RECROWN the barrel?

Scott · Post by **Scott** » Tue Jun 22, 2010 11:37 am

I have a 1413 that was made in the late 60's that I shot in high school and in college, now it is 20 years later and I’m getting back into shooting. Does anyone have any advice on re-crowing the barrel?

weilers · Post by **weilers** » Tue Jun 22, 2010 12:34 pm

What does the crown look like now? Pitting, scratches, etc?

1813benny · Post by **1813benny** » Tue Jun 22, 2010 10:36 pm

Shoot the rifle..if it shoots good leave it alone. If not, put on a new barrel.

luftskytter- · Post by **luftskytter-** » Fri Jun 25, 2010 4:09 pm

Read discussions on airgunforums ("yellow forum" etc.) about cowning.
A really good crowning job is not very easy unless you have special tools.
If your crown looks good and shoots OK, why recrown? If it's not OK, recrowning can give a substantial improvement, especially with airguns that shoot short light pellets that are easily thrown off course.

tsokasn · Post by **tsokasn** » Sat Jun 26, 2010 7:55 am

Now that was very interesting!!!

Barney · Post by **Barney** » Sat Jun 26, 2010 9:59 am

I think Scott is talking about re crowing a .22 not an air rifle

luftskytter- · Post by **luftskytter-** » Sun Jun 27, 2010 5:19 am

Crowning . 22s vs airguns: that's the reason I stressed pellets as more vulnerable. Mostly you'll notice this with cheap air rifles where a new crown can give a very noticeable accuracy improvement. I guess a longer .22 bullet will be less affected by a slightly rough muzzle crown.
Depends what kind of accuracy you are looking for.

As a matter of fact, some "sporting" air rifles shoot "match quality" single hole groups at ten or even twenty meters, but are outperformed by the best Field Target guns that shoot good groups at 50 or even 100 meters.
Making a 10 meter gun is not very challenging........

Roodaddy600 · Post by **Roodaddy600** » Sun Jun 27, 2010 8:34 pm

what does re-crowning an air rifle have to do with this thread?

Guest_66 · Post by **Guest_66** » Tue Jun 29, 2010 4:07 am

Luftskytter:
A .22 bullet will definately be affected by a rough or bad muzzle crown.
But rough is not the only problem. Some factory barrels might also have a tiny uprising edge exactly where the bore ends at the muzzle (as a result of a poor finishing job). I have recrowned two of my barrels that had this problem.
The way to check the muzzle is to use a precision steel "hook" (like the dentists use) that you slow and easy pull from inside the bore and towards the muzzle. It the crown has a edge, you will feel it. And if it is there, you can imagine what it will do to accuracy shaving the bullet a little just as it exits. If you want to fix it, don't try to do it yourself, it has to be done with great precision by a experienced gunsmith.

luftskytter- · Post by **luftskytter-** » Mon Jul 05, 2010 5:00 pm

OK, air rifle just happens to be where I've got practical recrowning experience. I realise other guns may have different problems, but I guess the basics of crowning are similar.

Testing with a Q-tip may show up tiny burrs in the muzzle. It doesn't take much to hook some of those cotton fibers.

You can buy special tools for recrowning, and yes, they have a pilot that must be an exact fit in the barrel of your gun to stay in centre, and should be used with a bit of care and dexterity, after a perfect 90 degree cutoff job.....

Rover · Post by **Rover** » Tue Jul 06, 2010 5:51 pm

A simple trick for improving a muzzle crown is to take a round head brass screw and chuck it in a drill. Smear the screw head with valve grinding compound and spin it in the muzzle.

If this is not high tech enough for you, you can always have a gunsmith do it. You will not have made things worse.

adds033 · Post by **adds033** » Thu Nov 04, 2010 5:02 am

Guest_66 wrote:Luftskytter:
A .22 bullet will definately be affected by a rough or bad muzzle crown.
But rough is not the only problem. Some factory barrels might also have a tiny uprising edge exactly where the bore ends at the muzzle (as a result of a poor finishing job). I have recrowned two of my barrels that had this problem.
The way to check the muzzle is to use a precision steel "hook" (like the dentists use) that you slow and easy pull from inside the bore and towards the muzzle. It the crown has a edge, you will feel it. And if it is there, you can imagine what it will do to accuracy shaving the bullet a little just as it exits. If you want to fix it, don't try to do it yourself, it has to be done with great precision by a experienced gunsmith.

Guest 66,
I done my first crowning job on one of my .22s and it almost halved group sizes. Theres no rocket science to it just a basic engineering knowledge of keeping it all square and true in the lathe, and taking your time to get a smooth surface finish. Based on my experience anyway.

Levergun59 · Post by **Levergun59** » Sat Nov 27, 2010 12:39 pm

Boots Obermeyer has recrowned a few of my rifles. He checks them with a 20X streoscopic microscope. At that definition things can get really ugly at the crown and down the bore a little ways, but you can tell if the crown needs to be cleaned up. Most of the ugly comes from chatter with a piloted crowning tool. I doubt this is the way that Anchutz crowns their barrels, but I'm not sure. Either way have it recrowned in a lathe by someone that knows his business. Hope this helps.
Chris

Hemmers · Post by **Hemmers** » Sat Nov 27, 2010 6:32 pm

adds033 wrote: I done my first crowning job on one of my .22s and it almost halved group sizes. Theres no rocket science to it just a basic engineering knowledge of keeping it all square and true in the lathe, and taking your time to get a smooth surface finish. Based on my experience anyway.

LOTS of precision! As you say, it's not a complex job nor rocket science, but it does need to be precise.

If you're not capable of setting up a lathe to a high degree of precision, then it's best to hand it over to a gunsmith/experienced machinist ("basic engineering knowledge" is an eitrely subjective term). The face and crown need to be absolutely square to the bore.

It does however make an enormous difference. If the crown is damaged, pitted or not square (i.e. wasn't done properly in the first place, or has been redone poorly), it will make a big difference to group size.

Crowns can be the bit that goes first, being most exposed and an easy area to damage. However, on a rifle from the 60s, I'd have the rest of the barrel checked over before getting work done.At that age the throat of the breech will likely be worn and a bit wide, and the rifling will be somewhat worn (and pitted if it hasn't been cared for as well as it should).

In that case, it would be far better to just get a new barrel than worry about haveing work done on the crown and possibly even the breech.

Also, if it shoots straight already, don't "fix" it. If it's shooting straight enough, no amount of work is likely to make a barrel of that age shoot any straighter!

Rover · Post by **Rover** » Mon Nov 29, 2010 5:27 pm

Since my last post on this topic, I came across this. This guy is almost smarter than me!

http://www.surplusrifleforum.com/viewto ... 79&t=63966

timinder · Post by **timinder** » Tue Nov 30, 2010 9:27 am

Wow, one day I hope to shoot a group like the one on page 2 of that thread.

NOT!!!

If a homebrew re-crown does THAT to a rifle, I think I'll leave it, thanks! :)

Hemmers · Post by **Hemmers** » Tue Nov 30, 2010 9:42 am

Yes, and the odd thing was he seemed pleased with the result, and it's only at 50yds according to the scribble in the corner of the target!

Guest · Post by **Guest** » Tue Nov 30, 2010 10:55 am

gwsb · Post by **gwsb** » Thu Dec 02, 2010 11:35 am

How to re-crown a barrel.

Take a 20 penny nail and stick it in the muzzle and.....

The bottom line on old barrels like this is that the crown and chamber are equally important. My 1413 from the same era has a ring around the chamber almost the whole 360. Still shoots ok though. My daughter has it now.

My opinion is (and its worth what you paid for it) if you want to shoot prone use the 1413 with a new barrel. If you want to shoot 3p sell the 1413 and get a 1813 for not much more money.

The 1813 has advancements that were significant. When I made the change the difference in the trigger lock time was scary fast. It doesnt really matter so much in prone through, but in standing it is amazing.

TargetTalk

RECROWN the barrel?

RECROWN the barrel?

Not much precision really!

Re: Not much precision really!