Mystery is driving me nuts - what's wrong with that round?

[CocoBolo]

With your latest post considering the OAL is 1.245 same as the other bullets, you have an over sized bullet aka bad profile. I have seen a 45 bullet in a 40 case and it was fired in a 40 SVI limited gun. Yes he got the un-expected outcome since he didn't notice it till afterwards. A split barrel.

Not to say you have a 40 bullet since they are normally flat nose but with hitting the rifling at the same length as other it has to be fat in the wrong part of the nose..

Edited May 4, 2010 by CocoBolo

[Supermoto]

maybe the ogive is off and you have a bad bullet

[Foxbat]

maybe the ogive is off and you have a bad bullet

It kinda sounds that way, doesn't it? Bullets are MG CMJ, and in decades I have not yet seen such a case of serious shape variations.

[G-ManBart]

Wow, that's pretty weird, especially since it chambers in the other gun. It would be interesting to compare a casting of the chamber/throat of the two guns and see if that sheds any light on the difference. R,

Edited May 4, 2010 by G-ManBart

[usmc1974]

This may sound crazy, but did you look in the bore to see if a bullet wasa stuck in the barrel.

[Foxbat]

No... no bullet stuck there!

[redwoods]

I know you already have thought about the oal and chamber checked them. I was having jams in my open gun and it would not run 100percent. I changed from a sprinco guide rod to a one piece steel. I put in a stronger recoil spring. That did not work. I worked on the aftec extractor claw and also took it out and worked the springs. That did not work. I changed my oal from 1.245 to 1.235 or 1.230 and it runs 100 percent now. The rounds chamber checked when they were longer and I even changed the crimp from low to high. I even tuned the feed lips of my mags. Make smaller rounds, 1.230 oal, and see if that works. It worked for me when my gun would not go into battery. It is a simple thing to do, and if that is not it, then you would not have changed your gun around, only your die.

Randy

[RoryW]

check the bullet to see if it is straight. i have had bullets get bent and load fine but will do similar things. how this happens is if the pin that holds the round in the shell plate is missing during an up stroke and the base of the case is slightly off the plate, when entering the die it will leave a slight bend in the case or the bullet might have seated crooked.

[Larry White]

Thats one round right? Throw the thing in the trash and find something else to worry about.---------Larry

[Aircooled6racer]

Hello: Larry you are the best Thanks, Eric

[Bob DuBois]

Have you checked the thickness of the rim where the round goes in the extractor? If it's thicker than the other rounds may not have enough clearance to slide under the extractor.

A while back I ran into some brass that thicker and wouldn't run in my gun. Think it might have been run through a case pro with the wrong die in it, spreading the rim. As 38 super through a 9mm or super comp case pro die. A quick check with the dial indicator will check for that problem.

[Foxbat]

Thats one round right? Throw the thing in the trash and find something else to worry about.

Yes, one round that passes both the gauge check AND APPARENTLY chamber drop check, but that locks up the gun 100%. To me that is something deserving an investigation.

I am now convinced the reason is misshaped bullet, it is fatter than the rest, and it is also shorter. Problem is when you drop it in the chamber you can't tell it is not going in all the way, as it is only a small amount it sticks out, and the case wobbles in the chamber, as it should. But that small amount prevents the gun from going into battery.

[benny hill]

It's right in front of you, not enough crimp. Crimp it & all others @ .377 and retry.

[Foxbat]

It's right in front of you, not enough crimp. Crimp it & all others @ .377 and retry.

I already described the cause above.

[GrumpyOne]

Thats one round right? Throw the thing in the trash and find something else to worry about.---------Larry

I had the same thing happen with one of my super rounds (well, several of them!). After much investigation, aggravation, etc., the problem was figured out. The extractor groove was .004 bigger in certain brass than what it was supposed to be. Pulled the bullets, pounded the brass into a stump in the back yard, no more problems. Larry is right, if it's only 1 round, toss it. If it's more than one (as it was in my case), investigate. There is a thread somewhere on the forum that I started when I was having this issue, and the resolution. The problem brass has a head stamp of 1*OPT and nothing else.

[Foxbat]

There are different "one round" problems. The reason this one warranted a closer look was - it passed two checks, and it STILL jammed the gun during the match.

Maybe this is just me, but in my view this made it special. Like many here, I rely on those checks to assure 100% reliable match ammo.

The problem turned out to be rather unusual and hopefully extremely low in probability, which makes me feel comfortable going back to my routine.

[Powder Finger]

and you found out the problem?

please write more.

[Foxbat]

I did already - miss-shaped bullet. It is shorter and fatter than the rest. Net result - that one hit the rifling. It was clear from the fact that the bullet was pushed in when I forced the action closed, and there were visible rifling marks on it.

The bullet is about .020" shorter than the rest.

Edited May 6, 2010 by Foxbat

[Powder Finger]

that seems odd to me. if it droped in the chamber it should have had the back of the case above the back of the hood.

[revomodel10]

Thats one round right? Throw the thing in the trash and find something else to worry about.---------Larry

It's right in front of you, not enough crimp. Crimp it & all others @ .377 and retry.

Listen to these men,

They know things about shooting..............

[Foxbat]

that seems odd to me. if it droped in the chamber it should have had the back of the case above the back of the hood.

It did, but very little. By looking casually that was not possible to spot - only the fact the bullet was pushed in and had marks prompted me to look closer. It stuck back on the order of .020".

[ty34984]

It didn't work because it was broke

[gmantwo]

Check the rim thickness. I've had several of this headstamp brass that has a rim too thick to even go into my loader. Way too thick

[Aloha Robert]

I am a little late to party, but I have had a similar experience in 40 but not .38.

The bullet head it self was slightly mishapped. I think the clue in your case is if you force it into battery you get (what I am assuming, perhaps wrongly )rifleing marks on the bullet head. If that's what they are,that should never happen. So I think possibly your barrel has too little freebore (the transition zone from where chamber ends and riffleing begins). Increasing freebore will make all IPSC types pistols more reliable in any event and make them more amo friendly for the odd round. Off course I am assuming you checked your bullet seating die, because the odd piece of debris can definitely cause a head to seat assymetrically. The debris then becomes dislodged later and all subsequent bullets seat normally.

Part of mystery is when chamber check (even with the barrel) you check with axis of bullet aligned with case gauge or chamber itself, but when feeding it comes in comes in from angle so if you have a mishaped or incorrectly seated bullet it will stubornly lodge at top of barrel near hood. And if you really want to be super duper sure you have to check each round in multiple rotations from the angle of feed. I dont go that far any more....but once upon a time.....

But I tend to agree with Larry, If its only one round, toss it and forget it.

Edited May 21, 2010 by Aloha Robert