Originally Posted By AlexanderArms:
Thank you for the interesting reference
We are not going to field a 17 HMR, we are already fielding it. The unit uses an 18" barrel with a 1/2-28 threaded muzzle. This was shown in our testing to be about the most efficient for the cartridge. We have run this both with and without suppresion with no function issues. It worked out to be quite an involved conversion as we needed not only the upper but also a mag block, extended mag latch, recoil cassette, magazines and even a chamber brush. The uptake has been nothing short of stellar for this product so perhaps I worried too much about the costs. Demand has been so high that we now run a 17 HMR designated lower in which the block is cross pinned so it is legal for California without the use of a mag button. Mags are 10 round currently.
Interestingly this has taken nearly 3 1/2 years to get to a position where we are actually confident with the design during this time we built upwards of 20 prototypes not including some rebuilds and shot well over 50,000 rounds of ammunition. The longer pressure duration is problematic and demands a careful system balance if it is to work well. To date the only field problems seen have been in guns fitted with two stage or target triggers ( the stock conversion is designed for regular hammers). The lighter hammer and spring weights allow excessive bolt acceleration which causes the bolt to loose control of the empty case at too high an incident. We have just completed testing a heavy replacement buffer which will be an optional replacement for those customers who wish to run such fire control groups.
The 22 WMR you are interested in, was easy to balance for bolt speed but this cartridge does not want to feed reliably. The long parallel case can be persuaded to shuck from the magazine into the chamber but lead nose bullets cause failures. Working prototypes are easy, but a production route for the ramping on the barrel is not easy to achieve in a robust manner suitable for mass production. This is not to say the project is abandoned just we are already scheduled to work on the new weapons system and never intended to dive into the 22 WMR.
Interesting. For your information I believe Remington pulled their semi auto rifle in 17 HMR off the market. They had a recall for the rifles. I wonder what the problem was.
A good number of years ago Rick Jamison was taking 22 mag ammo and pulling the bullets and dumping the powder, then necking the case down to 17 caliber. Thiis is way before any of the 17 rim fires came about. He cautioned against doing it as the case is still primed and being a rim fire more susceptible to an accident. I'm not saying he was the first to do this, but he did write about. I'm sure others experimented with it