disco mods how much will shorter barrel affect fps and fpe?

disco mods how much will shorter barrel affect fps and fpe?

Joined: April 30th, 2012, 11:43 am

August 2nd, 2012, 12:44 pm #1

OK so I've been planning what all I want to do to my .22 disco. Currently it has an hdd and three screw trigger mod. I don't currently have a curing and only other air rifle I had was a 392 I sold to upgrade to the disco which I have now had since like April or May.

Little advice if possible, please.

I want to add a BNM multi shot breech. Will the hdd still fit and work?
I would also like to ad a shroud or half shroud and use a barrel something like 4" shoter so the overall length of the gun stays about the same. Does anyone know how much this would affect the crosman barrels? Velocity? Energy? Precision/ accuracy?Or should I upgrade a a Lothar Walther? Is there a cheaper alternative to LW that would work?
Lastly I am thinking of swapping out the disco trigger pack for a prod trigger. I know at that point I will need to replace the stock, but has anyone had any issues with this?

Thanks!
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Joined: November 29th, 2009, 9:53 am

August 2nd, 2012, 4:03 pm #2

in my experience a crosman barrel usually performs better with a cut and crown job
as far as loss in fps from what i have seen its around -10fps per inch removed
adding a p-rod trigger group to your disco you will lose the stock,a 1399 stock would be needed
alternative is to use a marauder trigger group.iirc you lose the trigger guard
with either trigger group the hammer either has to be modded ,custom made or
use the p-rod hammer/striker
Last edited by 1377needshelp on August 2nd, 2012, 4:14 pm, edited 1 time in total.
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Joined: February 17th, 2010, 3:30 am

August 2nd, 2012, 4:19 pm #3

OK so I've been planning what all I want to do to my .22 disco. Currently it has an hdd and three screw trigger mod. I don't currently have a curing and only other air rifle I had was a 392 I sold to upgrade to the disco which I have now had since like April or May.

Little advice if possible, please.

I want to add a BNM multi shot breech. Will the hdd still fit and work?
I would also like to ad a shroud or half shroud and use a barrel something like 4" shoter so the overall length of the gun stays about the same. Does anyone know how much this would affect the crosman barrels? Velocity? Energy? Precision/ accuracy?Or should I upgrade a a Lothar Walther? Is there a cheaper alternative to LW that would work?
Lastly I am thinking of swapping out the disco trigger pack for a prod trigger. I know at that point I will need to replace the stock, but has anyone had any issues with this?

Thanks!
on the state of tune of your Disco.... The more power your gun is putting out, the more you will lose by shortening the barrel.... For a stock Disco in .22 cal, you will lose about 25-30 fps (1.5-2 FPE) with 16 gr. pellets by shortening the barrel to 20"....

Bob
Last edited by rsterne on August 2nd, 2012, 4:19 pm, edited 1 time in total.
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Joined: April 30th, 2012, 11:43 am

August 2nd, 2012, 11:10 pm #4

thanks for the input guys! any barrel suggestions or save for LW?
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Joined: April 28th, 2010, 12:23 am

August 4th, 2012, 2:53 am #5

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