Best Bullet for Reamer
- Thread starter Gappmast
- Start date
JerrySharrett
Senile Member
A JGS 1045 is the "standard-Boyer" reamer. Not really standard nor Boyer officially but probably the most common benchrest 6PPC reamer. It is normally ground with a 0.045-0.060 freebore length. It has a 0.262" neck diameter.
The JGS "1045 Boyer #3" has a 0.263" neck.
Now to add to Wilburs question, what is a JGS 1046??
The JGS "1045 Boyer #3" has a 0.263" neck.
Now to add to Wilburs question, what is a JGS 1046??
I'd guess that the "30 degree" is the (case) shoulder angle. I've never heard of a 30-degree throat. It's possible it is the angle of the step-down between the case neck & the freebore; typical here is 45-degrees, a few with 33 degrees, but 30-degrees would be uncommon. The throat angle is the one after the freebore going into the rifling, BTW.
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That's pretty standard. Any of the 66-68 grain bullets on a .820 (or is it .810, I forget) jacket with a 6.5 to 8 ogive should be candidates. You can try .790 jackets, or 9-ogive bullets; you just won't have the same amount of bullet in the neck. But matches have been won with just a little bullet in the neck.
I've seen a lot of theoretical talk about fitting the bullet ogive shape to the throat angle, but no proof. Same with throat angle -- current "experimental" fashion is shallow (1-degree or less) but there was a prior fashion of 2-degrees. I have one of the 2-degree half-cone angle throats (.090 freebore); it shoots anything from the old 6.5-ogive 66-grain Fowlers to the 9-ogive 68-grain Knights. But 1.5 degrees is still the standard.
Also of importance is freebore diameter, some are so tight that certain bullets are ruled out. I'd want at least .2438 & find nothing wrong with .244. Of course, .244 is considered heresy by some. If yours is .2435, it's possible that a bullet with a .2435 pressure ring won't shoot as well as one a bit smaller.
FWIW
I've seen a lot of theoretical talk about fitting the bullet ogive shape to the throat angle, but no proof. Same with throat angle -- current "experimental" fashion is shallow (1-degree or less) but there was a prior fashion of 2-degrees. I have one of the 2-degree half-cone angle throats (.090 freebore); it shoots anything from the old 6.5-ogive 66-grain Fowlers to the 9-ogive 68-grain Knights. But 1.5 degrees is still the standard.
Also of importance is freebore diameter, some are so tight that certain bullets are ruled out. I'd want at least .2438 & find nothing wrong with .244. Of course, .244 is considered heresy by some. If yours is .2435, it's possible that a bullet with a .2435 pressure ring won't shoot as well as one a bit smaller.
FWIW
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Thanks for the reply Charles. As always an answer brings on more questions. The freebore diameter of this reamer is .2433 on the print. When I first started shooting with this reamer I had some Bruno 65 FB 00 bullets and they shot great even though there was little bullet in the case. I haven't been able to get any more of these, it seems Bruno never has them, so I tried Folwler 66 and they don't seem to shoot as well. The Bruno's measure .2431 and the Fowler's measure .2433, on the pressure ring.
Why do you feel a preasure ring the size of or larger than the freebore won't shoot as well? My experience agrees with you I would like to know why.
I'm using a Krieger barrel that is .243 on the minor diameter. Not measured going on what is stamped on the barrel.
Why do you feel a preasure ring the size of or larger than the freebore won't shoot as well? My experience agrees with you I would like to know why.
I'm using a Krieger barrel that is .243 on the minor diameter. Not measured going on what is stamped on the barrel.
JerrySharrett
Senile Member
Are you sure the freebore diameter is 0.2433" not 0.2435"? 0.2433" is the body diameter of most benchrest bullets and would be a bit tight, and sho-nuff, like Charles says, not shoot very well.
Your Krieger barrel MINOR diameter is wither 0.236" or 0.237". The MAJOR diameter is 0.243"
Charles E, the jackets are 0.825" for J4 and 0.810" for Sierra.
As to Freebore diameter -- actually, I don't know. I do know that in my years of experimenting, whenever I try to get certain tolerances too tight, things go wrong. And the likes of Randy Robinett (bulletmaker) have advised people that too tight a freebore hurts accuracy, so since it fits with my general experience, I repeat it. But I've never specifically tried less than .0005 clearance, so I don't really know -- and even if I had, it would only be a sample size of one or two; it takes more.
You might repost a general question of the effect of freebore diameter, but I believe you'll get a lot of varying opinions.
Some people (newbies, best I can tell, but I could be wrong) think that very tight freebore in some way helps "align" the bullet when it is fired. I don't believe it, but how could anyone know for sure?
A rather more experienced crowd think that you don't want freebore diameter more than .0005 over bullet diameter, but I think they would not recommend a zero or an interference fit.
Then there are those of us who ascribe to "clearance is clearance, as long as it is within reason." Which includes me. I like .001 over nominal bore diameter for freebore diameter. I also use .0025 total on neck clearance with big cases (1,000 yards) and at least .001 neck clearance with the PPC; I usually use .0015.
FWIW
You might repost a general question of the effect of freebore diameter, but I believe you'll get a lot of varying opinions.
Some people (newbies, best I can tell, but I could be wrong) think that very tight freebore in some way helps "align" the bullet when it is fired. I don't believe it, but how could anyone know for sure?
A rather more experienced crowd think that you don't want freebore diameter more than .0005 over bullet diameter, but I think they would not recommend a zero or an interference fit.
Then there are those of us who ascribe to "clearance is clearance, as long as it is within reason." Which includes me. I like .001 over nominal bore diameter for freebore diameter. I also use .0025 total on neck clearance with big cases (1,000 yards) and at least .001 neck clearance with the PPC; I usually use .0015.
FWIW
Gappmast, I am pretty new to Benchrest shooting, so I can only tell you what works for me. I use a JGS 1045 reamer on all my barrels. I do not have a barrel that will not shoot Barts Ultra's great! Barts Head Hunter 6's, if you can ever get them seem to be the ticket! . All 68 grains. The above bullets will out shoot my flag ready capabilities!
Mike
Mike
Both of thee have a published base diameter of .2435. IMO, that's too big for your .2433 freebore. Bart's original bullet was .24325. If you want to use Bart's biullets, that is the one I would try. By all accounts, it was a very good die.
But if your freebore really is .2433, I'd stick with the boattails. There are others out there aside from Bruno's.
Your right Jerry the minor diameter is .237, I must be a bit dysleyic today its to early to blame it on Budwiser.
The print for a 1045 and 1046 JGS reamer show the freebore diameter as .2433. That is the print size I have not measured what size the reamer cut. I'll have to get out my dial bore gage later today and measure it.
http://benchrest.netfirms.com/Reamers.htm
The print for a 1045 and 1046 JGS reamer show the freebore diameter as .2433. That is the print size I have not measured what size the reamer cut. I'll have to get out my dial bore gage later today and measure it.
http://benchrest.netfirms.com/Reamers.htm
Boyd Allen
Active member
The design of your reamer ( I have one of the same design.) is so common that you might as well be asking what is the best bullet.
One thing that you might consider is that the bullet that you started with is, I believe, a double ogive design. The Fowlers are not and they are likely to require a very different seating depth, in relation to jam. In my experience (FB only), double ogive bullets do well with 133 at or very near jam. Single ogive bullet that I have tried are more seating depth sensitive, and have done better much farther from jam, in some cases with marks that are short of square. Ignoring this difference can lead to a misevaluation of a bullet's potential.
Recently a five shot unlimited group was submitted as a possible record. It was shot with Fowler 66 grain bullets.
Or I could be all wet.
One thing that you might consider is that the bullet that you started with is, I believe, a double ogive design. The Fowlers are not and they are likely to require a very different seating depth, in relation to jam. In my experience (FB only), double ogive bullets do well with 133 at or very near jam. Single ogive bullet that I have tried are more seating depth sensitive, and have done better much farther from jam, in some cases with marks that are short of square. Ignoring this difference can lead to a misevaluation of a bullet's potential.
Recently a five shot unlimited group was submitted as a possible record. It was shot with Fowler 66 grain bullets.
Or I could be all wet.
G
george ulrich
Guest
heres another question .what do you suppose happens to the base of any flat base bullet when it's hit with a powder charge regardless of freebore diameters?
R. G. Robinett
New member
The reamer freebore diameter must be large enough to COMPLETELY remove ALL of the lands, creating . . well, freebore. Leaving any vestige of the lands will probably, regarding precision, result in a wreck. Thus, the "standard" 0.0005" over nominal groove diameter; this is an attribute where smaller/tighter is NOT better. RG
Chances are the majority of custom bullets will work well with your reamer. The other piece of the combination is the barrel. Some barrels seem to shoot better with different bullets. This is just a generalization but for example; Boattail bullets and Krieger/cut rifle barrels are shooting very well. Also the double radius bullets seem to shoot pretty good in them.
I bring this up because you may get a different brand of barrel (use the same reamer) and not have as good of results with the same bullets.
Bart
I bring this up because you may get a different brand of barrel (use the same reamer) and not have as good of results with the same bullets.
Bart