Tubular magazine rifles

[Oldnamvet]

I think that I was told from birth that you couldn't use spitzer type bullets in a tubular magazine rifle since they could detonate a primer and then the whole tube/rifle would blow up. Sounded reasonable and I have always believed in being safe. The thought of losing a part of your anatomy from a rifle explosion didn't appeal to me at all.
However, has this happened in the past? How much recoil is needed to set off a primer? Did anyone ever scientifically study this? Is it related to the strength of the magazine spring? A stiffer magazine spring doesn't allow separation between rounds during recoil so they could hit together harder? I guess I want to convince myself that this really happens. What is the effect of different types of bullet (lead tip vs FMJ vs polymer tip)? I keep thinking that the new lever evolution bullets may not be that necessary. Would the polymer tipped ballistic tips do as well? Anyone have any real scientific information on studies done on this issue? I have no intention of trying it myself.
Some days I have too much time to just think about things. It sometimes takes me in wierd directions.

 

[Roudy]

Pointed Bullets

Hey Oldnamvet,
I don't have any experience with tubular magazines, but have recently read and article somewhere that one of the major bullet manufacturers is introducing a bullet with some kind of polymer tip that is pointed to improve ballistic performance but apparently is soft enough to preclude detonation in a tubular magazine.

Since I reload I have steered away from tubular magazines so that I could use pointed bullets.

Roudy

 

[Howie38]

Hey Oldnamvet,
I don't have any experience with tubular magazines, but have recently read and article somewhere that one of the major bullet manufacturers is introducing a bullet with some kind of polymer tip that is pointed to improve ballistic performance but apparently is soft enough to preclude detonation in a tubular magazine.

Since I reload I have steered away from tubular magazines so that I could use pointed bullets.

Roudy

Hornady- Leverevolution, 160g 30WCF

 

[Jim K]

The stories are true, but not many people know what really happens and why a discharge is dependent on more than the bullet shape.

First, it won't happen with a full magazine, a magazine short one round of being full, or with only one round. What happens is that when the gun fires the recoil drives the gun back, but the rounds in the tube try to remain where they are due to inertia. (See Mr. Newton about this.)

So, the rounds in the magazine move forward compressing the magazine spring. When the recoil force stops, the magazine spring reasserts itself and slams the rounds back. The rearward round stops abruptly on the shell stop, and the primer of the forward round can impact on the bullet point of the round behind it. The greatest danger is when there are only two rounds in the magazine, since that is the time when the spring can move the rounds to the rear with the greatest force.

It is often said that the way the rounds lie in the magazine prevents the bullet nose from being in the middle of the forward round. That would be true if the rounds were just lying there. But they are not, they are in mid-air, moving to the rear, and the bullet point can be anywhere in the tube.

It is not necessary that the bullet involved be pointed. One round went off in a .45-70 magazine when the sharp edge of the flat point round dug into the primer ahead.

Now, does the gun "blow up"? Not really. Since the fired round is not confined enough, all that usually happens is that the magazine tube is bulged out or split, but sometimes the shooter's forearm is burned or bruised from either gas escaping or from a blow by the magazine tube or a piece of the foreend wood.

The old Remington pump rifles have spiral grooves in the magazine tube to prevent this. All kinds of magic has been attributed to those grooves, but in fact all they do is put enough of a drag on the rims of the rearward moving rounds to slow them down. Slowed down, they don't have enough force to drive the primers into the bullet point of the rearward round.

Jim

 

[The Real Hawkeye]

True. And, in fact, if you are happy with a two shooter, you can load .30-30 with any kind of pointed bullet you want. Just load two in the mag. No possible detonation that way because when one of them is fired, the other is all alone. Pointed bullets are a great improvement for the .30-30 in terms of retained velocity, foot pounds of energy on target and extended effective range due to those factors, plus flatter trajectory. After all, how many hunts have you been on when a fast third shot was necessary. With practice, the third shot can be loaded pretty quick anyway, if you think it might be needed.

 

[Father Knows Best]

I've seen two mag tube explosions in the last few years. Both involved reproduction Henry rifles, and happened when the shooter let the follower slip out of his hand and slam down on the rounds in the tube. One was using round nose lead bullets (a no-no), and one was using flat points.

In both cases, the gun (retail $1100!) was basically destroyed because the barrel and mag are one piece on a Henry. Neither shooter was injured, though they were severely embarrassed.

 

[The Real Hawkeye]

I've seen two mag tube explosions in the last few years. Both involved reproduction Henry rifles, and happened when the shooter let the follower slip out of his hand and slam down on the rounds in the tube. One was using round nose lead bullets (a no-no), and one was using flat points.

In both cases, the gun (retail $1100!) was basically destroyed because the barrel and mag are one piece on a Henry. Neither shooter was injured, though they were severely embarrassed.

What did it sound like? Was it like an M80, or just a loud fizzle?

 

[Ares]

The interesting thing is that I just read an article last month that Hornady has now made a spitzer type bullet specifically made for lever guns. They call it LEVERevolution. Supposedly the tip is softer than others so it will not set off a primer while being stiff enough to hold shape in flight.

 

[Roudy]

For history buffs

One of the very early bolt action rifles, it might have been a Lebel, had a tubular magazine and pointed FMJ bullets. The picture I saw of the cartridge base showed a circular depression around the primer. The explanation that I recall was that the point of the rear bullet was "captured" by the depressed ring and prevented discharge in the magazine. One would suspect that the tube somehow kept the bullets canted a little to provide room for the pointed bullets to ride in the groove.

Now since I wasn't around at the time I'll just have to take their word for it.

 

[DevLcL]

One was using round nose lead bullets (a no-no)

I have a Winchester 94 and I mainly shoot the white box 30-30 Win. It has a round nose and a lead tip, are you saying this is bad?

-Dev

 

[Father Knows Best]

I have a Winchester 94 and I mainly shoot the white box 30-30 Win. It has a lead tip, are you saying this is bad?

-Dev

I'm saying that round nose bullets are a bad idea in a tubular magazine, for the same reason that spitzers are a bad idea. A round nose, flat point (RNFP) is a modified round nose for use in tubular magazines.

 

[Ares]

The factory made ammo for the 30-30 is fine. Those Winchesters will work just fine and are perfectly safe.