RF Sterling - detents in breech?

[flyweightnate]

Hey all,

I noticed on my Spyder-threaded (third gen?) Sterling bronze, there's around an inch of breech between the bolt face and the barrel. Seems like roll-out city.

I'm planning to tap for a detent to prevent double feeds; has anyone tapped for a second (or third) to help with ball position prior to the shot?

My second gen with the longer barrel threads didn't have all this space... ironic that I was excited about Spyder threads to size for paint, but it's not even close. Might have to drill for a new feedneck and make a longer bolt to get it "correct" but that's obviously a much bigger project.

[Chuck E Ducky]

You can freak bore the spider barrels they have enough meat to them.

Brian has his done and my new one coming in is freak bored. They are both SC STP but should not make a difference.

But if you figure out a detent mod Im all ears. I just sent my old one to it’s new owner so I can’t pull it apart to look but maybe sandwich oring off the bottom using the Frame plate separating the frame and body. Do like an ASP mod for the phantom. One for pre and post travel so it don’t matter what barrel size is in front.

[Spec]

I was shocked when I first saw that design "choice". That inch of freebore that the ball can roll around is a bummer as the ball will hit the bore with varying amounts of force depending on where the ball has rolled in the beach. I beta tested multiple types of finger detents during development and had the same problem. A rubber nubbin like Lapco uses could hold the ball at the back of the breach, giving the most consistent velocity but maximizes the impact of ball into the bore.

If you were to bore the barrel 4 inches and 1 into the body and place the insert like a reverse freak xl system, perhaps that would be the best solution.

Plenty of aficionados like the 3s but I have to use field paint, live in a cold weather climate and have experienced far to much ball breakage and inconsistent velocity even with a secondary reg so I blame the freebore issue. I got fed up with the design and moved on.

Of course a well tuned MVP made for a soft landing.

[flyweightnate]

I was shocked when I first saw that design "choice". ...

You and me both. I understand moving away from the proprietary thread to the more common (if shorter) Spyder thread, but seriously... at least mill away some of the top tube so the barrel sits at the right depth. I'm guessing there wasn't enough "meat" between the two, but I haven't checked yet.

Boring for a Freak or iFit seems the best option, just beyond my machining capacity. The flange on the iFit slides down inside the Spyder threaded bore, but of course it's just a hair too long, so I'd need a custom, shortened barrel thread to hold it in place if I don't go with the custom, Freak-bored barrel with an inch sticking out. On top of sending it to someone with a 4-jaw on their lathe.

Ugh. Give it a year and I'll probably have just made a whole new body for the thing, solving this and the three or four other "suboptimal" features.

[Chuck E Ducky]

I have seen CCM top tubes modified to bolt on the Sterling lower machined down. One sold here not long ago I forget who was experimenting with the idea but it looked pretty well thought out and there were a few different ones he made.

I thought it was a pretty good idea and a great way to make one cocker threaded.

[flyweightnate]

Ok... so this little guy is getting round-topped and getting a longer bolt, but now the question comes down to the feed block.

Any cool tricks for installing a feed block in the tiny amount of material above the barrel? PEM stud from the inside, like a gargoyle front frame stud?

[flyweightnate]

Weekend update:

This started as a junkyard dog, with stripped frame threads in the valve body and a gnarly paint job.

Got a new valve body made, then extended the bolt. Didn't feel like making a new one from scratch - the back half with the scallop for the valve looked tricky - so I just made an extended nose that pressed in. By keeping the ID of the nose a bit smaller (I mean, really... the valve port is 1/4", but the bolt is 7/16"?) I'm able to keep it smooth the whole way, and hopefully see a slight efficiency boost. Gotta control the pace of expansion...

Next is plugging the old feedneck, then drilling and reaming the top bore to trim the plug, and drilling for a CCI block. I'm a bit worried I didn't leave enough meat up top for the block. Might just have to mount it backwards.