Canadian Airgun Forum

The #1 Community for Airguns in Canada!
It is currently Fri Mar 29, 2024 1:02 am

All times are UTC - 5 hours


The Canadian Airgun Forums are a place for people to discuss and learn about airguns and the airgunning sport in Canada. There are lots of discussions about airguns, airgun accessories, reviews, modification and repair information, airgun events, field target and free classifieds!

 

You need to register before you can post: click the register link to proceed. Before you register, please read the forum rules. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload your own pictures, and access many other special features. Registration is fast, simple, and absolutely free! To start viewing messages, select the forum that you want to visit from the selection below.







Post new topic Reply to topic  [ 14 posts ] 
Author Message
PostPosted: Mon Oct 30, 2017 3:22 pm 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
I picked up one of these yesterday, still available for sale so I don't know if it qualifies as an antique but it certainly looks like one, being based on the Crosman 160 rifle design from the 60s but fitted with a 32 gauge barrel with a removable bolt allowing darts to be loaded.

In my enthusiasm to take it apart, I forgot to take a "before" picture, but here's a similar example fitted with a scope:

Image

Here it is broken down:

Image

Trigger detail, a much cruder affair than the original 160 trigger and the return spring pushes directly on the stock. Clearly veterinarians are not as picky as target shooters. Note the two grooves on the hammer that allow for a high/low power setting to be selected:

Image

Valve body and stem detail, in spite of the relatively massive 0.5" bore the transfer port is a mere 5/32" diameter, presumably unchanged from the original 160 valve. The barrel is also rifled, with 8 shallow right hand grooves, which is unusual given that tranquilizer darts are usually drag stabilized.

Image

Barrel markings identifying it as a "Red's Special", presumably an older variation of the one currently being sold as a "Long Range Rifle Type Projector". I believe the current version is made for a single CO2 cartridge, while this example takes two back to back.

Image

I'm not sure if I should reseal it and keep it as is, or redo the internals to turn it into a big bore PCP. As it is I doubt it would have any useful velocity with "proper" projectiles given the tiny transfer port, but it seems to have some potential if the rifling would be sufficient to stabilize such projectiles.

That being said, I already have a Farco Air Shotgun in this caliber.


Top
 Profile  
 
PostPosted: Mon Oct 30, 2017 3:50 pm 
Offline
Supporting Members
User avatar

Joined: Mon Jan 01, 2007 10:54 pm
Posts: 6267
Location: Saint John NB
Hmmmmm.......52cal pellets anyone lol

_________________
Jonathan

Moderator


Top
 Profile  
 
PostPosted: Mon Oct 30, 2017 4:45 pm 
Offline

Joined: Wed Jan 05, 2011 12:35 pm
Posts: 11301
Location: P.G. B.C.
With the air pushing from behind, the rifling will cause a slight spiral which will merely help initial stabilization. Any wobble prior to the shuttle-cock stabilization will decrease the BC, increase drop and decrease accuracy. I can "see" the possible benefits of rifling 'starting' rotation of the dart.

Conversely, study has shown that most or all shotgun bores have a slight & usually invisible spiraling inside the bores caused during the reaming of the drilled bore. This usually invisible spiraling causes tight fitting plastic wads to turn or spiral in the bore as they travel down it.

The Russian International Team captains of their trap and skeet teams recognized this spiraling due to photographing emerging shot cups and shot columns noting they were twisting in flight although there was no rifling visible in the bores. When steps were taken to eliminate or stop this twisting or rotating of the wads and thus shot columns, pattern densities increased & the Russian teams were unbeatable - for a year or two.

Most all international teams (gun smiths) use variations of the Russian chokes & bore designs & are on a level playing field, again.

_________________
Best Wishes
Daryl


Top
 Profile  
 
PostPosted: Mon Oct 30, 2017 5:46 pm 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
Fair point, I can see it being useful to stabilize the dart especially at low subsonic velocities.

In the meantime I receiver a reply from Palmer, they could not provide me with an exact manufacturing date but the serial number would have been from the 70s, making me less inclined to want to butcher it as a project.


Top
 Profile  
 
PostPosted: Fri Nov 03, 2017 10:07 am 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
A little update, I machined a two part fill nipple with check valve held by the original cap that holds pressure well:

Image

This allowed for some testing at 1200 psi with my 3 stage Chinese pump which is still working well, very happy with it so far.

I tried with 3/8" steel ball bearings in 50 cal muzzleloader sabots as well as a dummy dart I machined to get an idea of how it would perform with the sort of projectiles it was intended for:

Image

The dart weights 8.84 grams, 3.54 grams for the steel ball and 0.68 grams for the sabot. Filling to 1200 psi for each shot I got an average of 357 fps for the steel ball and 254 fps for the dart, a fair 15 and 20 ft lbs respectively. It's worth noting that the valve body is effectively blocked off by the steel pin that acts as a spring guide for the valve stem spring as well as a piercer for one of the CO2 cartridges as it was intended to be used, which turns it into a "firing chamber" that might be limiting performance. More testing for accuracy and damage shots to follow eventually.


Top
 Profile  
 
PostPosted: Wed Nov 08, 2017 12:57 pm 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
Finally got round to making a test video: https://youtu.be/7KPhaYSg4uo

Some detail images:

Image

Image

Image

Image

Image

Image

Image

Image

Image


Top
 Profile  
 
PostPosted: Wed Nov 08, 2017 6:32 pm 
Offline
User avatar

Joined: Mon Feb 11, 2013 12:46 am
Posts: 5698
hey PZAM little off topic but what camera did you use to snap those picture.. ?

_________________
"A candle loses nothing by lighting another candle"

Image


Top
 Profile  
 
PostPosted: Thu Nov 09, 2017 10:09 am 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
This beauty, sadly not my own.


Top
 Profile  
 
PostPosted: Thu Nov 09, 2017 10:38 am 
Offline
User avatar

Joined: Mon Feb 11, 2013 12:46 am
Posts: 5698
cool thanks
very similar to the point and shoot that i use,
im guessing your using very good lighting 8)

_________________
"A candle loses nothing by lighting another candle"

Image


Top
 Profile  
 
PostPosted: Thu Nov 09, 2017 11:10 am 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
Quite the opposite, little trick I picked up from scale modellers - relatively poor lighting but using a tripod and long exposure time (5-15 seconds depending on ambient light).


Top
 Profile  
 
 Post subject: D ft
PostPosted: Thu Nov 09, 2017 11:28 am 
Offline
User avatar

Joined: Sat Nov 03, 2007 4:19 pm
Posts: 9517
Location: Coalmont BC
Interesting project.... You are correct that the piercing pin is keeping air from flowing freely into the valve, and likely limiting performance....

One comment about the brass male QD fitting you made.... It's hard to tell from the angle of the photo, but it appears to me that there is the beginnings of dents on the shoulder where the balls of the female Foster are gripping.... Check that and if you are seeing ANY dents appearing, then do NOT increase your fill pressure.... as they are an indication you are exceeding the yield strength of the brass.... Using steel is a better idea for anything beyond CO2 pressures....

Bob

_________________
Dominion Marksman Silver Shield - 5890 x 6000 in 1976, and downhill ever since!
Airsonal; Too many! Springers, Pumpers, CO2, but I love my PCPs and developing them!
Proud Member of the 2000+fps Club!


Top
 Profile  
 
 Post subject: Re: D ft
PostPosted: Thu Nov 09, 2017 2:33 pm 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
Thank you Bob for your comments.

rsterne wrote:
You are correct that the piercing pin is keeping air from flowing freely into the valve, and likely limiting performance....


I think I'll leave it as-is, I like this more for the "curio" value so no point in having it shoot much harder.

Quote:
One comment about the brass male QD fitting you made.... It's hard to tell from the angle of the photo, but it appears to me that there is the beginnings of dents on the shoulder where the balls of the female Foster are gripping.... Check that and if you are seeing ANY dents appearing, then do NOT increase your fill pressure.... as they are an indication you are exceeding the yield strength of the brass.... Using steel is a better idea for anything beyond CO2 pressures....


Well spotted, there are indeed some minute indentations on the nipple. I figured 1200 psi being "CO2 on a hot day" would be the limit of what the original tube was made for and had no intention of taking it any further.

Quote:
the shoulder where the balls of the female Foster are gripping


So glad to be on a forum where that phrase makes perfect sense :D


Top
 Profile  
 
PostPosted: Thu Nov 09, 2017 3:36 pm 
Offline
User avatar

Joined: Mon Feb 11, 2013 12:46 am
Posts: 5698
PZAM wrote:
Quite the opposite, little trick I picked up from scale modellers - relatively poor lighting but using a tripod and long exposure time 5-15 seconds depending on ambient light).

yes that would do it ... 8)

_________________
"A candle loses nothing by lighting another candle"

Image


Top
 Profile  
 
PostPosted: Tue Mar 20, 2018 10:32 am 
Offline
User avatar

Joined: Wed Oct 29, 2014 10:49 am
Posts: 258
Location: QC
Odd thing happened the other day, someone brought a similar example in for repair! Took the opportunity to take a picture of the two rifles together:

Image


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 14 posts ] 

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 14 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
News News Site map Site map SitemapIndex SitemapIndex RSS Feed RSS Feed Channel list Channel list

Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group

phpBB SEO