Do suppressor covers damage accuracy?

[Montana]

Before I get into the issue let me outline the scenario.

Accuracy International AE in .308 with Bartlein 20" barrel.
5/8x24 thread pitch.
Liberty Freedom Suppressor
Tab Gear Chord suppressor cover

I am seeing no evidence of baffle strike or similar.
The TAB gear cover does not cover the full lenght of the suppressor, there is 1/2" uncovered at the end so that blast does not damage the cover etc

Long story short, with the suppressor cover on, accuracy is worse than when I remove the cover.

At 100 yards I performed the following test:


Using Lapua Factory ammo (175gr Scenar)
5 shot groups
It should be noted that my reloads are more accurate but I decided to use factory ammo for this test to reduce variables

WITHOUT COVER
Group 1 - .635"
Group 2 - .635"
Group 3 - .634"
Notes: Although not as accurate as I'd like, this ammo is super repeatable!


WITH COVER
Group 1 - .730"
Group 2 - .809"
Group 3 - .869"
Notes: Notice lack of repeatability


I then decided to do one 5 shot group with and without cover at 300yds.

I saw the following:

Without Cover - 2.502"
With Cover - 3.201"

So the results show that with the cover in place, accuracy is reduced.

Results at 100 showed a change from .6MOA to .8MOA. (Rounded)

Results at 300 showed a change from .8MOA to 1MOA (Rounded)

Thus I am seeing a repeatable change of .2MOA overall moving to less accurate when using the Tab Gear cover.

Have anyone ever seen this before or am I just ridiculously OCD?

 

[Rob01]

Not sure why you are getting that but I have always used TAB Gear covers on my 2 cans and they shoot very accurately with or without but without mirage is no bueno after a few shots.

 

[Montana]

Yeah, without cover the mirage is terrible and you wait 2-3 mins until its clear enough to see correctly again.

I'm wondering if with this cover and can combo, I may be creating excessive heat or something which is causing the accuracy issues.

If the trade off is mirage and accurate or no mirage and .2MOA worse accuracy, then I'm going to keep using the cover, but I was just astounded I saw the issue.

I'm guessing this isn't a common phenomenon then?

 

[Lowlight]

If the cover hangs over the end of the suppressor it acts like a crown and can throw fliers

You need to have the cover stop before the end of it to insure accuracy, don't let it hang over

 

[Montana]

It doesn't, the cover stops half an inch short of the end of the suppressor.

 

[Lowlight]

My guess is, it's your suppressor.

It's reacting to the extra heat because of the cover holding it in.

No experience with a Liberty Freedom Suppressor, but clearly it has been demonstrated that not all suppressors are created equal.

I bet the extra heat is doing something, get someone with someone with FLIR and see if it changes things back near the threads

 

[Jon Lester]

I have a 308 that has 2 distinct different impact points with cover on vs. off.

 

[orkan]

I've wanted to test this before... but it would require a benchgun or railgun that is threaded for a suppressor. Don't find too many of them, and I've not noticed accuracy or precision differences with my TAB cover on any of my rifles.

 

[JByrd]

that is my expierence with liberty freedom at 966yds. they are quality. call david. he will get ya squared away.

first, i would try the can on a few diff rifles and see if its repeatable on them as well. better yet let those rifles owners do the test. and get a double test out of it.

this is a very strange scenario and those can be frustrating to remedy

 

[JByrd]

that is a single continuous string fired with tab cover. tony @ tab gear's quality is great as well.

 

[ZombieMonkey]

I notice no measurable difference with the cover on or off.