"Bluesdaddy .30" Build almost done!

[SeanMP]

Sean are you near Ottawa area? I'm Just south of Ottawa myself.

Ya pretty close actually. Westport is the closest geographical.

Lapping is not terribly scary. It's a very slow steady process and I think if your using a lead lap and a true bore compound there is virtually no risk. Yes guys have mucked things up using aggressive compounds that get embedded in the steel.

[bitterman]

Ya pretty close actually. Westport is the closest geographical.

Lapping is not terribly scary. It's a very slow steady process and I think if your using a lead lap and a true bore compound there is virtually no risk. Yes guys have mucked things up using aggressive compounds that get embedded in the steel.

Thanks, I've got some reading todo. LW supposedly lapped it at the factory so was not looking there... I'm not that Far from you really maybe an hour and a bit drive west from my place.

Bruce

[bitterman]

Fired a few shot tonight.... both this thing is a MONSTER AND LOUD!

It is raining so no chrony work and tuning tonight. I can tell its up way too hot right now... major air wastage..... 10 shots from 2900-2200psi

Did is say its LOUD!!!! I'm sure tuing will help that.

Bruce

[bitterman]

So I decided to do some testing as it was sunny and I needed to relax after a 12 hour day at work.

Fill gauge 2800psi (showed 2600 on gun)
assuming End 2300 psi (showed 2100 on gun)

Had to turn the gun in as first shot was int he 700's at 3/4 a tune preload on the hammer so I tuned it into 2.25 turns and firs over the chrony was 956..

Fired 11 shots did not chrony the last but was still same poi at 40 yards.

So based on http://www.calc.sikes.us/1/index.php
2800-2300 11 shot averaging 950 fps (I know a few shots before shooting on target was 967)

I stopped there as I blew the breech o-ring out.

Based on the efficiency calculator the .30 is doing 1.14 FPE/cuin per shot and 14.4 avg bar-cc/FPE per shot and an average of 100.5 FPE with this tune. avg PSI used per shot was 45.

I'm impressed!!!!!! Its not that loud dialed back either when shooting pellets.

Bruce

[bitterman]

Wnet back and look at numbers and I mad a typo... average FPS was a bit over 950 more like 961 but since not every shot was chronied just used average of high and low. Regardless good enough for the girl I go with... efficiency is better than I expected.

Bruce

[rsterne]

Measure the pellet across the rifling marks with digital calibers.... I'm guessing 0.297-298"....

Bob

[bitterman]

Measure the pellet across the rifling marks with digital calibers.... I'm guessing 0.297-298"....

Bob

Got a set of callipers at Canadian Tire.

Bob you were right the minor diameter of the bore is about .298 and the Mr Hollow points are showing .303 on my callipers.

The head size of the jsb are showing .300 and the skirt that went through the barrel is showing about .306 maybe .0005 larger as the odd measurment was .307 ... I did not measure a fresh pellet.

Bruce

[rsterne]

If you are measuring 0.306-0.307" on the skirt of a pellet that was pushed through the bore, then the bore is at least that big.... The FX Pellets I have here measure 0.300" head and 0.308" skirt fresh from the tin.... It would appear your barrel is a whisker tighter than the LW barrel I have (0.300" lands - 0.308" grooves), but a lot bigger than the new barrels Sean and I had made for the JSB/FX/Daystate pellets.... Our barrels are 0.294" lands, 0.300" grooves....

Bob

[bitterman]

Bob,

Wish your and SeanMP's barrels would have been around when we started this project or even before the barrels were paid for. I think you are right that this is a standard .308 barrel only slightly on the tight side. Maybe lap this barrel and chamber'd for bullets... and get one of your barrels for pellets. and do interchangeable barrels :) Then have the best of both worlds pellets or cast.

Bruce

[bitterman]

Other night I pushed a 96 grain through the bore getting about .3075 to .308

Tonight I resized 6 68 grain to .308 using lee press with lee lube and size kit. Actually showing as .308 after resizing.

First shot was slow so getting close to valve lock at 3100 psi
3100 to 2750
850 905 error error 913 917 so average of 900.8 (used 910 for the errors).. longer string really needed to check efficiency... But not bad for a big bore. Darn these are hard to load.

If I ignore the first shot.. not a bad 5 shot string. Thats about 1.0+ avg FPE/cuin per shot not bad.... 125 ish FPE too!

Lots more left in it but with a nice 5 shot curve like that I'm hoping levels out and get a 10+ shot string per fill starting about 3000psi

Bruce