Cold bore shot is high

Sendaro

Active Member
#1
My Springfield 03-A3 seems to shoot shot #1 high. This happens with a cold bore and it does it if clean or fouled. I have an idea that it is an issue with the lube when the bore is foul and what I like to called seasoned. The lube I'm using is from NOE and is the 50/50 that was recommended to me as a good all around lube. I believe some one said it was the old NRA lube formula. The bullets I'm shooting are cast at what I believe is close to a number #2 alloy and at speeds of 1550 to a little over 1600 fps. Bullets ranging in weight 170 to 205 grain with a GC. I'm not getting any lead build up in the bore just some powder and primer residue.
At this time I'm working on developing an accurate load for use at ranges out to 500 yards. I shoot steel silhouettes between 100 and 500 yards.
Would like to hear your perspective pertaining to lube on this subject.

Thank you, Sendaro
 

Sendaro

Active Member
#3
Ben, Thanks for getting back to me. I'll try to contact 35SHOOTER.

I got the suspicion that it is nearly unavoidable. I base this on my experience shooting rim fire benchrest. I'm not sure what other shooters call it but I call it a "SEASONED BORE". That is when starting with a cold clean barrel the bore has to become fouled with powder adn primer residue along with whatever wax or coating the manufacture coats the projectile with. Some times it take several shots to over 10 to get the rifle running true. If the barrel is allowed to cool the viscocity of the lube in the barrel becomes different than what it was a few minutes before while the shots being fired with less time between shots. That fouling in the bore needs to remain consistent or the shot to shot speed deviation becomes greater. That shows up at the target with inaccuracy.
I would have to say here that I'm looking for a lube that is less effected by the bore temperature . Am I looking for the holy grail of lube? Maybe.

Again your thoughts and suggestions are always welcomed.
 

Ian

Well-Known Member
#4
A group of us spent several years intensely studying this problem and exhaustively trying to fix it. The solution isn't necessarily simple because it is dependent on a number of variables that each handloader has to factor in to come up with their own fix.

"Old" NRA formula is actually very good at putting the first shot into the group, but it isn't the one you're using. Col. Harrison's formula of beeswax and Alox 2138F is the "New" NRA formula, or NRA 50/50 and has been sold by at least half a dozen commercial vendors until the Lubrizol corporation ceased making 2138F. The old formula is equal parts Beeswax, paraffin, and Vaseline.
 

Sendaro

Active Member
#5
Ian, Thanks for that information. When you state----------->The old formula is equal parts Beeswax, paraffin, and Vaseline.

Is that in weight or volume? Please advise.
 

Ian

Well-Known Member
#6
A pint is a pound, the world around. I.E. with hydrocarbon waxes and oils all coming in at about the same specific gravity, it doesn't matter what method you use. I weigh wax and Vaseline on an old postal scale, using a piece of waxed paper when weighing Vaseline so as not to make a mess.

You may take an interest in what 35Shooter does, many others do the same thing and it works fine for some situations. When you throw wild temperature variables and extremely low or high velocity at the equation, the method may not work. My solution ended up being a recipe, later tweaked by members JonB and Barn here on the board, it's a soap lube using a microwax blend plus some beeswax and finally a small amount of medium-hardness paraffin wax. I think it's called SL-71B and is very good for just about any bore, any bullet, or any temperature. Drawback is a severe learning curve to making it.
 
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fiver

Well-Known Member
#7
so lets explain what is happening so Sendaro has an idea of what he is facing here.

the best way for me to explain it is the floor wax scenario since it somewhat relates to our ingredients and experiences.
I'm sure most of us here have either been involved in a Sunday GI party or have been in a K-mart/gas station convenience store.
we all have looked down at the floor somewhere and either remarked on how nice and glossy it looked or noticed the middle is getting a bit hazy and lost it's clear gloss look and remarked the floor needs a new wax job.

that's what is happening in our barrel too.
the wax in there has hazed over and lost it's shine and buff.
that first shot is adding a new layer of wax and polishing the barrel back to it's former glossy shape.

so what does this mean?
and how do we fix it?
I could tell you but then......LOL

can't tell you how to fix it to be in the same state a week later because oxygen just does that to stuff.
but there are ways around it.
one is to try and pre-prep the barrel before shooting it. [a patch with something on it to partially repair the haze so the first shot is only 2% off, not 4-5% off]
another is to use a wet lube that floats the bullet down the barrel overcoming the extra friction the haze creates.
a third is to manipulate the powder volume of the first shot to play nice with the extra friction, in essence tricking the first shot into thinking it is one of the others while preparing the way for them.
 

Sendaro

Active Member
#8
Fiver, Thank you for your observations and suggestions. My lube education continues. Much to learn and test.

Sendaro
 

Eutectic

Active Member
#9
A couple of things.......

If you think this is a problem in most environments you ought to try it when temps are double digit below zero..... And your gun and ammo is too!

It also depends on how strict your personal criteria is......

If you can live with a 3 minute of angle error downrange for that first 'cold shot' then several lubes will get you there. A moose can buy you some wiggle room!
I have chased this 'cat' much more than most because my favorite hunting is both frigid and demands (IMO) 1/2 moa accuracy. This is a tough pill to swallow! I call my criteria "minute of grouse eye"!
I've gone down the road of modifying load or bore condition for the first shot...... Trouble with this is it opens a 'new' line of variables that can follow a different line of behavior when temp is bitter like say minus -10°F below zero.

A couple of lubes I use can accomplish 'minute of grouse eye'. The new 'NRA' formula (beeswax and Alox 2138F) WILL NOT! Some soap lubes like Ian uses will get you there pretty well and carry you through higher temps as well. I continue to use my favorites however and sacrifice some top end (temps) for ultimate cold performance.
We still have something that eludes us for a perfect "Extreme Lube" formulation! C.O.R.E is a tough guy to handle!

Pete
 
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fiver

Well-Known Member
#10
it's the change not the constant.
if we could powder coat our bores and shoot naked bullets down them we would still have powder fouling to contend with.
that would of course eliminate some problems but then create a whole set of new ones.
 

Ian

Well-Known Member
#11
To keep all the shots in the group, we need consistent CoF between bullet and bore. As temperature fluctuates, so do the properties of bullet lube which affect that CoF. So, our challenge as lube cooks is to manage friction while the lube is in three different physical states:

Solid plasticized by liquid of lower freeze point, full liquid which willl experience the full range of temperature/viscosity change, and vapor.

The solid/liquid "mush" phase acts as a high-viscosity, deep-drawing lubricant that prevents the bullet metal from abrading or galling as it is forced through the throat and into the form of the rifled bore. I also theorize that this thick phase of lube helps create a good seal (obturates) between both bullet and throat, and between case neck and chamber as the bullet transitions from case neck to bore because lube displaced from the grooves fills voids. In some instances, lube will fill all the space at the end of the chamber and make a sort of bridge that keeps the bullet from flowing into that area before entering the throat. The temperature of the lube on the bullet at the moment of ignition will have some effect on all this.

Further up the bore, the lube is liquified by heat and pressure and acts as a dynamic film lubricant. Since liquid lube temperature is relative to viscosity, viscosity is relative to "friction", friction is relative to bullet time in the barrel and the shape of the pressure curve, and bullet time is relative to point of impact, it's easy to see why temperature of the bullet and barrel affects the way lube will perform during any given shot.

Some lube can be vaporized during the firing event and some remains behind as a liquid slurry mixed with powder/primer residue. Vapor remaining in the bore condenses in time, and with more time the residue solidifies. Depending on time between shots, bore condition can change drastically.

If you can put together a recipe that has the same drag characteristics no matter the state, then you have solved some major issues. The secret seems to lie in blending wax, oil, and other additives to achieve a lubricant that always acts the same between bullet and bore, regardless of temperature. Unlike microcrystalline and paraffin waxes, Beeswax has very high film strength in the liquid state. Ester oils and castor oil (among other things) also have high film strength and low viscocity indeces, so those types of things work well in the high-speed, liquid phase. The oils help plasticize the solid wax for the initial flow. The problem with some of these super-lubricants is they can be too slippery, and beeswax can be too sticky when cold. Microwax can help control oil flow and reinforce beeswax, but also tends to increase friction when cold while decreasing viscosity when it melts, so it has to be balanced out with other ingredients. Paraffin wax is brittle and doesn't absorb/retain oils as well as some other types of wax, but it does make a very slick, hard film when cold. Carnauba wax makes a very hard film when cold, but it almost acts like an adhesive when a bullet rubs across it at high speed.

A lube also needs to transition from soft wax to liquid very quickly, and resist burning. Sometimes metal soaps extend the useful velocity or upper temperature range, but often cause problems in extreme cold. "Extreme bullet lube" is a monster challenge. It's much easier to make a lube that shoots consistently within a 40-50 degree temperature window and 1000 fps velocity window than one that does it all.

A balanced mix of broad-spectrum microwax, beeswax, paraffin, plasticizing oils, and high film-strength lubricating oils all held together with a metal soap works out pretty well for a lot of us for addressing the cold bore issue, heat fade, leading, high velocity, low velocity, and other issues like hot ammo storage conditions and unheated lube-sizers.
 

JWFilips

Well-Known Member
#12
FWIW: I do not know all the math & tech of this issue: However I have found since I have switched to PC coating; My first shot ...cold barrel goes in the same hole as the 2nd thru 5th shot at least with 80 % of my rifles. But I do not clean my rifles between range trips ( just a dry tight patch through the bore when I get home to see if I'm getting any leading!) One or two of my rifles I see a slight displacement but noting serious.
Jim
 

Eutectic

Active Member
#13
I'm not sure CoF covers all the 'bases' involved any more than C.O.R.E. ???

Lamar makes a good point about things other than friction that affect what is happening...... These things may or may not march to the beat of their own drum further complicating our study!

Cold is a funny thing..... I'm talking cold now not just chilly. Let's say -20°F below. In my tests I notice things as I have time between shots in a 'saturated' test. The bore appears dirtier. Not with lube (although some do build up) but say some lube with a low% kicker like POE in them... Mostly incomplete combustion to my eye. What I can guess by observation is the time pressure curve has changed too.
Chronograph usually reads lower velocity..... Double base have been quite consistent even to -30°F below going still lower fps.... So we're good huh? Better watch it!!!!! Double base has been know to give dangerous VERY HIGH pressures at double digit minus temps. Hercules is said to have taken HiVel #3 of the market just before WW2 because of gun blow ups in northern Canada at minus -30°F or lower.... Too bad too! It was a good cast bullet powder according to my mentors. Alliant still is spooked by very cold. Some comments from them said 410 got crazy in the cold. I ran tests one winter with it down to -32°F below. It behaved for me getting slower and dirtier. Very uniform though. Not a recommendation now! Just my inquisitive mind for my own knowledge.... It's a pain in a lot of ways testing that cold! The ammo stayed out all night..... Gun for two hours. You had to chronograph fast as the led display didn't last long! I'd bring it in between shots to get a reading for the next 1/2 hour if you were quick!
Things change in this frigid world. I've tested enough out there that I 'read it'. You even sense it will get worse at even lower temps...... They say at absolute zero or 0° Kelvin all molecular activity stops! What will happen to my lube! Lucky they haven't reached it! Yet......
 

Ian

Well-Known Member
#14
To reinforce JW's point, here's a group I literally just finished shooting at 100 yards (will post more about it on the HV/PC thread). First shot is marked. Barrel was normalized at about 80°F before the group, and was too hot to hold after ten slow shots. 5.56x45mm, 1/2" grid. Powder coated bullets with no lube.

20181006_172923.jpg
 
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Ian

Well-Known Member
#15
I'm not sure CoF covers all the 'bases' involved any more than C.O.R.E. ??
It doesn't, but I'm not sure Sendaro is up on our terminology so I used CoF instead. Consistency of Residuals Encountered is a good way to visualize what's going on, particularly with purging issues, excess antimony wash, dirty powder burn, soap dumping out of the lube in the bore, and how temperature affects everything. Then there's the fit thing, relax point, drive side abrasion, and all the other stuff we talked a out on the second quest thread.
 

Sendaro

Active Member
#16
Thanks for recognizing that I'm not up on your terminology and translated it for me. The C.O.R.E. you made mention of is well put. I recognize the condition of residue from powder, primer, lube and bullet material left in the bore after firing. I called the condition a seasoned bore once the residue became consistent and the accuracy returned while in a long string of fire. It became apparent to me while I was involved in rim fire benchrest. The course of fire was 25 record shots. The consistency of those residuals influenced the projectile velocity enough that it was very apparent at a distance of 50 yards (the range we most competed at).

For an example of what I experienced I offer the following. While shooting RF BR there would be times when a preferred atmospheric condition would not hold and I'd have to wait for it before I'd take another record shot. If that time took too long the bore residue would cool and the shot would stray. So I learned to fire at the sighter target at a slow but constant rate of fire till the condition retured or I became confident in what the shot placement results were in the sighter.

Again thank you for the translation.
 

Intheshop

Well-Known Member
#17
Heck,I'll give you what "seems" to work here. First off,I never change lube recipe.... the ratio changes but the ingredients stay the same.Further,the amt used definitely changes... Further,the degree at which it gets mixed changes( lumpy vs thorough incorporation). BW/Vaseline.

Now barrel cleaning; take a worn out,slightly too small bronze bore brush. And one a calibre too small will work to.... it's a numbers game(brush diameter vs # of wraps). Viva brand kitchen towels,no substitutes,get torn into strips and get wrapped around undersized brush.
You're making a "dry mop".

"Cleaning" in my pea brain is different from dry mopping..... and there in,starts some confusion. The purpose for dry mopping is or has several purposes or reasons. It has to be a clean viva wrap..... what you're looking for is amt of powder fouling and what lube got left after a preset # of shots. Confusion 2; How many shots? If this process gets started at "break in" of new barrel you should get a clue on the barrels behavior..... which is what I do. Trying to figure out the frequency on an old barrel? Experience tells me,along with load intensity. But figure about 20 shots.... for awhile and see,may get down to every 10 or up to 50.

Gravity; Fouling is gonna be more at the bottom of the bore.Run 50 shots with a weak'ish intensity where powder boogers and carbon are heavily deposited...... confusion 3, What's fouling to one guy,is S.O.P. to another so good luck with this. But one thing I am NOT referring to is "leading" in the sense of noticeable deposits. Just pay attention to the bottom of the bore more than other sides.

Once you get in the habit of dry mopping as a visual fouling check,and can define that barrels frequency requirements, I feel you're on your way. Next is gonna be difficult for some folks but; You need to be checking this on a day to day basis. Without changing anything,keep going after cold bore groups. And the number of shots start to enter the picture but,3 is gonna tell you whether the 1st is either an "inney" or an outy". This practice also reinforces bag setup.

Once you have a pretty solid baseline established,start reducing the amt of your present lube.What is the dry mopping telling you after you shoot? Shooting the next day,did the results repeat? Has the dry mop frequency seemed to change? About this time you should be really getting a handle on the bores "static" condition. Can we add a little more powder and clean up any boogers? Did that help or hurt the cold bore shot? Once here..... you might want to consider a different powder if the fouling just isn't behaving. Maybe a primer change just to keep it all honest. But don't change the lube recipe because it's start all over.Change the quantity, change the mixing.... which is darn interesting.A lumpy BW lube is not the evil it would seem.Oh,it may be trying to run it through a lube sizer but if you're handloading and testing cold bore shots under MOA,you really should be lubing by hand as a separate step.Forcing lube under pressure through orfices is effecting your lube even before sending down the pipe. A few lumps in the lube can be an eye opener.

Gotta go,need more coffee.
 

fiver

Well-Known Member
#18
funny you mention that BW.
part of the process for the complex moly lube is to extrude it out of the stars bleed hole before actually applying it to the bullets.
that's a little trick I learned from our friend in San Francisco.
and I thought it a worthwhile step to explore because of the [poly glycol based] moly stick addition.
before I do the extrusion the lube itself is a solid wax that I have to pry, cut, and break pieces off anyway I can.
afterwards it's like play dough and stays that way.
 

Ian

Well-Known Member
#19
Grease mills exist for that reason, breaking up the stiff parts. Lithium grease and wax are terrible at making a hard-setting mixture that collapses into paste when worked. Aluminum soap will make a thixotropic lube that stiffens back up when it sits still for a while. Seems like a desireable quality, but not sure it matters that much. Making it all the same on every bullet matters, though. Double-pumping with a 180 rotation eliminates air pockets.

The gravity part of CORE is important, not mentioned much if ever. Condensed vapor and soot fall to the bottom of the barrel, easy to see the sheen difference looking through it in the right light. I think the reason it isn't more of a detrimental factor than it is probably lies in the fact that its always in the same place.
 

JWFilips

Well-Known Member
#20
I'm not sure PC coating is the answer Even after all the proof I see I still find PC great but at what cost ( for me) it is an expeience in frustration when it comes to sub 30 cal to bake a batch all standing up! Granted I have different nose standing screens to bake with but not for all calibers & I don't shoot fast so nose defects may manifest itself at 2000 fps Now if we are taking 30 cal + well it is easy to keep those buggers standing on the tray for baking...I can even do 8 mm ranch dogs nose down standing proud!