Controlled feed vs Push feed?


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gvnwst
November 27, 2008, 09:44 AM
So, I learned that controlled feed holds the round while feeding it whereas push feed just pushes the round into the chamber. Is there any big advantage to controlled feed over push feed? The context is in precision rifles chambered for rounds like the .338 Laupa mag, .30/378wby mag, ect. Also, how does controlled feed work? Meaning, how does the round get activly grabbed and held from the magazine?

Thanks for the help.

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Z71
November 27, 2008, 09:55 AM
Controlled feed is where the cartridge is grabbed up/slides up with it's groove held captive by the bolts extractor. The "Mauser system", any old surplus bolt action Mauser is controled feed.

Most modern rifles with some exceptions are push feed. The bolt just pushes the cartridge into the chamber. The extractor doesn't have a grip on the cartridge until the bolt closes.

Supposidly the controlled feed is better because it always has controll of the cartridge. Won't leave it loose in the chambering process if you short stroke the bolt, or drop the round out of the gun if your upside down or whatever.

Dangerous game rifles are generally built with the Mauser type extractor for just such reasons.

For hunting and plinking general useage, probably not a big deal.

dagger dog
November 27, 2008, 09:56 AM
The bottom portion of the bolt face that is toward the magazine , is cut away the magazine spring forces the round under the claw of the extractor.This happens on closing after the spent round is ejected.

The Mauser brothers can be thanked for their contribution of the controlled round feed. It was intened to keep battle rushed troops from short stroking their rifles and causing jambs.

Another advantage of controlled round feed is, if the round is securley held by the extractor it cannot be bounced or misaligned under high stress movements(having to dodge the oncoming rush of a wounded animal).

gvnwst
November 27, 2008, 01:57 PM
so it wouldn't make much of a difference in a LR rifle?

Thanks.

Coronach
November 27, 2008, 02:39 PM
Probably not. IIRC, the rifles currently used by US snipers are push-feed, but that's completely off the cuff.

One way or the other, it shouldn't matter much.

Mike

lefteyedom
November 27, 2008, 03:24 PM
Control feed has been push for years as a better system. Truth be told it this did not become an issue until the Winchester change the Model 70 after 1964 doing away with its control feed. So for the next 40 years gun scribes have made having control feed as something "one must have". Winchester started making it model 70 classic with control feed so they sell pre 64 style 70 model rifle to people that already had post 64 rifle and would not pay the outrage price for pre-64 rifles.
Nothing wrong with control feed. but really how many hunters find them selves up side slowly chambering a round while being attacked by killer deer?

ArmedBear
November 27, 2008, 05:26 PM
AFAIK it's much easier to make a very accurate rifle with push feed. All the bolt has to be is flat on the face, tight and consistent when locked, perpendicular to the chamber face, and headspaced right.

Now this isn't as easy as it sounds, hence the price of a REALLY accurate long range rifle. Still, the CRF has more to booger up the accuracy.

This is no big deal in a hunting rifle. Getting 1 MOA with CRF is not a problem.

Bottom line? A good CRF is a far better feeding system -- but you probably don't need the best feeding system, especially at the cost of ultimate accuracy. PF is a better shooting platform for extreme accuracy, or for a relatively inexpensive rifle that is plenty accurate for practical use.

I'm not a CRF snob; my primary hunting rifle is a PR, and I don't own a CRF rifle other than milsurp.

(I do covet a new M70 Featherweight, but CRF is only a very tiny part of that equation. Fit, weight, balance and handling come first.)

Apart from tree stand use, dangerous game, and military applications that have been obsolete for the better part of a century, a PF will serve you fine. For what you want, it will serve you better.

ants
November 27, 2008, 05:40 PM
I hunted with both since 1960, and didn't know there was a controversy until they invented the Internet.

ArmedBear
November 27, 2008, 06:02 PM
Controversy?

One offers a certain set of pluses and minuses, the other offers a different set. A given application may favor one or the other.

No controversy there.

gvnwst
November 27, 2008, 07:16 PM
@ArmedBear

Thanks, that is what i was looking for (post #7 that is):)

MountainWalk
November 28, 2008, 03:54 AM
while not a snob about it, I do prefer crf.

While bear hunting in rainforest condidtions, in near jungle conditions, I prefer the safety and security of the claw. Up here, the foliage is dense, green, wet, and darn near inpenatrable. The bears grow heavy, long, and testy. It just makes me feel better when it comes to follow up a shot bear.

earplug
November 28, 2008, 10:58 PM
As the choice between push or control.
The M-16, M-60 MG are push feed weapons as are countless others.
Its not a issue. Unless you really think the 1911 and M2 Browning design are better!
Its a matter of little plunger springs mounted on the bolt face pushing out a fired round, or a big extractor controling the round until a postive ejection takes place from a frame mounted fixed block.
I can't recall what a AK design uses?

jlmurphy
November 28, 2008, 11:12 PM
For accuracy work the PF is better. The CRF bolt is open on the lower side and generally has more clearance around the case head, and unless the bolt to action tolerances are tight, the firing pin alignment with the primer varies. The PF bolt face completely encircles the case head, guaranteeing firing pin alignment, also most PF actions use a spring loaded ejector that pushes the case into the chamber and the bolt backward against the action lugs.

ArmedBear
November 29, 2008, 08:43 AM
MountainWalk-

A perfect example of why someone WOULD really want CRF! Bears are much bigger and more dangerous than prairie dogs, so it makes perfect sense to choose your rifle based on the feed system, instead of dime-sized groups at 200 yards.

RyanM
November 29, 2008, 04:45 PM
As the choice between push or control.
The M-16, M-60 MG are push feed weapons as are countless others.
Its not a issue. Unless you really think the 1911 and M2 Browning design are better!
Its a matter of little plunger springs mounted on the bolt face pushing out a fired round, or a big extractor controling the round until a postive ejection takes place from a frame mounted fixed block.
I can't recall what a AK design uses?

Generally, 99% of autoloading rifles (including the AK) are push feed, while 99% of centerfire autoloading pistols are controlled feed.

I dunno why.

But the fact that autorifles are push feed doesn't mean push feed is best. The cycle time on those is fast enough that you don't have to worry about the round flopping out if you're upside-down or something.

USSR
November 29, 2008, 06:19 PM
I have Match Rifles using both Winchester pushfeed and CRF actions, and there's not a dimes worth of difference between them accuracy-wise or otherwise. Get whichever trips your trigger.

Don

buttrap
November 29, 2008, 10:01 PM
The control feed idea is to eliminate the chance of a double feed jam if the operator gets over excited. All in all not a big deal for targets or most game but in the days of the bolt action battle rifle it was a big deal.

jmr40
November 29, 2008, 10:21 PM
Everyone brings up the better feeding of the CRF rifles. While it is true I prefer CRF for another reason. More positive extraction. I believe the debate over which will feed better is over rated. Most of my rifles have been and still are push feed and I have never had a single one that would not feed rounds into the chamber just as good as a CRF rifle, even upside down. Never had a problem with double feeding.

I have had push feed rifles give problems when extracting empty brass however. Especialy if the ammo is slightly out of spec or if the rifle is dirty. I have never had the same problems with a CRF rifle because of the large extractor and the more foolproof ejector. I will continue to use both types, but if in a situation where I may have to count on my rifle when in harsh dirty conditions and keeping the rifle perfectly clean is impossible. Such as on a backpack hunt, I have more faith in the CRF to keep working.

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