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All Springer/NP/PCP Air Gun Discussion General => Air Gun Gate => Topic started by: UlteriorModem on September 26, 2018, 08:50:34 PM

Title: Chamfer the breech?
Post by: UlteriorModem on September 26, 2018, 08:50:34 PM
I was reading another thread about a break barrel gun where the guy was having problems with getting pellets to seat consistently.

I cant find the thread now but in that thread it was mentioned a couple of times to try to 'chamfer' or taper the breech end.

I have a Benjamin NP2 that has a similar problem in that the pellets sometimes to not seat all the way in or seat 'crooked' with a little of the skirt hanging out on one side. Some pellets are better than others but it happens pretty consistently.

Maybe a little chamfer might help. But I am clueless on how to go about doing it and not putzing things up. I looked around and did not find any 'how to' for such a thing.

Maybe I don't know what terms to look for or whatever.

Any advice tips or directions on how to go about this?

Thanks!
Title: Re: Chamfer the breech?
Post by: mobilehomer on September 26, 2018, 09:49:28 PM
Use a conical Dremel stone. I chuck mine up in a cordless drill in low speed/high torque gear and chamfer just enough to let the pellet seat flush. No need to go deeper. Clean the barrel before firing.
Title: Re: Chamfer the breech?
Post by: UlteriorModem on September 26, 2018, 10:02:41 PM
Cool, that is exactly what I was going to try but thought I would ask first.

Will this work?

(https://farm2.staticflickr.com/1956/44218842034_2a78ff6a4c_c.jpg) (https://flic.kr/p/2ant8bb)20180926_205822 (https://flic.kr/p/2ant8bb) by Tom Whit (https://www.flickr.com/photos/152306872@N04/), on Flickr
Title: Re: Chamfer the breech?
Post by: Back_Roads on September 26, 2018, 10:28:33 PM
 This is an old skool option I use when I am in the need to shoot a tighter fitting pellet. The guy in the video knows his A G stuff, many miss his in depth videos, only a few come close to the truth in testing.
https://youtu.be/cy2pOTaqr_U?t=16
 
Title: Re: Chamfer the breech?
Post by: Roadworthy on September 26, 2018, 10:30:54 PM
I took the more conservative approach.  I used a Dremel stone as well but only turned it by hand.  I didn't have to remove much material.  It was only necessary to remove the squared edge from the breech - putting a slight taper to the lip.
Title: Re: Chamfer the breech?
Post by: Motorhead on September 27, 2018, 12:38:23 AM
That stone will work ... but suggest "DRESSING" the angle of the stones tip that will do the work to closely match the skirt angle of pellet.
In this way the pellet will always flush up to the same depth when loaded and stay put better before it launches increasing consistency.
Title: Re: Chamfer the breech?
Post by: TF89 on September 27, 2018, 03:03:48 AM
I use a counter sink found in most quick change combo  drill bit and screw kits found at most hardware stores.   I also do it by hand, it does not take much pressure, just a light touch as you do it by hand.  Real easy to take off too much.  Remember you can always take off more, however you can't put it back once it's gone.
Title: Post self deleted due to incorrect information. nt
Post by: Jeff Marshall on September 27, 2018, 04:32:15 AM
nt
Title: Re: Here...
Post by: UlteriorModem on September 27, 2018, 10:31:31 AM
https://www.gatewaytoairguns.org/GTA/index.php?topic=148377.0;topicseen (https://www.gatewaytoairguns.org/GTA/index.php?topic=148377.0;topicseen)

I don't get it, I read most of that thread and did not see any mention of chamfering the breech? Maybe I overlooked it.
Title: Oops, I linked the wrong thread; Sorry about that! Try this one.
Post by: Jeff Marshall on September 27, 2018, 11:21:46 AM

https://www.gatewaytoairguns.org/GTA/index.php?topic=148593.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=148593.0)
Title: Re: Chamfer the breech?
Post by: bandg on September 27, 2018, 12:30:06 PM
Look for Cratex points.  They are quite capable of removing metal in coarse grit but are much less aggressive than a stone and less likely to overdo the work.  They are available in many shapes including a pointed type that can be easily contoured.
Title: Re: Chamfer the breech?
Post by: JnJHess on September 27, 2018, 05:07:33 PM
I had to do that on my Crosman Fire NP. When I tried to get some longer pellets, like the Crosman Piranias in .177 cal into the breech it was very very hard to get always in there, I think the skirts are a little better bigger in size.
So I got myself the same Dremel #952 and used after very carefully trying to centereng it moved it in a few circulations about 4 or 5 with very little pressure and voiala that all it took.
Now I have had no problem with any other pellet to get I to breech fully seatted and flush.
For preparation I would like get some cut of ends of q-tips put down the barrel just shy of touching the stone, to prevent shavings falling into the barrel, and push them out with a wood dowel towards the breech after you done it would help holding gun upside down that the shavings will not fall anywhere into the insides of the gun.
Worked like a charm.
You are right I have seen a post here on GTA myself that brought my too it to do it.
If I remember right it was Roadworthy who wrote a post about it.
I'm not hundred percent Shure if it was from him, but I think he was coming up somehow in this post, forgive me if I didn't go e credit to the rightful member if I was wrong.
Title: Re: Chamfer the breech?
Post by: UlteriorModem on September 27, 2018, 08:14:09 PM
Thanks for the input everyone. I pretty much did what some of you suggested and ran the Dremel stone by hand. It sure did not take much. I would be afraid to put a drill or Dremel to it. Wish I had heard the Qtip trick before I did it but I ran a few patches down the barrel and it seems fine.

I was surprised at how fast it went.

I also got one of those air venturi adjustable pellet seating tools and set it to where it seats the pellet flush.

Have yet to to any test other and seeing how pellets load and discharging them into the stop from about 2 feet away :D

It's raining out...  :(

Oh well I will get to the testing soon enough.

Thanks again everyone it was easier than I thought.