I have an AR 6x45 that is a great shooter, easily at 1/2 MOA shooter. My two favorite loads were 70 gr ballistic tip and 85 gr Sierra. I decided I wanted to put a suppressor on this rifle. I have ordered the suppressor and I already had the barrel threaded and have attached a muzzle break. It now shoots 1 inch MOA at best. I am not quite sure what I need to do to improve this. The suppressor is still in jail, what can I do to help the groups?
AR and Suppressor
- Thread starter nativecat01
- Start date
The first thing I would do is inspect the crown, If the person who threaded the barrel dident do it correctly they could cause a lot of problems, secondaly adding a muzzle break is changing the harmonics of the barrel and you will have to retune your loads to compensate. Now when you install the can your going to change it again .
From what I can tell, the crown looks ok. I see nothing out of the norm. When you say, retune, do I need to go to a complete different bullet or what do you mean? I can't change the seating depth on the AR. I have not shot it without the break since it was installed.
DirtySteve
Gold $$ Contributor
My wife's 6X47 Lapua was shooting well under 1/2 moa. It was threaded for a suppressor. Screwed said suppressor on and the groups opened up. I am in the process of packing my stuff up for a move in the spring and have not had time to work on the issue. I suspect the weight of the suppressor has changed the barrel harmonics. As Hal said take off the break and shoot it. If it is back to normal then you will have to develop a load once your suppressor posts it's bail and gets released from ATF jail.
jepp2 touched on my first thought. Next would be how did they re-assemble? Is the gas block on right? Is the gas tube free floated and entering the key with no load? Did the barrel nut get torqued different? Did they use a thread locker on the barrel extension before they slid it into the receiver? Was anything else changed at the same time? (handguard, etc)
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I watched the gunsmith but the break on and I don't remember him putting on any type of washer. I know he took a long time to align the break.
Shynloco
You can lead a horse to water, but ........
nativecat01,
Pay close attention to killahog's words! They apply to any barrel where things are added or subtracted. The threading alone changed the barrel harmonics and your nodes of the past are history. So you must retune your load to find what load(s) NOW works best. In my experiences, sometimes you may spend a good deal of time trying to find that sweet load and there is no guarantee that barrel will ever shoot as well as it did before.
Alex
I had a friend of mine tell me not to let anybody touch the rifle because it shot very well. I have been using H335 powder, I can try some Varget and see if that helps.
Shynloco
You can lead a horse to water, but ........
Wise friend. Too late now so may I suggest you give VVN140 a try. I have a custom built Match Grade STTAR15 and my JP Precision Barrel likes VVN140 the best using Berger 55's, Sie 69's and 77's. Worth a try if you are just looking around as I did using just about every powder listed in the Berger and Sierra Manuals.
Alex
hope your gunsmith didn't mess it up.
retune your load
tweak your charge weight
you don't have to use mag length for a seating depth. you can go shorter
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These guys are right, you may have to treat it as a new barrel and start fresh, not the end of the world.
I got into suppressors going on 3 yrs ago and now have 8 or so stamps. My rifles had brakes, the transitions were painless, I think a couple improved. Any new barrels start with the can.
My magneto acts as a tuner on a new 6 creed barrel, it can shoot or has shot a few 1/2" groups at 500 yards, pull it off, 2" at best, so it's real.
I got into suppressors going on 3 yrs ago and now have 8 or so stamps. My rifles had brakes, the transitions were painless, I think a couple improved. Any new barrels start with the can.
My magneto acts as a tuner on a new 6 creed barrel, it can shoot or has shot a few 1/2" groups at 500 yards, pull it off, 2" at best, so it's real.
Kind of making me nervous now. Bought two suppressors to move around on rifles. It looks like I better keep the suppressors on the rifle permanently.
No, that can work.
You definitely want to get an adjustable gas block ordered if you haven't, your going to get an education in over gassing.
^^^^^, yep.
nicholst55
Brass Whore
Dick Culver told a story of how the Army wanted to borrow an M40 sniper rifle, in order to get an idea of what to expect from their M24 sniper rifles that they were planning for. Before the M40 left Quantico, Dick had the RTE armorers drill and tap the barrel for a target sight block at the muzzle, then verify accuracy. The addition of that tiny sight block turned that rifle into a shotgun, figuratively speaking! With the sight block removed, the rifle resumed shooting bugholes. This is the same reason that Krieger used to recommend only hand-tightening muzzle devices on AR-15s, and loctiting them in place. The moral of the story is that anything you add to the barrel of a rifle, especially on the muzzle, can have a drastic effect on accuracy.
I've got several TBAC suppressors that vary in weight quite a bit, lightest to heaviest - Ultra 7, old 30BA re-cored by the factory with Ultra 9 baffle stack & CB mount, and a 30CB9. Though my first preference is to use the Ultra 7 on most everything (because it's lighter & more compact than the two 9" cans), I think it pays to shoot groups on a new rifle (or barrel) with all three to compare accuracy. I haven't done a lot of that yet, but did compare the effect on the 600yd zero on one rifle by shooting it with the re-cored 30BA & 30CB9 - the lighter can's POI was around 10" higher than the heavier 30CB9's, although the group size was about the same.
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