+1 DT. For me that boolit would be on its way to the range or the hunting blind.
+1 DT. For me that boolit would be on its way to the range or the hunting blind.
I have shot the Ranch Dog 190 with substantial base divots from a friend cutting the sprue too soon. After GC’s were applied and shot through a particularly accurate Ruger 350 mag at 1400-1600 fps these shot just as well as the bullets without sprue divots....and the divots present were quite substantial. Being centered more or less probably helped.
Under 3X magnification I find no visually perfect cast bullets. Everything has something like a band which does not have perfectly sharp edges or something to that effect.
One of the most common things cast bullet shooters do is talk about the occasional exceptional group and ignore statistical representations of how their guns actually do shoot.
Post five, five shot groups on the same piece of paper or something statistically representative of that sort and then let’s talk about how your rifle or pistol shoots. Posting the occasional bragging group always leaves doubt.
At last someone that has both feet firmly planted on the ground. Handgun shooters are some of the worst when it comes to talking about their ability. As I have said before on this forum most handgun shooters are poor to mediocre shooters. Only rarely will one see someone who can cash the check their mouth writes. Seen it too many times. Rifle shooters are a somewhat different story since most stay on sandbagged rests. Of course some handgun shooters do the same. It is what YOU can do over a PERIOD OF TIME that determines how good you are. Even I have had extremely lucky days but it in no way defines how good I am. Neither do the extremely unlucky days.
Oh well.
I will agree, there is no such thing as a perfect cast bullet, especially in numbers, and it goes deeper than visual inspection. I think the base has more effect on rifle accuracy. A gas check gives the opportunity to normalize the base to a degree. I reject a bullet that shows a divot in the base, or a hump. But the edges can vary a bit. A gas check has a rounded "corner" where it was formed and you can seat a gas check squarely if done properly.
A rifle/bullet/load must prove itself for consistency. That's why I like shooting CBA matches where you shoot 4 targets each at 200 and 100 yards. That will show how consistent your gun combo is.
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
"I judge my shooting by my worst groups using my best ammo. Ammo is only as good as its worse rounds. To claim a gun shoots under 1MOA groups over 1MOA need to be rare and explainable by some cause other than the gun."
Mr. dtknowles,
You lost me in that one. Please explain. I am getting old.
Last edited by 44MAG#1; 05-15-2021 at 01:45 PM.
He said that he judges his ammo by its worst groups and if you claim to get 1 MOA, then you need to do that more often than you don't!
Say I have worked up a new load. If I go shoot 5 ea. 5 shot groups at one hundred yards and the groups are 1.12", 0.78", 0.92", 0.85", and 1.07" I would claim that gun and load shoot a little over 1 MOA not is shoots under 1 MOA. Yeah, sometimes is shoots under 1 MOA but not always. A gun/load is only as good as its worst group in idea conditions.
Tim
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
No doubt but were you shooting a gun that could notice the difference. Also the distance to the target matters. At longer ranges small differences in bullet weight make a bigger difference. At 100 yards a divot might make a couple tenths of an inch difference in group size in a gun that can shoot groups under 1 MOA. Few people own a gun that can shoot plain base cast bullets with enough precision to notice the difference a divot on the base might make. Even fewer people shoot enough of those small groups that they could tell if the difference was the divot on the base of the bullet or just the conditions that day.
Tim
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
Words are weapons sharper than knives - INXS
The pen is mightier than the sword - Edward Bulwer-Lytton
The tongue is mightier than the blade - Euripides
I don't think I retained the hard data, but I recall the experiment.
When casting up some NOE / Lyman 299 gas check clones for my .303's, I had a good handful of them on which the sprue plate climbed away from the base of the bullet on cutting, leaving a small "stem" that was visible even after the gas check had been installed.
Since I was accuracy testing anyway, I separated those out to shoot a segregated group with, with no change in the load other than the not-smooth base - the logic being that if it didn't matter, rate of production could increase without loss of performance.
Unfortunately, as it turned out, it matters - significantly at only 100 yards - and good lab technique is still required.
WWJMBD?
In the Land of Oz, we cast with wheel weight and 2% Tin, Man.
Here's the thing with chasing accuracy. EVERYTHING matters. It just differs to what degree, and if you care. In the case of a sprue cut, just do the best you can. As I said, the only "perfect" base you will ever see is from a nose pour mold. Base pour molds do a dang fine job too. If you are chasing accuracy, cast the best you can, then sort the best ones you can get out of those. When working up loads, I'll often cast 300-400 of the best bullets I can, and maybe only keep 50-100 of the best of those for testing.
This why posts such as this one is difficult to really hash out.
The thread title is "Accuracy loss from ragged sprue cut".
What degree of "accuracy"? What type of "loss"?
If one is going to compete in a "Big Time Match" the accuracy requirement may be different from someone deer hunting at 100 yards etc. etc. etc.. "Loss", how much is a "loss"? There is insignificant "loss" and major "loss". Is an insignificant loss a real "loss" or not? Will that "insignificant" loss be something that would cause "major" problems? Where will it cause the most problems, in the persons mind or in the actual shooting?
Can one tell the difference if they are not on a benchrest using top tier bench shooting technique? Again, where will that loss make the most difference? In the mind or in real world?
Perfect versus imperfect? Since nothing is perfect let's disregard that term to begin with. We have near perfect to severe imperfect. Where between the two are we talking about? If near perfect is a 10 and severe imperfect is a 1, where are we being impacted on that scale? That would be determined by the person being impacted. Some would swoon and turn pale with major fits of anxiety if they had some bullets with a very, very, very, very small tear, divot, or rough place on the base while others wouldn't be bothered if it looked like a major sinkhole that could be used as a bowl for their ice cream.
What level are we talking about from 1-10? That makes a difference as to what level we are talking about. Is the bullet base imperfect or is it I M P E R F E C T?
Just something to keep in mind.
Load 30 bullets straight off the casting bench, then load 30 bullets that you have sorted to as best as you can create. There is a difference, and it is often quite dramatic. People talk about tenths of an inch at 100 yards. I've seen bullet imperfections make inches differences. In handguns, I've seen sorted vs unsorted bullets double group size at only 50 yards. Which of the imperfections caused the worst issue, I can't say.
Bullet weight matters, fully filled out drive bands matter, bullet bases matter, cases matter, powder weight matters, primers matter.
Take a very accurate target rifle, but load it with random head stamp brass (no annealing, and fully size without regard to headspace), with a mix of "dads old primers", with sloppily thrown powder charges, and with bullets you did not inspect at all. I'll show you a rifle that might not even hit paper.
Can you tell which degree of imperfection caused the terrible accuracy? Was it just one type of imperfection or was it a conglomerate of imperfections?
If it was a conglomerate of imperfections would the accuracy be less affected if it were only one imperfection?
What if it was only very minor ragged sprue cut versus a minor sprue plus a minor lack of a drive band filled out along with a bullet maybe sized out of alignment (I have seen that happen many times by over zealous casters just jamming them into the sizer to hurry up) ?
What about a base that had an imperceptible slight rounding of a small spot on the edge?
What about a middle band not fully filled out while the front band and base band are filled out?
Is any one of this things slight in nature enough to cause great concern or a few slight ones that added up make a major concern the problem? What about a larger single example of a malformation only by itself?
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |