ELDMs Blowing up mid flight

[Recon$$]

For the guys that understand this more, generally how much over twist/stabilization are we talking about generally? A 1/2 inch 1 inch when you run into this scenario?

 

[mudflap621]

There is a pretty extensive thread over on snipers hide about the eldms blowing up but most specifically the 147 gr in 6.5. I stumbled upon it after buying 500 for a buddy's load development. We have ran over 500 through his creedmoor and no hiccups yet but we aren't pushing them hard either.

 

[BillLarson]

If you got a borescope look at the throat you'll see firecracking as the bullet goes over the firecracking it hurts the jacket integrity, then the torque on the bullet from the rpms tears the bullet apart.

I,ve had this happen with a barrel with only 400 rnds.fired.

 

[DJ Fergus]

Curious if you tried them at distance? I noticed 208's and 140's having trouble between 4-500 yards but they looked great at 200

Last time it was shot, I hit the small size tannerite canister from 500 yards from a cold bore. The tannerite blew up. I assume it held together to that distance.

 

[DJ Fergus]

N570 & 5 shot strings make for a short barrel life. I would consider it a hunting only powder. Not so great for a day of target shooting.

 

[tankgijohn72]

Had same issue with 147 eldm in 26 nosler. Plenty of fire cracking in throat. The helical lead spray is a spray and not cut through the target. Dont have exact MV, but was around 3200+. Switched out to barnes LRX 127 and have never looked back.

 

[Tagnbagem]

Is it possible that being a new rifle and a 100 rds in it , is the barrel speeding up. Not unheard of to see 75 to a 100 FPS increase causing the bullet to become unstable.

 

[MagnumManiac]

One thing misunderstood here.
Bullets are either stable or unstable. There is no such thing as over stable.
This phenomenon is simply centrifugal force, possibly a rough throat and high rpm.
Talking of powders being nice on throats.
In most high intensity cartridges, US869 is very good on throats and runs right around RE33.

Cheers.

 

[shinbone]

No comment on the ELDMs blowing up, but you are really going to like the 177 gn Hammer Hunters.

 

[slowshot18]

I'm fully aware that 5 shot strings in a 28 is a death sentence on barrel life. I run a barrel kuhl through the gun after every 2 shots on normal strings. This test today I ran 3 straight, waited 5 minutes then the final 2 to try and see if it was just from being too hot. The 5 shot string had no failures.

And yes it has sped up quite a bit. From rounds 20-80 the average was 3070 FPS now at 120 it's 3170. Still grouping decent when they don't come apart.

Once the rifle is dialed in, it will stay a hunting rifle only. Once season is over, I'll remove the barrel and throw my 300wm barrel back on (it's a bartlein MTU so it's heavy for hunting).

I'll have a few boxes of 177 hammers delivered this week and we'll see how those do! Haven't been able to find 175 eldx, 180 vlds, or 195 eols. 177 HH were in stock so those will have to do for this season.

 

[slowshot18]

No comment on the ELDMs blowing up, but you are really going to like the 177 gn Hammer Hunters.

Have you used the 177's in a 28 by chance? Thanks

 

[Nevrsummr]

I have 100 rounds through a custom 28 nos shooting 177 hammers proof 1:8 @26". I seem to have a slower barrel as im seeing about 3050 fps and most others are seeing 3150. I run h1000 instead of N570 to help with throat erosion, and after 100 rounds ive only seen .007 of change.

 

[Varmint Hunter]

FWIW - I put 1,000 rounds of A-Max bullets through an 8' twist at 3,670 ft/sec without blowing up a single bullet. You can only imagine how rough that throat was after the first few hundred rounds.

At that time I moly coated and waxed every bullet. I "think" that the slippery bullets contributed to the bullets ability to maintain its jacket integrity.

 

[Swamplord]

only one thing remains constant F the ELDM b's


can't stress that FACT enough