Removable Brake Question (Results)

[Tstate59]

I recently purchased a 308 that came with a R&D removable brake. Shooting at 100 yards impact is just slightly higher without it attached, but as the range gets longer impact begins to shift dramatically downward with brake installed. Aprroximately 4 inches lower at 200, and at 375 I had impact about 13 inches lower than un-braked.

Its a SAC rifle so I know the muzzle threading is square. Having never shot with a brake I am at a loss to this phenomenon. Any advice would be greatly appreciated.

 

[Chiller]

Re: Removable Brake Question

lever arm......???

 

[SScott]

Re: Removable Brake Question

With my TRG in .308 it shot 1" high at 100 yards with the brake off. Just make a note in your log book and keep shooting.
SScott

 

[Tstate59]

Re: Removable Brake Question

Chiller I'm guessing by lever arm you are referring to the part that clamps down. I inspected this when I started noticing the impact shift and i could not see any obvious flaws. It screws down smooth, no burrs or acting like a misalignment and clamps well.

Scott, I did expect a little shift on POI but it seems excessive. Like I said I don't have any experience with brakes so maybe this is normal. Really nothing I can do but drive her naked if it bugs me that much huh?

Thanks for you input

 

[netranger6]

Re: Removable Brake Question

Rifle/Specs? Crown in good shape? Notice any tumble marks on inside of brake? Have you shot paper to see if round is impacting properly?

 

[Tstate59]

Re: Removable Brake Question

Rifle Specs: Suregeon RSR action with a 24" 1-11.25 Bartlein 5R barrel, MTU contour (if I remember right), bedded in a T4 Manners stock.

Crown is perfect and no marks in brake. I have shot paper as close as 50 yards without any signs of bullet tumbling. Accuracy remains good, the same, between the two, just a shift.

 

[Black-X]

Re: Removable Brake Question

I just ordered a RAD brake and this isn't what I want to hear..

 

[Tstate59]

Re: Removable Brake Question

Now I'm not ragging on the RAD brake here as it does its job very effectively and makes shooting a joy. These variations could definitely be on my end as I have not found any info on the same problem from this brake. Matter of fact I only hear great things.

 

[Tstate59]

Re: Removable Brake Question

Ok apparently I can't see worth a dern. I just had some better eyes, and a frikin bright flashlight, find a small burr in the outer chamber. Maybe causing uneven pressure on exit?. Will polish, test and report back.

 

[Wild_Bill]

Re: Removable Brake Question

also make sure you dont over tighten any brake with a clamp if you do you will reduce the bore dimensions and cause accuracy issues just hold the small end of your allen key in your fingers and gently tighten so the brake does not move dont overtighten them see if that helps.

 

[netranger6]

Re: Removable Brake Question

Cool. I'd like to know what that burr is all about.

 

[Tstate59]

Re: Removable Brake Question

Good info Wild Bill. Will follow advice on the tension

 

[netranger6]

Re: Removable Brake Question

Any update on this burr?

 

[netranger6]

Re: Removable Brake Question

Anything? Kyle...Kyle...Buehler?

 

[Tstate59]

Re: Removable Brake Question

I should get to shoot today if the "massive" amounts of tropical storm rain don't catch me. Lol. I'll post something by tomorrow afternoon

 

[netranger6]

Re: Removable Brake Question

Yeah, you should definitely pack some waders and a good poncho....

 

[Tstate59]

Re: Removable Brake Question

Results:

I was only able to make it out to around 225 yards but things looked a much better. At that range impact was low just at 2 inches compared to without brake. Ya quite a difference! If it holds a 1 MOA or so drop I can definitely live with that.

I changed quite a few variables so this was not a truely scientific test. Polished inside of brake knocking down small burr, relieved tension on clamp (yes I did have it torqued a little too much) and I changed to my handloads which area little hotter than factory. But something worked out of it all.

 

[netranger6]

Re: Removable Brake Question

Good deal man. That sounds like you eliminated it hard. So, are you leaning more towards the burr or load as the primary "x"?

 

[Texar2]

Re: Removable Brake Question

I always recess the bore deeper than the length of the threads to prevent any ditortion.

 

[Shortdraw]

Re: Removable Brake Question

Harmonics can do pretty dramatic things. Also, reduced recoil can make a POI shift depending on how you drive your rifle. Glad to hear you got it sorted out.

 

[Tstate59]

Re: Removable Brake Question

I think I'm going to lean more toward the load. Just don't see how that tiny burr could have caused that much of a problem.

Barrel harmonics was a probable cause. A load tuned in on the node for the rifle will produce less variation. I would think the same applies when you hang something on the end of the barrel. Less flex unbraked = less flex braked, more = more. If there was more wobble initially it would be more pronounced on the latter. Plus my handloads produce better accuracy as they should.