Thompson center .17 hm2

Oldman11 · April 30, 2018, 06:58 AM

Could someone educate me on the Thompson center .17 hm2 auto,please

taylorce1 · April 30, 2018, 11:44 AM

Are you asking about the T/C R55 semi auto rimfire rifle? I've seen very few of them, and have never owned one. I can tell you that the 17 HM2 works very well on prairie dogs.

T. O'Heir · April 30, 2018, 12:21 PM

Issue is more about the availability of the ammo. Midway shows both bullet weights from Hornady as being on back order. So do the Walmart Test first.
If it's a T/C R55, Midway shows 5 round steel mags as being discontinued as well. No .17 HMR2 rifles listed on their site either.

Mobuck · April 30, 2018, 08:37 PM

17HM2 has shown up on the internet ammo sellers' ads lately.
I went out of the 17HM2 business last year selling a couple of Green Mountain 10-22 barrels for a small profit and 2 cases of Eley ammo for 4x profit.
For my purposes, 17HMR is a far better choice.

bassJAM1 · May 1, 2018, 12:22 PM

After owning a 10/22 converted to 17 hm2, I'll never own one again.

It was a super accurate rifle, but I like to stock up on 5 or so years of ammo at a time. Around year 3 I started having issues with my rifle sounding like it was blowing up when I'd shoot, it was happening about 10% of the time. I was finding that my spent brass had a split in it. I started inspecting unfired cases from unopened packages and ran across a LOT of cases with split brass, all in the neck of the cartridge. This was from CCI, Remington, and Hornady.

After some research I discovered I wasn't the only one having this issue with ammo that was a few years old. Apparently the combination of a thin sidewall and a bottleneck creates a weak point, and if the annealing isn't perfect the brass will eventually split.

If you're OK with always having fresh rounds on hand it really is a sweet shooting round. But it wasn't for me and I ended up scraping around 600 rounds that I could no longer trust.

Ledslnger · May 14, 2018, 06:05 AM

With semis you need a chamber brush and you need to use it every 150 rounds. Well, give or take. If you do that there shouldn’t be issues. Carbon buildup is changing headspace and causing problems.

Oldman11 · May 14, 2018, 10:49 AM

I just bought a R55 .17hm2 auto for $450.00 with scope. I’m shooting ammo that was bought when dealers discounted their prices,I think being less than $4.00 box. No problems so far with 250 rds being shot. A great gun and great caliber. I have about 2000 rds of old ammo left and have bought 500 rds new ammo. I have a CZ bolt action to use if I have trouble with the old ammo. Plenty of ammo out there now.

April 30, 2018, 06:58 AM	#1
Oldman11 Member Join Date: April 28, 2016 Posts: 77	Thompson center .17 hm2 Could someone educate me on the Thompson center .17 hm2 auto,please

April 30, 2018, 11:44 AM	#2
taylorce1 Senior Member Join Date: November 18, 2005 Location: On the Santa Fe Trail Posts: 8,242	Are you asking about the T/C R55 semi auto rimfire rifle? I've seen very few of them, and have never owned one. I can tell you that the 17 HM2 works very well on prairie dogs. __________________ NRA Life Member

April 30, 2018, 12:21 PM	#3
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	Issue is more about the availability of the ammo. Midway shows both bullet weights from Hornady as being on back order. So do the Walmart Test first. If it's a T/C R55, Midway shows 5 round steel mags as being discontinued as well. No .17 HMR2 rifles listed on their site either. __________________ Spelling and grammar count!

April 30, 2018, 08:37 PM	#4
Mobuck Junior member Join Date: February 2, 2010 Posts: 6,846	17HM2 has shown up on the internet ammo sellers' ads lately. I went out of the 17HM2 business last year selling a couple of Green Mountain 10-22 barrels for a small profit and 2 cases of Eley ammo for 4x profit. For my purposes, 17HMR is a far better choice.

May 1, 2018, 12:22 PM	#5
bassJAM1 Senior Member Join Date: March 31, 2017 Location: Cincinnati Posts: 147	After owning a 10/22 converted to 17 hm2, I'll never own one again. It was a super accurate rifle, but I like to stock up on 5 or so years of ammo at a time. Around year 3 I started having issues with my rifle sounding like it was blowing up when I'd shoot, it was happening about 10% of the time. I was finding that my spent brass had a split in it. I started inspecting unfired cases from unopened packages and ran across a LOT of cases with split brass, all in the neck of the cartridge. This was from CCI, Remington, and Hornady. After some research I discovered I wasn't the only one having this issue with ammo that was a few years old. Apparently the combination of a thin sidewall and a bottleneck creates a weak point, and if the annealing isn't perfect the brass will eventually split. If you're OK with always having fresh rounds on hand it really is a sweet shooting round. But it wasn't for me and I ended up scraping around 600 rounds that I could no longer trust.

May 14, 2018, 06:05 AM	#6
Ledslnger Member Join Date: March 20, 2018 Posts: 60	With semis you need a chamber brush and you need to use it every 150 rounds. Well, give or take. If you do that there shouldn’t be issues. Carbon buildup is changing headspace and causing problems.

May 14, 2018, 10:49 AM	#7
Oldman11 Member Join Date: April 28, 2016 Posts: 77	I just bought a R55 .17hm2 auto for $450.00 with scope. I’m shooting ammo that was bought when dealers discounted their prices,I think being less than $4.00 box. No problems so far with 250 rds being shot. A great gun and great caliber. I have about 2000 rds of old ammo left and have bought 500 rds new ammo. I have a CZ bolt action to use if I have trouble with the old ammo. Plenty of ammo out there now.