Bending bullets?

[SmartDonkey]

In a recent gun store conversation a customer was talking about a shooting video that he had just seen- and in the video they said that if you seat long bullets deeper into the case that when the powder ignites it can bend them. Never heard this before- always tried to avoid this because it takes up powder space- but never worried about bending the bullet??

The video was marketing a new round so is this the usual BS marketing to justify something- or a real issue?

 

[Brettmparker1]

I call bullshit. But should be interesting to see everyone’s opinion on this.

 

[KnowNothing256]

I don’t really see how you could get substantially asymmetrical forces from the ignition pressure unless the case was significantly underfilled, which brings other problems with it. The bore would force any gross bend back into shape too, although even a little spring-back from that forcing would affect accuracy. A ton of things have to go very right for a sub-MOA group, especially at longer ranges, so if a bullet got bent at all you’d get issues downrange.

In short, I don’t really see it happening but if it did you’d have accuracy problems.

 

[m1match]

Me too I call bullshit. An igniting powder charge generates gas which pressurizes the case, with said pressure being exerted evenly on all surfaces in the case including the bullet, the bullet moves out of the case into the throat because that's the path of lease resistance. There's no bending forces anywhere on the bullet

IMHO this is typical internet BS where anyone who thinks they know what they are talking about are really idiots and really shouldn't be putting any info out there.

 

[Supersubes]

Shot way too many 260 rem with 140’s at 2.8” OAL to believe that.

 

[FN15]

First thing that came to mind

 

[Steel head]

Shot way too many 260 rem with 140’s at 2.8” OAL to believe that.

 

[Temper]

Sounds like fuddlore.

 

[J.J.chago]

Only thing I can think of, is too much bullet jump, making the bullet engage the rifling off center. Maybe he didn’t know the “correct “ terminology. For instance some of my old reloads not being concentric and engaging crooked

 

[Feniks Technologies]

Only thing I can think of, is too much bullet jump, making the bullet engage the rifling off center. Maybe he didn’t know the “correct “ terminology. For instance some of my old reloads not being concentric and engaging crooked

Only issue with this common theory is only possible if:

- Somehow jumped so far, the bullet wasn’t in the throat (not likely).

- Throat has a ton of clearance around bullet


But on most chambers we run, there’s only about .0005” clearance around the bullet.

So any runout more than .0005” will be straightened to the .0005” of the throat.

 

[hafejd30]

It’s their excuse for “embracing the suck” in life

 

[Mooseknuckles]

Only thing I can think of, is too much bullet jump, making the bullet engage the rifling off center. Maybe he didn’t know the “correct “ terminology. For instance some of my old reloads not being concentric and engaging crooked

You mean something like this??

 

[Supersubes]

View attachment 7787894
You mean something like this??

Its cheating if you have to use an AR-10 to do it.

 

[J.J.chago]

View attachment 7787894
You mean something like this??

WTH. Ray Charles could see that run out

 

[Ledzep]

Me too I call bullshit. An igniting powder charge generates gas which pressurizes the case, with said pressure being exerted evenly on all surfaces in the case including the bullet, the bullet moves out of the case into the throat because that's the path of lease resistance. There's no bending forces anywhere on the bullet

IMHO this is typical internet BS where anyone who thinks they know what they are talking about are really idiots and really shouldn't be putting any info out there.

Pressure distributes evenly in the steady state, but not necessarily in the transient build up. Even so I have a hard time believing it's off-center enough to cause meaningful damage to the bullet.

Nonetheless, principle axis tilt is thought to be one cause for poor dispersion. Ultimately the bullet is going to conform to the bore and straighten out, but the thought is that an uneven start damages the bullet, contributing to more erratic flight. I guess we'll know when we start making clear barrels where the bore can be seen in ultra slow-mo...

Although the rise in pressure is rapid, it's not immediate, and as far as I'm aware in pretty much every case the bullet is started into the rifling, and the resistance from rifling engraving accounts for something like a ballpark of 20-30% of the total pressure build up (very rate dependent thing). In college I did a thick wall steady state pressure calculation/simulation for a Rem Varm barrel profile and was surprised to see that the bore was expanding in the ballpark of .0010-.0014" if memory serves, at peak pressure. You can bet that a soft little lead-core bullet is getting a good kick in the ass and obturating to seal the bore (mostly), essentially forcing a "tapered" bore as the pressure behind the bullet drops down the length of it... So it's not like no distortion of the bullet is ever happening, but to experience significant axial bending before entering the throat/bore is a stretch I think.

 

[Mooseknuckles]

Only thing I can think of, is too much bullet jump, making the bullet engage the rifling off center. Maybe he didn’t know the “correct “ terminology. For instance some of my old reloads not being concentric and engaging crooked

WTH. Ray Charles could see that run out

Haha FGMM stove piped in my ar10. Have a couple of them like that.

 

[Steel head]

 

[hafejd30]

View attachment 7787897

Winds left to right 56 mph,

Me:

“NOT A FUCKING PROBLEM!!!”

 

[J.J.chago]

View attachment 7787897

If you look close you see the culprit. Varget, obviously a bad lot, kernels spilled on the table. I can dispose of that properly

 

[Mooseknuckles]

View attachment 7787897

Stealing that