Tumbling Bullets

Status
Not open for further replies.

Laphroaig

Member
Joined
Feb 24, 2013
Messages
2,804
Location
W. PA
I had a hard time deciding which forum to post this in, and have decided to try Handloading and Reloading.

The background is I shot in a club highpower rifle match yesterday. The range has 200 and 300 yd. firing lines, so the 20 round slow fire prone stage is shot on reduced targets. Something happened during the slow fire prone stage that has me puzzled.

The load is Hornady 75 gr. HPBT over a thrown charge of Rl15, IMI brass, and Rem. 7 1/2 BR primers. Loaded single stage and seated on a Forster BR Seater. Rifle is a National Match grade AR15 that started as an Eagle Arms Golden Eagle but has went through some changes over the years. It now wears a BCM upper, is free floated and has a relatively new (400 rounds) RRA 1:8 barrel.

I love that load, and have used it consistently at 300 yds. for a couple of decades. It is extremely accurate and I've never had an issue. All of my sighters and rapid fire string (98-4x) were as expected. But during the slow fire stage, my 4th shot was a 6 at 10 o'clock, out side of the black. The fifth shot was a 7 at 9. I didn't call either to be that bad but did notice the wind had picked up slightly and was in my face. I took one click right :) and kept on, and ended with a 188 8x with nothing else worse than a 9.

Anyway, after the match the guy that was pulling targets for me told me that both of the bad shots had tumbled and the 6 hole was so big he had hard time getting the spotter to stay in. I've never had anything like that happened before. The fact that the 2 shots were back to back suggests some sort of external cause. Bad bullets? What's the odds that 2 would end up side by side in ammo box? A low charge that didn't stabilize the bullet? Elevation was good, considering, and I check the level in the case before I seat anything. Life was good both before and after those 2 shots.

Any ideas or similar experiences?
 
Last edited:
Sounds like you got out of rhythm on the powder throw or those two were a start stop point if I had to guess.
 
How close do you watch your loading procedures when loading for a match?
There are a number of issues that come to mind, but I would only be guessing.
I was loading some 150 grain SST 30.06 target loads and the last two bullets in the box were 125 grain SST. Now my 150s were Boat Tails and the 125s were Flat Bottom and easy to spot. Generally it's good to weigh every bullet and group them by weight. I've been reading that Hornady no longer recommends 1:8 twist for their new 75 grn. HPBT. Discussions in indicate seating depth or rather extended seating can cause tumbling. Contact Hornady directly and get some good info.
 
I would not take the word of the guy that was pulling targets. I would need to see it for myself.

Clean barrel well.

New Barrel may not be as smooth as it could be. A rough throat/leade may damage the bullet jacket, on firing. A damaged jacket/bullet may not even make it to the target.

A barrel that has groove diameter larger then normal will also cause keyhole. But not with all bullets of different length bearing surfaces. My 243, 70 match tumbled. 85 gr did not. 10 twist.

The extra heat build up in a rough barrel has an effect also. Can make lead cores liguid & lead tips melt, leaving a lead smear on target.

https://benchrest.com/showthread.php?49336-Berger-bullet-failure-test
 
Last edited:
A bad lot of bullets is always possible.

Hornady 75 gr. HPBT

Hornady lists 4- 75gr hpbt bullets. What one are you loading?

What's the difference between the 4? Yes, ones a cannelure.

What am I missing? 3 bullets seem to be the same? Website wrong.

Edit- It's the amount of bullets in the box. I knew that, forgot.:(
Item #2279B | 4000/Box
 
Last edited:
That’s a real mystery.

Are you using a flash hider?

That's what I thought. I can't come up with a logical cause. I check the powder level before I seat the bullet so I doubt that could be the cause. Plus, could an extremely underloaded cartridge maintain the approximate elevation at 300 yds. while tumbling at a lower velocity? Other than 2 extremely bad bullets that ended up in my ammo box back-to-back I'm at a loss. I knew a guy who claimed that Hornady bullets have a flyer in every box. I don't believe that. Time to move on and hope it never happens again.

No flash hider.

I would not take the word of the guy that was pulling targets. I would need to see it for myself.

I've known this guy for along time. He's an avid competitor and I trust what he said. I don't think that you could make up the part about the spotter not staying in the hole because it was too big!

Hornady lists 4- 75gr hpbt bullets. What one are you loading?

https://www.hornady.com/bullets/rifle/22-cal-.224-75-gr-bthp-match-4000#!/
 
One final thought...

I was on the far right firing point. I did notice a slight pickup in the wind during this anomaly. Could a previously flat lying stalk of grass or weed have been lifted into my bullet path by the wind and I hit it? The layout of that range is such that a hillside intersects the ground on the right side. In a previous match when I was on a high number I had to move because high grass was visible in my sight line. I'll check out that possibility the next time that I shoot there.

I don't think that I'm crazyo_O
 
Last edited:
If I was pulling for @Laphroaig I would have snapped a pic of his target. When I’m in the pits I’ll do that for guys when they shoot an exceptional match.

That would have been great. He did say that he thought about calling the firing line to tell me what was happening, but when it stopped didn't bother. His description was pretty detailed; the first 6 was a full profile of the bullet, and the second 7 was an oblong hole.
 
I generally clean the chamber after a match and finish by a couple of patches through the bore to soak up any solvent that might have leaked down there. I don't think anything could accumulate to cause something like that to happen even though the bore is fouled from use. I was banging 10's and x's pretty regularly before and after the incident.
 
I generally clean the chamber after a match and finish by a couple of patches through the bore to soak up any solvent that might have leaked down there. I don't think anything could accumulate to cause something like that to happen even though the bore is fouled from use. I was banging 10's and x's pretty regularly before and after the incident.
Mystery indeed
That’s a real mystery.
 
In my experience what you are describing is an unstable bullet. Probably too low on powder. Just my two cents based on what I have seen out there.
 
  • Like
Reactions: mdi
a full profile of the bullet
Edit- Meaning, bullet hit sideways. Full outline of the bullet. Mine was.

All 3 of my 70gr march bullets did this @ 100 yards. The factory barrel groove diameter was to big.

The 85 gr bullets needed at least 10 fouling rounds, till it started printing groups under 1" Needed a dirty barrel.
 
Last edited:
I am gonna assume that what he means by "full profile" is a perfect round hole the diameter of the bullet? I am in the bad bullet or it hit something camp.
 
Possibly a single bad bullet caused some gliding metal to adhere to the bore. The next round cleaned it out. Things go back to normal after. This is my thought as to your experience. Doubt two back to back bullets defective or same bad charges! If so you need to buy a lottery ticket now LOL.
 
For competition ammo, is a good idea to weigh each bullet. Sometimes a core dosent fillout or jacket isnt bound. Is not common, but not unheard of either. It would make sense the defects were in the same box.
 
I'm going with the grass possibility. I've had that happen. My scorer was relatively new to shooting high power, and was fascinated by watching the vapor trails through his spotting scope one nice humid day. He was even more fascinated by watching a grass seed head explode 525 yards out. The bullet crossed the singularity and registered a clean miss. It either came apart or tumbled way off target. This was also the Hornady 75HPBT. Another caught a grass blade with less deflection and scored an 8 with a nice oblong hole on a 10s and Xs kind of day. On the same match stage, there were a few keyholes observed.

Bad bullet is a possibility also. So is a freak wind that you didn't notice, but it would take a lot of deflection if you were dialed into the X to push to 6 and 7 ring. I'd take the pullers word that you got keyholes.
 
Status
Not open for further replies.
Back
Top