Sizing- Is there agreement?

[rangeball]

It's best to size a bullet down .002" less than the lands of your barrel, then knurl up for a tight fit and best accuracy.

True or false?

[edge]

Best is too subjective

I prefer a knurl to be tight in the lands since it ensures that the bullet will rotate. What you can live with as far as loading pressure consistent with your knurling process is up to you.

IMO. 0.001 - 0.002 is probably a good place but 0.0005 or 0.003 may be fine too

edge.

[jims]

It might work differently for different bullets. I have some Normas I use in my barrel I am trying to shoot sabotless. The bullets are from the factory .001 smaller than the lands. I have not been able to get them knurled up to size to find a good fit. Many others seem not to have difficulties with their different bullets at that size.

[dougedwards]

Should the bullets be knurled up to the exact land dimensions? Is it possible to knurl .003 increase into a jacketed bullet? Is there a possibility that an over knurled bullet might be pushed down the bore creating a creasing of the bullet from the rifling? If so, would that be a bad thing?

I was also wondering if the barrel manufactured would send a barrel drop after the bore had been rifled, would there be any advantage of installing the rifling grooves into the bullet using a press and then lining up the bullet at the muzzle so that the cuts from the rifling would match the twist of the rifling of the barrel? Might that help with the seal during ignition?

I don't know I am just thinking out loud here.....or maybe with my fingers. But I have never resized bullets before.....only knurled them trying to get a tighter fit in the sabot. My questions are concerning sabotless shooting of course.

Doug

[rexxer]

Mar 27, 2009 8:47:12 GMT -5 rangeball said:

It's best to size a bullet down .002" less than the lands of your barrel, then knurl up for a tight fit and best accuracy.

True or false?

The guys that size down and knurl up seem to use a sizing die .002 less than their bore size or atleast in this area. With the spring back they are probably only getting .0005-.001 less than their bore size. I would guess they are knurling .0007-.0012 over there land to land dia. In a couple of months I believe there will be alot more information out on this subject.

Rangeball-just remember there are guys getting good accuracy without any resizing! I would guess .001 would be about max.

[rangeball]

rexxer, I had forgotten how spring back comes into play. I was thinking they'd stay the size of the die, and was worried about having to buy several different sized dies. Thinking ahead as well, as I plan to try the hornady .50 ftx sabotless. Just trying to get my understanding straight so I'm prepared down the road if the need arises.

I'll be making a walmart run soon to get some lead fishing sinkers to slug my barrel, would be awesome if they'd load without sizing. Who knows, with the deep rifling, they just might.

[rexxer]

Dougedwards- I have always wondered about the idea of making a die to cut the lands deeper into the bullet. I agree it should help seal up better. Edge has cut sabots based on this theory. If I could get a print on the pacnor barrels inside dims. it might be worth a try. Maybe if I slugged my bore there would be a good enough impression to measure.

[Harley]

I think we will find that the answer to sizing and knurling will be mainly subjective, not determined by a set micrometer reading. First, if needed, you resize. If you are very lucky, that's it, the bullet is a perfect fit for your barrel. Most likely, though, the resized bullet will drop loosely down the muzzle, so you have to knurl, and that's the subjective part: how the knurled bullet "feels" to you as you seat it. In my experience, a too-light push results in lowered MV and POI changes. A too-heavy push results in increased MV, POI changes and looser groups.

I'm trying something that eliminates all measuring of the resized/knurled bullet: After resizing with the .448" die, I am knurling to the point that the base of the bullet will seat in the muzzle, but the ogive will not. (Incidentally, this approaches but is a little tighter than RB's recent pictures of hand-starting his own bullets.) I've prepared a couple dozen bullets this way and will test them when the weather clears.

Harley

[rexxer]

Mar 27, 2009 11:29:18 GMT -5 rexxer said:

Dougedwards- I have always wondered about the idea of making a die to cut the lands deeper into the bullet. I agree it should help seal up better. Edge has cut sabots based on this theory. If I could get a print on the pacnor barrels inside dims. it might be worth a try. Maybe if I slugged my bore there would be a good enough impression to measure.

I never thought about needing oversized bullets to even think about trying.

[chuck41]

Mar 27, 2009 11:29:18 GMT -5 rexxer said:

Dougedwards- I have always wondered about the idea of making a die to cut the lands deeper into the bullet. I agree it should help seal up better. Edge has cut sabots based on this theory. If I could get a print on the pacnor barrels inside dims. it might be worth a try. Maybe if I slugged my bore there would be a good enough impression to measure.

I have the "barrel drop" that was cut from my PacNor barrel during manufacture. I took bullets .002" larger than land dimensions and pressed them through the drop to groove the bullet for a perfect fit using the perfect die. That being end of the barrel I intended to use. Results looked quite promising with nice grooves in the bullet.

I carefully lined up the bullet and attempted to load this "perfect bullet" into my barrel. That sucker would take two men and a boy to push it down. I weigh 240# and I couldn't do it. And my barrel was polished out after the "drop" was cut off which should have made it easier! Based on that experience I don't think trying to cut the lands deeper into the bullet itself is likely to work. That certainly may be very different than engraving soft plastic to fit.

[Harley]

I agree with Chuck's experience; It's a great idea that probably won't work; BUT, maybe there's somebody on the Board who's not smart enough to know it's impossible, and.......makes it happen, anyway.

Harley

[rangeball]

Chuck, any chance you got spring back? Perhaps running them through several times over several days may be the answer?

[chuck41]

Mar 27, 2009 15:03:07 GMT -5 rangeball said:

Chuck, any chance you got spring back? Perhaps running them through several times over several days may be the answer?

Possible. There is a problem with proper keying of the groves for repeat trips through the drop. This might also be a contributing cause for the difficult loading.

I will likely try it some more in the future, but I don't hold an awful lot of hope for it. The reducing in my new .399" die seems to have worked very well so my immediate attention will be on that.

[rexxer]

Thanks Chuck-probably saved me a headache!

[Dave W]

I had pretty much the same results as Chuck with my barrel drop. Even though the drop cuts rifling into the bullet it is still a form of sizing so I think spring back occurs, the bullets had to be pretty much beat down the barrel to seat it on the powder. The drop did come in handy when I had my custom die made, so it was of some use.

[rbinar]

8-)This post like many touches on how it may be possible to make sizing a science. If not that at least something that can be done by following a list.

There are several reasons I'd think that won't happen. I have to agree with Harley's owner that it is and will continue to be subjective rather than exact. However that should not discourage new shooters.

There are several things that work. Because there are a number of possible good ways to manage if you try it very likely you'll have something working very well in a short time. If only one method works who knows how long it would take each one to find that way?

As an example of what I mean let's compare methods. Some of you like a very heavy knurl. When shooting 40 caliber where one must knurl up I've found that I never need heavy knurling. I've only attempted to knurl enough to give the bullet about the same friction a sabot might provide. Which would work work for you? Both probably if you gave it some effort.

I've tried un-knurled bullets, tight fit, loose fit, boat tailed bullets, flat based bullets most everything. They all provide some degree of success.

My friend Martin Katz is a prime example. When he first started shooting I don't think he thought he could fire a bullet if I didn't size it. However he shoots a lot. Necessity dictated he size himself in order to have enough bullets to not wait on me. He went through a few trials and errors but before long he was doing it better than I could.

So I'm saying if you want to try it sabot-less think less about how your going to size and more about doing the sizing. You can make it work everyone else does.

[Al]

so are we looking for the bullet to basically fit the bore?

or for the knurling to engrave the rifling?

[edge]

I am in the engraving camp, and I don't think that you can get a keyhole with enough knurl!

Belts AND suspenders

edge.

[chuck41]

I have found that the .400" bullets in my .400" bore will slide through the barrel very easily. In fact with a little light oil they will actually slip slowly down the clean barrel by the force of gravity alone.

I don't worry about how much knurling. I just place a file on the bench put the bullet on it and another file on top then roll the sucker between those two flat (bastard) files with a little hand pressure on it. I then throw it in a box and I am done.

After knurling some measure with my micrometer as little as .4008" and some go almost to .402" and I can not tell any difference in accuracy. The more aggressively knurled ones are a little harder to start in the barrel, but then seem to go down the barrel about the same as the others. All tend to overlap or nearly so at 100yd with a variety of powder loads. My experience so far has been totally with XTPs but at least with those, it really ain't that critical guys! More knurling might be helpful with the solid copper Barnes, I really don't know.

Apparently the only real benefit of the knurling is to make sure that bullet sits firmly on top of the powder without moving until you actually get ready to shoot it.

[rbinar]

Mar 28, 2009 6:03:05 GMT -5 Al said:

so are we looking for the bullet to basically fit the bore?

or for the knurling to engrave the rifling?

Hey that's the point of the post! Seems it depends on who you ask what answer you'll get. I'm in the just get it in snug corner and others want it tight.

If you go to sabot-less odds are you'll try it both ways and keep the one that works best for you.

[smokeless77]

I'am with chuck41 and rb knurled enough to keep it on the powder, and if there a hair tighter thats ok to. Doesn't seem to bother accuracy at all.