Marlin 336 30 30 Shoots bullets sideways

[Powderman]

Please bear this in mind: micing the cases doesn't prove anything.

Slugging the bore does.

First, remove the lever and bolt from the rifle. This is done easily, and is necessary because you're going to be doing this from the breech.

Start with a bullet or ball made of soft lead. Get a Dewey coated rod of the proper model. If you're going to use a lead ball, get one that is .310 or so in diameter.

Clean your barrel with bore brush and copper solvent. Now, get a good, heavy oil (like 10W-40) and patch out the bore with a saturated patch.

Assemble your rod with a "pusher" tip. Now, select one ball, put some 10W-40 on it, and drop it in the chamber. Invert the rifle, muzzle down and tap it in gently with the end of the rod until it goes no further.

Place the end of the rod on the bore, and tap the handle with a rubber mallet--gently--until the ball--now a slug--comes out of the other end.

Tips: It helps if you have someone else to help by holding the rifle while you tap the rod. Also, have a soft towel or something similar to catch the ball when it drops from the muzzle.

Now, measure the slug at 2 to 3 points along its length. Your reading should be .308 or very close. If it is more, you have an oversized barrel.

 

[BruceM]

Before you slug the bore and do any measuring of any kind, get the bore perfectly clean. If it is really fouled, use KG-12 to get most of the big chunks out followed by Kroil and then a more conventional bore cleaner. When all else fails, there is always the Outer's Foul-Out which will remove any fouling, copper or lead, by reverse electroplating. Do NOT use a stainless brush under any circumstances. After the bore is thoroughly cleaned, try conventional ammo to check for tumbling. It will only take a couple of shots to tell you what you need to know. If it still tumbles after the bore is clean, it's time to check bore diameter and possibly re-barrel. I suspect that the Micro-Groove rifling in the bore is totally fouled. I barrel crown damaged to the extent that it would make a bullet tumble would be readily noticeable and far less likely.

Bruce