Advice please

[dylan5588]

I am reloading for .22 K Hornet, I worked up to 13.25 gn of Lilgun Powder, Hogdons data quotes 12.5 starting load and 13.5 maximum. At the 13.25 the cases are showing signs of blown primers,

The cases are fire formed factory Hornady Hornet, and only once reloaded, I am using 40gn vmax bullets, and cci small rifle primes, Rifle is a cz 527 with a heavy stainless fluted Border barrel. any advice as to why I am getting blown primers when under the max loading?

Also the pressure from 13.5 gn lilgun @, 33.000psi, is considerably less than if using the max loading of H110 12.5 gn @ 45.000psi. I only have to neck size, so no case lube on the scene. I do use "Fork Juice" a silicon based spray, on the bolt, but I block the chamber when using this, but if it had somehow ingressed into the chamber, could this be causing my problem? I would really appreciate any suggestions or advice.

Regards Aj

[Finman]

Since you cannot take direct pressure measurements, you probably have to chronograph this load and see if your speed is higher than anticipated. If that is the case, your gun raises the pressure sooner than predicted by the 'book'. Then you lessen the load to find the right combination. That's what I would do anyway...

 

Best wishes,

 

Finman

[MrCetrizine]

What length and twist is your barrel and what barrel was used for the load data you are using? Also what's your seating depth and what was used for the load data?

 

There are more variables that affect pressure than just charge weight.

[dylan5588]

Since you cannot take direct pressure measurements, you probably have to chronograph this load and see if your speed is higher than anticipated. If that is the case, your gun raises the pressure sooner than predicted by the 'book'. Then you lessen the load to find the right combination. That's what I would do anyway...

 

Best wishes,

 

Finman

Thanks for the reply, so different chambers and barrels can affect the loading, am I reading you correctly?

Aj

[dylan5588]

What length and twist is your barrel and what barrel was used for the load data you are using? Also what's your seating depth and what was used for the load data?

 

There are more variables that affect pressure than just charge weight.

Mine is a 20 inch barrel with 1 in 16 twist, I think a 24 inch 1 in 16 twist was used in the data from Hodgdon, that is the limit of info given, I seat 20 thou off the lands. It does not seem to make much difference accuracy wise where I seat them, I started on the lands but backed off as I thought it would help keep the pressure down,

Aj

[rem700]

Hi Aj

ime fairly new to reloading but wouldn't seating the bullet deeper [away from the lands]

cause higher pressure in the case ,all though 20 tho off wouldn't do this [i wouldent have thought ]not unless it was a hot load

which you say its not

[dylan5588]

Hi Aj

ime fairly new to reloading but wouldn't seating the bullet deeper [away from the lands]

cause higher pressure in the case ,all though 20 tho off wouldn't do this [i wouldent have thought ]not unless it was a hot load

which you say its not

I don't know, I was under the impression that seating on or near the lands, can raise pressure, as its like trying to push a car up onto a kerb, if the wheel is touching the kerb it takes more effort to move it, but if it is away from the kerb you get a rolling start and takes less effort, If you get the analogy!!!!! seating at 20 thou off does not compress the load. I could go back another 25 thou before compressing the load at all.

Aj

[gazzar15]

How does the fit of the primers feel when priming ? Are they easy to fit or do they take some pressure?

I would perhaps try a different make as they could be slack in the primer pocket meaning they could blow under less pressure.

[dylan5588]

How does the fit of the primers feel when priming ? Are they easy to fit or do they take some pressure?

I would perhaps try a different make as they could be slack in the primer pocket meaning they could blow under less pressure.

I showed one of the cases to Spud today and he asked me that question, I fit them with a hand priming tool, they take a reasonable amount of pressure to seat, they don't seem to be a slack fit.

Aj

[Finman]

Thanks for the reply, so different chambers and barrels can affect the loading, am I reading you correctly?

Aj

Yep

[Jamie]

No doubt there are various possibilities on the cause of the problem. And the problem needs sorting long term. But short term maybe change brand of primers for half a dozen shots and compare primers? But as mentioned by Finman, if I were you I would buy or borrow a Chronograph and check your velocities.

[dylan5588]

No doubt there are various possibilities on the cause of the problem. And the problem needs sorting long term. But short term maybe change brand of primers for half a dozen shots and compare primers? But as mentioned by Finman, if I were you I would buy or borrow a Chronograph and check your velocities.

have managed to borrow a chrony from my brother for this weekend, so will try a few over it, I have reloaded some and starting back at 12.5 gn and will work up in 0.1gn increments, 0.1gn doesn't sound much but in a case like the hornet its quite a bit.

Thanks for the advice all, any more suggestions would still be welcome,

Regards Aj