Help with 127lrx

[Ktwebb]

18” barrel, 1/8 twist, 6.5cm on a 110 action.
I had 120eldm’s and 127lrx’s loaded…
All of them .030 jump.

20 rounds each, with 5 rounds at each charge weight. Middle of the road loads per book range.

I shot 1 round of factory 140 just to double check I was on paper (top left square). It was within an inch of my POA so I moved on to the first batch of 127’s….terrible…

Shot a second factory 140 back at the same top left square for POA. About an inch from the first 140 I shot. So I knew the gun/scope checked out.

I then shot 4 of the 5 next load of 127’s
A total of 9x 127’s…minute of truck door!

Drove to the target and they all look like they tumbled…

I then shot 5 of the 120eldms, (quicker than I normally would cause I just had to know!) and they’re what I would hope for for a first batch of 5 during load development.

Anybody have experience with anything similar? What little I’ve found, these Barnes LRX’s may like a lot more jump, but that still wouldn't make up the difference of what was a terrible showing from the 9 rounds I fired. And it still wouldn’t explain what appears to be rounds tumbling/not stabilizing.

The 120eldm results tell me that my barrel is capable of running these lighter bullets, but so far, not the 127LRX’s!!

Pics for better clarity.
Clean cardboard with yellow tape was the 120eldm’s shot after the 127’s

Any thoughts?

 

[acourvil]

I shoot them in my Rem 260 hunting rifle. I get best results with a jump of around .50; my experience with pretty much all copper monolithics that I have tried is that they need more jump, so I usually start with .050 go up (but .050 usually works for me).

I have no idea why they would be tumbling; what velocity range are you shooting?

Also, you might want to try starting with a clean barrel and just shoot the copper rounds. Some folks find that they get better results that way.

 

[Ktwebb]

I talked to someone at Barnes this morning. Came to the conclusion that it’s likely just too slow with what I was working with.
18” barrel + IMR4895 (trying to use it because I have a good bit of it on hand). I realize the IMR4895 would result in lower velocities, but it was listed on the Hodgdon data so I decided to give it a try.
Dropping down to their 120gr and/or using a different powder was what we came up with.
He did also mentioning accuracy issues when switching from jacketed to all coppers.

 

[acourvil]

Makes sense. I use H4350 and run them around 2750fps. You also want the faster speed to get them to open well in game. IIRC, the TTSX need around 2000fps and the LRX around 1800fps to open, and more is better.

FWIW, I didn't get much extra speed from the 120gn TTSX compared to the LRX with similar loads, and for me the LRX shot better and has a better BC.

 

[Ktwebb]

I’m not determined to run these lrx’s, so I’ll likely just find a different bullet. Just was something new to me, and I felt the need to dive into what was going on. Seems like a simple answer now that I have asked around. Slower mv due to powder choice and barrel length = flat out too slow for the lrx’s…I’m pretty sure simply moving to h4350 (which book’s ~100fps faster) and bumping up to around max gr would solve things

 

[KYAggie]

My experience shooting Barnes in several rifles, including the 127LRX in my 6.5, is that starting with a clean barrel is a must. That bullet groups just under an inch with R16 as powder in my AR10.

 

[Ktwebb]

My experience shooting Barnes in several rifles, including the 127LRX in my 6.5, is that starting with a clean barrel is a must. That bullet groups just under an inch with R16 as powder in my AR10.

Too much for me…I don’t abuse my stuff, but I’m not a clean it after every use guy either. To each their own, just not how I use my rifles personally. I may rehome them…fun to learn along the way though.