I am looking at a 17 Remington barrel for an AR15 upper. Does anyone have experience with this? Any ideas on buffers etc... It's a fast round (approx 4100 ft/s), the bullet about 1/2 the weight of a standard 223 (20-30gr), an uses essentially a necked down 223 brass. The bolt should be the same as a 223, and it would use standard clips.

I have no experience with this but I do wonder if reliable function could be had in a 17 Rem AR due to decreased "dwell" time with such a high velocity round. There has to be gas pressure on the port for a certain time/pressure curve. Just a thought...

I think OLYARMS makes one (maybe I'm wrong though)

If dwell time is a concern how about a dissipator setup (carbine gas tube) on a 24in barrel? (or just a 16 or 24in barrel as these should increase dwell time.)

I think the issue would be sufficient gas to feed to the bolt (would a .17 kick back a ar-15 bolt? )

[b] as for buffers if this is a problem maybe just lake out a few or all of the bounce weights? - or you could buy an AAC spring off one of the FA guys because they all bitch about these springs being weak and substitute them for a std spring.[/b]

I have no experience with the 17 Rem, but I have seen it on Tromix's website (www.tromix.com)   Hope this helps.

I have done about a dozen of them and they shoot extremely well.  Groups run around 3/8" for five shots at 100 yards using the Starke 30gr bullet.

I have a reamer inbound to do the 17 Mach IV as well.  That's the .221 Fireball case necked to 17 caliber.  It will probably need the 50AE style spacer block installed in the magazine in order to run the shorter round however.

Tony Rumore
Tromix Corp

Tony,

On the ones you've made, were the barrels different lengths?  I was wondering if a 24" barrel was really needed, or if a shorter one would be fine (assuming you don't mind taking the hit in velocity...).

All of the 17 Rem uppers that I made were the same.  24" Stainless Pac-Nor Super Match barrels with a 1:10 twist on DPMS hi-pro recievers.

I recently made a 21" .223 upper, 1:12 for my dad for Christmas and it blasted 5 rounds into 3/8" at 100 yards as well.  So, I think the shorter tube would still work fine, but I am not sure since I have never tried it in the 17.

The customer that ordered the 17 Mach IV, requested a 20" barrel, so we'll see how that does shortly.

Normally speaking the length of the barrel is not going to dramatically affect the group size.
Having built quite a large number of AR's
that will commonly shot 1/2" to 3/4" at 200 yards. the the shorty guns, 17" barrels shoot just nearly as well as the 26" guns.

Oppenheimer
Narwhalguns