17 HM2 case ruptures

[suhrken]

I have a converted 10/22 (New E. Authur Brown Barrel, and bolt handle) I took it to the range today and it ruptured the cases after about 20 or 30 rounds. Ran a cleaning rod with a brush on it the second time it did it, The third time it blew the magazine apart. I was using Hornady ammo. Had the rifle checked by a gunsmith he said everything appeared okay. Hornady wants to look at the cases, they blew at the rim or right by it. I havent been able to reach EA brown yet. Has anyone had this problem yet. the gun has had about 150 rounds through it all together

[Rocky Raab]

Welcome to HuntChat.

When you say the gun was converted, was the bolt and spring changed out, or just a barrel swap?

A proper conversion MUST have a new bolt and recoil spring, both much heavier than the original. The .17HM2 creates MUCH higher bolt thrust than a standard .22LR and if the bolt opens too fast, the inevitable result is a case rupture, exactly as you describe.

As they say in Texas, "Ever Tahm."

[suhrken]

The conversion was a new spring and heavier handle to add the extra weight to the bolt.