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weekly · Member

The 90 durometer o-rings didn’t blow out. I could only find 2 of them in stock at local stores. So since I gouged them I have been using the softer o-rings.

The softer o-rings extrude down the valve body and eventually little hunks rip off and there is no longer pressure to push against. Nothing spectacular I hope I didn’t give the wrong impression saying blow out.

It is going to be interesting to really try the 90 durometer o-rings. I think my next limit is going to be hammer strength then the strength of the small part of the pump arm.

I could keep going trying to get more power but in reality I don’t like pumping. So I will probably still only pump it 5 times most of the time.

This gun is very cool but at 60-120 strokes I can’t see myself using it very often. Although if I were a hunter I would probably have a different view.

.303 Custom MSP

AirGunEric · Site Admin

That's you with the 60 to 125 stroke pump?

I too would likely stick to about 5 pumps. 125 would be a bit much! Razz

weekly · Member

No that’s not me I just happen to see it tonight.

BRUCE · New Member

HEY WEEKLY ,Where is the green forum? Also you were talkin about a flat top piston and valve. Is the pump piston what you're talkin about ,and is the valve you're talkin about the one in the valve body itself? also I looked all over the place for springs and couldn't find anyone that had a good selection (napa, fastenall, true value, machine shop) where do you find the right ones???????????

BRUCE · New Member

Well I found a couple springs, the one for the valve was to light so I put the original back in and cut 3 wraps off it. Put the new hammer spring in it was to stiff so I cut 2 wraps off it Then I ground down the sear/trigger roughly 2# pull, nice and crisp with no creep!!! my dog enjoyed the 2 squirrels I got this morning out back. Oh yeah don't buy a b-square scope mount, there junk crosman sells another one that mounts directly to the barrel. Got that one on order. I'll have to get my bro's crony and let you guys know what the #'s are. Also I opened up the exhaust hole, I think that was a major improvement. Anyway I'll let you guys know how much improvement I gained over stock

AirGunEric · Site Admin

Good job there, Bruce- I'm glad you got up enough nerve to get something done and it worked out. Too often, people get nervous and worry about breaking their gun and end up sending it somewhere or doing nothing.

Where did you ultimately find the springs that you used? Also- which/what is the Crosman barrel mount- do you have a link? I was unaware Crosman had barrel-mount rings- was it specifically for the B-S 392- or was it a more 'universal' type unit?

BRUCE · New Member

http://www.airgundepot.com/b272-mounts.html there's the link to the scope mounts. I got the springs at ace hardware in canon city. I couldn't use the one I bought for the valve, to light, you have to find a happy medium between the valve spring and hammer spring, it has to be light enough not to activate the valve. A guy could probably make a decent living just selling a complete variety of springs. This isn't the first time I've run into this problem......

AirGunEric · Site Admin

Ah- OK, one of their intermounts- but you still need scope rings to go with it.

Any idea of the maximum size barrel to which those will attach (diameter)?

BRUCE · New Member

Have know idea, but, I would imagine that they would fit most pellet barrels. If you look at the reviews someone applied it to another rifle. When I get them I'll give you the id tight and loose. talk to ya next week..........

23ib0d0n · Moderator

Benji / Crosman intermounts seem to work best on barrels about .435" diameter or real close to that. They didn't fit a .41" Falcon barrel well at all.
Work real well on the 2260 barrel though.

weekly · Member

Yes I was talking about the pump piston and valve body. I just made a new piston. This one has tighter tolerances and is very smooth.

I am not familiar with the pump piston on the 392 so this may not be as beneficial to the 392 as the 2289.

I have gotten springs at a place called brofasco. They have a fairly good selection.