Marlin 336 - cold barrel problems

[lowelldogger]

I've been having some issues with my .30-30 grouping with a cold barrel. When I get to the range, the first shot is always at least 4 inches high until the barrel gets warm! What usually happens is the first shot starts 4 inches high, and each subsequent shot moves down an inch or so until I fire about 3 shots. Once the barrel is warm, my groups are decent. Has anyone experienced a "walking group" like this? Thanks!

 

[hoghunting]

Welcome to the forum.

Are you starting off with a clean barrel? Your first shot could be high due to the cleaning solvent or oil still in the barrel. Even if you run a few dry patches through the barrel, it still won't get all the oil out. The first shot will clear it out though.

 

[lowelldogger]

Thanks, hoghunting.

This problem persists even if I don't clean the barrel between range sessions. I'm not sure if I should sight in my scope for the cold shot, or an average of cold and warm. This is my deer rifle so the first shot is the critical one. I'm using Hornady LeverEvolution ammo, sighting in at 100 yds.

 

[Asherdan]

Yep, but my rifles do it in reverse, walking higher as the barrels warm up. Since they're hunting rifles for me I work with them while keeping the barrel cool, since that 'cold shot' is what's going to count for me. In between a forearm, mag tube and barrel band (in some cases) impacting the barrel at different points leverguns can and in many cases do change POI as barrel temp changes. If it's an issue for you, there are processes to go through to relieve the forearm, loosen the barrel band and add a silicone washer between the mag tube and barrel that can mitigate (but maybe not completely alleviate) the cold to warm to hot barrel POI shift.

Here's an example I shot with my 1895G. 2 three shot groups at 100 yards with 10-15 seconds in between shots. Notice how the third shot flies high right.



I'm not too torqued about it as knowing the first two will fall right on top of each other is good enough for me in a brush busting rifle.

In my rifles, on an average California day (75 and sunny, of course) about five minutes resting with the bolt open cools things down enough to keep them in the same POI.

 

[Yarddog]

"since that 'cold shot' is what's going to count"

Agree 100% Dial that baby in on a cold shot ; )
Y/D

 

[chas08]

I'd sight it in cold bore 2in.high at a hundred yds. and worry no more. Thats how I have my 30/30 sighted and it works for me.

 

[Abel]

You may have a binding issue with your barrel. Does your rifle have the double barrel bands? Have you tried loosening the bands' screws a few degrees? How old is the rifle? A new barrel will often not settle in until you sent a few boxes through the barrel. Have you tried different ammo? Try more than LeverEvolution. It isn't necessarily the best ammo for your rifle.

 

[quietman]

Loosening the rear band won't do anything as the threads are on the same side as the head and the rest is just a post.

Front band is a different story however.

You have several issues that can cause this, try the front band screw first. Marlin has NO torque specs for any of the screws, so over tightening does happen. If it's been cranked on hard, it may have squeezed the front band a little out of shape.

Next, check the tang screw and stock fit. make sure the stock doesn't have any play. If it does the first shot bumps the stock into position causing that shot to be a "flyer". You'll either need to tighten the screw, or bed the stock and receiver mating surfaces if tightening the scew doesn't work.

Might be a scope issue too. Try this. take a shot move your scope 8 clicks up, take a shot. Some scopes with a mfg defect actually take one shot to cause the crosshairs to "settle" after traveling or after being adjusted. Or see if the same thing happens with open sights.

I'd HIGHLY recommend "Accurizing the Factory Rifle" for any one with a lever gun shooting large groups, having vertical / horizontal stringing issues, or flyers. 99% of the fixes discussed can be done at home.

Half the book covers levers and or single shots with 2 piece stocks. Did wonders for a 30-30 for me.

Last, post your question on the Marlinowners.com forum. Lot's of experience there.