So!

[james t 36]

6 hours ago, Deker said:

I have still got good stocks of HMR ammo, not bought any for a while.   There is talk the latest offerings of the ammo have improved, has anyone got any hard evidence?

Cheers

put about 400 through mine so far no problems 

[ianm 2,594]

13 hours ago, Deker said:

I have still got good stocks of HMR ammo, not bought any for a while.   There is talk the latest offerings of the ammo have improved, has anyone got any hard evidence?

Cheers

I don't think the problem will ever disappear completely due to the manufacturing process. The cases are very thin and cannot be annealed, then they are necked down a substantial amount to get them to .17 calibre. I think there will always be an amount of split necks which then cause squib rounds.  

[Alsone 789]

I read some suggestions on another forum that the HMR rounds now are slightly heavier and slightly larger suggesting an increase in case thickness. I have no way of verifying this. Only way to know is if someone has old vs new to compare on the scales or even disassemble with a micrometer. Either way, the dialogue I read over there, seemed also to point to users no longer having issues.

[toxo 160]

14 hours ago, ianm said:

I don't think the problem will ever disappear completely due to the manufacturing process. The cases are very thin and cannot be annealed, then they are necked down a substantial amount to get them to .17 calibre. I think there will always be an amount of split necks which then cause squib rounds.  

I anneal 17 hornet when forming from 22 hornet. I believe they couldn't anneal because the powder (liquid) went in first. Maybe they do it differently now.

[Underdog 2,337]

6 hours ago, Alsone said:

I read some suggestions on another forum that the HMR rounds now are slightly heavier and slightly larger suggesting an increase in case thickness. I have no way of verifying this. Only way to know is if someone has old vs new to compare on the scales or even disassemble with a micrometer. Either way, the dialogue I read over there, seemed also to point to users no longer having issues.

They wouldn't chamber if they were larger.

[Underdog 2,337]

34 minutes ago, toxo said:

I anneal 17 hornet when forming from 22 hornet. I believe they couldn't anneal because the powder (liquid) went in first. Maybe they do it differently now.

The cases are primed via a special method being a rimfire and has to be done first, before sizing. No heat can be applied after so the cases are cold formed and quickly too...that's when the issues can occur.

[toxo 160]

12 minutes ago, Underdog said:

The cases are primed via a special method being a rimfire and has to be done first, before sizing. No heat can be applied after so the cases are cold formed and quickly too...that's when the issues can occur.

Yes Nathan but apart from the 17 hornet case being bigger there's not much difference and I can't see why the primer/powder can't be put in after annealing and case forming. Maybe some money saving issue in the process?

[Underdog 2,337]

4 hours ago, toxo said:

Yes Nathan but apart from the 17 hornet case being bigger there's not much difference and I can't see why the primer/powder can't be put in after annealing and case forming. Maybe some money saving issue in the process?

Possibly they are using existing equipment based around the WMR case.

Thought they could short cut the neck sizing.

Sure they could prime after with some engineering but it would cost to much as far as the board of directors was concerned!

[Alsone 789]

On 01/12/2018 at 12:46, Underdog said:

They wouldn't chamber if they were larger.

Unless the extra thickness was mostly on the inside except at the neck. Possible if the case isn't full of powder to the neck. Ultimately, I wouldn't know. All I do know is a lot of shooters are reporting they aren't seeing any bad rounds anymore. Obviously this points to either the case or forming process having changed.

Interestingly, at the same time, several new hotter hmr rounds are being announced. Again pointing to the issue being solved - I gather this was featured at Shot Show 2018:

http://www.varminter.com/new-cci-17hmr-vnt-rimfire-ammunition/
 

 

Edited December 4, 2018 by Alsone

[Underdog 2,337]

6 hours ago, Alsone said:

Unless the extra thickness was mostly on the inside except at the neck. Possible if the case isn't full of powder to the neck. Ultimately, I wouldn't know. All I do know is a lot of shooters are reporting they aren't seeing any bad rounds anymore. Obviously this points to either the case or forming process having changed.

Interestingly, at the same time, several new hotter hmr rounds are being announced. Again pointing to the issue being solved - I gather this was featured at Shot Show 2018:

http://www.varminter.com/new-cci-17hmr-vnt-rimfire-ammunition/
 

 

Interesting stuff.

Sales must be dropping, or people want to start using them on rats!