6 PPC barrel diameters?

B

bluechip

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I'm thinking about re-barreling my 6 PPC and just when I thought things couldn't get any more complicated, I find there are two diameters available (.236-.237). So what is the deal with the two diameters, pros and cons?
 
bluechip said:
I'm thinking about re-barreling my 6 PPC and just when I thought things couldn't get any more complicated, I find there are two diameters available (.236-.237). So what is the deal with the two diameters, pros and cons?
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Most ppc shooters use .237, and most long range shooters use the .236, don't really know why.
Dustin
 
I'll try to help

bluechip, My opinion only! OK
Both dia. barrels will shoot good it all depends on the bullets you are shooting through them, some of the bullet makers make a small dia. bullet and some make a fat dia. bullet, not all bullets, barrels are the same. I've heard both dia. barrels do very well, but I think the .237 dia. is probably the most popular. I hope this helps and does not confuse you any further.

Rich
 
I don't think it matters much but you're on your own on this one! A bullet measures .243...plus more than minus so go with the .237 if you need somebody to say it. .237 bore, 14 twist, cut to make weight. Thing is, the only item of importance is that the rifle shoots better than the others in attendance and nobody knows what that might be. Said differently....if 100 competitors shot a match using the same bore diameter and twist rate somebody would be first place and somebody would be last place. If continued indefinitely, the last place rifle will never, ever, win no matter who shoots it.
 
Butch Lambert said:
Use some Deltronic pins on both barrel diameters and let me know what they really measure.
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Bingo you are correct Butch and I will add to those that think its a bullet dia. thing what is the working tolerance of the groove dia.'s, IF this is not known how will bullet dia. matter unless they are grossly undersize which there are none at this time. good to see your still here to keep things straight Butch
 
geo.ulrich said:
Bingo you are correct Butch and I will add to those that think its a bullet dia. thing what is the working tolerance of the groove dia.'s, IF this is not known how will bullet dia. matter unless they are grossly undersize which there are none at this time. good to see your still here to keep things straight Butch
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George, I have found custom bullets to be so very close. The best barrels will not measure as close as bullets.
 
Question?

Butch if the barrel mfg, stamped the bore to be .236 or .237 dia. is that to be taken as accurate or just approx? The only reason I stated bullets varying in dia. is some bullet makers have been known on occasion to intentionally use more or less lube to change the dia. of a run of bullets have they not?

Thanks Rich
 
If you had Deltronic pins, you can easily see that they are approximation. I agree that custom bullets are not all the same, but I've never seen them measure over a tenth or two in a lot.
 
OK, I had a barrel once upon a time that would simply not shoot well with a normal sized bullet. Before I wore it out trying to get it to shoot, I tried some "fat" bullets as I called them....244+ diameter. The barrel immediately grouped equal to or better than anything I ever had. Got a whole bunch of trophies with that barrel. Just sayin'.

There are times when the diameter of the bullet makes a difference. Probably an exception.... I don't know if the bore diameter of the barrel affects accuracy or not but it would seem so based on this single observation. Too many factors to guess! How many folks know the volume of their bore? The only thing that really matters is that the rifle will shoot good enough to win.
 
Agreed Butch & Wilbur

Butch I also agree to not seeing much difference in a lot of bullets, but I also know the bullet maker can alter the dia. of the bullet intentionally if need be, thus the reason for my statement of possibly crafting a custom lot of bullets to fit the bore of a certain barrel better. It's been done a lot more than most would think and a good bullet maker can tailor a bullet to fit your barrel if need be. This may be splitting hairs, but hey isn't that whats make benchrest so great. Sorry to let the cat out of the bag, but a guy with a custom set of bullet dies can really do some unique stuff to the bullets he makes from lot to lot by adjusting a few things.

Wilbur I also agree there are small bullets, fat bullets, etc and that's why it is good to have an option of skinny, regular, or fat bullets, so the shooter can find out which bullet his barrel likes the best. Not all bullets and barrels are the same or equal.
 
SWASHBUCKLER1 - The bullet makers you know are different folks than I know. And..believe me when I say that Butch Lambert and George Ulrich know more about what makes a rifle "shoot" than I ever, ever, ever will.

Truth is...you take your chances. Sometimes it works and sometimes it doesn't.
 
LOL. Not really Wilbur, but I agree you certainly take your chances playing this game, but that's the fun in it. Recently a bullet maker took a little time to tell me about customizing his bullets and some of his ideas, like building a bullet with no pressure ring, or needle point bullets pretty interesting. Using more or less lube to obtain a certain dia. Using different length jackets or even trimming a jacket to his specific length, or point up dies or hollow tip dia. There are other things that bullet makers can do, like use a mix of dies from 2 different sets to achieve a certain bullet etc. so we probably know a lot of the same bullet makers, and some are just experimenting more than others and just not talking about it.

As far as the barrel's dia. go, like I said I've seen or heard of both shooting well, it's more about finding the right combination and both could or should shoot well.

Thanks Rich
 
Bullet diam.

geo.ulrich said:
Bingo you are correct Butch and I will add to those that think its a bullet dia. thing what is the working tolerance of the groove dia.'s, IF this is not known how will bullet dia. matter unless they are grossly undersize which there are none at this time. good to see your still here to keep things straight Butch
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For information sake what would be the diam of a "grossly undersized" 6mm bullet? Asked another way, based on a typical 4 groove cut rifled barrel .237 bore, what is the absolute minimum bullet diam that could reasonably be used and expect acceptable BR results?
 
Bro.D said:
For information sake what would be the diam of a "grossly undersized" 6mm bullet? Asked another way, based on a typical 4 groove cut rifled barrel .237 bore, what is the absolute minimum bullet diam that could reasonably be used and expect acceptable BR results?
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Durwood, the smallest die I have made is .24290 " AT CUSTOMERS REQUEST' with groove tolerances of .24300- .2435 this would be the smallest I would be comfortable with and not that comfortable at that. keep doing what you're doing I see it's been working.... I guess everyone thinks just because its marked xxxx size that's what it really is. not so much barrel co's do a real good job but they are still in a production so when production increases quality suffers its a fact of life not to a point that we can tell a difference but lets just say things aren't checked quite as well as could be. and now to the remark that bullet makers change lube to change sizes well only reason to make a bullet smaller is if die is to big to start with....
 
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One thing that nobody has mentioned is that regardless whether a barrel is .236 or .237, the groove diameter does not vary.

Now, I am talking about Krieger barrels in particular. They all have as close to a .2430 groove diameter as manufacturing tolerances will allow.
 
I fooled around with the idea that the volume of the bore made the difference in a hummer and a bummer. Glad I didn't waste anything but time on this as I realized I didn't have much (any) control over what I got for a barrel. Took me a while but realized it just the same. Pretty sure something Bill Saxton said about barrel making opened too many doors on that line of thought...so I gave it up. Maybe a good thought...but that's all it was. Better said....that's all it turned out to be.
 
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