6.5CM - Hornady CX 130 grn blowing primers - Help

[finnbear270]

Clue is in the title on charge weights .......... Firstly, don't start in the middle of the charge weights - start at the lowest charge.
OH!, & if you insist on ignoring chart data, invest in STANAG rated eyewear?

 

[Bowland blades]

Do you mean that FL sizing and setting the shoulder back increased the pressures? That won't sit well for the guys shooting Ackley chamberings. ~Muir

bit more than that, big tollerance chamber , small tolerance dies shoulder pushed back and a tad too and much clearance on the chamber to the walls. Had it myself years back

 

[Muir]

bit more than that, big tollerance chamber , small tolerance dies shoulder pushed back and a tad too and much clearance on the chamber to the walls. Had it myself years back

Interesting. ~Muir

 

[25 Sharps]

I'm a bit perplexed.

I am trying work up a load in my 6.5cm (24" 1:8 twist) for the Hornady 130grn copper CX.

I full resized some once fired Hornady brass (53.48 H2O grains of capacity), trimmed to length and loaded with...

41.9grn of Vit N160.

This should have been my starting load, but when fired it it blew the primer out of the pocket and left an impression of the extractor pin in the bottom of the case. I clearly stopped and didn't go any further.

I'm confused as there is not data for N160 for the CX but all the listed 130 grn loads are roughly between 40 - 44 grn so I thought starting in the middle and working up in 0.5grn increments would be safe.

This load also showed in QL as 98.7% fill so I was not worried about a compressed load. Also showed as 2536 fps so I thought it would not be an issue (used the closes bullet available).

Was thinking of starting at 39 grn and working up or is this still to hot. Also need to be effective at range while stalking.

Alternatively I have some N140 but not sure this would have enough poke for the 130rgn CX in 6.5cm.

Thoughts and advice would be appreciated.

Thanks,
Lee

Get some different brass and try again, hornady brass on CM is renowned for the pockets giving up prematurely.

N140 is too fast for 130s

 

[Lee2495]

So I pulled the lot and reloaded the hole batch. All triple checked at each stage.

No issues this time all good. 42.4 grns seems to be the most accurate load. 3 round group at 100 yrds - 15mm.

I had a thought - I may have left N140 in the mechanism of my powder thrower. The bottle on the top was definitely empty and I refilled it with N160.

This could have caused the first round to be loaded with N140 very hot! Lesson learnt, could have seriously injured myself. I'm quite annoyed with myself, I'm normally quite meticulous.

On another note, I have never pulled rounds before. Does it effect the neck tension on the case on reloading, do they need to be resized or can they be simply loaded.

Thanks again for the collective thoughts of the SD knowledgeable.

 

[cjs66]

Neck size the cases once bullets pulled.

 

[weejohn]

.

 

[weejohn]

bit more than that, big tollerance chamber , small tolerance dies shoulder pushed back and a tad too and much clearance on the chamber to the walls. Had it myself years back

I agree , my first ever experience of blown primers was due to oversized brass.

 

[25 Sharps]

I agree , my first ever experience of blown primers was due to oversized brass.

I bet it wasn’t, it was just coincidental.

If that was the case why are my .223 AI or .22 k-hornet not always over pressure?

 

[Utectok]

Copper bullets need a decent jump 50thou minimum

 

[NullMac]

Clue is in the title on charge weights ..........

Yes that is inserted by the lawyers. And the max charge is reduced by the lawyers. Viht data is now so conservative to be nearly useless. If you look at old loading manuals/data for the same powder the loads are often wildly different yet the powders have not changed.

Firstly, don't start in the middle of the charge weights - start at the lowest charge.

I have never ever started at the minimum charge weight for the reasons above ASSUMING I am loading the exact same bullet with the exact same powder.

You are allowed to use your brain. And responsible for your own outcomes....

Use multiple load data resources if you cannot find a matching data set including something on Quickload if you can. Start from what appears to be a safe point (too low can be more dangerous). Always wear safety gear when load testing, particularly glasses. Beware of interpolating on the basis of powder burn rate.

Powder increment of 0,5 is too large, 0,2 is better. OP needs a proper crony ie Magnetospeed (or Labradar if flush with $$). Then an optimal powder load could be found in 10 shots.

 

[One on top of two]

Buy lapua brass in either large or small primer it will make no difference , this alone will solve 95% of your issues . Also what primers are you using ? I have had a look through and may have missed it but I can’t see any mention .

And what rifle are you using ?

 

[Muir]

To start at minimum listed charge is one of the oldest, most basic rules of reloading. Load data at one time would say to start at 5% below minimum and work up.
Never assume that a powder is the same as it was in the past, even if it goes by the same name. It probably isn't..... which is why it is a good idea to toss all old loading data when new data is available. ~Muir

 

[wellywoodie]

I'm a bit perplexed.

I am trying work up a load in my 6.5cm (24" 1:8 twist) for the Hornady 130grn copper CX.

I full resized some once fired Hornady brass (53.48 H2O grains of capacity), trimmed to length and loaded with...

41.9grn of Vit N160.

This should have been my starting load, but when fired it it blew the primer out of the pocket and left an impression of the extractor pin in the bottom of the case. I clearly stopped and didn't go any further.

I'm confused as there is not data for N160 for the CX but all the listed 130 grn loads are roughly between 40 - 44 grn so I thought starting in the middle and working up in 0.5grn increments would be safe.

This load also showed in QL as 98.7% fill so I was not worried about a compressed load. Also showed as 2536 fps so I thought it would not be an issue (used the closes bullet available).

Was thinking of starting at 39 grn and working up or is this still to hot. Also need to be effective at range while stalking.

Alternatively I have some N140 but not sure this would have enough poke for the 130rgn CX in 6.5cm.

Thoughts and advice would be appreciated.

Thanks,
Lee

Hi Lee
load data is now available for the CX Bullet, start load is 37 and max is 42.3, so you are well under max. ive just bought some of these to try, so I'm interested in what you are saying. I did have this problem with a 6.5x47 a few years ago, I was using federal primers, and had to change to CCI Match to stop this happening. but this does point towards high pressure, the CX bullet is also very long, did you load to lands or Standard length?