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7/21/2013 4:00:23 PM EDT
Has anyone made a .17HMR in a semi auto yet?
7/21/2013 4:22:46 PM EDT
[#1]
Yes, and they stopped.

Come to find out, when you make a rimfire cartridge that is bottlenecked and put it in a semi-auto, you're creating a recipe for OOB detonations.  Not every time, and not even very often, but often enough.

Now, I guess I can't say that manufacturers completely stopped, there are at least two smaller ones that still do, IIRC.  I think that AA might make an AR15 like that, and IIRC, someone makes a 10/22 clone in it as well.
7/21/2013 4:47:52 PM EDT
[#2]
Valquartsen makes  a 17 HMR semi auto similar to 10/22 magnum.  Alexander Arms makes an AR-15 in 17 HMR but they  are out in limited numbers so not much is reported on them.
7/21/2013 4:59:40 PM EDT
[#3]
Why are rimfires prone to OOB's?
7/21/2013 5:09:00 PM EDT
[#4]
Because the rim is slammed around by the nature of the semi automatic action.  Even more so when the round is more powerful than your standard 22LR.

I was a little young when they came out with the 10/22 magnums, but I don't think they made them very long.
7/21/2013 5:38:03 PM EDT
[#5]
I do know I had a case separate once and left a piece of brass on the chamber... that bad boy slam fired the rest of the magazine on my 10/22 MANY years ago... no locking breach I guess..
7/21/2013 6:36:59 PM EDT
[#6]
Quoted:
Has anyone made a .17HMR in a semi auto yet?
View Quote


Well yes....and the big companies like Remington did a recall on them and rebarreled them for either .22 Mag or gave you money towards a new (different) gun.. They got tired of the law suits or threats there of after they kept blowing up in people's faces. Ruger made a 10/22 magnum which was a natural to convert to .17 but they dropped that rifle long ago. Too many cracked receivers.

There are many issues with blow back type firearms just not working well in "hotter" loads, especially the .17. There have been many technical articles written about this and I will not try to duplicate the fine work others have done. I will just say if it were a good idea, you would see lots of them. The fact that none of the big names want to build them tells you something. Too darn much liability due to all the problems.

As for the aftermarket ones, you should know you really have to keep them clean. I have read that some recommend cleaning them every 50 rounds or less. That little chamber gets dirty from the blow back and doesn't let the next round seat fully. KABOOM in your face! OBD big time. If you want a .17, get it in a bolt gun and keep your eyes and hands safe.
8/15/2013 5:49:07 PM EDT
[#7]
Is Alexander Arms still making this upper?  .17 HMR  Sounds like it goes beyond a simple blow back, but I have 0 experience with this.  Saw they had a .17 HMR upper in a recent magazine, and the wheels got to turning in my head.
8/15/2013 10:14:58 PM EDT
[#8]
I think the round is fine in a semi automatic... just not in a blow back action.
You have to respect the higher operating pressures and powder charge in that larger Rimfire.
8/16/2013 4:22:54 AM EDT
[#9]
This is all second person so please take it that way but it was mentioned here of ARFCOM that the Valquartsen 17HMR semi-auto does not have any problems and never did. I asked over on Rimfire Central if anybody ever saw or heard of case ruptures or OOB kabooms with the Valquartsen 17 HMR and there was nobody that had seen or heard of one. To top it off, Valquartsen is working on a semi-auto for the 17 Winchester Super Magnum. Now I believe Valquartsen has two different designes -- one is similar to the old Ruger 10/22 magnum but, I believe, using a heavier bolt and a second one called a TF rifle that has some type of counter weight added to the bolt that's hidden in the stock. Only thing I can imagine is, the Volquartsen rifles cost a lot and that may be because they do more work to get them right -- I honestly don't know but they don't seem to have the problems that converted 10/22 magnums had.
8/16/2013 8:09:34 AM EDT
[#10]
I think the problem was isolated to the firearm design allowing it to fire out of battery.  All of the reports i saw involved the Smith and Wesson and Remington rifles.
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