LW Barrels

No doubt that barrels are subject to harmonic changes from almost anything you do to them, or hang on them. But I am more interested in the threading process and its effect on internal bore dimensions. 

I share your observations on the simple and sometimes junky appearance of the insides of many moderators. And that their materials cost is modest. But as they say, beauty is as beauty does, and some of them are very effective. As long as length isn't a constraint, I prefer them over a shroud, but that's just my preference.

I'm not a machinist, so I can't tell you from experience. But two precIsion smiths whom I respect, said the bore diameter may increase with the external threading. Regardless, I guess the important thing, it apparently can alter it enough to affect accuracy. I had the bad experience with the threaded Red Wolf barrel. But, my HW100 barrel and Veteran barrel are also threaded, and shoot great. Which makes me wonder, who does the threading, and when? Ideally, it seems the threading should be done before the rifling work, but I don't know if that's possible.

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I've worked on a good number of the RW barrels and have seen a single one that seemed loose compared to the rest. It's possible it was even yours, as AoA gave it to me to try to salvage. I've also fitted a fair sampling of others. The threading is done after the choke process , so should never be an issue on choked barrels. The problem is on unchoked. A stressed tube will grow in internal diameter if the outside diameter is reduced. On a recent one, it appeared to grow by 0.0002 on the machined section. Still seems to shoot ok, but that's not really ideal. It SHOULD be ok if it is stress relieved, but I don't have good equipment for that OR choking a barrel, so my experience here is limited. From the appearance , it would seem most I've looked at were single point threaded which is much less stress inducing than die threading. The barrel making process is creating a tube, rifling it, choking it, then fitting it. It is probably possible to choke after the fitting but if threaded, will be difficult to control the choke and outer dimensions. I believe that LW does most , if not all, of the machining for the more prolific companies like DS and AA. As mentioned earlier, it's done to a price point. They walk a fine line between good enough and low expense. LW can and does make some of the best in the world but that means more expense. You can literally order barrels to YOUR OWN SPEC, that are unique to you.... it's just about money.

You could always order a tight dimension TJ and lap it to your preferred dimensions

Bob

Thanks Bob, great information. One question, if the threading is done after the choke process, could that not tend to partially increase the choke diameter, or lessen the choke?

Ed

Absolutely ... but if you consider that in the case I cited, it resulted in 0.0002" increase in bore from a 1mm reduction in outer diameter. That's not much, unless it is a nice, even straight bore, then it's enough to notice. If I experienced the same on a choked barrel, it would normally be a positive, not a negative. The majority are choked too much, even LW.

Keep in mind also, the ratio of growth is probably not a constant. It likely varies depending on the stresses of rifling and the individual barrel material .

Bob

Taking a 16mm LW blank down to .500" for threading has relaxed the choke in the few that I have done. However, threading didn't change a thing as far as I could tell, the damage was already done so to speak. I don't have tools to measure this, I simply go by feel by pushing a pellet through the bore. 

I started cutting the choke off, turning to diameter, adding the choke back in, and THEN threading and have had good results this way. 

I agree with Bob that most are choked too tight. And also agree that the barrel type and material. FWB springer barrels are HARD and don't seem to be affected as much as LW, and HW are softer and the most prone that I've dealt with. I actually had a stock .177 HW100 barrel that was threaded at the factory, and it was bellmouthed at the choke. The pellet would literally fall out the bore at that point. Hacked it off, turned down, choked and threaded and it's lights out. 

Just rambling out loud about things I've tinkered on. I have no credentials.

... turned down, choked and threaded and it's lights out.

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Whats your process to produce good chokes?