I am testing different bullet lubes, in a 308 Winchester.

I am shooting 5, 5-shot groups.

Starting with normal uncoated bullets as a reference.

Then trying the following lubes.

Vaseline
SPL - this is sold as a ballistic lube for both rimfire and centerfire
Ceramic lube used for bike chains
Spray on Boron
Spray on Tungsten
Spray on Molly.

What percentage difference would you consider as being significant?

Saeed,

3% would be significant for velocity, if it's repeatable. I'm thinking each percent of 3000 fps is 30fps, and 90fps is enough outside the extreme spread of most of my "good" handloaded ammo to be attributed to the lube.

I'd also be interested in whether the accuracy is improved given less friction on the bullets.

Finally, I saw a video the other day with Speedy Gonzales saying he finishes cleaning his benchrest rifles with a graphite lube (Lock Ease, colloidal graphite) that evaporates and leaves a graphite coating in the throat to prevent erosion. Might be interesting to consider in your test.

Not interested in velocity at all.

In previous tests coating such as Molly did give a slight velocity advantage, but not enough to make a difference.

My concern is accuracy.

I know for a fact that Molly and Tungsten do reduce copper fouling.

As an aside, I also tried Vaseline, SPL, and Ceramic which is used for bicycle chains.

I did this just for a laugh, and got some results.

I will post them all once I am done.

Yes, I was wondering what measurement you were interested in once I saw the post. For accuracy, I guess an overall change across the five, 5-shot groups that's greater than the average delta between each of the groups would be significant.

Since you arent interested in velocity you should give the tried and true cast bullet lubes a go. The old NRA lube is just alox and beeswax 50/50. Carnauba is good stuff too or you could try some of the overpriced MFG lubes from Lyman, RCBS or ?

Many years ago, an older reloader friend (I’m now the age he was back then ) swore by lanolin on his cast and jacketed .45 ACP target ammo, dipped them and let it “dry”, but it wasn’t really “dry”. He won lots of matches, do it worked for him. I tried it on .357 cast bullets and didn’t have muck luck, Lee lube worked better for me, didn’t try it on rifle bullets. Never heard of using Vaseline, those results will be interesting.

Liquid lube is not really very practical for rifles.

I just thought I would try it for a laugh.

Here are some results.

Rifle is a Sako A7, 308 Winchester. 5, 5-shot groups at 100 yards, 125 grain Walterhog Pointed bullet.
This is the exact same bullet design I used for the aluminium bullet.

Plain un lubed bullets for reference.

Average 0.8272"
Smallest 0.592"
Largest 0.986"

SPL - This is a bullet lube for rimfire and center fire. It is water based, waxi feeling.

Average 0.8975"
Smallest 0.295"
Largest 1.409

Vaseline - Johnson and Johnson.

Average 0.9445"
Smallest 0.785"
Largest 1.224

Ceramic - this is sold in bike shops as a chain lubricant.
I had some on hand and thought of trying it.

Average 0.9798"
Smallest 0.598"
Largest 1.237"

Boron

Average 0.8764"
Smallest 0.687"
Largest 1.251"

Tungsten

Average 0.5899"
Smallest 0.599"
Largest 1.114"

I am shooting another test with a different bullet and in a different rifle, and using only Boron, Molly and Tungsten.

Will update once that is done.

Another rifle, another bullet.

Tried only Boron and Tungsten, as my supply of Molly was old, and it was powdery and falls off the bullets.

Kimber Model 8400 Patrol Tactical 308 Winchester.

163 grain Walterhog. Shot 4, 5-shot groups at 100 yards.

Plain, no lube.

0.559
0.560
0.626
0.778 average 0.6308

BORON coated

0.407
0.449
0.500
0.530 average 0.4715

Tungsten coated

0.316
0.568
0.597
0.708 average 0.5473