New Benjamin trail np2 dieseling?

[Tn_airgunner]

I just got my new benjamin trail np2 and started shooting it. I have less than 50 shots through it but it still smokes when I shoot it each shot. Is this normal for a new np gun? And will it go away after shooting a couple hundred shots? I've never had one before I've always used pcp's but got this on cyber Monday.

 

[outdoorman]

Likely just oil in the barrel to prevent rusting by the manufacturer. Just run some cleaning pellets or patches through.

 

[Goodtogo]

Air gun dieseling comes from the compression chamber. They load those down with oil since they want to make sure no rust if it sits for a long time on the shelf. So a combination of oil and high compression does it. There are oils sold that wont do this and most of them say chamber oil on the product. Its worth breaking down a new air gun just to see the mess of "grease" left inside many of them.

 

[outdoorman]

https://www.airgunsofarizona.com/blog/2014/06/the-tale-of-a-smoking-gun-a-springer-story.html

 

[outdoorman]

Well, I just finished reading/studying THE definitive book on spring piston air guns, "The Airgun From Trigger To Target". VERY enlightening, to say the least. Minor dieseling, more appropriately called combustion, is totally normal and desired in a piston type airgun. It provides for about half the power of the gun. As long as the gun is not detonating (excessive dieseling), not to worry. If detonating, it will be very loud and may produce spark or flame from the muzzle and pellet velocity will be excessive. BTW, their testing showed that compression ignition takes place primarily in the transfer port, not the compression chamber. It also showed the burning of lubricant continuing along at least the first few inches of the barrel so thoroughly cleaning that new barrel of lubricant would be a good idea. There was lots in the barrel of my new Crosman nitro venom that I cleaned out before first firing.

 

[wahoowad]

Both of my Crosman NP guns dieseled badly - far more and longer than they should have. One burned a piston seal, the other was sent back. They are cheap guns, don't expect much out of them.

 

[crosman2016]

My Ruger Impact did that too, at first. I don't notice it now.

 

[Bobbed06]

Its a nice rifle, wouldnt hurt to clean the barrel. Enjoy the new rifle.

 

[addertooth]

Tn_Airgunner, my trail NP2 had it's bore cleaned before the first shot, even so, it would periodically diesel until I had almost 200 shots through it. Your situation is quite normal.

 

[Smaug]

"Tn_airgunner"I just got my new benjamin trail np2 and started shooting it. I have less than 50 shots through it but it still smokes when I shoot it each shot. Is this normal for a new np gun? And will it go away after shooting a couple hundred shots? I've never had one before I've always used pcp's but got this on cyber Monday.

Yes, it's normal.

I cleaned the barrel on my Summit NP2 (same as your gun, except the stock) before firing it. The first shot detonated anyway, and the 14 gr. pellet went supersonic with a loud CRACK and a spark flew out the barrel.

I looked at it again, and cleaned off the excess oil around the breech O-ring, pivot, and transfer port. I shot 60 rounds last night and there was still smoke coming out of the barrel after every shot. We can see that Crosman REALLY likes oil in their new guns, presumably so the parts don't rust in storage or on boat over from China. I bet there's oil in the compression chamber that is being compressed and burned.

I had this problem with my Stoeger X20 too. If I shot the lighter pellets, it smoked 100% of the time. Heavier pellets, not so much. 

It still shoots pretty accurately though, so I'm not going to worry about it. Our buddy Tom Gaylord says some ongoing dieseling is normal. I'm wondering now if that's how Crosman arrives at their velocity figures they print on the box.