sizing bullets down .004

  • 9.1K Views
  • Last Post 14 November 2007
billwnr posted this 08 July 2007

Conventional wisdom (and many cast bullet articles) says one is not supposed to size bullets too much from their original dimensions.

What's your thoughts on sizing a .314 bullet down to .310?   Is this going to affect accuracy, and if so what's your thoughts on why.  What would one look for for induced problems on the bullet.

Bill

Attached Files

Order By: Standard | Newest | Votes
JeffinNZ posted this 08 July 2007

Hi

My thoughts are try it and see what your rifle/pistol likes.

 

Cheers from New Zealand

Attached Files

RicinYakima posted this 08 July 2007

My thoughts on this is that a properly cast bullet has the closest center of mass to center of form as it comes from the mould. Everything you do to after that makes it worse.

If it comes from the mould at 0.314 and will fit into a fired case, that is what I size the body when I seat the gas check. Now, if it will not fit into the throat, I will turn the bullet nose first into the sizer and reduce the first driving band small enough to push up against the origins of the rifling. Yes it is more work, but I shoot better groups that way, at least most of the time.

The problems with sizing tools are that the nose punch is not centered in the die. I gone through multiple tools until I found a couple that were very close. If the nose punch isn't centered, it will push the bullet sideways into the die, which I don't think helps accuracy very much.

Ric

Attached Files

Westhoff posted this 08 July 2007

I have a Lyman 311299 mold that casts (lino) .314. I have been sizing to .310 and getting 1 minute groups (ave.; some under i/2 min. with my Savage 12 BVSS .308 Win., and under 2 min. with my issue '03-A3. This mold casts a ROUND bullet. Sized down, the driving bands are still even width all the way around. I think maybe that helps.

Attached Files

CB posted this 08 July 2007

Use a nose first sizer like the Lee then lube in a .001 over H&I die and you won't have a problem. Could even use one of the liquid lubes if velocity permits.

 Conventional wisdom is wrong when it comes to sizing down bullets. It's the method used to size down bullets that hurts not the sizing itself.

My 2 cents.

Pat

Attached Files

JeffinNZ posted this 09 July 2007

Surely it is a factor of proportions.  4 thou off a .458 bullet is nothing compared to 4 thou off a .257 right?

I do like the idea of as close to cast a possible though.

Cheers from New Zealand

Attached Files

CB posted this 09 July 2007

 Of course a bullet casting as close to desired diameter would be best but I don't see why caliber would make a difference. If anyone wants to get rid of those useless oversized moulds for a good price let me know.

 IMHO the commercial mould companies would be doing us WW users a big service if their cavities were a little bigger or gave us the option of a mould based on the type of alloy used.

Pat

Attached Files

billwnr posted this 09 July 2007

I just wondered what everybody's thoughts on this was. I'm testing out a new bullet in my military gun and it looks like cranking it down by .004 doesn't affect performance.

I'm more of a “shoot it and see how it does” rather than a series of many tests. If it doesn't do good...try something else the next time.

Attached Files

CB posted this 09 July 2007

billwnr wrote: I'm more of a “shoot it and see how it does” rather than a series of many tests. If it doesn't do good...try something else the next time.

Must be some statistic we can apply to this statement like “Statistically you're included in the vast majority of reloaders". :D

Pat

Attached Files

RicinYakima posted this 09 July 2007

It is know as “empirical” data, “based upon practical experience withour reference to scientific principles", ref. Webster's New World Dictionary.

Attached Files

CB posted this 10 July 2007

pat i. wrote:  IMHO the commercial mould companies would be doing us WW users a big service if their cavities were a little bigger or gave us the option of a mould based on the type of alloy used.  

Exactly right Pat. Mould makers would do all of us a big service if they offered moulds in .001” increments in diameters. Don Egan usually offered 2 diameter dimensions for his moulds. I find quite an accuracy difference using one cast bullet design in a used rifle to other used rifles, because of the vast varying degree of throat wear (enlarged diameter). If a bullet rattles around in the throat, it ain't gonna shoot competitively..............Dan W.

Attached Files

Mnshooter posted this 31 July 2007

Sometimes radical sizing is about the only way to go. Also accuracy depends upon the game. I have found for hunting loads for my 8mm that I can get usable accuracy from the Lee .329 mold (cast diameter about .330)made for the Steyer by sizing down to .325 and sizing the nose doen to .314 as RICIN suggests. Actualy Matthews suggests sizing down the nose for long range BPC events which implies that it cannot be too inaccurate. I also have had good luck in the Steyr sizing down .338 bullets to .332. I do not claim bench rest accuracy with these bullets but they work for hunting and plinking. For competition I would buy a custom mold that fits better as this is a lot of monkeying around.

Mnshooter

Attached Files

Westhoff posted this 31 July 2007

re my July 8 post on this subject: I have since tried sizing that 311299 bullet (that comes from the mold at .314) to .311 rather than my customary .310. Fired a couple of 5 shot groups at 100 and a couple at 200. In both cases groups were definitely larger. I know a couple of 5 shot groups are not enough to satisfy the statisticians among us, but I'm satisfied. I took the .311 sizer die out of the lubrisizer, and I ain't gonna do that again! As I mentioned before, I think if your mold casts a truly round bullet, sizing it down as much as .004-.005” is not going to hurt it. If it's not round, and your sizer smears the driving bands unevenly (which, of course, makes the grease grooves vary in width as they go around the bullet) then you've got troubles.

Wes

Wes

Attached Files

billwnr posted this 01 August 2007

Wes, My scoped 1903 shoots .310 bullets lots better than .312. I've found that out over the course of 8 matches.

I had a good test target trying out the .314 NEI 72A's sized down to .310 but when I shot them in the last match I wasn't at my “best” so the shots were spread out some. It still was a 198-something at 100 yards.

Attached Files

CB posted this 01 August 2007

Wes,

If you're worried about out of round bullets put a little index mark on the ogive with a punch and size & load them the same way every time. You should also try my suggestion of using a .310 Lee Push Through Sizer and lubing in the .311 H&I die. I've looked at a lot of bullets sized both with a lube sizer and the Lee die and haven't been able to tell if a bullet was being sized off center no matter how hard I tried looking and measuring unless I used a full diameter bullet like the LBT. 

I'll say one thing though, the Lee die does a much better job of getting things straight.

(I think I should clarify that you use a punch to put a little index mark in the mould so it shows up on bullet's ogive.)

Pat

Attached Files

Westhoff posted this 01 August 2007

Yeah, my molds are marked so I can segregate between cavities and also orient. Should probably mention - whenever we suggest punchmarking the molds - that it does void the manufacturer's warranty.

Wes

Attached Files

Hepburn posted this 11 August 2007

I've had very good luck sizing the Lyman 323470 to 319 for an old German single shot rifle with a 318 groove However the design of the bullet makes an easy task. The best yet, I found a Remington Hepburn Creedmoor rifle in a stack of military rifles. The caliber is 44 2/6.10 with a 452 groove. I had 5 45-70 moulds at the time with no desire to buy a custom mould. So I use Lee push through sizers in 458,454 and 452 and sized my 45-70 bullets to 452 in a compound lever press. They were extremely accurate and shot better then a custom I later ordered. Remember with extreme sizing, there,s a biit of springback. Joe

Attached Files

Hepburn posted this 13 August 2007

I might add that reducing the bullet 6 to 8 thousands also reduces the lube grooves proportionatly. However there was no leading at all down the 34 inch tube. Do lube grooves need to so deep? Joe

Attached Files

Molly posted this 13 November 2007

My own experience suggests that if you can chamber them, the 'right' size is as big as you can make them, and don't worry abot sizing: I once had an 11MM Mauser and no bullets. I sized some .460 slugs (for 45-70) down to .445 to fit the Mauser. I had to pre-lube them or the sizing would close up the lube grooves. Supposedly, this much sizing will ruin all potential for accuracy. But lube 'em first, and it works fine. Shot fine too. At least, it shot as well as slugs from an 11mm Lyman mold that I picked up later, that didn't take so much sizing. Yeah, I size as little as I can get by with, but it's to fill the throat, not to keep from damaging the bullet.

HTH Molly

Attached Files

CB posted this 14 November 2007

Sizing in the Lyman 450 is a complex business. I have a DC 314299 mold that casts not-round bullets ~.314". I have sized them to .312", but it ain't .312", it's more like .3124” and shot them for a while new, in the belief that bigger is better. I like to seat bullets as far out as possible without having to whack the bolt handle. The sizing diameter varies the max OAL. For a while now I've been trying smaller bullets, in the hope of finding more accuracy. Sizing bullets a lot = .003” or more in one step bumps the nose up a lot ~.002” sometimes more, if the bullet is soft. Harder bullets are more difficult to get through the 450. Trying to go from .314” to .3095” say gives big noses and bent bullets when soft, and much harder bullets are difficult to get through the sizer.

I can get .314” soft bullets down to .308"(.3085” or so) without damage or hard sizing by .314” to .312", .312” to .3095", .3095” to .308". And I have to run each bullet through the sizer twice turn 90 degrees to get the bands round.

Any sizing at any hardness thru linotype makes 314299 noses bump up, bump dia determined by size jump. If I bump the nose .0015” or more, the max OAL  reduces cause the nose now doesn't want to go in.

I've got a man working on a top punch for the 450 to allow downward nose first sizing that should eliminate the bumping.

Its taken a lot of measurement and fiddling to see what's going on with the 450, I'm thinking I'm seeing better accuracy at .3095” than at .312".  

I have no mold that casts a bullet round to .0002” and never had one that I know of. All my 30 sizer dies don't hold .0001", generally .0002” or more, hence the 90 degree turn and size again.

The lesson for me has been that sizing bumps the nose, big sizing bends the nose-sometimes, bumping depends on sizing amount and bullet hardness, and smaller bands allow seating out but bumped noses mean max OAL reduces.

I think what all this drivel means is that nose first sizing is probably the way to go.

joe b. 

Attached Files

Molly posted this 14 November 2007

Hi Joe,

Yes, I found much the same thing with bumping bullets like 311291 or 311299. I actually broke the push lever off at the pin holes! But I cut a heavy washer in half and brazed the halves across the tops of the pin holes, and never had any more trouble. I lathe-turned a long nose punch with a .300 hole to prevent over-bumping, but had to polish it before the bullets would come out of the nose punch. I polished a slight taper into it, ending up with ~ .301, that worked fine. Regarding the 11MM sizing above, the alloy was ordinary wheel weights, and it was a Loverin design, so nose bumping was not an issue. Molly

Attached Files

billwnr posted this 14 November 2007

Joe Brennan wrote:

Its taken a lot of measurement and fiddling to see what's going on with the 450, I'm thinking I'm seeing better accuracy at .3095” than at .312".  

joe b. 

Good call Joe.  That's why I started this thread.   I reviewed my scores at the military matches I shot in 2006 and 2007 and found I scored higher (with my particular rifle) when sizing to .310 instead of a larger .312.

I also noted that my .310 sizer wasn't really .310.  I decided not to get hung up on that and just accept it was marked .310.  It ain't worth the aggravation trying to make them .310 on the nose and probably not more accurate than .3106.

The difference in scores was about an average of 14 points higher

Attached Files

Ed Harris posted this 14 November 2007

Agree with Joe, size no more than you have to. If the throat is large enough to accept the bullet without deformation, turn necks to get safe clearance. But don't turn necks thinner than about 0.011” as too thin they don't last long at all. If you must size the bullet in order to have safe neck clearance, do so in stages, not more than .002” at a time. That way less force is required and you will damage the bullet less. Also agree that pushing through a Lee sizer nose-first is less damaging than the Lyman or RCBS style, but the latter do a better job of seating and crimping gaschecks.

This will not give match accuracy for benchrest competition, but is adequate for hunting purposes, handgun and mil-surp use.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

Attached Files

CB posted this 14 November 2007

I also noted that my .310 sizer wasn't really .310.  I decided not to get hung up on that and just accept it was marked .310.  It ain't worth the aggravation trying to make them .310 on the nose and probably not more accurate than .3106.

Over 40 years ago I was complaining to a guy at work that my new .309” (I'm making up all the numbers” sizing die produced bullets at .3086", not very different from my .308” die that sized bullets to .3084".

He explained and convinced me that a dimension such as .XXX", less any note to the contrary, means that the item must be from .XXX-.0004” to .XXX +.0005". a .309” die owns the space from .3086” to .3095", that's the “domain” of the number. This has nothing to do with tolerances.

Since then I've looked and measured, and have yet to find a Lyman die that sizes to .XXX0", generally the bullets are bigger, not always, sometimes smaller. Then we have the “spring back” theories, and the plug gauge guys-but Lyman dies are tapered.

I've had reasonable luck honing these dies out using the knee trick.

I was stuck on the 1st Lyman CB handbook and the article about changing size .001” and halving group size. Those were the days of the 311413, that single handedly made more people give up on CBs than any other thing. What a lot of lead I shot down range into 3” and 4” groups. And bigger. 

Those were NOT the good old days.

(Now I suppose the 311413 lovers, both of them, will start dancing.)

joe b. 

Attached Files

Close