SAK suppressor inaccurate

[davidTOZ]

Hi guys,

 

i recently had a gunsmith cut a thread on my rifle to fit my SAK silencer on it. After i got the gun back it was inaccurate. I have seen marks of the bullet touching the silencer slightly.

 

So i brought it back to the gunsmith to fix it.

 

After a while i got the rifle back and i shoot a lot better.

 

But i recognized that the bore of the silencer, at least the front end seemed to be bigger in diameter. I think the smith drilled it out a bit so that the bullet is not touching it anymore.

What is the diameter of your SAK bore at the frontend?

Sometimes i still got fliers. Today i cleaned the SAK an saw a rought "crown" like from a drill inside the silencer at the end of it where the bullet leaves it.

I removed it. Could that be the reason for poor accuracy?

 

Regards David

[drut]

My SAK measures o.29in at exit.

[pat g]

Sounds like your gunsmith has done a botch job tbh m8. Drilling the end of the moderator is by no means a solution and if i were you i would return the rifle. Threading for a moderator has to be done properly by a thoroughly competent person otherwise you will get no end of problems. Some of the other guys on here will pop up shortly i'm sure, and may have a solution. You're on the right forum though for some good advice. Hope you get it sorted soon. .

ATB Pat

[drut]

Sorry the last reply was so brief,the real proof lies in trying the accuracy of your rifle without the suppressor against with it.My experience tends to show that if the bullet is out of centre compared to silencer bore,even if not clipping,accuracy suffers.Strangely I have found it more pronounced on airguns than rimfires.I think "pat g" is spot on.

[davidTOZ]

I also fired the rifle with a piece of masking tape on the exit hole off the suppressor. The bullet punches the paper of center. I shimed the supressor on the opposite site and the bullet hit dead center.

 

Does the threading job needs to be redone or maybe just sand down the opposite site a little down?

Edited April 4, 2011 by davidTOZ

[cleaner4hire]

take it to another more reputable smith and find out if the thread has been cut badly then if necessary take it back and get it redone or better get a refund and get somebody else to do it!! Drilling out a mod to cover up a shoddy screwcut is not on in my book.

 

I had a similar experience with a cheap thread job and although it wasnt clipping the mod it didnt shoot properly until i had it redone by somebody I trusted to do it

[Frenchieboy]

From what you are saying it certainly does sound like the thread on the barrel has not been cut properly/accurately enough and this should be corrected rather that drilling out the moderator - This to me this sounds very much like a botch job and unacceptable. If it were me I would take the rifle and moderator to a reputable gunsmith and ask them to check the rifle and if need be give you a written report before taking it back to the gunsmith that did the original cutting of the thread and asking him to do the job properly! If however the threading job appears to have been done properly you should try firing the rifle without the moderator fitted and check the grouping as there could be a problem with the crowning!

This is not a definitive answer, it is more of a generalisation, but I hope it helps.

[cooter]

It is very rare to get a SAK with a dodgy thread on it, and the new ones are very good, but it is very easy to cock up a barrel.

 

If you can find something long with a thread of the same size (1/2" UNF) fit it on and any error in the thread will be more pronounced (the long piece you fit will sit at an angle to the barrel), but your best bet is a decent gunsmith, and get them to chop and recrown the barrel.

[CharlieT]

If your assumption is correct in that he drilled out the end of mod to correct his non concentric threading job then it's a poor do and needs to be re done.

 

Good idea of yours to measure the "hole" and compare it to another. Also another check would be to examine the paint work round the hole. If your theory is confirmed take it back and ask him what he intends to do about it. I would not trust him to do the remedial work but would demand that he pays for the work to be done by a smith of your choice and also replace the Sak.

 

It needs to have the thread chopped off and be re threaded and crowned. Unless this is done properly any moderator you put on in future will not fit correctly.

[snowz]

You need to check of it shoots ok without the mod fitted.

 

If it does and then when you fit the mod it then starts clipping the mod it's possible he never trued up the barrel in the lathe properly and the screw cut is off centre to the bore an useless.

 

Contact the gunsmith again saying your rifle still has a problem and your not happy with his last 2 attempts and your going to another for a second opinion and will pass on any cost to him.

 

From the above post tho it sounds as if it wasnt trued up properly in the lathe and he's tried a quick fix of opening the exit hole up in your mod to avoid clipping, you also need to check the crown for this will also make a huge difference in accuracy,

 

can you post any pictures of what the screwcut job looks like?

[davidTOZ]

Hello,

 

i am sick and tired of this gunsmith. Second thing he screwed up. First was a barrel chop off on a K98 for hunting. It was also not square.

 

I will post a pick of the thread later this day.

 

Thanks so far!

 

David

[cockercas]

Name and shame I'm waiting for my .243 back from the gun smith its having its barrel threaded he best not **** it up

[Dekers]

If your suggestions about the thread and the mod prove to be accurate this so called Gunsmith should be strung up!

[Jaguar Warrior]

I had a similar problem with an air-rifle, though the problem there was with the moderator. It was visibly ok, until i did as someone suggested and slid a few feet of pipe over it. The offset showed up as I rotated the moderator.

 

In the States, where they rarely use moderators, they put great weight on the crown of the rifle, and don't just just remove any burrs but insist on specific crown profiles. The burr inside the moderator probably disturbed airflow in an inconsistent way and from that point you were dooooomed! :blink: Until you drilled it away.

 

I wouldn't rely on re-centering the hole in the moderator, because the moderator would have to be screwed on to the barrel at the same clock position forever. Not what you need.

 

I had my rimmy done at the same time as barrel shortening at S Yorks shooting supplies / rimfire magic and they did a brilliant job

 

My receiving RFD (not the jolliest chap) mumbled 'I could have done that cheaper'...........