I was hoping someone could explain how the headspace is set on a 336? It appears that it is controlled by the bolt and the depth of the counter sink for the rim. I dont see any counterbore at the breech end of the barrel.

I have a 20+ year old Marlin that's only had maybe 6 boxes of factory ammo shot through it. Three of which were at last weekend's lever action silhouette match. The primers are backing out quite a bit. It shoots great but the headspace needs fixin.

Thanks,

Mike

Z1r--

The headspace on a 336 is the distance from tbe bolt face to the bottom of the rim recess.

Increase your load and the protruding primers will dissapear, but check the HS first.

All are very sloppy. It's just a fact of the model. Don't be surprized to see .009 HS on a new 336 Marlin. It's no big deal on a rimmed, low pressure case.

Mike,

Some lever action designs require a certain amount of slack in their running gear to provide trouble free operation. The design uses a locking bolt which, operated by the lever, slides up behind the bolt and holds it in the frward position for firing.

There is slop present in the locking bolts track and in the lever assembly and is the main culprit of the excess headspace of these designs. Similar touble exist with the Winchester 94 as well.

In some instances, this excess slack can be diminished some by holding the lever up tight against the frame to reduce the slack while firing. This can sometimes reduce the problem you are experiencing with factory ammunition. I have seen some of these weapons ruined because some clown welded the back of the bolt to increase locking bolt contact. Stupid!

If the weapon has seen a lot of use and abuse, fitting a new locking bolt can sometimes aleviate the problem to some degree. Have the headspace checked by someone familiar with the Mod 336, but like Jack says, it shouldn't be too big a deal. If you're uncomfortable get it checked.

Malm

The distance from bolt face to the bottom of rim recess is .064". The rim on my brass is .055". This puts me right at the .009" figure Mr. belk mentioned. Since I don't have a gage I'm not sure what the spec should be but at least I know what the "clearance" in my combo is.

So, is the cure to fit a new bolt. And do you know if these are already recessed by the factory? I'd hope not.

Thanks,

M.

Mike,

A replacement bolt would come recessed from the factory.

My go guage measures .063 and my no-go measures .067.

If you don't feel comfortable shooting the rifle, you should contact the factory's service department and see what they advise.

The cure would be to do whatever is necessary to close the gap. Your options in ascending order from least expense to most expense are 1, locking bolt 2, bolt or 3, barrel setback... Good luck.

Malm

Thanks Malm.

I'll probably leave it as is. It just bothers me when I know something isn't working as it should be. These days though I seem to be spending more time fixing guns (or trying) than shooting them. Since this one shoots plenty straight I'll just have to live with it til things calm down.