New Bam B4

[kellyj]

I just finished whacking Grackles with my new Diana 21 Panther and guess what? Now I have air gun fever... Sound familiar??

I went down to the local surplus store and found a variety of nice air rifles and air soft stuff. Well, I'm not into air soft so, the nice Chinese rifles there caught my attention. I walked out with a $50 Bam XS B4 .177.

The stock has a lot to be desired as do the sights. I put a 4X40 scope on her and started a few groups to get it sighted in. Today I had fun with a formal test using Crosman  competition wad cutter .177 pellets and then a test with Ruiko .177 pointed shot. I managed to mount the scope on the rail system provided but it's a strange rail that clamps down on the receiver. Works though.

I found the trigger pretty hard and it could use some tuning but I don't know how to do that. It's pretty accurate though and has a nice under barrel pull lever that works just fine. Obviously this gun is built to shoot and shoot some more.

The first group (13 shots) was with the Crosman wad cutters and the 2nd (six shots) was with the pointed lead. All at 15 yds. I'm over 50 so there's a little shake The pellets seemed to have good penetration going about 3/4" through the Yellow Pages back stop!

 Is this good shooting? I'm not sure since it's been 30 years since I've shot...Does Bam make other decent product?

I really like this little rifle and it seems built to last except for the sights

[fisherdude]

A B4 is a good rifle on which to hone your tuning skills.  The trigger can be improved by stoning the mating surfaces for the trigger and your groups should improve. The rest of the rifle can be improved by removing burrs, polishing the mating surfaces and honing the compression chamber, then putting it back together with the proper lubes. There is tuning information in the library on how to do all this - Its really not all that difficult.

[fnash]

I have had a B4 in .22 for many years. Being .22 I cannot tell you the best pellets for it. Except for the trigger which can be improved it shoots very well and fairly accurate. I have tuned it as mentioned in the last post. Mine shoots about 500 fps which is not bad for .22. What I did to the scope rail was put double sided tape under it to keep it from moving side to side, so far so good.   Frank
Oh, Yes, BAM makes alot of nice rifles...... better quality and higher priced....

[kellyj]

Fnash, fisherdude Thanks!
Seems to be the trigger that is the worse. I think  I will tune according Charlie's method.
What do you think of Ed's WD40 compressor wash and replace with Slick 50? Is there a special tool for honing the pressure chamber or could fine emory paper be used?

-kellyj

[cole5169]

The inexpensive guns like the B2's, B3's, and B4 are great candidates for home tuning.

Here's my favorite cheapie:



I smoothed the trigger and sear contact with nothing but fine sandpaper (I think I used 300, then 600 grit).  Disassembled with a homemade spring compressor, and cleaned up everything inside to get rid of old grease and gunk.  Deburred using a wooden dowel wrapped in sandpaper.  There are some very sharp edges in there, so be careful.

Scuffed up the leather piston seal and soaked it in 30W non-detergent motor oil overnight.  I reused the factory spring, and coated it with Maccari's heavy tar.  I did use a replacement breech seal from a QF-2 kit, because my original was split.

I also cut about 8 inches off of the barrel with a common hacksaw (had to shorten the cocking arm, too), recrowned the muzzle with a brass round-head screw chucked in a drill, and added the muzzlebrake (got it from Pyramyd Air, I think).  I replaced all the hardware with allen screws, just because the factory crews were pretty chewed up.

It is a very well behaved shooter now.  NOT a HW-77, by any means, but then, it is what it is.  This is 5 shots at 21 meters using a cheap Crosman 4x32 scope. (Gamo Match wadcutters, rested on a sandbag)

[geewhiz380]

I agree i like bam airrifles plus they are affordable for my pocket and my children learn very much using them ...jorge

[fnash]

I use a brake cylinder hone. Have to be careful the stones don't catch on a slot and break the tool. I don't know about the WD40 Slick50 treatment.
Frank

[kellyj]

Hi cole and all,

Same gun as I have. Nice work..

I noticed you removed the stock rail mount. How is your scope attached?

-kellyj

[cole5169]

Hi, Kelly,

I'm sorry, mine just had dovetails on the receiver, no scope rail.
I checked my notes, and I have my gun recorded as a B3-F (I don't know where I got the "F" from...).  Anyway, I saw yours was a B4, so I can only guess that one of the production differences was the rail?  Otherwise, they look pretty similar, don't they?

I like how it turned out, too.  It's shorter by a few inches and the firing behavior is miles ahead of what it was like from the factory.
It isn't perfect; the rear sight assembly was welded to the front of the receiver, and I have no way to remove it cleanly, so that is one thing I wish I could fix (you can see it in my picture, ahead of the loading port on top of the receiver).

If I remember (no guarantee...) the B4 had this sight?  This is from a TF-41 I'm currently working on.  I didn't know about the rail, though.  Is it welded on?  Maybe you can post a pic of it for me?



I have 3 more of the B3's sitting in my hall closet -- I bought them for spare parts, but never needed them
If you want one to practice on, let me know, you can have it.  I'm sure my wife would love to see one of them disappear.

Have a good one,
-Joel

[fnash]

I have a B3-F in .177.  I purchased from a Cummins truck sale has got to be 20 years ago. Had to rebuild it once as the catch on the piston wore out, and is one of my better shooting rifles for accuracy.
Frank

[rocker1]

i have been seeing those at the loca flea market, i haven't looked very close at them but looks like these on here. they had several different sorts  i never gave them much mind but after reading some of the post on here i am going to buy one now . the one i noticed was about 40 dollars and looks like these  posted. thanks david

[kellyj]

Nice posts all onthe B4.

I just did the tune simple WD40 Slick 50 tune found online.
Wow! What a difference in power.
Pointed pellets went through an 1.25" of the yellow pages. Prior to this they went through 3/4". Almost scary the increase in power.
I think the original Chinese crap they put in the chamber as "oil" had fully dieseled into gunk prior to this tune.

I will report on accuracy later.

-kellyj

[USNCop]

Keep in mind that it's new.  After you've shot several tins through it, give us another report.