammo. We compared it side by side with my Colt 11.5" "Commando" and my older M4-2000 (pre '07 model). We fired 62 grain Federal AE junk through the Colt.
The Colt was noticeably quieter than the Grendel, but not by a whole lot. I couldn't say how much obviously, but reasonably close to my ears.
The shorty cycled perfectly on full auto, and gobbled up mag after mag. I picked the SD for use on my Grendels because I figured it would keep the back pressure down, and it did seem to do a good job of that. While the SD is longer than my M4-2000 can, it actually weighs noticeably less. Even in the hand you can tell the difference! The longer length wasn't too much of an issue in my book compared to the volume you get and less weight than the old M4-2000...
I didn't try accuracy, as I only had an Aimpoint on the shorty, and we were mostly just goofing and shooting 2 liter bottles.
Now the best part: The subsonic loads!!! Oh my god that rocked! I had hoped that maybe my subsonic loads would be as quiet as my SWR Trident on my G34, but I way overshot the mark on that one! Both Grendels sounded like a BB (or weak pellet) gun when fired. There was a weird "Ptink" sound, and that was pretty much it. My friend (who can hear better than me) said he could clearly hear the bullet in flight while I was firing. We giggled like maniacs, and fired up the 80 rounds I had loaded through both guns. The bullets appeared to stay stable, because I was able to hit a couple 2 liter bottles at 200 yds. using the mildot reticle on my 14.5" for hold-over. There was no expansion of course, but lots of penetration! This load easily penetrated 2 liter bottles placed end to end lengthwise, rectangular 2+ gallon detergent jugs placed lengthwise, and 8" into a hardwood log we fired into.
The 14.5" Grendel:
It also fired perfect on full-auto, accuracy appeared great, and the shift didn't seem to be much. We didn't have time to shoot paper targets and be formal and all, so I can't say the exact shift. Firing at the jugs (starting at 250yds with the Wolf 120's) required one moa of windage adjustment to the right, and I couldn't say for elevation because I haven't worked that load in that gun at range. We just used the mildots, and it was easy to hit 2 liter pop bottles out to our max-available range of 450 yds. This can kicks ass on an M4 Grendel carbine! I really look forward to trying serious handloads at longer distances with this setup!!!
P.S.-- Is there any way to get an 18 tooth Blackout mount in a 3/4X28 TPI thread???? I have a 19.5" Grendel that I want to use this suppressor on also, and I would hate to change anything on it because it shoots like gangbusters!!!