.001" or '002" over?

[Fugowii]

I was telling a friend that I had slugged my 30-06 recently and was discussing boolit
size and he mentioned something about .002" over the slugged barrel size as the
target size of the boolit. Is there something about a rifle that calls for a larger
boolit? I size my pistol boolits at .001" over (work just fine!) and my .32 Win Spl gets
no different treatment with great results at .001" over. My bore measured a skoosh
under .309" for a Rem 700.

[cbrick]

.002" over isn't bad advice. I would say more like incomplete advice. I strive for about.0015" - .002" over but in reality it depends on many things. Velocity, pressure, twist, rifling condition etc.

If I have a mold that casts a bullet at .001" - .002" over a rifles measured groove diameter I would probably size with a die .001" over bullet diameter, lube only and call it good assuming it chambers properly into the throat.

Is it necessary to size .002" over? Probably not in many rifles but I've had very good luck with it in both accuracy and not leading so that's just how I do it.

Rick

[Gtek]

PB ?, GC ?, Certified Alloy ?, ACWW ?, WDWW ? Powder ? Welcome to the game. Gtek

[Fugowii]

PB ?, GC ?, Certified Alloy ?, ACWW ?, WDWW ? Powder ? Welcome to the game. Gtek

ACWW with 2% tin (pewter)
311291 GC, 170gr.
Powder - probably 2230 since I am trying to cut down on my powder varieties.
Use - range fodder, whitetail hunting.

[btroj]

I would start with whatever size die you have. Then go from there. Each gun is an individual. I tend to go .002 over but that is not written in stone. I rarely slug a barrel so I really don't always know how much over I am. I try what I have and if it works I leave well enough alone.
Brad

[HARRYMPOPE]

I size as big as the throat and neck diameter will allow to chamber.In custom 30 BR's with Ardito chambers with its not uncommon to use a .314 dia bullets in a .308 bore. The chamber takes off at .314 with a 1 deg(or 1/2 i cant remember) taper and the bullet squeezes right down and just plain shots.1/2 MOA or under in matches(not just wallet groups) is not unusual.This is a a bit of cheating as you swage/bump the bullet to fit your throat,but it shows that you can shoot pretty large bullets if they chamber properly.

HMP

[uscra112]

There's nothing about rifles per se that mandates one or the other. As with revolvers, the cast boolit must fit the throat. After that you can consider groove diameter.

[HARRYMPOPE]

There's nothing about rifles per se that mandates one or the other. As with revolvers, the cast boolit must fit the throat. After that you can consider groove diameter.

Said better and in fewer words than i did.Darn it!

HMP

[MtGun44]

Most rifles seem to do better with .002 to .003 over groove diameter - probably because
this fills their throats better and keeps the boolit straight as it starts it's trip down the
bbl.

For revolvers, about throat diam to +.001 is usually a good place to be, in semiauto
pistols, about .001 over groove usually works well.

BUT ----------- Every gun is a thing unto itself. Start where the most have had success but
do not be shocked if your particular gun has something else "in mind".

Bill

[357shooter]

.003 over works the best in my 357s, revolver and lever rifle.

[XWrench3]

my glenfield 30-30 likes .311 sized boolits, and the bore on that measures .308". it may be the microgroove rifling, or just that rifle. but that is what it likes, so that is what i feed it. same goes with my marlin 45-70. it likes boolits sied at .460, with a bore size of .4585. so that is what it gets. my 300 win mag, likes them sized @ .309. go figure.

[largom]

If the throat will allow the boolit to chamber I will shoot them "as cast", no sizing.
Most of my 30 cal. guns shoot .312 dia. boolits. I have even opened the throat up on some guns to allow larger boolits to chamber.

Larry

[3006guns]

Ever since I got the advice (on this board) to load the largest boolit that a fired case mouth would allow, the performance of my loads has improved greatly. You must make sure that there's enough room left for case mouth expansion of course, and here's where I inject my advice....

DON'T "gauge by eye" or use the dial slide calipers on your bench. Your eyes aren't that accurate and neither is the caliper because of it's squared jaw edges. Get a set of small hole gauges and either mike or caliper the result..it will really open your eyes! I recently got a nice set of Mitutoyos from Ebay for $1.99 and measure the mouth of a 7.7mm Jap case I was working with. My calipers told me that .314 was pushing the limit, but after measuring with the small hole gauges I found that .317 is the correct measurement. Quite a difference!

[blackthorn]

If your firearms group well with little or no leading at +0.001 over slugged size, that is all that is important. Each gun is different! No need to fix what aint broken!

[onondaga]

The largest that I can chamber and usually .002-.003" over groove to groove does it. The oversize also gives me confidence against gas jetting and loss of accuracy.

Bore finishes that are not glass smooth and shiny but are average or rough, like the biggest boolits in my experience. I do have a Sauer in .458 WM with the shiniest bore finish I have ever seen and it slugs at .4570", it likes .458" boolits just fine but I size at .459" for the better gas jetting protection.

Are you a member of the Fugowii clan? Where the Fugawii now? I am a member of the Genesse Clan of Oogabooga in Western New York and am the clan Shaman specializing in harmonious relationship improvement spells and the treatment of hand injuries from Flint Knapping.

My given tribal name is Fly Hunter, and that has a wonderful story.

Gary

[prs]

Kinda depends upon what your M die or other internal sizing die is giving you in the brass. You can seat .311 boolits into .307 case mouths 'til hell freezes over and you will get about .309 or kess boolit bases.

prs

[1Shirt]

Go with what's best, and what works. And if it works, don't fix it!
1Shirt!:coffee:

[Doc Highwall]

The rifle will tell you what it likes, other then that how much money and time do you have.

I have been shooting a .310" bullet out of my Remington 40X and I have spent more money for sizing dies that I polished to give me bullets in .3105", .3110" and .3115". Now this is all for nothing unless you have a good rifle, are a good shooter and you are looking to get the best accuracy.

In other words you have to be partly anal in your quest for accuracy where you keep meticulous records and every thing is sorted and weighed.

So far my record five shot group at 100 yards is .305" and at 300 yards is 1.600" so I guess I fit the anal part, besides I like to experiment and gives me a excuse to play with my Bridgeport and lathe.

[nanuk]

So far my record five shot group at 100 yards is .305" and at 300 yards is 1.600" so I guess I fit the anal part, besides I like to experiment and gives me a excuse to play with my Bridgeport and lathe.

Heh.... Wow.... I love to read and dream about being able to do that...

but right now, I'm too poor to be anal. got no time also.

7 years, 1 month, 1 week.... THEN I'll have more time!

[Billwnr]

My experiences are similar. I shoot one gun with the Ardito (.314 taper to .308) throat and another with a smaller, but similar (.3105 to .308. I've done a .303" at 100 yards and a .525 at 200 yards in CBA matches.

[Fugowii]

The largest that I can chamber and usually .002-.003" over groove to groove does it. The oversize also gives me confidence against gas jetting and loss of accuracy.

Bore finishes that are not glass smooth and shiny but are average or rough, like the biggest boolits in my experience. I do have a Sauer in .458 WM with the shiniest bore finish I have ever seen and it slugs at .4570", it likes .458" boolits just fine but I size at .459" for the better gas jetting protection.

Are you a member of the Fugowii clan? Where the Fugawii now? I am a member of the Genesse Clan of Oogabooga in Western New York and am the clan Shaman specializing in harmonious relationship improvement spells and the treatment of hand injuries from Flint Knapping.

My given tribal name is Fly Hunter, and that has a wonderful story.

Gary

I was in N. Tonawonda some time ago visiting a fellow who lived there. Dominick Sorto if I remember correctly. I doubt he is still in the area. No, I am a member
of the O'Casian sect of the Fugowii clan. My given name is WhereamI.