suppressor POI shift question

[Love308]

I have a 308 remmy 700 5r with a 24 inch barrel and an older suppressor, I want to say the brand is cobra or something similar. When I first put the can on I tested the rifle POI with and without it attached. The test showed no change of impact plus my groups were tighter with the can on. This was 5 months ago. I retried the test today and had a change of impact while my group with the can on was around 1 MOA, not good in my option. With the can off it was back to sub moa. So my question is why would it change now and not when I first started using it. An additional note, I used hand loads the first time; today I used UK surplus sniper rounds.

 

[Nimrodmar10]

I think you answered your own question, change in ammo.

 

[PhulesAu]

1. the change in weather? it's a **** site hotter weather. Gun, suppressor, and Ammo will be effected.
2. is can back on in the exact same place, ie. clocking?

 

[Love308]

1. the change in weather? it's a **** site hotter weather. Gun, suppressor, and Ammo will be effected.
2. is can back on in the exact same place, ie. clocking?

What do you mean by clocking?

 

[PhulesAu]

take a look at muzzle brakes on some of the rifle photos. you'll see that they are lined up to be horizontal when the rifle / action / barrel are vertical. so blast from firing is evenly distributed. also to insure the bullets path out from barrel through brake / can is not obstructed in any way. If the gasses don't flow out evenly, this will effect bullet stabilization. this aligning process when mounting brakes and flash suppressors and "silencers" is called clocking. hope this helps.

 

[Love308]

Thank you this does help with me understanding how everything plays off each other and how it effects each other to some degree. I will take apart my suppressor to ensure I'm not getting any baffle strikes. After that I'll run some hand loads through it and will share the results.

 

[Bravo 4]

I think you answered your own question, change in ammo.

This!!! Anytime you change ammo you should expect a POI and/or grouping size change. And don't expect your rifle to shoot surplus ammo as well as tailer made ammo.
I can't tell from your post if you meant a POI change or your groups opened up. Doesn't really matter, as I stated above it can change both.

Also, you can expect a change of POI when shooting with a suppressor on and then taking it off. On our 3 M110's we get a POI change of 1 MOA when the cans are mounted, each one to a different spot. We shoot mostly with them on, so the optics are zero'ed as such. Just keep a log of the difference.

 

[Love308]

I finally got a chance to load some bullets for my gun to test. I loaded 175 Bergers with 40 grains of benchmark(brand new load for me). I shot them at 100 yards and still had around a minute group, slightly less. I checked my suppressor and there were no signs of baffle strikes. So I still don't understand why I have lost accuracy. I do understand that it's fairly normal for POI change with the suppressor on/off now, which makes me feel a little better about that problem

 

[Bravo 4]

You said this is a new load, did you do any load development?
Not trying to be rude, but by your posts you don't seem to understand that anytime you change something with your ammo (or the ammo period) it can effect accuracy and/or POI. Just because your rifle shot small groups with one load (or type of ammo) doesn't mean it will shoot everything into small groups, or into the same spot (POI).