Just received my Vulcan .25 cal from Topgun Air Guns. Lots of power for sure. Accuracy seems excellent so for although I have not gotten a chance to check it out long range yet. Happy so far!
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Vulcan .25
- Thread starter allen652
- Start date
I own the .25 this thing is beast i think you'll be impressed it can be very accurate at long range especially for a BP. Let us know how it does.
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The Vulcan really is a remarkable air rifle. I have shot it side by side with my 22 Daystate AirWolf and the Vulcan 25 beats it in accuracy every time.
I have added the TGAG moderator and a spring guide which quiets the gun down nicely.
Enjoy!
I have added the TGAG moderator and a spring guide which quiets the gun down nicely.
Enjoy!
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Allen, welcome to the Vulcan .25 family! I would be interested to know if you have experienced this phenom yet.
First shot on a new fill. My first shot has been weak. At 30 yards it's dropping approx 1" from POA. Second shot is better only down maybe .5" and the third shot is right back into the B.E. region.
Now I have found a very simple solution and I have a theory as to why it works, but I am still testing my theory and have had predictable results so far.
Here is how my typical shoot goes.
I finish my day with the gun around 150 to 180Bar. Before retiring the gun for the evening I go out to my garage and put a new fill on the gun. I don't shoot it again or load a round till the next morning. Low and behold the phenom begins as described above.
My fix: I am experimenting as to when this exercise needs or can be performed either right after filling or just before shooting but here is what I have found to fix the problem. READY?
I simply cock the gun without a round in the chamber and then de-cock the gun. Sometimes I do it twice just for grins. But it works. My first shot has been on the money ever since I started doing this. Now I am experimenting as to whether I need to do this just before the first shot of the day or if I can do it right after I fill the gun the night before and it will still be good in the morning.....More later.
I think I know what is going on, but would be interested in others and their own experiences or theories? (don't mean to hijack Allen's thread, but being a new Vulcan owner thought he might like this subject?)
EDITED 10.18.15: I bragged too quickly that this cock/decock works everytime. Maybe a bit to quick to conclude this fixes the first shot issue. Still working on it, more later.
First shot on a new fill. My first shot has been weak. At 30 yards it's dropping approx 1" from POA. Second shot is better only down maybe .5" and the third shot is right back into the B.E. region.
Now I have found a very simple solution and I have a theory as to why it works, but I am still testing my theory and have had predictable results so far.
Here is how my typical shoot goes.
I finish my day with the gun around 150 to 180Bar. Before retiring the gun for the evening I go out to my garage and put a new fill on the gun. I don't shoot it again or load a round till the next morning. Low and behold the phenom begins as described above.
My fix: I am experimenting as to when this exercise needs or can be performed either right after filling or just before shooting but here is what I have found to fix the problem. READY?
I simply cock the gun without a round in the chamber and then de-cock the gun. Sometimes I do it twice just for grins. But it works. My first shot has been on the money ever since I started doing this. Now I am experimenting as to whether I need to do this just before the first shot of the day or if I can do it right after I fill the gun the night before and it will still be good in the morning.....More later.
I think I know what is going on, but would be interested in others and their own experiences or theories? (don't mean to hijack Allen's thread, but being a new Vulcan owner thought he might like this subject?)
EDITED 10.18.15: I bragged too quickly that this cock/decock works everytime. Maybe a bit to quick to conclude this fixes the first shot issue. Still working on it, more later.
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FunGun, you may want to do a chronograph shot string for your gun. You may find that you could be overfilling the gun. The Chrony should tell where the "sweet spot" for the gun. With the chrony you will know what the best pressure and number of shots will be. This is more of an issue with non-regulated guns but it could be that you regulator is not kicking in on the first shot.
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AJ3 where did you get the TGAG moderator and what is the spring guide set up? Also the rifle still has the loud hammer sound even though I was told it was the newest generation rifle and it has the cut piece of tube on the hammer spring. Is the loud hammer whack normal?
Thanks for the comments
Thanks for the comments
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Fun gun, my gun seem to be a tack driver right out the box. I haven't shot past 25 yards on paper yet but I can shoot dime size groups at 25 yards. In still working out my scope/scope ring set up. I haven't done a full shot string test with my chrony yet but the shots I did chrony were in the 910 range pretty consistently.
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I will PM you on the moderator which reduced my 25 from 108 db to roughly 90 db. The spring guide is a plastic bushing that inserts between the hammer spring and the hammer. It significantly reduces the spring 'twang' noise on the first gen Vulcans. If you have the second gen, then your tube on the spring should serve the same purpose. I really don't hear a loud hammer slap on my 25...just a bit of a ping from the air reservoir now that the spring noise is reduced.
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NMshooter,
I appreciate the input idea about overfilling as a possible problem but the vulcan can be filled to 250Bar. I am only filling to about 220Bar and sometimes 230Bar when I have a full scuba tank.
(3500 psi HP Steel 100 cubic ft tanks) I am still looking for ideas so keep em coming.
Allen-
That is a pretty darn good string shooting dime size groups at 25 yards. I was shooting a little looser groups at 25 Meters and have now moved out to 30yards and putting 3 shot groups in the same hole after 774 rounds down range. Yours will probably tighten up believe it or not. As you said, this gun is a tack driver! I have found that my best groups and best BE (bullseye) groups occur at about 220bar down to 190bar. At 2bar per shot, 15 shots that are dead on POI is POA. I have not run the chrony since finishing the first tin of JSB 350 count, but the speeds were around 895fps in this pressure range. You seeing anything similar? ( I am going to run some more recent chrony data for comparison) I know the first 350 rounds down range could not meet the grouping the gun is shooting now. They seem to respond well to a "break-in".
I appreciate the input idea about overfilling as a possible problem but the vulcan can be filled to 250Bar. I am only filling to about 220Bar and sometimes 230Bar when I have a full scuba tank.
(3500 psi HP Steel 100 cubic ft tanks) I am still looking for ideas so keep em coming.
Allen-
That is a pretty darn good string shooting dime size groups at 25 yards. I was shooting a little looser groups at 25 Meters and have now moved out to 30yards and putting 3 shot groups in the same hole after 774 rounds down range. Yours will probably tighten up believe it or not. As you said, this gun is a tack driver! I have found that my best groups and best BE (bullseye) groups occur at about 220bar down to 190bar. At 2bar per shot, 15 shots that are dead on POI is POA. I have not run the chrony since finishing the first tin of JSB 350 count, but the speeds were around 895fps in this pressure range. You seeing anything similar? ( I am going to run some more recent chrony data for comparison) I know the first 350 rounds down range could not meet the grouping the gun is shooting now. They seem to respond well to a "break-in".
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Hey Allen,
How do you fill your Vulcan? What pressure do you typically refill? After your last shot before a refill do you leave the magazine in? Do you take the magazine out and decock, then fill?
Or do you take the magazine out and leave the bolt in the open locked position while your filling? thanks for answering in advance. EDIT: should read thanks in advance for answering....was a long day yesterday. lol.
How do you fill your Vulcan? What pressure do you typically refill? After your last shot before a refill do you leave the magazine in? Do you take the magazine out and decock, then fill?
Or do you take the magazine out and leave the bolt in the open locked position while your filling? thanks for answering in advance. EDIT: should read thanks in advance for answering....was a long day yesterday. lol.
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I'm interested in these different fills. I just never fill all the way plus like I stated extra baffles.
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Fungun,
The reason for the regulator is so that All the shots should be very close to the same in a given range. Not sure of the total shots you should get but you should have about 30-40 shots that shoot identical. I have a .22 Cricket carbine and I get 45-48 shots that are consistent. The last three shots of my fourth magazine my POI is slightly lower. You should be getting similar results. It might be worth the extra bucks to send it back to the dealer or have it professionally tuned just to save you all the headache. The Vulcan from all the reviews is a great gun as long as it is working properly.
Doc
The reason for the regulator is so that All the shots should be very close to the same in a given range. Not sure of the total shots you should get but you should have about 30-40 shots that shoot identical. I have a .22 Cricket carbine and I get 45-48 shots that are consistent. The last three shots of my fourth magazine my POI is slightly lower. You should be getting similar results. It might be worth the extra bucks to send it back to the dealer or have it professionally tuned just to save you all the headache. The Vulcan from all the reviews is a great gun as long as it is working properly.
Doc
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Thanks for the suggestion NMShooter, but I think you may have missed a little of the point since I didn't really spell out everything. The gun is getting 45+ good shots. The "sweet" spot shots are in the range as I described where instead of .1 variance in POI in other words 1/2 a pellet width, the 15 or so shots in the describe range are hole in hole at 30 yards, 3 on top of each other kind of accuracy. So I don't think the gun needs any tuning at this point, that I can't take care of myself. Besides we are all still really trying to get these vulcans broke in. So far they only seem to get better the more they get used. I did some chrony work yesterday to compare the chrony work that I did when I first got the gun, I have not analyzed the data yet but it all seems pretty good at this point. My first shot yesterday was a B.E. and was withing a few fps of the avg so my change in procedure yesterday seemed to work, still have to get repeat-ability on it before claiming success.
The point or the issue I was having and wanting other vulcan/regulated gun owners to chime in on is the issue of my first shot after a fill is up to 3" low and 3"left. As I laugh when this happens I know it was not me flinching, for those of you who might chuckle and think its the shooter....LOL!
I am experimenting with fill procedures and cock and de-cocking the gun prior to the first shot of day to see if I can find an explanation. I suspect since the regs are designed to see drastic changes in pressure over very short periods, such as firing and re-cocking for the next shot that this possibly related since the vulcan like the cricket has a slow fill port that might be part of the phenom. It could just be that over time as the reg gets better set and exercised this phenom will go away. For now I am just looking for others ideas or experiences and further experimentation on my part. Oh this is such a FUNGUN to shoot! Thanks for the help to all!
The point or the issue I was having and wanting other vulcan/regulated gun owners to chime in on is the issue of my first shot after a fill is up to 3" low and 3"left. As I laugh when this happens I know it was not me flinching, for those of you who might chuckle and think its the shooter....LOL!
I am experimenting with fill procedures and cock and de-cocking the gun prior to the first shot of day to see if I can find an explanation. I suspect since the regs are designed to see drastic changes in pressure over very short periods, such as firing and re-cocking for the next shot that this possibly related since the vulcan like the cricket has a slow fill port that might be part of the phenom. It could just be that over time as the reg gets better set and exercised this phenom will go away. For now I am just looking for others ideas or experiences and further experimentation on my part. Oh this is such a FUNGUN to shoot! Thanks for the help to all!
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Sorry to state the obvious.Now that I think about it this happened to me. I use to just test fired before shooting a group after a fill. The 1st shot is 3 in low and then eveything is fine. You probably are correct as this rarely happens now. I received my Cricket in April and now it is shooting spot on. Probably like anything else new, you have to "break it in". Keep shooting!
Doc
Doc
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Did you reduce just the spring noise or did you use an additional silencer for the barrel?
Does anybody know how the total noise of the .25 is compared to the .22 ?
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Hi Fungun
I have same gun Vulcan .25 , the MK2 .I live in France so purchased here.
Basically very pleased but less so with Chrono readings.
Using JSB kings 25.40 .
Fill pressure 220 bar down to appx 150-160 bar.
Barrel cleaned when new.
First readings when new
Error,910,916,915,909,910,922,926,error--now 200 bar
913,907,920,920,error,907,909,907,915----now 170 bar
909,911,912,909,899,error,error,905,900----now 150 bar
895--off regulator
after 350 shots
853,872,901,883,884,892,885,887,883--now 210 bar
886,889,887,896,891,887,891,895,900---now 190 bar
886,894,890,898,904,904,894,896,905--- now 170 bar
895,903,902,900,907,910,905,904,906---- now 160 bar
904,898,895,893,888,881 think off regulator here then, 875,830 ---now 130 bar
I would guess any regulated gun fired down below regulator set point produces the first couple of shots below set point resulting in inaccuracy and low fps. Regulator reaches set point very slowly hence either stop shooting before regulator drops below set point or waste the first two shots.
I am halfway though a second tin (350) and will clean barrel and rechrono afterwards. I am hoping that the rather poor ES and SD figures will improve. Certainly as above figures show the shot count has grown from appx 30 to 40+ useable shots.
The gun is easy to obtain 1.5 inch groups at 100 yards, and I am not a good shot!
Hope some of the above is of use.
Safe shootng
I have same gun Vulcan .25 , the MK2 .I live in France so purchased here.
Basically very pleased but less so with Chrono readings.
Using JSB kings 25.40 .
Fill pressure 220 bar down to appx 150-160 bar.
Barrel cleaned when new.
First readings when new
Error,910,916,915,909,910,922,926,error--now 200 bar
913,907,920,920,error,907,909,907,915----now 170 bar
909,911,912,909,899,error,error,905,900----now 150 bar
895--off regulator
after 350 shots
853,872,901,883,884,892,885,887,883--now 210 bar
886,889,887,896,891,887,891,895,900---now 190 bar
886,894,890,898,904,904,894,896,905--- now 170 bar
895,903,902,900,907,910,905,904,906---- now 160 bar
904,898,895,893,888,881 think off regulator here then, 875,830 ---now 130 bar
I would guess any regulated gun fired down below regulator set point produces the first couple of shots below set point resulting in inaccuracy and low fps. Regulator reaches set point very slowly hence either stop shooting before regulator drops below set point or waste the first two shots.
I am halfway though a second tin (350) and will clean barrel and rechrono afterwards. I am hoping that the rather poor ES and SD figures will improve. Certainly as above figures show the shot count has grown from appx 30 to 40+ useable shots.
The gun is easy to obtain 1.5 inch groups at 100 yards, and I am not a good shot!
Hope some of the above is of use.
Safe shootng
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this has already been poster on the forum but cant remember where
https://www.youtube.com/watch?v=f6yHTuM76kw
https://www.youtube.com/watch?v=f6yHTuM76kw
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ericgs Thanks for the link! I have enjoyed some of Roberts videos in the past but haven't seen that one. That is very helpful! I have learned to waste the first couple shots but it's good to know exactly why it happens. And it makes sense now that I see it.
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