SVI 5.4" sight tracker barrel in a 5" gun - PICS!

[EngineerEli]

Loaded up some of the dummy rounds last night with the new .400 bayou 180's and the longest I could do, getting the round to reliably drop free from the chamber was 1.168" I loaded one to 1.700 exactly and while it would get a little hung up when I pushed it into the barrel and tried to pull it out, when I reassembled the gun, and chambered the round with full force, there was no extraction difficulty, so that may be ok, but the very upper limit I would say for my barrel. Anyone ever load one of these bullets with WST arround that length? What loads worked for you? Looking at the Hodgdon websight they say max load for a berrys 180 at 1.125 is 4.9gr. (932FPS in a 4" barrel) I figure this could be a decently safe place to start and work up from there. When I get a chace I try a few out and report back.

[beltjones]

I don't get this problem at all. Why not send the barrel back to Brandon?

[EngineerEli]

I am most concerned about negatively effecting the accurate of the barrel. The Jacketed bullets can be loaded out to 1.200". It is just the shape of the truncated cone coated lead bullets, and the fact that they are normally .001 oversize, that causes the problem. I also would hate to have to send the whole gun back in, or even part of it and be with out it for another month or however long it would take to get it reamed.

This is what I got from Brandon at SVI when asking these questions shortly after getting the gun back, "We function tested with 40 round of 1.185in OAL 180gr Zero Projectile from Atlanta Arms. I have experienced bayou bullets that are a .401+ and most commonly a full .402 diameter that will not clear the freebore. I would measure the projectiles with micrometers to confirm the diameter. There is not a reamer on the market that will increase the freebore for the over sized projectile. The freebore is where accuracy and velocity are sacrificed by increasing in diameter."

Are there different opinions on this, or is the loss of accuracy a relative thing? I realize I don't need to, and myself probably can't, hit a quarter at 50 yards, but I do want as much accuracy as I will need to optimize my performance during stages.

[EngineerEli]

After looking around the web for some shorter loadings with 180's with lead or coated and WST powder, I think some test rounds of 4.2, 4.4, 4.6, and 4.8 grains are in order...

[EngineerEli]

I don't get this problem at all. Why not send the barrel back to Brandon?

Well, I took your and many other peoples advice and sent the barrel back to Brandon. That's where things got a little strange. I had to pay for shipping there and back, on a barrel I just paid hundreds for. He said after running a few tests and running the tooling through the chamber with no metal coming off, that the barrel was fine, and sent it back. Only now when I chamber check my ammo, the load using the 180 bayou .401 bullets that could only drop test up to 1.150" now move freely in and out of the chamber at 1.181" so I'm not sure what the deal is. Is it possible there was just a tooling mark or something that smoothed itself out with the additional 1-200 rds I shot through it? He mentioned he though the test rounds I sent him didn't have enough crimp on them, and he crimped them a bit more, but I could have sworn that when I sharpied a round and chambered checked it, it was showing marks at the free bore (on the bullet shoulder), not the chamber (on the case).

Either way I'm just happy I can run the loads I wanted to now in the gun. I must say it shoots great. Balance is good and it cycles like a champ. I'm also really liking the extended sight radius. Hopeful I can get my current loads over a chrono soon, I'm using 4.6gr WST under the 180 bayou .401 at 1.180-1" OAL.

I attached before and after pictures of these loads in the barrel.

[gmg]

Hello: I'm using 4.5 - 4.6gr of WST with my 180 bayou pills in my AET sighttracker and it runs great, except for the occasional glocked brass that gets thru. Be wary of these.

[EngineerEli]

Hello: I'm using 4.5 - 4.6gr of WST with my 180 bayou pills in my AET sighttracker and it runs great, except for the occasional glocked brass that gets thru. Be wary of these.

Very cool! Do you have the OAL for that and any chrono numbers? What length barrel?

I use the EGW undersized sizing die, and have it cranked all the way down to the shell plate, so far, knock on wood, I haven't had any issues with glocked brass and I don't sort it out.

[eric nielsen]

Our local 1911 smith let us borrow his chamber reamers when we dropped by to visit. Every single pistol barrel I ever brought had at least one noticeable burr either pop right off or scrape noisily for 1-2 full revolutions of the reamer. Takes about 1 minute. After shipping both ways I would've been happier if my chamber was reamed wide enough for pickup brass and freebore sufficient for OAL 1.220 or more. My Cheely 40 does both with no problems, it's an SV barrel. I'm loading out of a huge box of brass I shot through a stock G35 barrel, zero malfunctions, no fancy sizing dies.

Edited September 18, 2013 by eric nielsen

[JaeOne3345]

Eli,

Your gun has a brother now.

[EngineerEli]

Yay! Mine has been telling me it desperately wanted a sibling

It looks great, I love the stainless, and the dustcover/slide cut at the front. Is that halfway between a butler cut and the standard cut? Really like the radial flute too! Are you happy with the way it shoots too? Maybe you noticed something I missed that would help others out in their decisions.

[Ken Mays]

... and the case rim somehow getting in front of the extractor hook. I have been in touch with Brandon at SVI and he said those sounded like magazine related problems, I still have to look into that, but my mags are a year old SVI mags so I don't know about that. They did send the gun back with a fresh 12 lb recoil spring and a blue shock buff which I have never used before. I wonder if that is effecting the dwell time at the rear of the recoil cycle and effecting the feeding reliability.

This happens because the cartridge on top is jumping out of the magazine during recoil and the extractor is not snapping over the rim. I would try fresh mag springs to increase the tension on the cartridge stack. I have been given the recommendation to increase the OAL of the rounds if this is occurring. If the IBF is not perfectly flush with the rest of the cartridge pickup rail, there's also a chance it could be helping to drag the top round forward as the slide returns.

At any rate, the extractor should be able to snap over the rim if it does occur. I personally think the new SV extractor is a little too stiff to do this. You could try an extractor with a more conventional design.

Some experimentation with a slightly stronger recoil spring might also lessen the bump at the end of the slide travel and reduce or eliminate the frequency of occurrence... though this will alter your muzzle flip behavior somewhat.

Edited October 1, 2013 by Ken Mays

[EngineerEli]

I was loading some ammo last night after getting the XL650 switched back over to .40 and i was able to load the.401 bayou's out to about 1.195" and still have them drop freely in and out of the chamber. Interesting, but I'm happy all is well now! What length are most people loading their Bayou 180's at? I feel like there shouldn't be much reason to go beyond the 1.181" I'm loading to at the moment.