usbp379
28 February 2013, 18:59
We haven't seen much posted about this different and unique rifle. Yes, it's a piston but I say it's different and unique because Colt's approach to the parts is quite unusual. Rather than use a solid rod, Colt added a swivel joint. This joint allows the piston to "float" free of the rod. This, in theory at least, keeps the piston from adding any undue stress on the barrel when things start heating up.
Here's the assembled rifle. Note that Colt used a built-in folding front sight rather than a railed gas block. Excess gas is vented out the small bleed-off hole located on both sides of the block.
http://img.photobucket.com/albums/v221/tokarev/P1020010_zpse40fe559.jpg
To access the piston, the small captured pin is pushed out as far as it will go. This allows the piston parts to be removed as a complete unit. Note the opposing grooves in the block. These help free the piston if it's frozen in place from carbon. Twisting the plug will cam it against these surfaces and help with removal.
http://img.photobucket.com/albums/v221/tokarev/P1020007_zpse2430066.jpg
The piston assembly removed from the rifle.
http://img.photobucket.com/albums/v221/tokarev/P1010986_zps690bcb09.jpg
The piston parts disassembled.
http://img.photobucket.com/albums/v221/tokarev/P1010987_zpsab78bd58.jpg
The transfer rod is attached to the piston by means of a small internal snap ring. The two parts are easily seperated by simply pulling them apart.
http://img.photobucket.com/albums/v221/tokarev/P1010989_zps51515f87.jpg
The piston. Note the three small gas rings.
http://img.photobucket.com/albums/v221/tokarev/P1010990_zps8497dbc2.jpg
The ball on the end of the transfer rod that works as the joint for the piston.
http://img.photobucket.com/albums/v221/tokarev/P1010992_zps5f5ae048.jpg
This is the latest style from Colt with the solid bolt carrier.
Here's the assembled rifle. Note that Colt used a built-in folding front sight rather than a railed gas block. Excess gas is vented out the small bleed-off hole located on both sides of the block.
http://img.photobucket.com/albums/v221/tokarev/P1020010_zpse40fe559.jpg
To access the piston, the small captured pin is pushed out as far as it will go. This allows the piston parts to be removed as a complete unit. Note the opposing grooves in the block. These help free the piston if it's frozen in place from carbon. Twisting the plug will cam it against these surfaces and help with removal.
http://img.photobucket.com/albums/v221/tokarev/P1020007_zpse2430066.jpg
The piston assembly removed from the rifle.
http://img.photobucket.com/albums/v221/tokarev/P1010986_zps690bcb09.jpg
The piston parts disassembled.
http://img.photobucket.com/albums/v221/tokarev/P1010987_zpsab78bd58.jpg
The transfer rod is attached to the piston by means of a small internal snap ring. The two parts are easily seperated by simply pulling them apart.
http://img.photobucket.com/albums/v221/tokarev/P1010989_zps51515f87.jpg
The piston. Note the three small gas rings.
http://img.photobucket.com/albums/v221/tokarev/P1010990_zps8497dbc2.jpg
The ball on the end of the transfer rod that works as the joint for the piston.
http://img.photobucket.com/albums/v221/tokarev/P1010992_zps5f5ae048.jpg
This is the latest style from Colt with the solid bolt carrier.