Marlin 336 with Micro-Groove bullets stable?

[Spoons01]

Hi all, first post on here.

I was wondering if there's anyone out there who has had issues with the old marlin 336's with the micro groove rifling and stablizing Factory .30-30? so far i've only taken it to the range once (it's my first rifle and i can't get out to the range often), but every single round i put through it tumbled, keyholed and went all over the target at 25-50m, i put 18 rounds of Winchester SuperX 150gr HP through it as well as 5 rounds of Hornady Leverevolution 160gr FTX just to see if there was a difference. I know it's not a lot of information but hopefully someone can give me some guidence on whether this may be a simple ammo issue or something with the rifle.

My rifle is a JM stamped Marlin .336SC in .30-30 and made in 1960.

[bigpete]

I'd suggest the barrel.is rooted

[Bill]

Sounds a bit strange, I had a 60s micro groove Marlin and it would put 3 x 150gr into a dime a 100m. Either you need to get some else to shoot it or its rooted

[Blr243]

I won’t be firing very well either when I turn 62

[bigpete]

Sounds a bit strange, I had a 60s micro groove Marlin and it would put 3 x 150gr into a dime a 100m. Either you need to get some else to shoot it or its rooted

If the pills are tumbling it won't matter who shoots it.

[bladeracer]

Hi all, first post on here.

I was wondering if there's anyone out there who has had issues with the old marlin 336's with the micro groove rifling and stablizing Factory .30-30? so far i've only taken it to the range once (it's my first rifle and i can't get out to the range often), but every single round i put through it tumbled, keyholed and went all over the target at 25-50m, i put 18 rounds of Winchester SuperX 150gr HP through it as well as 5 rounds of Hornady Leverevolution 160gr FTX just to see if there was a difference. I know it's not a lot of information but hopefully someone can give me some guidence on whether this may be a simple ammo issue or something with the rifle.

My rifle is a JM stamped Marlin .336SC in .30-30 and made in 1960.

Something very wrong there, even Microgroove should stabilise jacketed bullets just fine.
Is the muzzle fine? Hasn't been shortened with a hacksaw?
Does the .30-30 bullet just barely fit into the muzzle? Maybe it's not a .30-30?
I generally see tumbling if the bullets are under-size.

[pomemax]

First rifle 25-50 range have you shot much before next time at the range try shooting of a rest and bag you can hire at most range,s can I suggest for you next rifle a .22 that you can shoot a few thousand a week

[Spoons01]

Something very wrong there, even Microgroove should stabilise jacketed bullets just fine.
Is the muzzle fine? Hasn't been shortened with a hacksaw?
Does the .30-30 bullet just barely fit into the muzzle? Maybe it's not a .30-30?
I generally see tumbling if the bullets are under-size.[/quote]

Muzzle/crown are fine, it seems to be factory length with no modifications, haven't tested a .30-30 bullet in the muzzle and it's definitely chambered in .30-30. I've also checked the barrel and the rifling looks perfect as far as i can tell.

[Spoons01]

First rifle 25-50 range have you shot much before next time at the range try shooting of a rest and bag you can hire at most range,s can I suggest for you next rifle a .22 that you can shoot a few thousand a week

I've shot a decent amount before, I've been hunting/shooting for about 2 years just haven't owned a rifle until now, whilst I'm not the best shot around it's not me, the bullets were tumbling and going through the target sideways

[bladeracer]

Muzzle/crown are fine, it seems to be factory length with no modifications, haven't tested a .30-30 bullet in the muzzle and it's definitely chambered in .30-30. I've also checked the barrel and the rifling looks perfect as far as i can tell.

I don't have any other ideas just now, but I hope you let us know if you find the cause.

[straightshooter]

Hi all, first post on here.

I was wondering if there's anyone out there who has had issues with the old marlin 336's with the micro groove rifling and stablizing Factory .30-30? so far i've only taken it to the range once (it's my first rifle and i can't get out to the range often), but every single round i put through it tumbled, keyholed and went all over the target at 25-50m, i put 18 rounds of Winchester SuperX 150gr HP through it as well as 5 rounds of Hornady Leverevolution 160gr FTX just to see if there was a difference. I know it's not a lot of information but hopefully someone can give me some guidence on whether this may be a simple ammo issue or something with the rifle.

My rifle is a JM stamped Marlin .336SC in .30-30 and made in 1960.

Marlin microgroove barrels from that era were noted for excellent accuracy so there must be a reason for the issues you are experiencing.
You must understand that bullet holes all over the target and keyholeing can be due to two unrelated issues especially at such a close target range.
I assume you understand what keyholing is: that is the bullet going sideways through the target.
I also assume that you have the original factory barrel with original factory stampings telling you it is 30-30 cal. and not 32 Win Special and you have tried pushing a bullet into the muzzle as others have suggested but without success.
First thing is to inspect the barrel.
Open the action until you feel the bolt reach round about the half cock position. Unscrew the lever pivot and pull it out. Pull out the lever and the bolt. Don't lose the ejector.
Clean the barrel. Look down the barrel to see if there are any "rings" or bulges.
If there are none and the rifling looks generally OK, (don't worry if there is a bit of pitting or other marks), the barrel is not the problem.
A barrel can look quite ugly and still shoot OK.
Next step is to look down and center the bore on the target by setting up the rifle securely on some form of rest but preferably in padded jaws of a solid vice. Now compare where the scope is pointing in relation to where the barrel is pointing. If the scope is pointing a long way above the target then you have your answer.
Even if you happened to have a very loose barrel or even a 32 cal barrel the bullets would be unlikely to keyhole at such a short range but accuracy would be poor.
I suspect your keyholeing could be due to ricocheting because of a badly set up scope. Understand that the scope would have to be set such that the barrel is pointing down quite a lot in relation to the line of sight.
IF that is the case then take the opportunity to rectify before reassembling but when you do remember to position the ejector in the receiver first.

[deanp100]

First rifle 25-50 range have you shot much before next time at the range try shooting of a rest and bag you can hire at most range,s can I suggest for you next rifle a .22 that you can shoot a few thousand a week

How does practice stop a bullet tumbling.?

[bigpete]

First rifle 25-50 range have you shot much before next time at the range try shooting of a rest and bag you can hire at most range,s can I suggest for you next rifle a .22 that you can shoot a few thousand a week

How does practice stop a bullet tumbling.?

Yeah.....it doesn't....

[Gamerancher]

I'd be slugging the bore.

[wrenchman]

you will find many of the 3030 marlins are bigger then 30cal put the round in the front

[bladeracer]

I suspect your keyholeing could be due to ricocheting because of a badly set up scope. Understand that the scope would have to be set such that the barrel is pointing down quite a lot in relation to the line of sight.
IF that is the case then take the opportunity to rectify before reassembling but when you do remember to position the ejector in the receiver first.

A very good point if the target is close to the ground.
I have had Carcano bullets hit the target after bouncing off the ground when I was trying to get it to shoot lighter .264" bullets.

I'm still convinced this must be an issue of the bullet not fitting the bore, most likely because it's not a .30-30.

[Oldbloke]

I suspect your keyholeing could be due to ricocheting because of a badly set up scope. Understand that the scope would have to be set such that the barrel is pointing down quite a lot in relation to the line of sight.
IF that is the case then take the opportunity to rectify before reassembling but when you do remember to position the ejector in the receiver first.

A very good point if the target is close to the ground.
I have had Carcano bullets hit the target after bouncing off the ground when I was trying to get it to shoot lighter .264" bullets.

I'm still convinced this must be an issue of the bullet not fitting the bore, most likely because it's not a .30-30.

Bouncing off the ground seems possible, but unlikely to me.

Wrong ammo seems more likely.

Wasn't the parent cartridge of the .375 Winchester the .30-30?? Just a thought.

[bladeracer]

A very good point if the target is close to the ground.
I have had Carcano bullets hit the target after bouncing off the ground when I was trying to get it to shoot lighter .264" bullets.

I'm still convinced this must be an issue of the bullet not fitting the bore, most likely because it's not a .30-30.

Bouncing off the ground seems possible, but unlikely to me.

Wrong ammo seems more likely.

Wasn't the parent cartridge of the .375 Winchester the .30-30?? Just a thought.

Mine weren't richochets, they were just bouncing due to the extremely low velocity from not sealing the bore, like 700fps and less. If this .30-30 is chambered for any of the .30-30 based cartridges, most likely the .32, that would explain the bullets falling out the muzzle. I can't think of any other potential cause.

[Gamerancher]

Not exactly, parent case for the .30-30 was the .38-55. The .375 Winchester is in reality just a +P version of that original cartridge, they are .010" shorter and are thicker in the case walls. They will fit but they should never be chambered in an old .38-55 rifle for obvious reasons. The Model 94 " Big-Bore " Winchesters they designed for the .375W cartridge had a beefed up action to handle the higher pressure.
Question for the O.P, what do the cases look like after firing?
There was a move in the U.S in the late 60's early '70"s to re-bore and re-chamber .30-30's to .38-55Win as no "new" rifles where being chambered for it at that time, although it is a big change, I'm pretty sure you would notice your cases coming out with a straight wall after firing...
I have two .30-30's that have been done, one was done by P.O Ackley himself.
.32 Winchester Special is another possibility for a rebore/rechamber job.
P.S. Re-chambered /bored rifles are usually stamped to that effect, although it is not guaranteed.

[pomemax]

First rifle 25-50 range have you shot much before next time at the range try shooting of a rest and bag you can hire at most range,s can I suggest for you next rifle a .22 that you can shoot a few thousand a week

How does practice stop a bullet tumbling.?

Not at all but if your going to the range a .22 and a few rounds sent down range mellows you out a bit I find.