BAM B26 sporter first impressions

[preez]

Thank you Bob for clarifyng that. As always, You da man!!

Chris

[CharlieDaTuna]

As long as I get a spread of anything inside of 20, I consider it pretty good but of course inside of ten is great.

You didn't mention how many coils are in the new spring or the wire diameter.

In the stock spring, counting the end coils, there are/should be 41 coils of .118 (3mm) wire. This will give you a stacked coil height of approximately 4.83"

 In your new spring, multiply the number of coils by the wire diameter.
Example:
  Coils .........38 x
 Wire dia.    .121
 -- ------------------------
 >>>>> =4.598

Now subtract your new spring stacked height. from your factory spring stacked height.
.......... 4.838
.......  - 4.598
------------------------
>>>> =.240 difference
                                         
You now know that you can now add a .240 (or 1/4 inch)  spacer to the spring, preferably out of Delrin or a hard Nylon.   This should provide you with a bit more power but still be close to the factory specs and yet be pretty smooth. You would/should be able to push the spring close to 3/8 inches but you will be close to coil bind I believe. I always figure in about .125 for future wear and tear and not have to worry about it not cocking. If you add a steel spring spacer there is a good chance that the weight will cause it to shoot a bit harder and harsher.

Now don't be goin' round tellin' everbody    :0   :p

[CharlieDaTuna]

Ooops... fer got to answer yer question.... duh...

When prepping the cylinder, it should be polished smooth for leather, first 200 then 400 then 600. I usually use  220 to 300 grit for cross hatching for synthetic seals depending on the material of the seal. I always use a three point hone (broke my four point and can't find another one like it)  although some guys use paper or emery with a dowel. It will work but it's no where near as efficient and as even as using a hone. Do not use a 2 point hone.

[DanoInTx]

Thanks Bob, I figured I could space her up a bit.  I've consulted my preacher, my astrologer, my family doctor, and finally Dave Dunn and decided that I am going to leave well enough alone, she is shooting real nice and I don't feel like getting more spring tar on my wifes kitchen counters:)  I think all that is left is for me to learn how to shoot it correctly and we'll be in business....and like I said before, if I am feeling real low about my shooting skills I'll just pull out my PCP to cheer myself up:)

BTW: I believe I used the standard B26 tune kit JM sells:
http://www.airguns.citymax.com/catalog/item/251488/4038389.htm
Not sure what spring that came with and I didn't hook the calipers on it to find out.  If at some point I do decide to take her back apart to space it up I'll let y'all know what I find out.  It's set length was a fair bit shorter than stock though, like somewhere between 1"- 1 1/2" IIRC.  Dangit, now you've got me thinking, and thinking is dangerous....I'd better leave well enough alone...hehe!!!!

Thanks again,

[Jaymo]

Why not use a 2 point hone?

[CharlieDaTuna]

Using a 2 point hone does not stay centered and hone evenly as well as a three point hone. A three point hone will always be centered with even pressure as long as it is straight in the tube.

[Jaymo]

Sound good to me. I need to get some new stones for my 3 point hone anyway. This'll keep me from being tempted to buy a 2 point.