Barrel woes

I would think most gunsmiths would have the ability.

what is issue>: :w are good barrels , I have had issues with crowns and or throat issues causing ammo to be instable put npics here or send me pics

so pic or barrel in video , looks like transfer port drilled int barrel and dimple for probe 90 degrees from port , if barrel fits snugly I cant see poi shift from hole , kind of stinks if it was made too big but some pcp guns use no dimple like some fx and just a snug screw retains it , did he have gun or spare barrel to copy

Hi
PRVITE MESSAGE ME
LOOKS LIKE 30 THOUS OVER SIZED IN THE DRILLED retention HOLE ! INSIDE MEASUREMENTS ARE DIFFICULT to get proper read AND ALL MEASUREMENTS SHOULD BE MEASURED WITH A ANOLOG Caliper your caliper could be different from his.

Excuse the caps ) you could send it to me probe the two barrels I could take the barrel down to size and check how probe fits original and
look over crown you did not mention the crown.

privet message me and we can get this sorted with the exception of the shorter barrel or figure something out

Anyone check the pellet to bore fit before machining, often I have to pick the best part of the bore as typical L.W. barrel can open up after the first 8" or the chokes are to tight /

Also depending on the diameter of barrel you need , a T.J. hammer forged BARREL would be totally consistent thru the bore and better than the LW BARREL but they have a waiting list when ordered and takes time
Thanks Mike E

Treks said:

Thank you kindly for the offer, but I gave that barrel the ol' heave ho. I went back and forth on ordering a TJ or a couple more LW blanks and went the LW route. The wait time for a blank 17.7'' twist in .25 is 3-6 weeks and am currently on week 4. I did find a local gunsmith whose owners is interested in taking this on as a way of doing something new. The bonus part is that we can sit down together to go over everything.

In the meantime we got a factory 17'' in .177 to play around with and boy is it nice to have such a compact DW.

Click to expand...

Ok sound like your in great hands.
Be careful on the L.w. barrel dont be fooled by the name its all about how the pellet fits the bore and most lw barrel coming in around the 23" off the inventory shelf open up after the first 8" to no pellet to bore contact and the pellet with rod free falls.
I had to use the best area of the bore for the crown end and use the over sized end for the machined work or breech end and go heavy on the turning to tighten the bore as well as usually coming up with a 16" long barrel thats usable.
I pretty much pissed them off after telling them what they dont care to hear, but they did offer me a special order to my specs if I order 10 barrels

They would not do a pellet to bore test before shipping again I would of had to order 10 barrel minimum for that

I would clean that barrel then do a pellet to bore test before having it machined for your project
Here is a video I did on pellet to bore test, I may of forgotten to mention to use bigger head pellets if need be.

4888blues is absolutely correct an the LW "name" being a good barrel. Decent but over the years they are know to use tooling TOO long and you might get 1-2 truly Good barrels out of 10. Also no matter the barrel prep is EVERYTHING.
I know an excellent manufacture and he scraped more LW barrels than anyone else. Some scraped after intentional inspection some after cut,crowm, hand lapping. And not just LW I have seen 3 of 4 benchmarks barrels pitched because they just did not make the grade and THAT is costly.
You gunsmith will hopefully 1 get a very nice LW to start with and then be an absolute perfectionist in machining, lapping .... sometimes (were it me every time) a true airsmith is the way to go.
Please do keep us posted.

John

I've finished around probably 600-700 LW barrels now. There might have been 2 that had defects that I couldn't fix....and I believe I could have made those shoot well with the knowledge I have today.

The ubiquitous LW airgun barrel is made from tubing. The bore is not concentric with the OD. Sometimes it may be close enough for some people. This is where the idea that there is a low rate of success comes from mostly. The makers that throw away barrels machine them in a cnc lathe and spend zero time aligning the actual bore. This isn't speculation....this is from the actual employees or former employees.

There is no barrel made by any manufacturer where the bore is perfectly aligned to the OD.... so whether it's off by a half thou or off by 10 thou makes no difference to me. I'm still going to perform the same process when machining. That process is way more time consuming than throwing it in a chuck and pushing the green button....which is all any of the manufacturers and most amateur gunsmiths do.

Mike

Not all... I don't do work for hire, but I do all of my work based off the bore, not the exterior. As you said, many times the exterior is waaayyyy out of sync with the bore. Even very premium barrels can have the bore out of sync by 0.004". I've argued with professional machinists that well understand machining, but poorly understand barrels about this. You need to know both worlds...

GST

GeneT said:

Not all... I don't do work for hire, but I do all of my work based off the bore, not the exterior. As you said, many times the exterior is waaayyyy out of sync with the bore. Even very premium barrels can have the bore out of sync by 0.004". I've argued with professional machinists that well understand machining, but poorly understand barrels about this. You need to know both worlds...

GST

Click to expand...

I've edited my post to account for the rare situation.

Yes I agree with Gene T and Thomas air.
machinist are not air gunners and the barrel should be turned set up from the center of the bore, set up is time consuming and should never be rushed.
Turning down the barrel also is done lightly unless you are trying to snug the bore area your working on
you should have the barrel done by a air gun smith
only way I been able to save a LW barrel when it opens up after the first 8" is to use the over sized end for machining and go heavy on the turning and usually I am left with a 16" barrel when I paid for a 22" barrel its a waste and aggravating

when I purchased LW barrels from others who sell them often I get a better one because they have ordered a bunch that have been checked before shipping but now seams that vender is not reliable
T J. BARRELS ARE HAMMER FORGED and made / sized correctly

4888blues said:

Turning down the barrel also is done lightly unless you are trying to snug the bore area your working on

Click to expand...

Maybe I’m misunderstanding what you’re describing, but when turning down the OD of a button-rifled barrel like a LW, the bore will open slightly. In earlier discussions, Mike (thomasair) and others have been unequivocal about this behavior, and I have observed it as well.

Here is where things get screwy, how slightly is slightly 1/4 of a thou ? referring to the barrel machined when its hot from turning
before cooling. Typically very light lathe passes are done while keeping the bore cool.

But when you have a over sized area of the bore its machined heavy to snug it up , steel has its characteristics

4888blues said:

Here is where things get screwy, how slightly is slightly 1/4 of a thou ? referring to the barrel machined when its hot from turning
before cooling. Typically very light lathe passes are done while keeping the bore cool.

But when you have a over sized area of the bore its machined heavy to snug it up , steel has its characteristics

Click to expand...

You're not gonna be snugging up any button rifled barrels by removing material from the OD. Doesn't matter what steel it's made from.

Mike