This Camp 9 Ain’t Doing So Fine

posted on June 15, 2022
Marlin Camp Carbine’s buffer

By engaging in regular maintenance and periodically replacing the Marlin Camp Carbine’s buffer, owners can ensure their firearm functions optimally for decades.

Our family has a Marlin Camp Carbine in 9 mm for personal protection, target shooting and general use around our camp.

This afternoon, my boys were out with it target shooting, when it stopped working. The bolt was locked partially open and there was some white particulate material leaking out of the action and from around the trigger.

The boys were shooting standard 9 mm FMJ factory ammunition in Smith & Wesson Model 59 factory magazines. We clean and lubricate our firearms religiously, so it is unlikely that maintenance or ammunition is the problem.

I know this gun is out of production and parts may be scarce, but I’d like to get it fixed, if possible.

Any help in getting our Marlin back in working order would be welcome and greatly appreciated.

Gene Danmore, Denver, CO

The Marlin Model 9 Camp Carbine was designed to fill a need similar to what you and the boys have put it in service to fulfill. I have found them to be good for the uses you mention, as well as the next step up from a rimfire rifle. They are accurate with low recoil and, with selected ammo, possess the ability to take small game for the pot and to dispatch small to medium-size predators. 

The service life for these rifles is generally considered to be in the neighborhood of 5,000 rounds before some parts need replacing and an overall inspection and function check should be performed to ensure its continued operation. 

The type of ammunition used in the Camp Carbine has a direct effect on general maintenance and intervals for parts replacement. The Model 9 has a blowback-operated action, which means there is no mechanical lockup in the gun to control the pressure of the cartridge as it fires. Only the weight of the bolt and the strength of the recoil spring are present to contain the pressure in the chamber until it subsides sufficiently to allow safe extraction and ejection of the fired cartridge case.

Although the gun will chamber and fire any 9 mm cartridge, I recommend firing only standard-pressure-rated ammunition through it to extend the longevity of operation for the rifle.

The one Achilles’ Heel for the Marlin Camp Carbine is the buffer in the upper receiver. Its job is to cushion the impact of the bolt against the receiver so there is no metal-on-metal contact every time the bolt cycles during firing. Over time, the continuous impact of the bolt against the plastic buffer causes it to crack and eventually break apart in pieces small enough to stop the bolt from cycling and the gun from working.

It sounds like your buffer has fractured and failed, causing the problem you describe.

This is a relatively easy problem to remedy if you are familiar with how to fieldstrip the gun for maintenance as recommended in the owner’s manual.

The buffer (or what’s left of it) will be located in a round hole at the back of the receiver. All of the pieces of the buffer must be removed from inside the gun before installation of the replacement buffer, which is commonly available from Brownells, MidwayUSA or other gunsmithing and parts suppliers. In addition, replacing the recoil spring would help to ensure the longevity of the buffer as well.

After removing all of the buffer particles and further cleaning the inside of the receiver, lubricate all of the bearing surfaces with a lubricant that will stay on the parts until the next cleaning. The factory recommends cleaning every 250 rounds or after every shooting session.

The new buffer is shaped so it is unlikely to be installed incorrectly. It will fit, with light pressure, in the hole at the rear of the carbine’s receiver.

Once the buffer is in place, insert the bolt, recoil spring and rod back into the receiver while joining the charging handle through the ejection port and locking the bolt to the rear.

Reposition the bolt stop with the trigger group, then connect the trigger group to the upper receiver with the action assembly pins in the reverse of how they were removed.

Position  the barreled action in the stock and tighten the screws to hold the action firmly in place.

Finally, finish with a function check to ensure the bolt is working smoothly, the safeties are working properly and the trigger operates as expected.

Your Marlin Model 9 Camp Carbine should be working as good as new.


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