Effect of WD-40 left in barrel?

[rangerider7]

Does WD-40 left in Barrel cause erratic shots? The first couple I mean. I was out at the ranch yesterday and shot my Marlin 1894 25-20 to make sure it was on target before I went calling coyotes. My first two shots were erratic then the next two right on. I was shooting the same ammo. Was it just me or does this happen?

[Chuck 100 yd]

Yes. If first shot accuracy is needed it is best to dry the bore with a patch or two first. It is not like a fouled bore but as good as you can get short of a fouling shot or two.

[20cows]

As I understand it, WD-40 is basically a heavy oil dissolved in acetone. If it's been in the bore quite awhile, all that's left is a thin coat of 90 wt. oil. I could see it taking a couple of shots to clear it out.

[Blaine]

Could be, or since every gun is different, it just don't like shooting clean or cold......

[Old Savage]

I would say yes, Shooter's Choice seems to have the least of this but I like to have a dry fouled bore if I care where the first shot goes.

[Rodfac]

Yep...but each rifle is an individual...that being said, Hoppe's left in the bore overnight (and the rifle stored muzzle down to prevent drainage into the receiver/stock area) will keep it rust free for short time storage. Prior to hunting, wipe it out with a cpl of patches and you're ready to go. If it's raining and I have a concern about rust in the bore, I leave a LIGHT coating of Hoppe's in the barrel. The service rifle teams have used the "leave the bore wet overnight and wipe it dry before shooting" technique in the past to prevent rust.

As a further rust preventative and for really miserable conditions, wet continuously for a week or more, you might try disassembling the piece and coating all metal parts accessable with Johnson's floor wax. Like your car, it'll keep the water off. Generally, we give the outside of our weapons more attention than necessary, ignoring the hidden danger of rust to the wood covered areas.

For stocks, a THOROUGH coating of polyurethane, a cpl of coats, to the inletted areas will prevent water soaking, and don't forget to pull the butt plate off an do the end grain there. It absorbs water at a much higher rate than the flat grain areas. Doing so will help prevent zero changes when the humidity changes radically, as when living east of the Mississippi and travelling to Colorado for elk. Or here in KY where the summer humidity usually runs in the 80% range, and winter when we're down well below 40%.

For my Sako .308, Hoppe's left overnight in the bore then wiped dry results in less than an inch shot displacement at 100 yds. In my AR-15, it's the same but at 200 yds with Nat'l Match type loads; same for a cpl of '03's and two M1's I shoot. For my Marlin 336 .44 Magnum and hunting purposes, there is no discernable difference between an overnight soaked but wiped dry bore and one that has been fouled with a cpl of shots. For practicable purposes, unless I'm testing loads and checking exact grouping, I wipe the bores out with a dry patch and go hunting. All this applies only to Hoppe's or Ed's Red. I can't speak to the use of other solvents. The use of regular gun oil type lubricants in the bore is a whole different ball game where large impact changes can and most likely will happen. HTH's Rodfac

[Rodfac]

Just an aside: OLD SAVAGE, that's one heck of a good lookin' knife you post with. Can't say much about the sheath but the blade looks great. Rodfac

[colo native]

I have a bore snake for each cal and shotgun bore, and before I use any wepon I pull the snake thru. and do so after each session of shooting.. realy helps on shotguns... I use em dry, but after a few uses they pick up a small amount of lube, then in the wifes washing mochine they go...

[Pisgah]

Always swab oil -- any oil -- out of bore and chamber before firing a rifle. 99% of the time, at least, it's the right thing to do. Just about every rifle I've owned will trow the first shot or three wide unless the bore has been wiped.

[rangerider7]

Learn something everyday on this forum!

[RIHMFIRE]

Learn something everyday on this forum!

we sure do!
its probably why i missed that deer last year...
or was it buck fever!