Need to crimp bullets?

[CouldBeWorse]

I just started reloading for my M1917. I'm using a Lee Classic, to get my feet wet. My first batch shot well (for me) doing slow-fire. I used 125 gr. Speer TNT for reduced recoil, and they felt nice.

Then I reloaded the same casings a second time, and tried them in rapid fire: the first two cartridges both fell apart during feed, with the bullet pulling out of the casing.

I'm wondering if I need to crimp bullets if I want to use the magazine? The Speer TNT have no crimp ring. Or maybe there's another factor (the smaller bullets are shorter in the neck; or that I didn't polish inside the neck; or that I need to check the feed ramp)?

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[mannparks]

couldbe, my first thoughtis the sizing die.
did you run the cases all the way up into the sizeing die,the neck of the case should be tight when running in the bullit.
with a bolt gun you should not have to crimp.

[browningautorifle]

The only time you need to crimp is with automatic weapons, tube fed magazines and military ammo that receives a great deal of handling. I agree that assembly is at fault. I've see this very thing, and even though I've gone over the steps with the reloader,They would claim they did all that. Then when I ran the cartridges through my dies the error was eliminated. Just make sure you full length size and they will hold the bullet fine.

[CouldBeWorse]

I neck-sized only for both the first and second reloads, as it's a bolt gun and the neck-sized cases load, fire and extract fine when I load one round at a time. I will pay extra attention to seating during neck-size.

I had planned to trim every 3 or 4 reloads, but didn't get that far.

[emmagee1917]

Of course , the other opinion holds that those who load target loads where the bullet is a few thousands away from the rifling and do not use crimping and get excelent results is due to the slight hold up getting the bullet out of the case due to the resistance of the rifling before the bullet gets up some steam. In other words , they duplicate a crimp situation without a crimp. Just buy a Lee crimp die ( they're cheep ) and see if it makes a difference. I load for several different non-target type rifles ( M-1s , 1903A3s , M1917s , an OOW BAR ) and just throw together a load of 47grs IMR 4895 and pulled 150 gr M2 bullets and still get good groups , usually better than 2 inches out of these GI spec rifles though a couple of worn ones push 3 . I use RCBS small base dies and a lee crimper .
Chris

[mannparks]

not to be a smart as; but what is the bullit dia.

[Patrick Chadwick]

QUOTE=mannparks;227131]not to be a smart as; but what is the bullit dia.[/QUOTE]

Standard 0.308" diameter, nothing special. But you are likely to get better results with a Sierra or Lapua 168 gn HPBT, seated to be about 10 thou off the lands, as this gives a better fit of the bullet in the throat.

With the light bullets, either there is very little in the neck (i.e. poor friction grip) or if there is plenty in the neck (about 1 caliber length is sufficient), then the bullet is way, way off the lands on starting, and you can have a "freebore" situation, where the neck expands and hot gas flows round the bullet before it can reach the transistion cone in the throat. Since the case has some play in the chamber, and will sit on the bottom of the chamber, this means an assymetrical thrust on the bullet, tending to cause it to be engraved on the skew (bad for accuracy) and the gas blowby will, in the long run, tend to erode the throat.


Patrick

[Bruce_in_Oz]

If the case neck is not gripping the bullet sufficiently, several problems will arise.

Bullets will float around in the necks during recoil.
Probably worse than that, bullets can be fored back into the case during feeding. This will cause erratic pressure rises and poor consistency on target.

For quite some years now, I have been using the "Lee" collet-style crimpers sold as "Factory Crimp" dies and recommended above by Emmagee1917.

These can be set up to form anything from a subtle "squeeze" to pressing the end of the case neck well into the bullet, pre-cannelured or not.

These dies are pretty much essential for semi-auto toys.

One of the most intriguing things about these dies is the effect on grouping. In many instances, for a given bullet, powder, case and primer, grouping will improve. I suspect that this is a result of the crimp slightly but consistently controlling the initial release of the bullet into the throat. This would contribute to a more consistent burn regime and pressure curve.

I have had good results with "Factory Crimp" dies in .223, .7.62 x 39, 308Win, .303 and 7.5 Swiss.

[Mohillbilly]

Plus 1 on the bullet set back . I was lucky as I had a couple do just that , setback . I was useing a soft point hunting bullet and was haveing hard chambering .I shot two and they kicked like a Missouri mule . the third one I pulled out of the rifle and that 180 gr. was half way back in the neck of the case. No it did not setback the bolt or bulge the chamber ,and I still got my eves and fingers but I was really lucky . Those shots (the second one ) did put small cracks in the stock behind the back stock bolt. I have glued them up and recessed behind the action and all is well now . GI ammo does fine and does not set back but I am on the lookout .

[paul34]

I shoot a lot of 308 pulled bullets I have found that I need to crimp if I am shooting one of my 1917s. I never have to worry about it with any of my 03s. I think it is basically the loading ramp of the 1917. I have 3 of them and I have 6 03s and 2 03A3s. I never have any problem with the Springfields, only the 1917s. Good luck Paul