Author Topic: 7mm Hayabusa Build (Read 22774 times))

Tofazfou · « **Reply #60 on:** March 14, 2015, 10:16:11 PM »

Bob,

Seriously Sir! Nothing unattractive about anything in that complete UPPER unit. NOTHING!

It all looks good the way it is..........WOW!

Bill G · « **Reply #61 on:** March 15, 2015, 05:08:06 PM »

Quote from: Tofazfou on March 14, 2015, 10:16:11 PM

Bob,

Seriously Sir! Nothing unattractive about anything in that complete UPPER unit. NOTHING!

It all looks good the way it is..........WOW!

+1! It really appeals to my function over forum.

ToRmEnToR · « **Reply #62 on:** March 15, 2015, 06:37:03 PM »

cant wait to see it!

rsterne · « **Reply #63 on:** March 16, 2015, 11:31:44 PM »

The mold arrived today for my 94 gr. Bob's Boattail bullets, with two cavities converted to HollowPoints....

The Mold is available from Veral at LBT under # 284-94-BST.... and the HP conversion was done by Erik at HollowPoint Mold Services....

Bob

rsterne · « **Reply #64 on:** April 09, 2015, 04:16:36 PM »

I finally, after a month, got the Metric O-ring I needed to seal the bolt into the thimble.... Last week I had the opportunity to cast some of my new 7mm Bob's Boattails, and that gave me the samples I needed to use the chambering reamer I got from Sean Pero to chamber the barrel.... Here are the results....

In the photo above, you can see the system that retains the barrel into the breech, a threaded sleeve that presses against a collar threaded onto the barrel, the O-ring that seals the barrel to the thimble, the thimble itself, and the chambering reamer.... I ran the reamer in until when the bullet was properly seated the base was flush with the back of the barrel, which sits against a shoulder in the thimble just ahead of the transfer port.... The bolt pushes it home to that location.... Below is a closeup of the thimble, showing the internal 7.5mm x 1.5mm x 10.5 mm O-ring that seals on the OD of the bolt, and a bullet which has been chambered....

You will notice that the rifling marks on the front driving band are approaching full depth, but the middle band is just entering the tapered leade.... There are no rifling marks on the rear band, it sits in the parallel section of the chamber, which is about 0.001" over the groove diameter of the barrel.... You can feel resistance for about the last 1/8" of bolt travel, but it is not hard to chamber, you are just aware of the bullet engaging the rifling, which I like....

My replacement ShoeBox Compressor (a Freedom 8 ) has been shipped, and with this work completed, I should be ready to test the 7mm version of the Hayabusa once I get it and top up my tanks....

Bob

Bill G · « **Reply #65 on:** April 09, 2015, 09:19:46 PM »

Hey Bob, did the CF tubing ever show any indication of comression with that 750 lbsF on it?

rsterne · « **Reply #66 on:** April 09, 2015, 10:56:16 PM »

Nope, absolutely none.... I left it for nearly a month and the gap between the Bellevilles was unchanged....

Bob

Bill G · « **Reply #67 on:** April 10, 2015, 12:19:21 AM »

NIIIICE!! that is gonna work out so well. Your the best I ever saw.

rsterne · « **Reply #68 on:** April 14, 2015, 07:30:32 PM »

I assembled the 7mm Hayabusa today and fired it for the first time.... I tethered it to a regulator at 2900 psi and tested the hammer spring preload to determine if I have enough hammer strike to max the gun out at that pressure, and I do....

The velocity falls off slightly at the top end, not sure why, but I have seen it before.... It doesn't matter, as the gun would be an Air Hog at anything over 5 turns out from coil bind anyway.... The maximum FPE at 2900 psi was 193 FPE, which is right about where it should be using the 96.5 gr. Bob's Boattails, so I'm very pleased.... My new ShoeBox Compressor is at the Post Office and I'll be picking it up tomorrow, so within a few days I should have some shot strings to share with you....

Bob

CHUCKSTER · « **Reply #69 on:** April 14, 2015, 11:48:24 PM »

Hi Bob,
Have been following your progress with the Hayabusa project and I for one hope to see you create some shot strings with targets in the background...I am sure many of us are curious as to the accuracy of your new rifle.
Hope all is well with you...
Fond regards, Chuckster

rsterne · « **Reply #70 on:** May 08, 2015, 02:03:09 AM »

Got to send a few rounds downrange today.... 1" at 50 yards and just over 2" at 100 yards seemed typical.... I didn't get a chance to index the barrel, play with the tension, or the air stripper yet....

Bob

KnifeMaker · « **Reply #71 on:** May 08, 2015, 02:13:01 AM »

Your going to be having some fun for sure with the testing Bob!

Enjoy!!!

Knife

Tofazfou · « **Reply #72 on:** May 08, 2015, 10:19:20 PM »

Quote from: KnifeMaker on May 08, 2015, 02:13:01 AM

Your going to be having some fun for sure with the testing Bob!

Enjoy!!!

Knife

YEP, LOTSA TESTIN AHEAD..............WOOHOO!

11william · « **Reply #73 on:** May 09, 2015, 01:30:15 PM »

You are very talented.
I have learned a lot from your post. Not just this one but all of them.
Sometimes the math goes over my head but it is all about the math.

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7mm Hayabusa Build

Author Topic: 7mm Hayabusa Build (Read 22774 times))

Tofazfou

Re: 7mm Hayabusa Build

Bill G

Re: 7mm Hayabusa Build

ToRmEnToR

Re: 7mm Hayabusa Build

rsterne

Re: 7mm Hayabusa Build

rsterne

Re: 7mm Hayabusa Build

Bill G

Re: 7mm Hayabusa Build

rsterne

Re: 7mm Hayabusa Build

Bill G

Re: 7mm Hayabusa Build

rsterne

Re: 7mm Hayabusa Build

CHUCKSTER

Re: 7mm Hayabusa Build

rsterne

Re: 7mm Hayabusa Build

KnifeMaker

Re: 7mm Hayabusa Build

Tofazfou

Re: 7mm Hayabusa Build

11william

Re: 7mm Hayabusa Build