GTA

All Springer/NP/PCP Air Gun Discussion General => Projectiles => Pellet Review Gate => Topic started by: Nobby.177. on October 03, 2011, 03:11:31 PM

Title: RWS: SUPERDOME question
Post by: Nobby.177. on October 03, 2011, 03:11:31 PM
Hi i was just wondering is anybody has the same problem as me, i just bough some RWS: SUPERDOMES and yea they shoot great but the skirt dosent fully load into the barrel the even after a hard push. Id say there was 1mm sticking out and when i close it up it squases it flat.

any ideas why ?? i though all .177 fit .177 rifles snugly

:Rifle = Sa2 swiss arms
Title: Re: RWS: SUPERDOME question
Post by: Lambchops on October 03, 2011, 03:44:20 PM
Some barrels have a tighter "choke" than others. Pellets are manufactured in different sizes like .172, .175, .177, .178 & even .180 all with the intent to be used in .177 cal air rifles.

I'm not home at the moment, but in the GTA Library, there is a link to a site where it shows the diameter of almost every pellet known to man :P
Title: Re: RWS: SUPERDOME question
Post by: Nobby.177. on October 03, 2011, 05:41:39 PM
Some barrels have a tighter "choke" than others. Pellets are manufactured in different sizes like .172, .175, .177, .178 & even .180 all with the intent to be used in .177 cal air rifles.

I'm not home at the moment, but in the GTA Library, there is a link to a site where it shows the diameter of almost every pellet known to man :P

holy peanuts batman do share :)

btw will it damage the rifle in anyway if i keep using them??
Title: Re: RWS: SUPERDOME question
Post by: northern lights on October 03, 2011, 05:54:40 PM
My rws 34 was like that. What I did was enlarge the hole. Get a drill bit slightly larger then the hole an slowing drill it. This will do two things give your pellets an better fit an keep them from being damaged. an might increase vel,s with better seal. Very easy to do just go slow an test fit the pellets.
Title: Re: RWS: SUPERDOME question
Post by: Lambchops on October 03, 2011, 06:50:10 PM
Some barrels have a tighter "choke" than others. Pellets are manufactured in different sizes like .172, .175, .177, .178 & even .180 all with the intent to be used in .177 cal air rifles.

I'm not home at the moment, but in the GTA Library, there is a link to a site where it shows the diameter of almost every pellet known to man :P

holy peanuts batman do share :)

btw will it damage the rifle in anyway if i keep using them??


No, there is no risk of this damaging your rifle. However, like you said, it does damage your pellets to a degree. It squishes the skirt and the skirt is essential for accuracy. I'll find the link and share it with you.

Title: Re: RWS: SUPERDOME question
Post by: EJB on October 03, 2011, 06:57:07 PM
I used a stone in a drill and just barley beveled the breach opening.  It sure made loading easy.  It did not bother the accuracy.  Almost always less than dime groups at 10 meters.
Title: Re: RWS: SUPERDOME question
Post by: Nobby.177. on October 04, 2011, 04:25:42 AM
I used a stone in a drill and just barley beveled the breach opening.  It sure made loading easy.  It did not bother the accuracy.  Almost always less than dime groups at 10 meters.
i get a good group of 10 at 10 meters but sometimes get a random flyer so maybe the tricks is just to drill a bit out the end.
Title: Re: RWS: SUPERDOME question
Post by: Nobby.177. on October 04, 2011, 04:27:53 AM
My rws 34 was like that. What I did was enlarge the hole. Get a drill bit slightly larger then the hole an slowing drill it. This will do two things give your pellets an better fit an keep them from being damaged. an might increase vel,s with better seal. Very easy to do just go slow an test fit the pellets.

ok drilling it sounds fine just when i change my pellets about will it matter much that some will be small and full right inside?? or will just taking the lip out make the fit tight but lower in the barrel.

sorry i have to ask these things :) thats how my brain works :)
Title: Re: RWS: SUPERDOME question
Post by: northern lights on October 04, 2011, 11:49:37 PM
Your other pellets will fit fine. you are not making the hole bigger all the way down the breech just the end. you only have to drill a 1/16 - 1/8 inch deep. Just go slow an test fit the pellets so they can be push in all the way so the skirt dosen,t get damage. I picked up 60 fps on the rws 34 got a better seal so got a vel,s increase.
Title: Re: RWS: SUPERDOME question
Post by: Lambchops on October 05, 2011, 01:13:44 AM
http://straightshooters.com/documents/pelletcomparison.html (http://straightshooters.com/documents/pelletcomparison.html)


Here ya go brother.. Sorry I took so long :P
Title: Re: RWS: SUPERDOME question
Post by: Nobby.177. on October 05, 2011, 05:53:44 AM
http://straightshooters.com/documents/pelletcomparison.html (http://straightshooters.com/documents/pelletcomparison.html)

thanks lambchops ill have a gander at it :)



Here ya go brother.. Sorry I took so long :P
Title: Re: RWS: SUPERDOME question
Post by: Nobby.177. on October 05, 2011, 05:56:08 AM
Your other pellets will fit fine. you are not making the hole bigger all the way down the breech just the end. you only have to drill a 1/16 - 1/8 inch deep. Just go slow an test fit the pellets so they can be push in all the way so the skirt dosen,t get damage. I picked up 60 fps on the rws 34 got a better seal so got a vel,s increase.

thanks for that i dint want to start anything and fnid out that other pellets would not fit right to make a perfect seal, not to find some tools i can rely on not to mess it up :)
Title: Re: RWS: SUPERDOME question
Post by: thekid on October 05, 2011, 10:33:15 PM
You do not even need a drill bit..
A brass screw and 400-600 grit sand paper wrapped around it and spin the drill slow changing the sand paper as needed.

Get some felt cleaning pellets or put a pellet in the bore first to keep the grit out of the barrel.

Sand some clean out grit then shoot out pellet, inspect the bore clean if needed then try putting in a pellet. continue till it sits flat... not much material will be removed.

Just remember you will have to keep cleaning the barrel as the grit could cause/will cause problems with the bore if left in and pellets are shot threw it.
Rob
Title: Re: RWS: SUPERDOME question
Post by: bradyman1 on October 05, 2011, 11:13:49 PM
I had the same problem with superdomes. I used a cone shaped grinding stone and turned it by hand. It didn't take long. I wouldn't trust a drill bit to leave a smooth transition. 
Title: Re: RWS: SUPERDOME question
Post by: Nobby.177. on October 06, 2011, 05:49:42 AM
ok thanks for the advice guys gonna try that today see what happens wish me luck :)
Title: Re: RWS: SUPERDOME question
Post by: MustangMike on October 06, 2011, 06:02:23 AM
Awesome idea, my titan is like that with every single rws pellet I have. I had thought about touching it a bit with my coned grinding dremel attachment but wasn't sure if that would be ok to do
Title: Re: RWS: SUPERDOME question
Post by: SAADE on October 06, 2011, 10:18:08 AM
Yes, what everyone suggested; and the brass, round-head screw works very well, just plug the breech about .25" down from the opening to keep the gunk out of the barrel. You can even use a valve grinding compound available from most (real) auto parts stores. I have done this many times with great results. You only need a .060" chamfer or relief to make a big difference in starting the pellet into the breech. As a side benefit, you will have polished the transition of the lands & grooves to the breech mouth, which also helps lessen any scarring of the pellet. (kinda like a crown job on a muzzle)

None of this will change the actual breech diameter where 95+% of the pellet will seat so, you will not limit the use of various diameter pellets, it just makes it easier to insert any brand or type.
Title: Re: RWS: SUPERDOME question
Post by: milkman on October 06, 2011, 10:27:28 AM
Yes, what everyone suggested; and the brass, round-head screw works very well, just plug the breech about .25" down from the opening to keep the gunk out of the barrel. You can even use a valve grinding compound available from most (real) auto parts stores. I have done this many times with great results. You only need a .060" chamfer or relief to make a big difference in starting the pellet into the breech. As a side benefit, you will have polished the transition of the lands & grooves to the breech mouth, which also helps lessen any scarring of the pellet. (kinda like a crown job on a muzzle)

None of this will change the actual breech diameter where 95+% of the pellet will seat so, you will not limit the use of various diameter pellets, it just makes it easier to insert any brand or type.


Thanks for posting this, the only glitch I have with my Beeman 1073 since I used LocTite on the screws is the rough edges around the breech that makes it hard to insert a pellet now and then. Didn't want to ask a dumb question and I hadn't seen it mentioned before, so I just thought it was normal.
Title: Re: RWS: SUPERDOME question
Post by: SAADE on October 06, 2011, 12:57:36 PM
No dumb questions here, I knew absolutely nothing about these crazy airguns 30 years ago, I now know a little more from many "dumb" questions.
Title: Re: RWS: SUPERDOME question
Post by: Nobby.177. on October 06, 2011, 04:19:27 PM
its fantastic that this question can help so many people with the same problem well done guys :)
Title: Re: RWS: SUPERDOME question
Post by: robert w on October 13, 2011, 09:48:23 PM
found a perfect way to taper the barrel opening get the screw off end from a plumb bob put it in a dremel use fine valve grinding compound put a felt cleaning pellet in the bore use light pressure at a moderate speed when getting close to desired clearence clean and use flix then clean swab your barrel out and it does a real nice job ;D
Title: Re: RWS: SUPERDOME question
Post by: TCups on October 14, 2011, 07:34:52 PM
Hmmmm . . .  Well, Superdomes have never performed that well in my springers.  And essentially "crowning" the breech still ends up with a pellet skirt that probably has a suboptimal fit for the rest of the barrel.  Superdomes, I think, are designed to shoot well in CO2 air rifles -- here's why.  Look up the skirt (of the pellet).  Inside the Superdome skirt, you will see a sharp, round hole much less in inside diameter than the inside of the actual skirt. The purpose it so that the "probe" end of the bolt of a CO2 air rifle will center inside the skirt of the pellet and drive it straight into the bore with no cant.  You will find that Superdomes are very accurate in guns like the Crosman 22XX and Hammerli 850 -- any breech loading air rifle with a bolt action.

If you read "The Airgun from Trigger to Target" (now back in print, I think) they describe air rifles of the "blow gun" and "pop gun" type.  Those of us of a certain age remember the pop guns that had a cork on a string.  You squeezed a rubber handle and the cork pops out.  Springers are pop guns.  Optimally, the pellet fits like a cork and only starts moving down the barrel when the piston driven power plant produces enough pressure to pop the pellet loose and send it down the barrel.  The spring-piston power plant also produces, instantaneously, a lot of heat.  The net result is that pellets that have a thinner, open skirt on the underside (unlike the Superdomes) soften and expand against the rifling to an exact fit.  The most accurate results are if you get a very consistent point where the "pop" occurs so that every shot has the same initial velocity at the same pressure.

Blow guns are like our old BB guns.  The BB will literally roll out the barrel in some cases.  And th accuracy depends on supplying the same volume of air at the same pressure. CO2 air rifles, and PCP air rifles are a bit different, but they are more of a blow gun than a pop gun. They don't develop the same, high instantaneous heat and pressure behind the pellet as a springer -- they only develop the PSI that the reservoir is charged to.  And they often perform best with pellets like the Superdome (especially the CO2 guns).

Anyway, if you modify the breech of your springer, it may indeed make the Superdomes easier to load, but it will change the POI of both the Superdomes and any other pellet you load in the breech.  I would suggest, unless there is a burr or some visible roughness  you NOT do it.  Find a pellet that fits your air rifle better.  

For springers, IMO, the JSB Exacts tend to shoot the best. Some might not have that experience, however, and there are probably a couple of simple reasons.  First, the pellet perhaps is not loaded exactly the same way and same depth each time (Solution -- pellet seating tool instead of your finger). Second, the skirts of the JSB pellets, which are thinner and softer lead than, say, Superdomes or Crosman Premiers (look under her skirt, too) get dinged or bent (Solution -- check the skirt and use a pellet seating tool to reshape and flare the skirt before you seat the pellet).
Title: Re: RWS: SUPERDOME question
Post by: robert w on October 16, 2011, 08:11:07 PM
how ever i seen an article in shotgun news that they strongly recomended and cheep also get a bic ink pin 1 of those hex sided clear ones and use it to push the pellet into the chamber it works i tried it and accuracy came up a tad and seemed to help seal to the barrel i got some crosman hps that some are loose fit and some are tight the pin works just fine dont mess up the roundness of the pellet all i can say so far it works for me tried it today in both of my springers hw55 and quest 1000x
Title: Re: RWS: SUPERDOME question
Post by: DMikeM on November 26, 2011, 01:50:39 PM
I have performed this mod on one of my B28's just for the RWS SD pellets. Once the pellet seated flush I gained velocity and accuracy. The pinched skirts were creating flyers and bad grouping. Pushing the pellet in with a tool (pen) made it lose velocity with no accuracy improvement at all. I checked against other pellets after-wards and they shot fine and even better than before. Just don't go deep when you open it up just use a greater angle to just fit the pellet you like the most.