"Junk" barrels

So far, have a 12” factory 5mm barrel, a 15” .22 barrel, and today I made a 16” .177 barrel. Had a take-off barrel from an old Gamo 126 match rifle (some of you might remember that old SSP), and rather than shorten it and lose either the choke or the nice chamber lead, decided to just make it fit the length it is.

Decided that fitting the barrel to the bushings (made from black Delrin) a very tightly “drive on with a mallet” fit, glued them, and set screwed them in place. Made sure the bushings are a push fit to the frame (won’t fall in…won’t quite finger push in…need to push with about 30-35 pounds of force to get it to slide in. Absolutely no play seems the way to go.

Made a fast frame extender, a few internal parts for that extender, and got to testing. Only have 20-yards from the shop to a backstop, and light was going fast so i did the initial tests at that range from a front bag on the shot bench and my fist as the rear bag. 5-shot groups, “kind of” bench rested.

SWEET shooting rifle. From a real rest, with bags front and rear, expect it will shoot a bit better. Have a bit of an over supply of .177 pellets; this should even out my supply before mid summer.

ribbonstone

Participant

April 2, 2009 at 2:17 am

Final tests.

Did my final tests of the “junk” barrel . Very limited range time, so tried to pre-plan how to get the most information for the lest shots. Ended up shooting 35 for score shots and a handful of sighers on a junk target.

If considering the drop values, then by measure the scope center line is 3.1” over bore line.

Things learned:

#1. The scope was canted. By shooting those first groups while adjusting JUST the elevation, can see that they formed a diagonal line. Had used a bubble level on the rifle and a bubble level the top of the scope turret. Not too unusual to have a reticule that is NOT set straight to the adjusting turrets (and this 30 mm tubed 10X42 only sells for about $60).

Readjusted the scope by leveling the rifle, hanging a plumb bob, then making the cross hair parallel to the plumb line. Fired the group on the far left as a check and decided to add a click of windage.

#2. the 1/4 MOA “clicks” of the scope are worth more like .3 MOA. No big deal as they seem to be consistent.

#3. Had nearly given up on these pellets. Are the worst CPH’s i’ve ever bought and the other .177’s tend to group them poorly. Might be the little stubby pellet “wings”. Later tests will probably find a better pellet.

#4. Estimated it would take 32 Clicks to get on target at 40yards…tested it on a “junk” target and found I needed to reduce that increase by 6 clicks. Fired the two targets on the far right.

#5. AVERAGE vel. readings aren’t all that great for figuring BC but unless you have two chronographs to set up to read individual pellet speeds, it’s all you have. Readings at 5 feet and 100 feet indicate these pellets are earning something very close to a BC of .02.

Not everyone’s cup of tea. Wanted to deliver about 7 foot pounds at 50 yards with small groups. Is on track to give groups in the 1/2” range at 50 yards, so that part of the equation seems right. Is delivering about 7 foot pounds at 40 yards, but once it gets warmer, the co2 will gain a bit of speed. And those CPH’s are earning a lower BC than hoped. A switch to Kodiaks and warmer weather should get to where I wanted to be.

April 1, 2009 at 10:52 pm

Did before 2005…Katrina washed the house and everything in it away and I never had the heart to replace those original ‘rollers’.

Although with the recent change in La. law that puts cartridge single shot BP or repro BP rifles in with the muzzle loaders for the primitaive season, may just have to pick up another good solid Rem….for hunting, was partial to the 50/70 as I shoot in the swamps/marsh/thick scrub were ranges are pretty short.