Does anyone go beyond visual inspection of the bullet base for female tears or male protrusions before size, gas check and lube?
Would it make any difference to group size if you did? Bill Cook.
A “Measured Response” is as effective as tongue lashing a stuck door.
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FWIW!
After I sized and gas checked them, if the edges were nicely rounded and the edges of the gas checks were level, I shot them in matches.
If the edges of the check were not equal all around, they became foulers.
I won four military rifle nationals, so take that for what it is worth.
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Ric, I understand what you mean about the flat sharp corner. Assume that was a 30 cal around 220g?
After casting I can see differences on how flat the base is by setting it on a flat hard bench top. Some plop down on their base straight up and proud while others may look good but they teeter enough that what visually was considered good, maybe wasn’t as good as I first thought.
I was wondering if anyone tried to uniform the base before gas check, size, lube. I lightly smoothed the bases on 600 grit paper on a couple different 120 piece cast sessions this week and will give it a go this week at the range. Nothing aggressive, just a couple wipes to make them sit up straight.
Even those that looked good, but wasn’t until after smoothing, lost about .1g to get them to stand flat and straight. Still have to size, check & lube. Bill.
A “Measured Response” is as effective as tongue lashing a stuck door.
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back when i wuz trying to get groups around a 1 moa .... one of the few things that actually impressed me was
lathe squaring the bases before i put on the gas checks ... i used a fitted collet and a very high rake ... sharp ... cutter .
so maybe there is actually another rule except bullet snug fit for maximum guidance ... maybe square bases
i did only a couple hundred of those bases, so i can only say that it seemed to help compared to " good " as cast bases ... with my current status as dedicated plinker/slacker shooting plain base cast, i only check for visually good bases .
i might add that small nose errors don't seem to hurt but off-center dents etc. on bases do ... at least at my 100 yard targets.
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the only way to tell if flawed or culled bullets cause flyers is to mark the bad bullets with a marker and them shoot them and see.Sometmes things that we think matter doesn't seem to show up on the paper.This is my standard practice and I've had horrible wrinkled bullets and ones that are light go right in the group.Only to have my match selected one be the off shot. Im.not saying all "bad" bullets hit in the group buy it wasn't as often as I'd thought or as far out as I'd expected.And with .22 bullets you hear nightmares about how perfect they need to be seem less fussy about how perfect they need to be??(this one baffles me?) I guess this is why it's "fun" ?
"if it was easy we'd let women do it" don't tell my wife I said that!
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Linoww is right. The first reaction most have about going to extremes such as trueing a bullet base is why in the world would anyone in their right mind chase a variable that is virtually impossible to prove.
With cast bullets in a production class rifle there are literally scores of variables that could upset conditions causing a group in the .6’s to open up to a group in the .8’s. Most but not all would be consider to be wall hangers.
However I think there’s a percentage of shooters that pursue accuracy with such ardency that they take on extra work for potentially small or uncertain gains in order to keep pushing the envelope. Ken’s effort to true bullet base is an example of that. And since I don’t think for a moment that I’m super creative I know others have looked at this.
Why do we shoot 10 and 20 shot groups? Is it to prove bullet to bore fit, our individual casting skills, bench practices, our bench equipment, our hand loading equipment, the platform you’re shooting with, your wind reading skills? Heck why were we just talking about suppressors (tuners) if not to tighten our groups.
Just to be clear, I’m talking about bolt action long guns in a caliber that most would considered to be capable of shooting small groups.
And I’ll be the first to agree with most of you that I’m a guaranteed half bubble off being this picky about accuracy.
A “Measured Response” is as effective as tongue lashing a stuck door.
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I mill bases....
First started awhile back because of a particular factory Savage 7-08 barrel. They produced a WAY too slow twist for about a year,maybe less. It was a complete nightmare for them.
I was chasing some pretty high velocity numbers at the time and fell into this barrel... the owner wasn't into cast and never fully appreciated the idea that anyone would actually want this thing.
So I get it with the notion that the Lee 130 7mm mould was "ripe" for taking off the lowest drive band and utilizing the next groove as the GC band. Made a gang fixture for milling 5 at a time on a Bridgeport...worked perfect and it all fell into place. Shoots fine at starting JB velocity/pressure. Forget the weight,and honestly the twist involved...
Still have it all so if anyone wants the dope I can dig it out.
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"Sat" on the idea for awhile...
Backing up a bit;
When shortening the 130's the resulting band that the check was seated onto... the top of the Hornady check,lightly digs into the drive band. "Everyone" kinda assumes there needs to be a space above a seated GC....
The experience told me different. Never was a problem. Now it gets interesting...
Moving on from the 7-08,I got into 260 Rem chambering,like really digging my heels in going down a rabbit hole. In that quest,I get a Saeco mould... copy in several key ways of an Eagen(sp) mould. Tapered,conical nose,etc. It matched up ridiculously well with a HV Brux 28" barrel on an old R700 action. It will shoot bugholes,just a delightful rig... the interesting part;
This factory,unmolested mould came with ZERO clearance above the installed GC...
So there was two examples of really good rigs that don't seem to care if that space exists.
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I did a comparison test of bullets that stood up strait and those with noticeable lean and reported in the Fouling Shot #212 several years ago. If I remember correctly those that leaned the most shot slightly larger groups, But noticeable leaners not extreme shot the same size. The worst leaners leaned up to 2 degrees but five groups averaged 1.3 moa about about 30% larger than the ones the seemed straight. But then 1.3 moa for AVERAGE for five shot group, is better then most
John
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One,at issue for me is our shop....
It's a working professional,some would say "job shop" and am OK with that label. It's way more complex but you sorta get the gist.
I don't handload in there.... have a beautiful spare bedroom that's a handloaders dream room. Corner room with 2 windows,yadayada.
I really didn't want to be going to the big shop to mill bases on the Bridgeport. Obviously it was completely overkill.... so a year or so ago I started thinking about milling bases on a much more appropriate "scale",and do it in the loading room.
Again,backing up....
One of the things we do(used to) here is rebuilding equipment. Lots of cool stuff,3k sq feet worth. Point is,finding donor pieces if equipment is well,dang easy for us. Back to the story;
I figured milling bases,along with a host of loading chores could be handled very nicely on a beefy little bench top DP(drill press)... so I put the word out to one of my equipment guys on what was needed.
He comes through with an absolutely amazingly clean Atlas DP... and at a "you suck" price (this is an endearing term in the biz when a VERY low price is paid). It is the perfect piece for what I was intending to do. The table doesn't have even a scratch on it.
I get it,then find a really nice XY "milling" table for it and a spotless NOS vise. This DP,like all of our Walker Turners in the big shop are of a collar retention design on the chuck. Meaning,the chuck isn't going to pop out when doing certain,"don't try this at home" type ops.
So now I was in business...
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One of my rigs is a R700VS in 308. Came with the HS precision stock. I put that stock on the Brux 260 for a cpl reasons. Which then put a nice walnut stock on the 308.
The Smooth-On EA40 epoxy(hint hint) bedding had barely cured when on another forum(THR) someone asked about H4895 for cast,in 308.
I was like,"give me a minute"... which was more like a week and by that time the thread had died,a decent death. Sayin,wasn't a whole lot of interest... mainly the OP doing sort of a drive by. So I took the efforts to the,what did you do in the loading room today thread. And it's still there,with pics.
Part of this deal was;
This particular 308 Varmint rig has always been a sweetheart. I used to use it whenever some big mouth was maligning how cast has accuracy issues. This rig will shoot one hole 10 shot groups with low node 4198 loads. It is just one of those rigs. But,there's this new stock thing and so part of the challenge was not the loading(getting to the milled bases),it was fleshing out the new stock. This could've been a train wreck,all things considered.
Well it wasn't.... 40 years of building bows,and buying epoxy in one gallon units,I know a thing or 12 about bedding. So the stock job came out swinging for the fence.
Onto the bases...
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I've burnt some 4895 in the past. It's a great powder. And have a good stash of it so the challenge wasn't,that big of deal powder'ly speaking.
Neither was the mould;
A very non descript Lee 150 rnfp of newer manufacture. I use a 2*(included) taper nose size die,about 60% of the way to the top drive band. No biggy here,it flat out works... and will spare the engineering on taper by push through vs rolled tapers...
Body of the Lee is as cast with a very mild "spin" to knock off any high spots.
The bases get milled on the little Atlas by .010" then the GC gets installed on a wonderful little C frame jewelry press. This same press is what I use for the nose taper die...old press from the 1930's.
Taking .010" off the base dosen't close the gap above GC like the 7-08 or the Saeco 260... but could @.015 or so, .010 cleans them up,and squares them to perfection.
Now is where it's going to get real stuff because,well just because...
I know this rigs capabilities,so no I'm not going to waste my time trying to give y'all dreams of data to prove a point. I maintain a heart rate BPM in the mid 40's... yes that is correct. I've been a competitive traditional archer for going on 50 years .... I can tell what this 308 is "doing" without having to right a book about it's statistical abilities.
The 1st 3 shots with the milled bases went into a barely larger the bullet diameter hole. I almost quit but went ahead and yanked 2 more at a hundred that blew the group up into the high .2's...
And gotta say,this is taking the rig outta the bags for every shot. No wind flags... NO FOULERS,and no warmups. We have an indoor range(WELL vented) and an outdoor range right out the shop door.... spoiled? Maybe but then I did build every last dang bit of it basically by myself so no,it's more like hard work.
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I will say,again not gonna argue about statistics...
Milled bases "can" if your rig is capable.... and you're already shooting bugholes or dang close to it....
Cut a third off your group size.
Flyers* should reduce over the long haul but honestly.... if you can't keep a cold bore shot in the group,or know where flyers come from.... milling bases probably isn't going to help you. Might not want to hear that but it is what it is.
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After weighing the bullets, I sort based on bases. (The selected bullets are within +.2/-.3 grains of a median weight.) The sharpest bases go into the rows reserved for record. The slightly rounded bases are used for sighters.
Note: I weigh bullets to find the hidden voids. Any wrinkled bullets are immediately sent back to the pot.
Does this make a difference, I think so. I want to do an experiment where there is a statistical basis for this methodology, probably this Fall.
Frank Marshall wrote of his first season shooting cast bullets. He sorted bullets at the start, reserving the culls for practice. At the end of the season, he was running short of bullets and thus shot some of the culls. He shot his best score of the season with these culls. Sometimes I think there ae no rules and definitely no absolutes.
Farm boy from Illinois, living in the magical Pacific Northwest
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Before GCing and lubing I inspect the bases to ensure the GC shank is fully filled out with a sharp edge. If there is any sprue protrusion, I cut it off. The bullet is then weighed for sorting before GCing and lubing also.
LMG
Concealment is not cover.........
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how come all of the "one hole group" cast bullet production guns never make it to the matches?
"if it was easy we'd let women do it" don't tell my wife I said that!
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that's a good point Pat I never thought about that. I used to anneal my checks and after bumping and they came out very sharp edged. Then I noticed some were tearing at edge as I'd softened them too much.
"if it was easy we'd let women do it" don't tell my wife I said that!
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Larry: how do you "cut off" such a thing as a small sprue portrusion??
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"how come all of the "one hole group" cast bullet production guns never make it to the matches?"
I think most of us know the answer to that. Best to chalk it up as an attempt at humor,
John
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Larry: how do you "cut off" such a thing as a small sprue portrusion??
I lay the bullet on its side on a 5 lb lead ingot and use a sharp knife to slice the sprue remains off smooth with the bullet base.
LMG
Concealment is not cover.........
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The above posts recite a lot of "best practices"
Does anybody know of any experimental work indicating that bullets with rounded base edges, either on the casting or the seated gas check, has any effect on group sizes. I have never seen any and I have been reading CB stuff for about 75 years.
My rounded bases seem to shoot the same as sharp but then I wouldn't claim to have done a proper experiment either.
Frank Marshall isn't the only CB shooter that has found that his culls seem to shoot as well as the good ones. Most of us throw them back in the pot so will never learn whether or not.
John
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John Carlson
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linoww
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Bud Hyett
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drone
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beltfed
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Lucky1
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RicinYakima
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MP1886
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mashburn
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Aaron
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