Need help with fliers

[RockyMtnMT]

Hey guys, need some opinions.

I have not had any time this summer to shoot much this summer, and now coming down to crunch time. I had a Painkiller brake installed on my rifle this summer, by a smith that I am not very impressed with. (Different story) Took the rifle to the range Sunday with the old load that I have used the last two years to verify zero. Now I am having an occasional flier. Off the paper at 200yrds.

So today I am going to start load development. Before I head to the range this afternoon any thoughts would be appreciated.

Thanks,

Steve

 

[Fiftydriver]

What is the bore diameter of the PK reamed to? Should be 20 thou over bullet diameter. If its to large you can often get turbulance around the bullet. If its to tight, or was not deburred, you may be getting some bullet to brake contact.

I have never seen a rifle shoot worse after getting a PK installed compared to how the rifle shot before. They always seem to shoot at least as well as before if not better.

Was the muzzle recrowned after fitting the muzzle brake. It should have been.

 

[RockyMtnMT]

Thanks Kirby,

I expected it to shoot better as well. I don't know that those things were done. So I will have another smith check it.

Steve

 

[edge]

Would it make sense to stick a dowel in the bore and check the clearance? I would guess that if the clearance is not uniform that it may allow the gasses to escape unevenly.

edge.

 

[rscott5028]

Also, the barrelled action had to come out of the stock to go in the lathe. So, check that your barrel is still floated and action screws torqued properly.

Same for scope, etc...

-- richard

 

[RockyMtnMT]

Thanks guys,

I took it to another smith yesterday. It appears that the bore diameter of the pk was not opened up enough, nor was the barrel re-crowned. This smith is getting it done for me by noon so that I can get to the range today and with some luck get out of here today to go hunt for the next four days.

Steve

 

[Fiftydriver]

Recrowning the muzzle is critical, at least if you install the muzzle brake the correct way by machining the muzzle threads true to the axis of the bore, generally to do this you use a live center to support the muzzle end which rides in the crown. This can create a small lip at the end of each land at the muzzle and really cause accuracy problems.

The bore not being large enough is a serious safety issue. I would probably not go back to that smith that installed the brake!!!

 

[AZShooter]

Kirby's comment on recrowning is absolutely correct.

Years ago I had my first brake installed. Subsequent shooting sessions produced poor groups. I performed a complete inspection of the rifle trying to pin it down. When I looked at the crown I saw one of the land ends had a burr. I brought it back to the gunsmith and he couldn't see it! I had quite a time convincing him it existed. (Would have been nice to have had a bore scope back then) He relented, recrowned and the rifle went back to shooting. That was the last job he ever did for me!

 

[Fiftydriver]

I have yet to see a CORRECTLY installed muzzle brake make a rifle shoot worse then before installation. There are several reasons why this happens.

1. Generally, especially with factory barrels, the muzzle crown is ALWAYS off axis to the bore, recutting the crown to match specs is probably the number one reason a braked rifle shoots better.

2. The weight of a muzzle brake changes the harmonics of a barrel. It seems that any weight positioned out past the muzzle has a positive effect on a barrels accuracy, likely because it dampens or at least makes barrel vibration more consistant while the bullet is in the bore. I am not saying the effects of the muzzle brake will improve accuracy, simply that its weight at the end of the barrel has tends to be a positive to consistancy.

3. Dramatic reduction in felt recoil which allows the shooter to relax and be more consistant from shot to shot!!! While the other two will have more effect on the rifles accuracy and consistancy performance, this aspect is what makes the shooter pilot the rifle more consistantly and for that reason, this is generally why you see better results down range above all other even though it has very little if any effect on the rifles pure accuracy potential.

Now, that is for a brake that is installed CORRECTLY. I have seen many a rifle that had their consistancy destroyed by a poorly installed muzzle brake.