MAX acceptable Pressure Ring on FB 66g 6mm (PPC)

B

benchshooter

Guest
I have a thousand count box of 6mm 66g flat base match bullets for shooting in a .262 necked PPC that I picked up from the maker at a match 15 years ago. I just cracked the box open and was doing some preliminary measurements with thoughts of probably using these bullets this Spring. However one measurement has me questioning these bullets.

These bullets have an overall diameter of .244 at the compression ring. This is the first bullet that I have ever used that had that diameter at the compression ring. Most all other bullets I have used measured .24325 to .24350 diameter at the compression ring.

While I can certainly turn brass necks to accommodate a bullet who's compression ring diameter is .244, I am a little concerned about pressures building up because of my barrel's ID possibly being too small to accommodate such a large compression ring. I don't have specs on these older Hart barrels that I'm using on my PPCs.

Anyway is a diameter of .244 at the compression ring acceptable?

Pro's - Con's ??

Dana
 
Dana,

Make sure your brass is turned down enough to fit your chamber and go shoot! That's the only way to figure it out! Or just fireform with them. It's not like you can get any more!

Bart
 
One time I ran into some .22 caliber FB bullets that measured .225 on the pressure ring. They shot fine, but I did have to return some necks for additional clearance. This was with a tight neck .222 chamber in a Hart barrel. Based on a friend's recent experience, if your barrel has a little choke at the muzzle, keep a sharp eye out for jacket fouling in that area. Other than that, you are good to go.
 
I shoot long range bullets that the shank is .2432 and the pressure ring is.2437 they shot so so till i opened the free bore diameter to .2438. Now thats all i use, with the change it cut a .1+ barrel to one that would agg less than a .1…….. jim
 
Simply turn the brass to the desired neck clearance, measuring the bullet at the ring. I've never worried about pressure when we're talking a few ten-thousandths.

Hell, look at .45 Colt Ruger Blackhawks. They used to ship the cylinders with undersized throats (some as small as 0.448"). Guys shot 0.452" slugs, both jacketed and cast, through them.....and that was 0.004". Of course, a cylinder throat doesn't have the same bearing surface as a 22" barrel, but you get the idea.

In the end, as long as you have adequate neck clearance and they shoot well, you're set.

-Lee
www.singleactions.com
 
I don't think it is an issue about working, it about bench rest accuracy loaded round clearance is an easy fix. Now to get it to shoot and be completive is an other, if your free bore diameter is less than than the bullet you are just spinning your wheels……. jim
 
Dana, I had the same experience a bunch of years back with a lot of bullets that I had purchased. They were fatter at the pressure ring than I was normally acustom to. The bullets that I normally shoot in Point Blank Benchrest are .24335 at the pressure ring. A good friend that has since passed away made these bullets of which I had purchased 5,000 of at the time. These other bullets that I came across was like yours, running .24400. First thing I had to back way off on the load to keep pressures within acceptable limits even with turning for a .002 neck clearance. But then I wasn't really sure of what my freebore diameter was with that barrel at that time which could have been another problem. Anyway I never could get those bullets to shoot but I can't say that it was because of the fat pressure ring. I am also not sure if there is an upper limit to what a pressure ring can be over the bearing surface diameter of the bullet but I'm sure there is a limit at some point. I just hope that the quantity of .24335 bullets I have left will out live the few years I have left at this game.

Regards...
 
Thanks for the reply everyone. I just wanted to see if this was normal or if I had some strange bullets.

Dana
 
I had a die that made a .244 bullet...plus a couple of tenths as I remember

They shot like the hammers of hell in some rifles and poorly in others. I had a barrel that wouldn't shoot anything else but those fat bullets. Actually, it was a barrel that Keith Gantt handed over that wouldn't shoot. Can't tell you how many but the trophies piled up before that barrel wore out - shooting those fat bullets. Don't shoot them without proper neck clearance!

I'm saying two things here:

1) Yes, the .244 bullets could do very well.
2) Don't give up on a barrel until you try different bullets.
 
I have and have access to some of the most accurate measuring tools in the world from the likes of leica and mitutoyo and i cant measure to the hundred thousanth. With a laser or a ruby tipped robot...
 
Wilbur said:
They shot like the hammers of hell in some rifles and poorly in others. I had a barrel that wouldn't shoot anything else but those fat bullets. Actually, it was a barrel that Keith Gantt handed over that wouldn't shoot. Can't tell you how many but the trophies piled up before that barrel wore out - shooting those fat bullets. Don't shoot them without proper neck clearance!

I'm saying two things here:

1) Yes, the .244 bullets could do very well.
2) Don't give up on a barrel until you try different bullets.
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Hi Wilbur,
Fat bullets just may have problems with certain barrels. I do not have reamer prints or specifications for the three barrels on my PPCs, one of which you gave me back in the mid 90's because it wouldn't shoot for you but put one piece of wood on the wall from Reidsville for me (just had to jerk your chain on that one). However, I do have reamer prints and specifications on my long range 6BR Bartlein barrel. I had a choice of two bore diameters. If I we're shooting flat base bullets through this barrel, the fat bullets might have pressure problems with the smaller bore option. It is reamed with a Rodney Wagner reamer. The reamer print shows the free born to be .2435. Now, none of this really matters since that barrel is chambered for long range boat tail bullets and not flat base bullets. But wonder if it was a 1:14 twist PPC chambered barrel with a free bore diameter of .2435 and the tight bore diameter option????

Now, the .24335 bullets I have are what's left of my 1998 vintage Fowler bullets. I purchase five 1000 count balls from him that year and he had written the pressure ring diameter on each ball with a sharpie. I measured one again the other night and came up with .243 on the main scale and almost half way between 3 and 4 on the vernier being closer to 3 so they are what he said they were. The .244 bullets were 1999 ventage Knights that Brady had given me to try out. Actually they measured out to .243 on the main and just a hair over the 9 on the vernier. I never could get them to shoot but watched Brady kick butt with them back then.

Anyway, long story short, I **guessed** that the reason the .244's didn't shoot was because of the fat pressure ring. This caused me to form an opinion, justifiably or unjustifiably, against fat pressure ringed bullets. I haven't had another thought about it in all these years until this thread popped up.

Regards....
 
Having just centerless ground some bullets and removed this die ring I'm getting a kick out of these replies. Actually I see people on Fark.com say, "getting a kick out of these replies", and that's why I said it. Mostly I find the post interesting.

Anyway knowing that the die ring on a bullet could be a match made in Heaven, still I have wondered for years if having a precision ground bullet for a precision rifle might just be the ticket.

I mean it's right there on the base like the way the mini ball bullets would flare and seal of the gases. They changed accuracy history.

Still I wondered.

A couple of months ago I told some guys I work with and they whipped me out some. They ground them to .2432. That cleaned off the die ring but left a precision ground bearing surface about .290 long. They looked beautiful. .2432 all along and from bullet to bullet.

I had them and a control group of bullets I matched against each other. The control were some I didn't grind.

Anyway I tried really hard to make those beauties win. Even to the point I figured I was cheating. I mean I really tried hard with them but then I still had to try with the control group and the test went on for several weekends.

Alas. Now I'm here wrecked. I'm off the precision ground kick for the moment and am thinking big die ring. The only person I've really heard describe the base of his bullet and the die ring so far is Bart at Bart's Bullets. Some day I might give some of the Wedge's a try.

I read of an old timer that tried grinding or turning bullets a long time ago. One rifle worked better. Another showed no improvement. My books are kind of spread out at the moment and I can't remember which one. Maybe The Accurate Rifle by Warren Page.
 
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The wedge has its place. I have a rather large collection of them. They shoot like no other in big barrels.
 
Carson said:
Having just centerless ground some bullets and removed this die ring I'm getting a kick out of these replies. Actually I see people on Fark.com say, "getting a kick out of these replies", and that's why I said it. Mostly I find the post interesting.

Anyway knowing that the die ring on a bullet could be a match made in Heaven, still I have wondered for years if having a precision ground bullet for a precision rifle might just be the ticket.

I mean it's right there on the base like the way the mini ball bullets would flare and seal of the gases. They changed accuracy history.

Still I wondered.

A couple of months ago I told some guys I work with and they whipped me out some. They ground them to .2432. That cleaned off the die ring but left a precision ground bearing surface about .290 long. They looked beautiful. .2432 all along and from bullet to bullet.

I had them and a control group of bullets I matched against each other. The control were some I didn't grind.

Anyway I tried really hard to make those beauties win. Even to the point I figured I was cheating. I mean I really tried hard with them but then I still had to try with the control group and the test went on for several weekends.

Alas. Now I'm here wrecked. I'm off the precision ground kick for the moment and am thinking big die ring. The only person I've really heard describe the base of his bullet and the die ring so far is Bart at Bart's Bullets. Some day I might give some of the Wedge's a try.

I read of an old timer that tried grinding or turning bullets a long time ago. One rifle worked better. Another showed no improvement. My books are kind of spread out at the moment and I can't remember which one. Maybe The Accurate Rifle by Warren Page.
Click to expand...

I'm glad the self anointed great ones are getting a "kick" out of these replies. I'm finding the replies to be informative and educational myself. But then I was never elevated to the level of being able to look down upon the great unwashed from the lofty ivory towers, so what do I know.

Have a good day....... Up There
 
benchshooter said:
I'm glad the self anointed great ones are getting a "kick" out of these replies. I'm finding the replies to be informative and educational myself. But then I was never elevated to the level of being able to look down upon the great unwashed from the lofty ivory towers, so what do I know.

Have a good day....... Up There
Click to expand...

Not sure where youre going with that post. You must have anger problems and fly off the handle and have to avoid people or apologize alot. I didnt get anything like that from any post here.
 
benchshooter said:
I'm glad the self anointed great ones are getting a "kick" out of these replies. I'm finding the replies to be informative and educational myself. But then I was never elevated to the level of being able to look down upon the great unwashed from the lofty ivory towers, so what do I know.

Have a good day....... Up There
Click to expand...


I was just making a joke. The second sentence expressed the same feelings for the comments you have.

Sorry if I offended you.
 
Dusty Stevens said:
The wedge has its place. I have a rather large collection of them. They shoot like no other in big barrels.
Click to expand...

How is it you can tell if you've got a big barrel? I'm shooting my oldest barrel but I'd be hard pressed to measure it.

It's marked .243.
 
Given that land heights vary, I think that my friend's method is the best. He casts laps to measure groove diameters. Of course barrels with odd numbers of grooves present a special problem, in that they require special tooling to to measure their upset slugs or laps. With a cast lap, one can feel how consistent a barrel is, where there are tight and loose spots, and the relative sizes of different parts of a barrel. It is really quite a useful tool, that my friend has learned to use with great skill. He checks out every new barrel before doing any cutting, except perhaps to remove a burr or upset at the ends of the bore. He also uses them to look for problem areas in finished barrels.
 
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