Controlled Round Push Feed


PDA






SkaerE
June 1, 2003, 02:25 PM
what is this?

read it on winchesers website. something new? how is it different from push feed?

thanks

If you enjoyed reading about "Controlled Round Push Feed" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
CMcDermott
June 2, 2003, 01:45 AM
:cuss: This is a bastardization of the Mauser Controlled-Round-Feed (CRF) concept that gunsmiths have occasionally done to CRF rifles in the past; and factories (Ruger) have done all too often when "adapting" the Mauser design. You change the Mauser extractor to remove the "foot" at the front of the bolt, put an extra large bevel on the front of the extractor and relieve the receiver around the extractor slot. Now the rifle will have a normal CRF action when fed from the magazine, but if you just drop a loose cartridge into the receiver and push the bolt forward the extractor can now ride over the rim of the cartridge to snap into place in the extractor groove.

The problem with this is you loose the Mauser extraction - if the extractor can snap over the rim of the cartridge going one way, it can snap over the rim of a cartridge stuck in the chamber and leave it there - something a real CRF Mauser extractor can't do. A real Mauser design action has to pull the cartridge case out of the chamber, rip the rim off the cartridge case or break the extractor. It's just not possible to get a Mauser bolt open and leave the case in the chamber without breaking something.

I don't know if Winchester has actually changed their CRF design, or if some marketer just decided to start playing up this "feature" because they only now found out about it. I've never had a Winchester model 70, but I don't remember there being the slot at the front of the bolt for the mauser extractor "foot" to fit into in the pictures of them I've seen.

Redlg155
June 2, 2003, 02:16 AM
Take a peek at this site...
http://www.chuckhawks.com/win70.htm . It offers some great information about the Winchester Mod 70 in the pre 64 controlled feed, post 64 push feed and post 92 revisions.

I think the controlled feed was touted in some circles as being more reliable when shooting from awkward angles or at dangerous game where it may be advantageous to have the round controlled from magazine to chamber.

It is an interesting and a good theory, but the U.S. Military doesn't put much stake on it by adopting push feed rifles as well for some it its sniper platforms.

Good SHooting
Red

SkaerE
June 2, 2003, 11:06 AM
the remington 700 is strickly push feed isnt it?

Steve Smith
June 2, 2003, 11:18 AM
Pander to the paranoia.

Kestrel
June 2, 2003, 11:58 AM
CMcDermott,

So you're saying the current Rugers are NOT true CRF?

Steve

nextjoe
June 2, 2003, 05:37 PM
The new Winchester "Controlled Round Push Feeds" are a modification of the push feed action that allows controlled feed, but without the long claw extractor. They just open up the bottom of the bolt face so the round can slide up under the extractor. The extractor is still the cheesy sliding Post-'64 job.

Current Ruger M77 MKIIs are controlled feed by design but some are so poorly made that they push feed instead; older M77s are push feed by design.

Best,
Joe

CMcDermott
June 3, 2003, 09:08 PM
SteveW13, I don't consider them to be true CRF actions since they will push-feed; and my opinion is that a CRF action that push-feeds has something wrong with it.

Jim K
June 4, 2003, 12:08 AM
There has been a lot written about "controlled feed", but very few writers are aware of the real reason for it. It may be more reliable or better able to function in awkward positions, but the actual problem is more serious.

A nasty situation starts if a round is fed from the magazine and pushed into the chamber but the bolt is not fully locked. Then, if the bolt is retracted without locking and firing (as might be done in the excitement of battle), a "controlled feed" rifle will extract the unfired round and eject it.

A "push feed" rifle will not extract the unfired round. Instead there is at least a fair chance that working the bolt fast will pick up another round and shove the bullet point of that round into the primer of the one in the chamber. Interesting things will happen very soon thereafter.

This does not happen in modern push feed rifles because great care is given to the magazine feed lips to prevent the bullet point from hitting that particular spot. In addition, the extremely strong action of push feed rifles is considered a trade-off for any potential problem. Also working for safety are soft point or round nose sporting rounds, and the less panicky nature of civilian rifle shooting.

Note though, that anyone rebarrelling a push feed rifle for a cartridge of a different case configuration should make sure that the cartridge guides are altered if necessary.

Jim

Jim Watson
June 4, 2003, 12:48 AM
And an '03 Springfield is designed for controlled feed from the magazine, but push feed in single shot with the magazine cutoff set.

If you enjoyed reading about "Controlled Round Push Feed" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!