DYI Mrod Barrel tune-up

[Teryx]

Doc,
I use an Oring pick for an Oring pick Seriously there are tools called Oring picks that are used just for this. Mine has a double bend. Here is one set that should work fine. Mine are really old. http://www.google.com/products/catalog? ... ps-sellers

When you get them check out the tips to make sure they are very smooth. 600 or 1000 grit sandpaper works well to smooth them if need be. I've found that getting the Orings in is a bugger unless you have something in the chamber to push back up with. I use a 3/16 wood dowel sanded smooth and inserted from the muzzle. I push the oring in so that one end of it goes into the groove. The rest of it will fold over and head down the bore. You can use the dowel to push it back up and it will usually pop in at that point with a little help. Grease it before you insert it, and make sure the groove is clean.

teryx

[oletom]

Teryx sorry to say I did try the inlead improvement with #600 sandpaper...hope I didn't go to far, I may end up with a new barrel...live and learn I guess...I used a dentist pick to remove the o-ring....worked pretty good

[sacshooter]

Teryx sorry to say I did try the inlead improvement with #600 sandpaper...hope I didn't go to far, I may end up with a new barrel...live and learn I guess...I used a dentist pick to remove the o-ring....worked pretty good

even if you did mess it up, easy fix order a new barrel from crosman $23.00 I think

roger

[ssscottg]

Try pushing a pellet down the bore with a thin wood dowel. If the pellet gives you resistance all the way through, you can probably make a shooter from that barrel. If the pellet is practically in a free fall by the 2/3 point, you will never make a tack driver from that barrel. I think most likely the good barrels are the ones cut on new tooling, and once the tooling begins to wear, the bore size increases. I've talked to Crosman about getting a barrel cut on fresh tooling but they say don't track that. The barrels get mixed up after drilling while waiting for further processing. It's luck of the draw.

Teryx,
I agree that a tight pellet fit will result in superior accuracy and a loose fit barrel will never be a tac driver. From what I have observed from pellet testing on various guns, the most accurate pellets have a snug fit in the breech, the worst accuracy comes from pellets with a loose fit. Regarding my Mrod barrel, the next step for me is to buy a Lothar Walter barrel if the Mac 1 tune doesn't produce the accuracy that I want. But we will see... soon.

Regards,
Scott

[ahs2185]

Teryx

I read on another post somewhere that you used a brass lap to polish/smooth the inlead transition in the barrel.
What shape should the lap be turned to Round nose, or angled ? Is there a specific degree that the inlead is supposed to
to be cut to? The reason I ask is I have a spare mrod barrel .177 and I would like to try the lap method. I believe that a brass lap would
yield the best results over the sand paper-earplug method because of control. Do you have any suggestions for machining a
lap, materials, ETC.