Primer Output pushes bullets into rifling.

[msinc]

I would imagine the weight of the bullet also comes in to play. I can't see the ignition from a primer pushing a 400 grain bullet out of the case.

I cant see the case remaining intact and the gas pressure from the primer staying compressed in the case. I agree that it wont/cant go far.....but I have seen one 45-70 lodge a heavy cast bullet right at the throat. It was an 1886 Winchester I installed a barrel liner in. The owner brought it back to get the bullet out and have the barrel assessed.
I also think there are two different things being discussed on this thread...there has to be a difference between what a bad primer that wont ignite the powder can accomplish and what a good primer loaded in a case with no powder is capable of.

 

[Beau]

I've had .223 cases loaded without powder using bullets from 52gr on up. Never had one leave the case using assorted magnum primers.

 

[Bart B.]

I had one Eley 10X rimfire bullet stop 2" short of the muzzle in a 26" barrel.

Had to load 42 rounds of 7.62 handloads in a Garand to put 2 sighters and 20 record shots on target in a 1000 yard match. 20 cases had no powder in them. No bullets in the duds left the case jamming into the throat; all manually ejected normally as complete rounds except no powder, inside was blackened with primer residue.

Real " ball and dummy" exercise.

 

[243winxb]

The first 2015 link/test is with powder.

Testing was both ways. With and without powder.

I find the with powder more interesting.

 

[Bart B.]

A 30 caliber bullet needing 30 pounds of force to push it forward in the case neck needs 403 psi in the case to do that.

 

[243winxb]

A 30 caliber bullet needing 30 pounds of force to push it forward in the case neck needs 403 psi in the case to do that.

Would this mean the bullet has left the case neck before the neck has expanded and prior to any significant propellant burn?

 

[Bart B.]

Would this mean the bullet has left the case neck before the neck has expanded and prior to any significant propellant burn?

No, because the bullet moves only a few thousandths before touching the rifling. Most of the bullet is still in the case neck. The neck behind bullet contact will expand a tiny amount, so thinks me.

There will be some propellant burn, never seen any data on how much.

I think many hundreds psi is needed to push a 30 caliber bullet fully into the rifling.

 

[Bart B.]

Theoretically, any expanding gas inside the case would move the bullet, no ? Especially if the case is full or near full ?

No. Only when pressure in the case pushing on the bullet is enough to overcome its release force.

Psi times cross section area in square inches of bullet equals the force on it.

 

[rr2030]

No. Only when pressure in the case pushing on the bullet is enough to overcome its release force.

Psi times cross section area in square inches of bullet equals the force on it.

Ok, I'll take you word on the math, is it unlikely there would not be enough force from a primer in a 5.56 or 7.62 case. These cartridges produce 30,000+ psi as they consume the powder/primer. Is it possible the spike in pressure from the primers enough to get things moving? Not arguing, just trying to understand.

 

[243winxb]

The smaller the spit hole (flash hole) the higher the primer pocket pressure.
NOTE: Military primers a crimped into the pocket. As everyone knows.

the No. 41 primer specification has not changed. The pressure in the primer
pocket is calculated to be approximately 23,890 psi

 

[Ggmac]

I've got pics from an old book of a 30-06 Frankfort arsenal ( I think ) anyway a US military case that was loaded but no primer flash hole . It compressed a loaded case , powder and bullet a considerable amount . Now remember , it couldn't release the bullet and the case was a std loading so it compressed the powder and mushroomed the case , sizing it to the rifles chamber .

 

[Bart B.]

I've got pics from an old book of a 30-06 Frankfort arsenal ( I think ) anyway a US military case that was loaded but no primer flash hole . It compressed a loaded case , powder and bullet a considerable amount . Now remember , it couldn't release the bullet and the case was a std loading so it compressed the powder and mushroomed the case , sizing it to the rifles chamber .

What part of the case was mushroomed?

 

[Ggmac]

Neck shoulder junction . I think it was Phil Sharpe book . It's old but reliable info .

 

[Laurie]

QUOTE="joshb, post: 37365208, member: 1293079" I’ll be the stubborn old mule that cries Bullcookies concerning the study. I’ve seen a bullet pushed out of a 308 case with .03 neck tension by a primer and no powder. I “loaded” it.

I've seen that happen several times over the years and the bullet was usually engraved enough to need the services of a cleaning rod or drop weight to clear the bore and resume shooting. These would be full-size cartridges - 308, .303 Brit, .30-06 and similar using LR primers. With powder in the case, I've also had instances of misfires where the bullet stayed in the neck as others report. Go figure!

QUOTE="joshb, post: 37365208, member: 1293079" I just can’t believe the bullet moves before powder ignition.

I imagine you're correct there too.

There is an interesting side to this however that people might ponder. It is generally accepted that maximum pressures develop after the bullet has started to move and in many instances has reached the rifling. So, the common view that COAL as loaded and unfired (as opposed to what it has become when the bullet is at the rifling) affects pressures in itself may be incorrect in some circumstances. If so, QuickLOAD will overstate pressures and MVs for situations where there is a lot of freebore (as in ammunition loaded short to fit a magazine and bullets make a large jump) if the COAL as loaded is input.

 

[JRS]

I just can't picture a primer alone generating enough pressure to push the bullet, which is bigger in diameter than the bore, very far.

 

[Bart B.]

Neck shoulder junction . I think it was Phil Sharpe book . It's old but reliable info .

That can happen if the case mouth slams into the chamber mouth from firing pin impact.

 

[Ggmac]

The Complete Guide to Handloading , by Phil Sharpe third edition , second revision supplement . Page 48 , beginning of chapter 6 , Primers - Development And Manufacture . I can email pics if someone can post them . I'm lacking in that stuff , only know how to email pics .
Gary

 

[Ggmac]

That can happen if the case mouth slams into the chamber mouth from firing pin impact.

You should see the compression / mushroom from the primer . It is a fantastic picture that's worth looking at . Just primer ignition can compress a 30-06 that much !

 

[243winxb]

The M16A1 barrel 17.7" with out flash supressor. No powder test.
All bullets recovered from the bore were partially engraved by the
rifling.



This test is to see if a round will chamber after a squib round lodges a bullet in the barrel

Note: Test is with 3 different M16s. New, 10,000 rounds fired and 30,000 rounds fired.

They blew up the old 30,000 round gun at end of test. Fired a round into the bullet lodged in the barrel.

 

[243winxb]

You should see the compression / mushroom from the primer . It is a fantastic picture that's worth looking at . Just primer ignition can compress a 30-06 that much !

Cool photo, thank you Gary.