Q:

Machined .25 blank LW barrel

Just recieved a machined lothar walther 25 Cal barrel (Machined from blank) for my shadow and fitted it but can’t obtain any reasonable grouping. 3″ at 27M! My 22 does sub .5″ groups. Any suggestions deeply appreachiated.

Mods/Machinists

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Curious how this one turns out!

Jim.

quote spinj:

quote j3magnum:

this may sound stupid on an airgun but,,barrel harmonics have alot to do with accuracy…my 24″ barreled tss won’t shoot in the 7-800 fps range ( groups look like yours)..but kick it into the 900 fps range and dime sized groups at 30 yds.. ANother factor could be how the tophat is set and your shot to shot consistancy…Do you have a chrony to check it…

Try removing the endcap on your TSS and try shooting again. I’ve noticed that the endcap can sometimes create some sort of turbulence in the empty chamber, thus affecting the pellet’s flight at lower velocities before it completely leaves the muzzle.

Oops! I’ve misread! You have the 24″ barrel installed, so no endcap is used 😆

barrel blanks are not crowned….what looks like a crown is where the tooling has been holding the barrel while it got worked by LW

they definaly need to be recrowned !

quote j3magnum:

this may sound stupid on an airgun but,,barrel harmonics have alot to do with accuracy…my 24″ barreled tss won’t shoot in the 7-800 fps range ( groups look like yours)..but kick it into the 900 fps range and dime sized groups at 30 yds.. ANother factor could be how the tophat is set and your shot to shot consistancy…Do you have a chrony to check it…

Try removing the endcap on your TSS and try shooting again. I’ve noticed that the endcap can sometimes create some sort of turbulence in the empty chamber, thus affecting the pellet’s flight at lower velocities before it completely leaves the muzzle.

this may sound stupid on an airgun but,,barrel harmonics have alot to do with accuracy…my 24″ barreled tss won’t shoot in the 7-800 fps range ( groups look like yours)..but kick it into the 900 fps range and dime sized groups at 30 yds.. ANother factor could be how the tophat is set and your shot to shot consistancy…Do you have a chrony to check it…

Yes the machinist has done many barrels and work on Airforce guns. He’s been a bit busy and I plan on contacting him to see if he can get me some pics of the pellets and the crown. I think on the pics side I’ll try my macro lens and see how a shot (pisture type) looks down the barrel of the 22 with a white backdrop.

I am wondering:

Is this machinist familiar with barrel work?
Have you had him do any other barrel work that ‘worked’?
What does he think is the trouble?
What do pellets pushed through the barrel look like?

Walter….

Have sent barrel back to machinist and he is trying several things and more shooting from a vise. Here are a couple of grp pics one with .25 and one with .22 I (obviously) prefer the .22 groups. LW have not replied to my e mails. I believe there barrels are normally extremely accurate. The .22 barrel is a LW as well.
.25 Cal Group (SAD)

Here’s a .22 Group (Much happier)

Hi, i would forget contacting LW, can’t see them throwing any light on the subject, two things i would do, recrown the muzzle propperly, and secondly scrub the bore with bore paste, i have encountered dirty bore’s in the past, and that will spit the pellets allover the place. If your running @ 12ft lbs, then Kodiak/Baracuda are not goin to be much use @ 31 gn. and that does not leave a great deal of choice in the pellet range as i have tried the other brands which i find inaccurate.Good luck and let us know when you have sorted it. Regards B51

It may be an obvious question, but how did the rifle shoot before you put the .25 barrel in it?

that barrel needs to be crowned… they come with a so-so crown job on them..

yes a pic would be great. A pic of a couple pellets pushed through would help as well.
Walter….

Can you take a pict of that muzzle end and post it here so we can have a look at it?

How about trying different pellets?

Thanks for all the advice/suggestions.

So far we have tried groups with and without mod. No effect
pressure from 200 bar down to 170 bar. no effect
We even had barrel in vice and checked results (padded) and still no effect.
We pushed a pellet down barrel from breech and incountered resistance all the way and could feel more at the muzzel so choke seems ok.
I have E mailed back to Lothar Walther for advice. Hope we are not being overly ignorant but are not the blank barrels already crowned? Thinking trying to recrown barrel. Do have pictures of groups with .22 vs .25 at same range.

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