Bolt Actions: Controlled Feed or Push Feed?
By Chuck Hawks
There seems to be a lot of attention paid to how a bolt
action hunting rifle chambers cartridges, either by controlled feeding or push
feeding. Both systems have been around for a long time, but it was not until
Winchester changed the Model 70 from controlled feed to push feed in 1964 that
a debate erupted about the merits of the two systems. (Winchester later
re-introduced controlled feeding in their "Classic" line Model 70's
and today all Model 70's use controlled feed actions.) Let's begin with the definitions, then list the advantages and disadvantages of each type of action, starting with controlled feed.
Controlled Feed
"Controlled feeding" means the cartridge is
captured by the extractor as it is stripped from the magazine and held against
the bolt face all the way into the chamber as the bolt runs forward. During the
feeding cycle, the cartridge is always held by (first) the magazine lips and
then by the extractor; it is never loose. That is the "controlled" in
controlled feed. Examples of classic controlled feed actions include pre-1964 Winchester
Model 70's, Husqvarna HVA, Mauser's Model 98 (and its clones) and the Mannlicher-Schoenauer. Examples
of contemporary controlled feed actions include the CZ 550, Kimber Models 84/8400,
Ruger Model 77 Hawkeye and all current Winchester Model 70's.
Controlled Feed Advantages
- Because
a fresh cartridge is captured by the bolt as it leaves the magazine, controlled
feed actions prevent jams caused by "double feeds."
- The
action will feed cartridges at any angle, including with the rifle turned
so the ejection port is facing the ground.
- If a
rifle with a "right handed" action is swung rapidly to the left
as a fresh cartridge is being chambered, the cartridge cannot be
inadvertently tossed out the ejection port before it reaches the chamber.
The same is true for a rifle with a "left handed" action swung
rapidly to the right. Unfortunately, cartridges have been inadvertently
thrown from push feed actions in just this way, particularly when a hunter
is unexpectedly charged from the weak side by a dangerous animal. This is one
of the reasons why controlled feed actions are preferred for African
safari rifles.
- Controlled
feed actions typically use receiver mounted ejectors, which means if the
action is opened slowly, a chambered but unfired cartridge or fired brass
can be neatly deposited in the hand or on the surface of a bench rest,
rather than tossed several feet away. Of course, when the bolt is operated
rapidly, the case is tossed well clear of the action when the rim hits the
stationary, receiver mounted ejector. How fast the bolt is operated
determines how far a case is ejected.
- The
large, controlled feeding extractor gets a bigger bite on the case rim,
allowing extraction of stuck cases that might defeat a smaller push feed
extractor.
Controlled Feed Disadvantages
- Other things being equal (such as labor and material costs), controlled
feed actions are generally more expensive to manufacture than push feed actions.
- A bolt
face, spring loaded, plunger ejector is not an option with controlled
feeding, because cartridges are held flush against the bolt face during
feeding and a plunger ejector would eject a fresh cartridge as soon as it
cleared the magazine lips.
- Cartridges
should be fed via the magazine, not single loaded directly into the
chamber, as it is difficult or impossible for the extractor to ride over
the rim of a chambered cartridge. Most modern controlled feed rifles have beveled
extractors that do allow single cartridges to be loaded directly into the
chamber (although it is still best to feed from the magazine), but most
classic controlled feed actions, especially Mauser 98's, do not.
- Because
of their large extractor, controlled feed bolt actions typically use two
large locking lugs and require a 90-degree bolt rotation to unlock the
action.
- Short-stroking
the bolt may cause a failure to eject a fired case and could jam it in the
action when the bolt is prematurely shoved forward.
Push Feed
"Push feeding" means when the bolt pushes a new
cartridge from the magazine lips there is no mechanical attachment to the bolt
face until the cartridge is fully chambered and the bolt closed, which is when
the extractor is finally forced over the case rim. Gravity (a rather dependable
force here on the earth) keeps the fresh cartridge in the action on its way
into the chamber. Hence, the cartridge is simply pushed into the chamber
without being attached to the bolt. The Browning X-Bolt, Howa, Marlin X7,
Mossberg, Remington Model 700 and Seven, Ruger American, Sako 85, Savage 110, Steyr-Mannlicher,
Thompson-Center ICON, Tikka T3, Weatherby Vanguard and Mark V are examples of contemporary
push feed actions.
Push Feed Advantages
- Push
feed actions are generally less expensive to manufacture than controlled
feed actions, allowing the finished rifle to be sold at a lower price for
a given profit margin. This is benefits both the manufacturer and the
consumer and is why the majority of today's bolt action rifles use push
feed actions. (There are exceptions to this general rule, such as the push feed
Weatherby Mark V and Sako 75, which are deluxe actions.)
- Push
feed actions allow cartridges to easily be single loaded directly into the
chamber and the bolt closed, a nice feature at the range or in the field
with an empty magazine when an additional shot is required.
- Push
feed actions typically (but not always) use extremely reliable plunger
ejectors that throw fired cases well clear of the action. (The Sako 85 is
an exception, as it has a receiver mounted ejector.)
- Push
feed actions allow a rim on the bolt face to completely surround the case
rim, i.e. a recessed bolt face. Thus, Weatherby and Remington advertise
actions that enclose the case with "three rings of steel": the bolt
face, front receiver ring into which the barrel is threaded and barrel
chamber. (The recessed bolt face might have some purpose with rimfire
cartridge or obsolete balloon head cartridges, but all modern centerfire
cartridges have solid heads, rendering a recessed bolt face superfluous.)
- Push
feed actions can use multi-locking lug bolts, thus potentially increasing action
strength and reducing the bolt rotation required to unlock the action. The
nine locking lug Weatherby Mark V, for example, requires only 57-degrees
of bolt lift, while the three lug Browning X-Bolt and T/C ICON require only
60-degrees. This makes these actions faster to operate than a typical controlled
feed action with two front locking lugs and a 90-degree bolt lift.
- Even
if the bolt is short-stroked and not retracted far enough to push a new
cartridge from the magazine, a push feed action's plunger ejector will
typically kick a fired case clear of the action. The result of
short-stroking the bolt is an empty chamber, but not a potentially jammed
action.
Push Feed Disadvantages
- Push
feed extractors are typically smaller and have less bite on the case rim.
This means that the extractor is more likely to slip from the rim of a
case stuck in the chamber, tying-up the action.
- A cartridge
can simply drop from the action on its way into the chamber if the rifle
is held on its side (ejection port down) or swung violently to the
shooter's weak side in an emergency. However, practically speaking, this
is only a serious consideration in a dangerous game rifle.
- Hesitation
feeding can cause a double cartridge feed jam.
Summary and Conclusion
Most experienced shooters and hunters own and use rifles with both types of actions. From the shooter's perspective, there is no difference in the operation of the two types. With either, you rotate the bolt handle upward to unlock the action, pull it back to eject a fired case, shove it forward to chamber a fresh round and rotate the handle down to lock the action. There is no inherent accuracy advantage with either type of action.
Controlled feed bolt actions are considered to be somewhat
more reliable (less likely to jam) than push feed actions. For this reason,
they are generally preferred for hunting dangerous game. For example, the
majority of African professional hunters who use bolt action rifles back-up
their clients with controlled feed actions. However, both controlled and push
feed bolt actions are usually very reliable.
When properly designed and manufactured, both controlled and push feed
actions are much stronger than required for safe operation with all cartridges
loaded to SAAMI or CIP pressure standards. Any action, of course, can be blown
by seriously over-pressure "idiot fringe loads."
At a rifle range with a "single load only" rule, a
push feed action is convenient. Single shot bolt actions use push feed bolts
and this includes deluxe varmint rifles. All bolt action "economy class" centerfire rifles
are based on push feed actions, but so are some premium actions.
Before closing, special mention should be made of the Sako
Model 85 action, which is incorrectly advertised as a controlled feeding
action. It uses a receiver mounted ejector, typical of controlled feed actions,
but a push feed bolt face. The extractor does not catch the rim of cartridges as they are fed from the magazine.
The Sako 85 ejects like a typical controlled feed action, but feeds cartridges into
the chamber like a push feed action.
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