tumbling bullets

[hamish dick]

Has any one had tumbling bullets from a brand new rifle?? with factory ammo?
tried factory norma 150gr and norma 130gr then home load 110gr v max all with and without mod and all tumbelled
the rifle is a .270

 

[matt_hooks]

There's a lot spoken about "tumbling" bullets. How do you know that the bullets are tumbling? What exactly do you mean by "tumbling"? What range did you fire them at, and what sort of groupings were you achieving? What sort of target were you using (paper/card/metal etc.?) and what were the weather conditions?

 

[User00003]

if that really 'is' the case, I'd say the bore of your barrel is not fitting the bullet diameter (bad lapping job?), perhaps a 'lemon' as BH says.

 

[Muir]

When I hear "tumbling" I think bullet-profile shaped holes in the target if you manage to hit it in the first place. Serious problems there and if your bullets are indeed the correct diameter, I'd consider humping it back to the place you got it from.

If you mean, "I'm shooting a 80 grain bullet from my 1-12" twist .223 and they're tumbling", I'd suggest changing bullets to something more appropriate for your twist rate.~Muir

 

[Offroad Gary]

were you clipping any grass on the way to the target?

 

[Yorric]

Are you certain you are getting tumbling? Did you see bullet shaped holes in your target? If not what did you observe?
Was your target paper properly supported on a back board? Soggy, wet or poorly supported targets sometimes result in holes that look similar to tumblers.
What was accuracy / grouping like?????
With that range of three different bullet weights something is wrong if you really getting all three tumbling. The 150 grain is getting a bit longish for 270 but not excessively so but the other two should stabilize every time.
Is the crown of the barrel damaged?
What make/model is the rifle?

Ian

 

[Brithunter]

Where and when was the barrel threaded?

factory or afterwards perhaps by importer or dealer?

The reason is that I am wondering if they have damaged the bore in threading.

 

[User00003]

will the OP ever let us know LOL..finally, an interesting and challenging thread

 

[bewsher500]

just to keep it all going until the OP comes back...

this is my tumbling bullets pic!

its what happens when you put on target at 100 yards and one at 70 in front of it!
trick shooting albeit unintentional
went through the 75 yd one, hit the earth cutting a groove about 3ft long and then tumbled its way into the 100yd one!
twice!

 

[wraith]

just to keep it all going until the OP comes back...

this is my tumbling bullets pic!

its what happens when you put on target at 100 yards and one at 70 in front of it!
trick shooting albeit unintentional
went through the 75 yd one, hit the earth cutting a groove about 3ft long and then tumbled its way into the 100yd one!
twice!

how the hell did you manage to get holes in that target im asuming its a pizza bottom foam thing itriyed that and every one blew up i must be going to fast confetey eney one no looking at the picture think you must be cliping the inside of sound moderator loosening of as you shoot have you cheked that

 

[bewsher500]

how the hell did you manage to get holes in that target im asuming its a pizza bottom foam thing itriyed that and every one blew up i must be going to fast confetey eney one no looking at the picture think you must be cliping the inside of sound moderator loosening of as you shoot have you cheked that

nope. just the ground.
two targets, one at 75yds, one at 100yds.
Shooting from a position 6ft above the ground.

not sure why your pizza bases would blow up. pretty much anything just punches neat holes in them. I use them for every target, waterproof and you can hold them up with one pin!

 

[wraith]

nope. just the ground.
two targets, one at 75yds, one at 100yds.
Shooting from a position 6ft above the ground.

not sure why your pizza bases would blow up. pretty much anything just punches neat holes in them. I use them for every target, waterproof and you can hold them up with one pin!

mabey your piza boxes cost more than mine

 

[bewsher500]

mabey your piza boxes cost more than mine

Tesco's Finest!!

 

[IainDB]

The last time I saw key-holing like that was with the SA 80 (5.56 / 223) in my Military days. 100 Yds, no obstructions, no moderator, just random key-holing. Possible causes, instability due to twist rate / bullet weight incompatibility, loose / ill fitting moderator, perhaps out of true, damaged bore causing bullet damage and instability. Have you checked the distance back off the lands? If home-loads, is the gap correct, maybe 10 - 20 thou off! Is factory ammo ok? Does the barrel need a proper cleaning? After checking all and cleaning, I would be tempted to get a boro-scope down the barrel asap. Good luck Iain

 

[Brithunter]

The last time I saw key-holing like that was with the SA 80 (5.56 / 223) in my Military days. 100 Yds, no obstructions, no moderator, just random key-holing. Possible causes, instability due to twist rate / bullet weight incompatibility, loose / ill fitting moderator, perhaps out of true, damaged bore causing bullet damage and instability. Have you checked the distance back off the lands? If home-loads, is the gap correct, maybe 10 - 20 thou off! Is factory ammo ok? Does the barrel need a proper cleaning? After checking all and cleaning, I would be tempted to get a boro-scope down the barrel asap. Good luck Iain

There is NO such thing as :-

If home-loads, is the gap correct, maybe 10 - 20 thou off

Correct gap ............................ i.e bullet jump. Different rifles will like different amounts of bullet jump. many find that their rifles shoot far better with the bullet seated deeper so the jump is more like 0.100". I believe Barnes Bullets are one of the only ones who recommend a jump for their products.

Some claim to seat their bullets 0.0012 off the lands others 0.010" or 0.020" however as every shot fired causes some throat erosion and wear the amount of jump will be constantly changing. How many shooters even consider this? how many check to see if teh wear/erosion has changed the distance?

Maybe some of the serious bench Rest crowd or the long range crowd but talk about throat and leade to most stalkers and I'll wager you get a lot of blank looks.

 

[IainDB]

I totally agree, however, given that this is a forum including Home-loading as a topic, it seems relevant. I did say 'maybe' . Many home-loaders only look at the complete overall length as quoted in manuals. I wonder how rigidly the home-load was made to the manual spec. Same case etc, as this can make a vast difference to the load. Was the load Chrono'd, to check velocity? Was thinking 'Heavy round / low velocity and instability here' If we could discount the home-load, use factory ammo and compare results. So many questions, it would be great to know what the outcome is of this one. Once again, good luck...

 

[Brithunter]

I must admit I never look at the COL in the manuals. if using a flat based bullet which I do when i can get them I seat the bullets base to the neck shoulder juncture and work out from there. Many years ago I fell for the close to the leade hype and started with them almost touching but in almost every case my best loads ended up with the bullet seated much, much, deeper so now I start deep and work out.

Only once can I recall having everything listed in the loading leaflet as they listed it case make, primer type and make exact bullet and of course the powder..

As to the OP's question I wonder if we ever get an answer to some of the questions asked?

 

[hamish dick]

Thanks for all the comments,I did not write to much in the first place as I was hopeing for some possible reasons, for a bullet to tumble, I am no fool but also are not a ballistics boffin or a gun smith, I know how to put a target up properly, and I know when a rifle isnt shooting as it should ie. bullet goes through paper pointy end first.,I fired 2 other rifle at the same board and they were fine with the same ammo. we recovered several bullets , nearly all intact. Muir makes a good point as the first sign that something was wrong was that we couldnt hit the boards and when we did it was hitting the wrong target lol. Matt Hooks, you asked what groups I got, well a large dinner plate at best and yes we had projectile shape holes in the board, which is why I used the term tumbling,we changed rifles and got little round holes. then took the mod off ,and no change.
All of the shooting was done at 100m, and for the record there was no wind and no grass or twigs between me and the target.The rifle was not a factory threading ,so there could be something in that???I have some brilliant pics of the target,may post them when I know how to do that.

 

[Brithunter]

Take the rifle back and tell the vendor that your rejecting it as it's not fit for purpose.

 

[hamish dick]

never thought of returning the rifle, lol Of coarse its going back!! I only posted on here to try and find out what the cause of this was,which is why I posted on a ballistics forum,as I thought it could have something to do with ballistics.
Seems like no one on here has had or known of this problem???