17hmr 10-22 magnum problem

[Prebanpaul]

Alright, so here is all the information, I am just trouble shooting the problem.

One I have a 10-22 magnum that I converted over to shoot 17hmr with a butler creek barrel. I have logged 1800-2000 rounds and the gun has shot flawless.

I was shooting the gun the other day and had a case blew out of the bottom. I started looking at it and decided maybe the round did not seat properly. So I brought it home and ultra sonic the hell out of it. bolt and receiver. I then gave the barrel a good scrubbing. Took it out to the range and shot a round, the bottom blew out and the case and head separated. I inspected the gun and everything is mechanical order. I am thinking that the bolt return spring may be weak . Thus allowing the round to come out early. I have ordered a new heavy spring for the bolt from wolf.

Is there anything else missing that I should consider.

 

[Changed]

It's probably time to change out the recoil spring. I'd also hand cycle a few from that lot.

TC

 

[Boxcar]

What brand of ammo where you using? Granted all 17hmr's are made in the same ammo factory. I had some 20gr winchester's that was splitting cases in a bolt gun.

 

[Prebanpaul]

ammo is Hornady 17 grain ammo. Good call on the lot ammo. I will try a different lot.

 

[RWSGunsmithing]

Chamber a round from the mag as though you are going to shoot it, but don't shoot it. Instead pull the bolt back and eject the live round and inspect it. Might want to do this a few times. What I noticed with one of my semi-auto hmr's is that when the bolt picks up the round from the mag the tip of the bullet makes contact with something and push's the bullet into the case. This in turn causes a massive pressure spike and then blows the rim wide open and sometimes completely off.