Experimenting more with taper bumping. I used a PTG 310 diameter .75 degree per side reamer to cut both the PTG die body and throat of my 308 Winchester short chambered 1-10 twist Shilen barrel.
Throat was cut deep to seat bullets long into throat. Gun shoots more consistently accurate now, but recoil is bad because of light weight rifle. Now I know why you need a heavy rifle to shoot more accurately on the bench.
Bullets left to right: LBT 310 175 .80, NOE 310 165 (30xcb), NOE 311 174 (Frank)
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I made a new extracting punch that will align the bullets tip during extraction after bullet is bumped in die. Also going to try powders with slower burning rate (n135, Varget)
Bullet on right was extracted using new punch with 40 degree included angle.
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I am going to try bumping and shooting the NOE 30-30 Winchester bullet. The good thing about multiple lube grooves is you can experiment by removing lube from certain grooves using dulled toothpick. I was experiencing hard powder fouling when filling just two grooves after 20 shots.
The 30/70 Lithium Beeswax works good.
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Maybe do another trail between the 311 and 309 size?
Frank
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Using Franks smaller bullet I compaired the NRA lube against the Lithium Beeswax (30/70) formula. The lithium seemed to do best.
Grouping seems to be getting worse the more I shoot. I wonder if rifle needs to be rethroated. Maybe I just need to take my time, slow down and do a better job behind trigger.
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Today I tried briefly the bigger bullet using 22grs. of Reloader 7 vs. 29 grs. of Varget. Lube was RCBS NRA rifle formula. The slower Varget powder did best with the heavier bullet.
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I am going to try the NOE 311-199-SP (bumped version far right) As cast with linotype the bands measure .315, bore ride section measures about .307. So there is plenty of area to taper.
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I am surprised to see how thin the RCBS NRA rifle lube is. This lube flows easily thru lubrasizer and sticks to bullets well without adding lanolin.
Also going to try White Lithium and Beeswax (30,70 ratio). This stuff is slick and nasty to fool with.
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"Regarding Indy Cars, since they been running them 65 years with the engine behind the driver (longer than they ran them in front of the driver) they must be doing that wrong now, by your logic.
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Wow! That sure isn't my logic. Is it logic at all?
Your history is a little off but close enough. the Lotus/Fords came in 1963 and the Roadster with a Meyer Drake in front was still king.
Always enjoy discussing things with you Frank and appreciate your posts.
John"
This is a little OT, John but, I've been a avid Indy Car fan, since I was 14, it started with my dad working for the company that owned the front wheel drive Novi and I raced Formula Atlantic, with 3 guys that went on to race Indy cars in the '70's and '80's. I know that know one cares about that but, I've always been proud of it.
The first rear engine car that raced at Indy was a Cooper-Climax, in 1961, that Jack Brabham drove to 9th, with a 4 cylinder, 152 CI engine against the 255 Offy or it could have been the 274, not sure when the eng rule changed.
The reason that I posted the above, was that I thought you where saying that, just because people had been doing something for a long time, others follow and don't try anything new. The front eng car was old and the rear eng car became new, 65+ years ago. There has not been a change since then and everyone is still following that technology. There is a reason for that.........nothing works better, so far.
For us, there not much we can do, either. Powder coating is new but, isn't being used in matches.
It's another area that scientific testing could be beneficial.
Lube "purging" is something that needs to be proven, too as, SS shooters use a lot of lube and don't seem to be effected with it.
It's always great to hear your thoughts too, John 
Frank
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DON'T TAZ ME BROS ... heh heh ....
believe it was gearnasher who opined that too much lube up front keeps those grooves from soaking up the lead displaced by the rifling ... else where does it go ?? .... makes fins out the back ?? ... like those 57 Dodges ?? ...
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the real reason for rear engines is that in case of a crash, the expensive engine is protected by the hydraulic cushioning of the driver ...
ken, who drives corvairs ...
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Comparing breach seated soft lead bullets lubed with Emmerts or Darr lube and a hard bullet fixed case load lubed with something along the lines of LBT or Thompson Blue Angel lube is comparing apples to oranges. I settled on LBT blue soft and tried different amounts of lube on multi groove bullets and always found using just enough to control leading was always the most accurate. I haven't tested every lube on the market so a different lube might lead to different results.
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I don't know John, it does sound a little Snarky but, did you miss this part of my post?
"While my rifles will shoot single groove, bore riding bullets, pretty well, my best results have always been with multi-groove bullets."
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Sorry Frank didn't mean to offend. I did read that part but type of bullet is a different subject then how many to lube in a multi groove bullet
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I don't know if you ever or have ever gone onto the ASSRA forum but, lubing less than all the grooves on a bullet has been talked about. The people that have promoted it, haven't done as well in matches and if you think that single shot shooters do less experimenting than CBA shooters, I don't think you would win a bet on it.
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I do hang out on the ASSRA forum and have never seen that discussion but I'm sure you are right. Has anybody done more than talk about it?
I DON'T think nor have I claimed that CBA shooters do more experimenting. I don't think either bunch do much at all and both would rather follow the crowd..
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I'm not trying to keep anyone from trying lubing any number of grooves that they might feel improves accuracy, I'm offering my experience and a reason that lubing all the grooves may be more beneficial, i.e. that the lube in the grooves, offers support to that area of the bullet, that may be unsupported w/o the lube.
I've offered my experience and thoughts, regarding this,can you suggest why a bullet will be more accurate by lubing a lesser number of grooves? If your not lubing them, why have them?
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I am NOT claiming or advocating less lube is better for all loads. I am advocating more experimenting.
As far as why less might be better see Tom Gray's lube purging and similar theories. My reason is that one groove shot better this year than two when I compared the two options. As far as why have grooves (a different topic) see Dan Lynch's article in TFS which reported on results of test firing.
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Regarding Indy Cars, since they been running them 65 years with the engine behind the driver (longer than they ran them in front of the driver) they must be doing that wrong now, by your logic.
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Wow! That sure isn't my logic. Is it logic at all?
Your history is a little off but close enough. the Lotus/Fords came in 1963 and the Roadster with a Meyer Drake in front was still king.
Alway enjoy discussing things with you Frank and appreciate your posts.
John
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I don't know John, it does sound a little Snarky but, did you miss this part of my post?
"While my rifles will shoot single groove, bore riding bullets, pretty well, my best results have always been with multi-groove bullets."
I don't know if you ever or have ever gone onto the ASSRA forum but, lubing less than all the grooves on a bullet has been talked about. The people that have promoted it, haven't done as well in matches and if you think that single shot shooters do less experimenting than CBA shooters, I don't think you would win a bet on it.
I'm not trying to keep anyone from trying lubing any number of grooves that they might feel improves accuracy, I'm offering my experience and a reason that lubing all the grooves may be more beneficial, i.e. that the lube in the grooves, offers support to that area of the bullet, that may be unsupported w/o the lube.
I've offered my experience and thoughts, regarding this,can you suggest why a bullet will be more accurate by lubing a lesser number of grooves? If your not lubing them, why have them?
Regarding Indy Cars, since they been running them 65 years with the engine behind the driver (longer than they ran them in front of the driver) they must be doing that wrong now, by your logic.
Frank
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throat wear ... i think throat wear is caused by the corrosion/erosion from burning powder gases ... not friction from bullets ... especially greasy lead bullets ...
pretty much how many pounds of powder the throat sees ... multiplied by some heat factor ... how hot the throat is when you shoot the next round.
my farm boy ( never shot hot ) 222 went about 50,000 rounds before it went over 1 moa ... ( took 30 years and a lot of ballc and mj bullets ) ... i wish i had measured the throat before i sold it.
but i have sectioned throats of 22-250 prairie dog barrels ... ugly, really ugly .... 1 to 2 inches of smooooth forcing cone ... as in a shotgun ... maybe 1000 rounds of rapid fire .
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several cba types have wondered about keeping the barrel conditioning the same every shot ... gotta be worth 1/4 inch ... ?? ... my contribution was in rimfire with a good barrel ... i shot all one season with jb compound in the lube i added ... never shot worse, never advanced the throat, made barrel real pretty inside ... heh ... so i think that was safe to try .,..
i do feel guilty that i have never put together a cb rig that would let me tell the difference with such efforts ... real guilty ... but then last night i was blowing up bottles with my first ever 270 win. ... custom stocked on a remmy 721 with a very tight chamber from the factory !! ... hey maybe i should start adding jb on this one ??
oh, 60 gr old 4831 with 130 gr. mj was way too hot !! ... ... didn't think you could put too much 4831 in a 270 with lighter bullets ... scared myself, first too hot load in 60 years !! ... :::: work, up from low, not down from too much !!
ken, returning thread to original subject ...
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I don't mean this as snarky but if you have never seen anyone that only lubes one or two it follows that all the records will be set with bullets with all grooves lubed. Do you know of any serious Schuetzen shooters that have tried lubing fewer grooves? The Indy used to be won every year by a car with its engine in the wrong end.
I hate to be a PITA on this point, but I have tried to make it in some of my writing with little apparent success so am tempted to keep trying. It used to be that all the good scores were shot by shooting bullets in the order cast. We eventually found out that that was silly. Most of the top CBA shooters used to shoot one case and most of the records at that time (and some since) were set using that dubious tactic.
Just because we have always done it and had good success doesn't mean it's worth doing, much less needed --unless we have tried it without. Simple principle, but one not often applied by CB shooters. End of rant.
John
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Regarding the number of grooves lubed, in my discipline (Schuetzen), we lube all the grooves. I've not attended a match and found anyone that only lubes one or two.All records have been shot with all the grooves filled, too.
We generally only shoot under 1500 fps so, we don't need it for leading issues but, it may lend support to the bullet, while it travels the barrel.
While my rifles will shoot single groove, bore riding bullets, pretty well, my best results have always been with multi-groove bullets.
Frank
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Don't want to get this thread off on bore life but since you asked my SS Tikka 223 with standard SAAMI throat is still doing well at the 10,500 round mark (Maybe 500-700 jacketed full charge and the rest light CB loads). Don't know why a tapered throat should do worse. Like Pat, I only lube in gas check gap but am not sure that's more accurate.
John
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It is interesting to see how much grouping changes because of fouling (I wish I could shoot 1/4" groups on demand). Next I will experiment with 70/30 alox beewax and different viscosities.
I have tried lubing just one groove and accuracy was no better and more leading was pushed out of bore when cleaning. More lube should help tapered throat last longer...maybe?
What is the life expectancy of a .75 per side tapered throat. So far I have put about 500 rounds thru this barrel's throat and it still shoots pretty good. I have read that a chrome moly barrel takes longer to wear out. Stainless is not as wear resistant, but is easier to machine more strait when bored. My barrel is chrome moly BTW.
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Nice reporting and groups Keith. I never had any luck with anything but the bare minimum of LBT Blue lube. I'd order my molds with a .090 check shank and only fill the space between the check and the bottom band. Ran some pretty hot velocities too. Testing two good lubes against each other can drive you nuts. One time A will shoot better the next time B will shoot better. I'd just pick the one who's color you liked better and build a load with it.
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I fired 25 shots with each lube without shooting fouler before each 5 shot group.
LBT Blue Soft lube on left. Felix lube on right.
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