Chop and crown
I was installing the 24″ .25 barrel a few days ago, and noticed the muzzle had a big clump of what I suspect was mouse shit stuck to it. Worse, it was in the bore.
I cleaned it up best I could, but the barrel was shooting much worse than I knew it was capable of.
After reading a lot of opinions about removing the choke end of a barrel, I took the plunge.
Took the barrel to work with me, and after considerable fussing about was able to get the bore running true to the chuck in the old lathe. How you guys manage to do this easily is beyond me, took me over an hour.
Well I get the barrel cut, took 1.25″ give or take a bit.
I decided it would be easiest for my limited skill to try a target crown. This left a fairly ratty surface to my dismay, and I “aint a suppose ta be in tha machine shop anymore” says my boss so asking for help is out of the question.
The cutter looked brand new to me so I’m not able to find out what went wrong.
I cleaned up the mess the best I could with sandpaper and Flitz polish, didnt make a dent in that steel.
The tailstock has a chuck mounted in it, and I figure I have nothing to lose now so I mounted my round head slotted brass screw, liberally coat it with Flitz and slowly push it into the muzzle. A few seconds the flitz turns black so I stop and check. Nice little beveled edge to the bore.
Took the barrel home and installed it. Heres the result. Pics of the crown are horrible I know, the iPhone just wouldnt focus on it right.
Shooting results were an eye-opener. Here is the full target.
I started with domed EJ pelllets. This barrel before the crown job absolutely hated these pellets. The best I could shoot at 50y was 3″
The 4 scattered shots in the middle were the beginning, the one to the right the first shot. Even though its bad, it is 3x better than this barrel could shoot them before.
Took aim at the upper right corner. 3 shots domed EJ at .653″ CTC
I was getting a warm and fuzzy feeling. The bore seemed to be settling in.
Switched to JSB kings and lobbed 5 of them to the left middle diamond.
.315″ CTC
Made a small scope adjustment, and fired 5 more at the right middle diamond.
.250″ CTC
To say I am stoked is a huge understatement. Apparently removing the choke improved this barrel tremendously for EJ pellets, and noticably for the Kings.
And yes I know, leave this sort of work to the professionals. LOL
I know I was lucky this time.
😛
All Replies
Viewing 13 replies - 1 through 13 (of 13 total)
Walt, everything you said about the machining aspect makes perfect sense to me.
All I know about using a lathe, I had to teach myself. Out machinist would just come over and make a suggestion if he saw something obvious. It was understood that if I ruined my parts, it was all on me. And if I ruined the lathe, it was all on me.
Your comments about EJs improving with a choke havent proven themselves in my experience though.
This barrels accuracy with EJs improved a LOT by removing the choked end of the barrel.
None of my other choked barrels will shoot EJs either, but this is the only one I wanted to try this with.
When you sold me the 17″ barrel, I sold my 24″, then missed it so I bought another. It shot Kodiaks and JSBs quite well, but EJs once again was like using a shotgun. After removing the choke its a dream barrel for the most part. EJs still wont shoot “great”, but are good enough I will hunt with them with complete confidence.
If anyone ever offers up a polygon barrel, I might have to splurge for one. I hear they do really well with the EJ pellets.
Riff, cosmetics count for little in my book, if it shoots great then it is great. Just that when things are smooth it makes it easier to measure and easier to grab consistently in the lathe. If you are getting rough results check your setup. The most obvious problem to check for is the sharpness of your cutting tools. Also the tool material. There is a whole class to be taught on simple tool geometry, the proper angles the cutting tool should have in reference to the work. The angles change depending on the material being cut. Carbide bits work great and all the new machinists seem to use them because then you don’t have to think about tool geometry; you just index the tool over to use the next fresh cutter, or buy a new insert. HSS bits have to be shaped by hand on the grinder, which is a pain but also a blessing as then, you can dictate what angles you form into your tool for specific jobs. If you get tired of the rough look, send it over, I can do a quick polish and recrown.
a choke is an odd thing. Mostly its optional if you are using high quality pellets that are very uniform. That’s why the EJ improve so much when they are shot with choked barrels. But if you take the next step and run your pellets through a sizing die prior to shooting them, as some target shooters do, then there is a good chance a choke will not improve your groups at all. But this has a lot to do with the size of the groove and lands in your particular barrel. Each barrel is individual, with slight variations (even in the same batch from the same manufacturer); so if you have a good one, hang on to it.
aloha,
walt
I did not achieve Nirvana with the Korean pellets with this barrel, but kings havent shot over .5″ at 50 yards yet. They literally stack at that range.
So far best to worst with EJs has been .45 – 1.2″ at 50.
A full 3x better than before, but not consistent like the Kings.
Want to shoot 100+ now but the wind and rain keep switching on me.
Good work! Just a note: my .25 LW barrel shoots the heavy EJ’s just about as accurate as it does the JSB kings (nearly hole in hole at 20 yards).
Wow good read Riff!!
You got balls bro!
To crown the HW barrels is always a bitch as there is a lot of grabby lead alloyed into the metal .The cuts need to be from the inside out , and need to be very light 0.0005″ at the last cut.
Very good info there. The last cut was as light as i could make it and it was from inside out.
I figured it was worth a try, and I got lucky. I had an out tho as Walt has mentioned to me before his machine skills are available to me if I screw up, and I was only going to this myself once.
RiffRaff : Good report, seems non-choked barrels for heavy pellets or bullets is looking better and better. Thanks for the report.
Tomorrow I’m calling my local gun shop and see who can chop and re crown my barrel.
Sam 😆
RR,
You got balls bro!
To crown the HW barrels is always a bitch as there is a lot of grabby lead alloyed into the metal .The cuts need to be from the inside out , and need to be very light 0.0005″ at the last cut ,then chuck your brass screw in the hand drill and put a bit of JB bore paste on it ,spin the screw while rotating the drill in a circular motion ,this does not take long ,you will feel a roughness to start , then it will suddenly go smooth , this is when you need to stop ,otherwise it will go rough again .You then do the Q-tip burr test and push a pellet through the barrel with a pull through ,go real slow in the end and feel for any snagging ,take a look at the pellet through a glass to see any signs of burring , you should be done .
I was sort of suprised the roughness on the end of the muzzle doesnt appear to be a factor. Before I used the brass screw, there was quite a lot of sharp flashing from the cut inside the bore. The screw seems to have cleared it up.
Interesting tho, my first shot was over an inch right, as was the 2nd shot. After the 3rd they seemed to be settling in. Possibly shot out the last of the burrs?
If anyone is about to ask, I do shoot with a shroud installed for all shots. My dogs just hate a loud rifle.
I compared this crown to the 11° on my Walt barrel, his crown is super smooth and has absolutely no bevel at the edge of the bore. Walts barrel shoots JSB very well too, but I dont know if he chopped the choke off of it? Accuracy wise, I have to give the nod to the new chopped one. Before the chop, Walts barrel definitely got the nod.
I just looked at my factory stock .22 barrel, and it has a very nice looking target type crown on it. Its a laser with JSBs as well. Im leaning toward a target style crown on Walts barrel now, if it ever needs redone.
I tried pushing pellets down all 3 barrels and they have no noticable (to me) extra resistance at the end, so that choke must be very gradual in a LW barrel.
Nice work!
I didnt look at brownells.
Midwayusa has quite a bit of the crowning tools in stock.
I was reasonably sure this could work, and I was quite pleased how it shoots.
I just shot another bottleful of air shattering acorns at will. I cant believe this shoots better without the choke, but it does.
I need to try kodiaks again and see if it clears up the flyers I alway got.
RiffRaff,
Looks like a nice crown, shoots like a nice crown.
If it looks like a duck and quacks like a duck, it must be a duck.
I have been cutting and recrowning my barrels by hand for years, got the info out of a old gunsmith Kinks book, it has worked fine for me for years.
Brownells used to sell brass balls to put lapping compound on for crowning, perhaps they still do. I have kept one of my 2240 brass bolt handles to do the next few, just chuck them up in a drill.
Now quit that job before you drop something on yourself again, and put out your gunsmith shingle. 😆
Anyway glad it worked for you.
Roachcreek
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I can see how any long projectile would fly out the barrel much better unchoked.