Quick question. Being new to the big bore scene, I have yet another question.

Are there any special techniques to preventing bullets from creeping forward in their cartridges while in the magazine after recoil?

I am not positive that this is happening in my 450 Dakota, but I plan to check next time I go out.

I ask, because I have a feeling that they might be. I know that even though I am using a Lee factory crimp die for my 45/70 Gvt, that if I shoot hot loads in my Magnum research revolver, that the bullets in the cylinder are moving forward.

The reason I suspect that my 450 loads are creeping is, I recently shot a reload in my 450 (I did not load it myself). It was shot #2 in my string, and had been sitting in the magazine when shot #1 went off. It jammed up when cycling the bolt. upon extraction, you can clearly see where the lip was pulled back and crinkled up in the chamber.

My assumption was, that the brass was deformed and I had not noticed it. But I am looking closer, and I now see that the crimp is rearward of the cannalure (SP?) in the bullet. I am not 100% positive, but I think the bullet slipped forward after the preceding shot.

See photo.


As I said, I plan to check this on my loads next time I go out.

Do folks who shoot big bores do anything special on crimping?

I don't crimp any of mine, but I do make sure I have tight neck tension.

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I crimp all of mine, doubles or bolts.

Rob...I also shoot a 450 Dakota. I've had two rifles in that chambering and both had magazine designs that allowed the cartridge to move forward during recoil, deforming the noses of Swift Aframes. The crimping prevents the bullet from being pushed back into the case as opposed to what you believe is occurring.
I always crimp the heavy recoiling chamberings.

I'd carefully inspect the rounds prior to firing...I think you have another problem.

Looks more like a deformed case neck that you ran through the die when seating the bullet.

Crimp them all. Only buy bullets that have cannalures so that you can crimp them.

I will definitely crimp. I picked up a Special order Lee factory crimp die for the 450 Dakota just for that purpose. I was wondering if there were any other techniques folks use in addition to crimping, or a specialized crimping method that helps reduce movement of the bullet.

quote:

Originally posted by bobgrow:
The crimping prevents the bullet from being pushed back into the case as opposed to what you believe is occurring.

Are you sure? I ask as I have two data points that make me think the opposite.

First is a scope issue I had on my 375 HH. I found that after shooting it with the rings not quite tight enough, the scope moved forward after shooting.

Second, is that 45/70 Gvt handgun I have. After taking one shot, My crimped hand loads (crimped hard into the Cannalure) had moved forward out of the case about 1/10th of an inch. They were fine when they went into the cylinder, and they did not impact anything on the forward motion as the revolver cylinder is of course open ended. So the only thing I can think that would cause a crimped bullet to move forward after a shot would be recoil.

What I was told on the scope, was, that as the gun moves back from recoil, the scope wants to stay put, so the gun is actually moving rearward while the scope stays in place. i.e. The gun snaps back upon firing, and then slows to a stop, rather than a gradual increase in speed followed by a sudden stop. The former would cause the scope to move forward in the rings, the latter would cause it to move backwards. If true, I would assume the same principle would apply to a shell sitting in a magazine or chamber (in the case of a double).

But again, I'm only into my first year of shooting the heavier recoiling firearms so I have much room to learn!

Rob,

I crimp everything from 375 up. Next time you are at the range leave a couple of rounds in the magazine for the whole session and then check them for length. Also make sure all your cases are trimmed to the same length and adjust your Lee crimp die to apply the max crimp without buckling the case.

Mark

quote:

Originally posted by Rob H:

quote:

Originally posted by bobgrow:
The crimping prevents the bullet from being pushed back into the case as opposed to what you believe is occurring.

Are you sure? I ask as I have two data points that make me think the opposite.

First is a scope issue I had on my 375 HH. I found that after shooting it with the rings not quite tight enough, the scope moved forward after shooting.

Second, is that 45/70 Gvt handgun I have. After taking one shot, My crimped hand loads (crimped hard into the Cannalure) had moved forward out of the case about 1/10th of an inch.

You are correct in both cases, but wrong about ammo in a magazine fed rifle. With a revolver or double rifle the case is being pulled to the rear by the rim under recoil. The bullet stays where it is and moves forward relative to the case.

In a magazine rifle, the front of the magazine is what stops the bullet under recoil. The case stays where it is, and the bullet moves rearward relative to the case.

OK, so that makes total sense!

So if after experimenting, I do end up seeing a bullet slip forward while experiencing recoil in a magazine rifle, what would cause that?

Mark, Agreed. In the past, I was not trimming brass if it fell in the range listed in my books (usually .010 between max and trim to length). But last year I started to trim all my brass to the trim to length prior to loading. And the beauty of the Lee die is that it crimps with a collet from the sides rather than by pressing down and potentially crushing the case. This also prevents the OAL from changing too.

Lee dies are not my favorite, but I love their crimp dies.

I'll try your experiment with leaving one in the mag too.

quote:

Originally posted by Rob H:
So if after experimenting, I do end up seeing a bullet slip forward while experiencing recoil in a magazine rifle, what would cause that? ?

The only thing that would allow the bullet to "slip forward" in the case during recoil would be something holding the case in place. That would be really, really rare.

Rob H, in bolt action rifle the bullets will get pushed into the case because they hit the front of the magazine during firing. I have seen the bullets move forward in the case only in a double rifle and only the barrel not being shot.

quote:

Originally posted by steph123:
Rob H, in bolt action rifle the bullets will get pushed into the case because they hit the front of the magazine during firing. I have seen the bullets move forward in the case only in a double rifle and only the barrel not being shot.

Correct, and if you look at the crimp groove on projectiles (not the cannelured type) these are usually set so that there is a definite lip in the groove towards the nose of the bullet i.e. when the case mouth is crimped into this groove the bullet cannot be pushed into the case which is ideal for bolt actions but the opposite to what is required for doubles. As you have rightly pointed out, the bullet from the unfired cartridge in the second barrel of a double can be 'pulled' if not a tight fit in the case neck.
It does seems that perhaps the cannelured type crimping groove on bullets may offer the best solution for crimping bullets in heavy recoiling bolt and double rifles.

great info, thanks everyone!

Hi all,

Recently, and for the life of me I cannot remember on which shooting forum, I read a thread about using some sort of adhesive on bullets to help keep them in place. At least I thought I read such. Any one else have any thoughts on this method? I thought it interesting though, perhaps, messy and what about peaking pressures?

Eh?

Stephen

Some factory ammo comes with a coloured lacquer around the bullet case neck area but I think this is only for water proofing rather than any grip on the bullet although the lacquer may provide a little grip.
You could use a wipe of lacquer on the bullet just above the base but most would be wiped off when seating the bullet. For this reason I would not apply any to the case mouth as this will be wiped down into the case. The micro layer of lacquer left on the bullet when seating may provide enough grip and maybe this is how it is applied on factory ammo with the 'wipe' showing around the neck/bullet join. To be effective, I suppose the lacquer would need to harden in the absence of air much like Loctite products do then again any exposed lacquer would have to also harden in air. I give up, I don't know how it is done.