Delayed blowback and barrel shortening reliability

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rockman96
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Delayed blowback and barrel shortening reliability

Post by rockman96 » Sun Sep 06, 2015 9:34 am

I'm looking hard at the Savage A17 semi auto .17 HMR, and don't fully understand the physics involved.

With the delayed blowback design of the A17, will shortening the barrel to 16" affect reliability (when suppressed)? I really want a semi auto .17HMR, but I really don't want a 22" barrel with a 6" can hanging off the end either.

quiettime
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Re: Delayed blowback and barrel shortening reliability

Post by quiettime » Sun Sep 06, 2015 3:44 pm

http://bulletin.accurateshooter.com/201 ... avage-a17/

There's a video in the link that will help you understand a little more about the operation.

I think 16" probably will function fine by itself but the great thing is the can acts as a "booster" to help with reliable function because it works by trapping pressure inside and releasing it more slowly than just a section of barrel would.

That said I probably wouldn't shorten it all the way to 16". Leave yourself a little room in case anything happens with the threading so you will still be legal length, like maybe 16.75" or 17"

rockman96
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Re: Delayed blowback and barrel shortening reliability

Post by rockman96 » Mon Sep 07, 2015 9:25 am

Thanks.

So I guess the balance between the mechanical delay, spring tension, and gas pressure in the A17 isn't nearly as delicate as it is in a standard blow back system (minus the mechanical delay of course.)

quiettime
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Re: Delayed blowback and barrel shortening reliability

Post by quiettime » Mon Sep 07, 2015 7:16 pm

That's the theory.

Your post got me doing some research and I've read mixed reviews on the A17 in the past day. Many complaints on the trigger, some on reliability and some folks are very pleased. I did note that the parent company of ATK has purchased Savage and as such they have introduced a special ammo "optimized" for the A17 :roll: . Apparently about 100 fps faster than regular 17HMR because "Savage engineered an action and bolt that are strong enough to handle the new 17 HMR ammo"...

SO.....you may want to give it a little while to see what others are saying about the compatibility of "regular" 17HMR ammo and for Savage to work out any bugs in early production. As hard as it is to get any rimfire ammo right now I'd be pissed to spend 400 bones on a gun that had to have one kind of ammo. But then some of us do like a project...

Accurate Shooter review and comments

quiettime
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Re: Delayed blowback and barrel shortening reliability

Post by quiettime » Mon Sep 07, 2015 7:43 pm

Jeff Quinn says in his review that it will shoot any 17 HMR ammo but most was not as "consistent" or as accurate as the Savage ammo HERE

rockman96
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Re: Delayed blowback and barrel shortening reliability

Post by rockman96 » Tue Sep 08, 2015 5:41 am

It likes the A17 ammo better from what I've read, but seems to do pretty well with standard fodder. I may hold off a bit, but I'm pretty sure I'll end up with one. Most of the issues I've read about seem to be operator error (mag installation.)

Thanks.

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