R5M .25 standard-- Pellet spiraling problem

[J_J_Hussey]

Checked speed with Chrono, it's consistent, change velocity by 5 is a good idea, I will do it and see any change.i shot several magazines, it looks happened every shot

 

[airgun14]

Im new here, read this forum for a while now, then decided to join



I know how frustrating it can be, could you please show a good picture of the crown, where we can see the end of the barrel.



Look at this link, the first picture , there you see the crown, 

https://www.alloutdoor.com/2017/04/11/watch-crowning-chamfering-gun-barrel/



Also try with a cotton swab to see if there is any burrs, sometimes you cant see them, try the cotton swab trick 

 

[Emu]

Insert an small amount of trydent silicone grease in the back of the barrel and shot three pellets. 

Confirm if it improves. 

 

[airgun14]

Insert an small amount of trydent silicone grease in the back of the barrel and shot three pellets. 

Confirm if it improves.

What does that do?

 

[Mikepr]

Take of the barrel and the rear block and push a pellet with a rod, check at the choke area how hard exit and check the skirt of the pellet 

Mine was too tight

Also i opened the halls of the magazines for free exit

At least i solve the problem with a new LW polygon barrel

 

[Emu]

Insert an small amount of trydent silicone grease in the back of the barrel and shot three pellets. 

Confirm if it improves.

What does that do?

Technically I do not know. 

Practically, it improves accuracy in all my rifles... And I mean all (Daystate, FX, Vulcan, Uragan, Air Arms, Jager, Evanix, Brocock, JKHan, all)!! 

 

[mercado]

I don't know if is me but when I opened the picture posted that crown looks rare like with dings right at the end..I can't even se a angle cut at the iner border. 

 

[mtnGhost]

You need to remove your barrel and inspect it. I'm betting that you have a real nasty burr somewhere on your rifling. Possibly a very bad crown chamfer, but that looks to me like the pellet is getting destroyed somewhere in the bore. If you're real lucky, you can polish it out or fix the crown. How are you cleaning the barrel and are you the original owner?

 

[J_J_Hussey]

1,Inspect crown and barrel, no burrs with cotton swab, see pic 

2,Magzine exit is fine and smooth, 

3, pushed a pellet out of barrel by hand, the pellet looks fine, but have no idea if it's too tight or not

4, I am sure the gun is new from ED to me, so nobody ever modified it.

5, rechecked the cap of shroud, obviously it's clipped by pellets before, see pic

But I changed the position of cap for several times to invoid clipping, not sure it's the problem, I have to go to field and remove the should for testing.

 

[airgun14]

yes, shot without any cap or shroud

 

[mtnGhost]

That deformation in the exit bore of the cap is likely interfering. I almost had similar problems with my R5 Matador .30 cal, but anytime I reinstall the barrel / baffle / shrouds, I do a careful inspection since it's easy to misalign so I never clipped.

 

[Joer]

I found a few old articles on pellet destabilization online that maybe of some use:

https://www.pyramydair.com/blog/2009/07/do-pellets-spiral/

https://www.airgunnation.com/topic/why-does-a-pellet-destabilize-as-it-loses-velocity/

I'm wondering if your seeing a spiral do to damaged pellet skirts. If you watch Ed load pellets into magazines on an R5M, he always taps them on the bench to seat the pellets. My guess is that this prevents skirt damage. Just a thought.

 

[J_J_Hussey]

Tested without shroud in the field, shot 2 magazines, no spiraling, no shift. confirmed it caused by the clipping, ordered BAT silencer, i think this is the final solution... it's very hard to install the stack to the exact position that doesn't clip...i know it can be done, but it's difficult to me. 

 

[Mikepr]

With a 9mm drill by hand open the hall of the silencer, works at mine

 

[J_J_Hussey]

With a 9mm drill by hand open the hall of the silencer, works at mine

Good idea! i will try it, and the bat is on the way now.

 

[Mikepr]

With a 9mm drill by hand open the hall of the silencer, works at mine

Good idea! i will try it, and the bat is on the way now.

Thats the problems of "plastic" parts

 

[DanielL]

Place a .25 diameter fiberglass rod in the barrel with a couple wraps of tape around it where it goes through the shroud. Those fiberglass poles they sell at hardware stores like Home Depot, for marking your driveway for snowplows work and are inexpensive. Have the rod in when you tighten the shroud down and it will align better.

 

[mtnGhost]

How many different tins of ammo have you tried? If you're seeing this from different tins sourced from different vendors, you might also want to start sorting by head size. If this is all from the same batch of pellets, you should test a different tin.

 

[J_J_Hussey]

To Daniell, Good idea, i will do it as a spare solution;

To mtnGhost, i opened a new tin for the test, sorted and weighted, i totally tired for the testing work, will change to BAT and enjoy the shooting ^_^