Simple Lube - Cold Bore vs. Warm Bore

Phineas Bluster

New Member
Last Sunday, November 17th, was the first cool day we have had this season. Temperature was about 15 degrees F. when we arrived at the range. I thought it would be a good day to shoot some groups and conduct a little experiment to see how the first round from a cold, fouled bore shot in relation to a warm barrel.

The carbine used is a late 70's Marlin Model 336C in .30 W.C.F. An older Bushnell Banner 3X – 9X variable was mounted in a Weaver one piece base and Weaver rings.

I have an ample quantity of surplus Reloder15 on hand that I wanted to try in the .30 W.C.F. Preliminary shooting two weeks prior had indicated that 26.0 grains was the best of the three charges tried, so the following components were assembled for the cold bore test:

Case: Winchester
Case Length: 2.005”*

Primer: Federal #210

Bullet: RCBS 30-180-FN
Alloy: 94-3-3
Heat Treatment: 60 Minutes @ 430 Degrees F.
Size: .310”
Gas Check: Sage .30 Caliber Copper

Lube: Fiver's Simple Lube (w/o Lanolin)

Powder: Surplus Reloder15
Powder Lot No.: 16J-084181
Charge: 26.0 Grains
Filler: Dacron 0.4 Grains

* Three of my carbines in .30 W.C.F. will only permit a maximum C.O.L. of 2.500” with the RCBS 30-180-FN. Cases were trimmed to 2.005” to permit crimping the case mouth into the bullets' crimping groove.

For the cold bore test, five (5) rounds were fired on an S-2 sighting target from a cold, fouled bore. Approximately twenty to thirty minutes elapsed between each of the cold bore shots.

For the warm bore test, a round was fired into the berm and then ten (10) rounds were fired on another S-2 sighting target. These rounds were single loaded, rate of fire was about one round every 45 seconds.

The point of aim for each group was the center of the large diamond to the right of each group.

The cold bore target:

11761

The warm bore target:

11762

The two targets were scanned and imported into a CAD program as raster images. The images were rotated to be plumb and level and then scaled. The bullet holes on each target were plotted and the center of each group was determined.

The two plots were then over-layed, using the center of each diamond aiming point for a common reference. The windage and elevation differences of each group are indicated on the plot below.

11763
The difference between the centers of the two groups are well within normal dispersion of this particular carbine. Of course one comparison on two groups is too small a sample to make any definite decisions, but the early evidence seems to bear out that Simple Lube will put the first round from a cold, fouled barrel in the group with subsequent rounds fired from a warm barrel.

PB
 

Ian

Notorious member
Neat program.

Generally, cold-bore flyers attributable to an out-of-range lube recipe will also be within the dispersion of your groups. 3/4" of windage is definitely minimal here, that's a pretty good all-around lube Fiver came up with.
 

fiver

Well-Known Member
there is a V-2 recipe out there somewhere if the sticky is still up over at Boolits it should be on-near the last page.
the consistency is real close to Felix lube on that second one.

anyway that's pretty good.
compress out the vertical dispersion and that is a real nice load.