SmallCaliberCentral

Fellow 204 shooters.

From my experince trying to shoot 40 grain bullets in a 1-12 twist rifle has not been very good. I cannot get the accuracy I would like. We used three different rifles with different loads and bullets tried in each one. From reading other members post, others also had trouble trying to get a very accurate load. There were a few whose one rifle/bullet combination worked out very well for them. But the majority cannot shoot all 40 grain bullets very accurate.

The Sierra 39 gr Blitzkings shoot very accurate in all my rifles. Most shooters on this forum have had them shoot well in there rifles also. I have shot over 1200 of Sierra's 39 gr. blitzkings at targets or PD's. This is my only choice of the heavier bullets. I am locked into buying Sierra bullets as my only choice.

Wayne Blackwells " Load from a Disk " program was used to get the rate of twist data for 204 caliber bullets. The 35gr bullets need a 1-13" twist. The 40gr bullets need a 1-10" twist. A 37 gr bullet would need a 1-12" twist as the ideal twist.

A 37gr bullet should work well in all 1-12" twist 204 Ruger rifles. A 37 gr V-Max, Blitzking, or Ballistic tip could be an option we would have to chose from. With a higher velocity it would almost equal the 39/40 gr bullets energy, wind drift, and flight path. This will give us more options as to whose bullets we prefer to shoot.

The Bullet Manufacturers I talked to know and look at 204 Rugerhunting web site. So please feel free to give you honest opinion of a 37gr bullet.

Thank you in advance for your opinion .

Grayfox

(please take this with a little bit of sarcastic humor....)

WHAT? Another bullet (or four from different manufacturers) that I will have to work up another load for in my 204? OH....YES...please...bring on the HOURS of time at the reload bench and range with the 15 different flavors of powder that my rifle "kind of" likes....of which...FOUR of them I have 8 pound kegs of. Please...at first...I WANT to buy one box of each manufacture...and then I will buy one more box of each, because I "just know" that I missed a node of accuracy....and then I will buy one more box of three of them (by now I have decided that my rifle just tends to shoot brand XXY to point of aim...but keyholes them EVERYTIME).

I believe it is PRIMER manufacturers who actually own ALL of the bullet manufacturers.

In all honesty...sure...why not. 37 grain bullet at 3999 to 4050 fps.....if I can make a prairie dog fly at 500 yards....BRING IT ON!

Grayfox,

I think 35 to 37 would be perfect. Like you I've shot thousands of 32's and 39's at gophers and prairie dogs and I do prefer the 39's. If there was a plastic tip bullet at reasonable pricing and readily available I would buy it.

It would be hard for me to give up 3850fps with the 39gr BK's to go with 4000fps in a lighter bullet UNLESS the BC was equivilant to the 39gr BK's. Or very very close anyhow.

However,, I would like to see it as another option for the 204 shooters out there tho. I think in time the 204 will cement itself even moreso in the shooting world & thats when new bullet experimentation will begin once again. Unless the price of lead & copper make it nonfeasible to tool up & start making a profit early on with the sales of the new bullet. Right now the 35gr Bergers are showing terrific accuracy & consistent one shot kills on coyotes & the hides are being taken well care of in the process. The 40gr Bergers shoot very good in a lot of rifles as well. It would still be a good thing to have another bullet to choose from tho. I would try at least 2 boxes if they made them!!

In my part of the world Bergers are spendy and hard to find compared to buying 39's in bulk at the Hunting Shack. I will try some Bergers for the next postal shoot, however, just to try and put a little pressure on the Top Dog Hawkeye Joe.

Grayfox wrote:Fellow 204 shooters.
................. Wayne Blackwells " Load from a Disk " program was used to get the rate of twist data for 204 caliber bullets. The 35gr bullets need a 1-13" twist. The 40gr bullets need a 1-10" twist. A 37 gr bullet would need a 1-12" twist as the ideal twist. ............................

A 37gr bullet should work well in all 1-12" twist 204 Ruger rifles.

Grayfox

Is the weight of the bullet somehow being used to determine twist rate, or is the program assuming an incremental increase in bullet length with weight changes to determine barrel twist? Just curious....

I can swage a 35 grain well balanced bullet that is too long to shoot well in a 12" twist barrel. Conversely. I can swage a 42 grain bullet that is short enough to shoot well in a 12" twist barrel. Bullet length is the key to determining twist rate.....

I began swaging my own 20 caliber bullets back in 2000 (long before the 204 Ruger), and I soon settled on a 38 grain HP as being the best balanced bullet (core length compared to jacket length) and the best overall length bullet to give excellent accuracy in a 12" twist barrel. But again the jacket length was the key......the length of the lead core that gave the bullet a good balance point just happened to weigh a total of x.xx grains. When this is added to the jacket weight (y.yy grains), the overall bullet weight was 38 grains.

-BCB

Bayou City Boy.

The 37 grain bullet data we used:
BC .245
Lenght .665"
37 gr Boat tail

We also tried a BC of .230. The BC did not seem to change the twist rate.When the bullet was longer than .665", the twist rate started to fall below 1-12".

I fully agree that your 38 grain HP bullets are the optimum heavy weight bullet for the 204 caliber.

Would you sell any of your bullets so we could try them? Is it hard to get materials to swage your own?

Thanks,Grayfox

I'm not sure that there is an optimum weight bullet for the 204 caliber. A lot of it depends on variables in jackets (thickness and toughness), lead core hardness, etc.

I'm guessing from what you said then that your "bullet data" is theoretical. I will comment that 0.665" for a total bullet length is fairly long for a 37 grain bullet - even with a boat tail. The 38 grain bullet I shoot is a flat base bullet as a boat tail actually does very little in the smaller calibers other than to serve as an aid in seating bullets. A boat tail only becomes important ballistically in larger caliber bullets where extreme range shooting is being done. And a BT has to be figured into the total bullet length for determining barrel twist. What I am saying from this is that additional bullet length due to a longer, more streamlined ogive is more beneficial to ballistic stability in a 12'"barrel and to BC than is a boat tail.

I realize that the commercial bullets with the polycarbonate tips are all longer than that, but not so much longer that a 12" twist barrel no longer applies even though its marginal, especially in a rough factory barrel. It been about 7 years since I fired any of my bullets over a double chrony set-up to determine a BC, but the numbers you are using are fairly conservative from the results I got with my 38 grain HP.

If you're interested in bullet swaging, this is the link to go to and read....and read....

http://www.corbins.com/index.htm

Materials can be had from Corbin or various other suppliers if you get to looking. I use Sierra .224" jackets swaged down to 20 caliber most of the time. I also use Corbin jackets and J-4 jackets, although I have not been happy with the overall peformance of bullets made with the J-4 jacket - both in terms of accuracy and terminal performance. Unfortunately no one sells 20 caliber jackets, so using .224" jackets and taking them down to @0.196" with a draw down die is a necessary first step in making 20 caliber bullets. Unlike the reloading of metallic cartridges, bullet swaging then involves using considerable controlled internal pressure to increase bullet diameter back up to 0.204" on the finished bullet

I ordered/bought my swaging equipment in late 1999 and paid just a hair over $1500 for a Corbin CSP-1 Series II press, dies, lead wire, 1000 jackets and a lead wire cutter. The cost of 20 caliber dies to make HP and lead tipped bullets was a little over half of the cost. I'm not sure what the same stuff would cost today.... Back then the only commercial 20 caliber bullets were a Hornady 33 grain V-Max and a 36 grain Berger HP and they were both extremely scarce as both companies only made limited runs of 20 caliber bullets each year. A guy by the name of Russ Lucas made custom 20 caliber bullets but he was the only dependable custom maker back then in terms of quick and reliable delivery. He quit the business soon after the 204 Ruger was introduced and more 20 caliber bullets became available to the public.

And I do not sell any of my bullets. For me....swaging bullets is fun only when you are done and have the finished product to shoot. And legally, the selling of bullets commercially involves having a Type 6 FFL and the collection of excise taxes and extensive record keeping. Making my own bullets for my use only is no more legally complex than reloading cartridges for myself....

HTH - BCB

BCB: I agree with you across the board in all respects to length being critical to twist rate. But I also suggest that the twist rate listed as "ideal" by the bullet makers is based on weight. This is borne out by looking at the various makers websites, as all twist rates are listed by both caliber and bullet weight.

You have a very valid point obviously based on good experience. We can only wish that the makers would integrate both values on their twist tables to make them more useful for planning a rifle, or for more valid bullet choices related to twist.

Rick in Oregon wrote:BCB: I agree with you across the board in all respects to length being critical to twist rate. But I also suggest that the twist rate listed as "ideal" by the bullet makers is based on weight. This is borne out by looking at the various makers websites, as all twist rates are listed by both caliber and bullet weight.

You have a very valid point obviously based on good experience. We can only wish that the makers would integrate both values on their twist tables to make them more useful for planning a rifle, or for more valid bullet choices related to twist.

And I agree across the board with your comments, Rick.

I'm not sure why bullet weight is used as the primary value for barrel twist other than folks look at and have traditionally been concerned about bullet weight in making bullet choices for their rifles. Hence, instead of grouping bullets by length, the makers use weight to identify bullets and then correlate weight to barrel twist (and completely leave out the fact that bullet length is the determining factor).

The various formulas (most all derivatives/improvements of the old Greehill Formula) for calculating twist rate all use the bullet length in inches, muzzle velocity, and the diameter of the bore grooves in inches. Bullet weight is not a factor in the math. The following link to a common twist rate formula is indicative:

http://www.uslink.com/~tom1/twistrate.htm

Incidently, Dave Corbin sells a ballistic software package that includes overall bullet design factors in determining barrel twist rate. His formula includes bullet ogive shape and length, shank length, etc., etc. It all looks like good math, but in reality bullet shank length and ogive length both help determine whether a certain/specific bullet design will stabilize in any twist rate . In reality, his formula and math simply includes good bullet design factors for any length or weight of bullets. In defense of Dave, he has done a lot for bullet making technology. On the other hand, he's an excellent salesman and could probably sell stale potatoes to an Idaho potato farmer if he put his mind to it.... And you're not listening if you don't learn something new from him each time you talk with him.

In regards to bullet length, I can make a long 38 grain HP that is ballistically balanced where it will easily stabilize in a fast twist rifle barrel, but it will tumble in a 12" barrel. In contrast, I have made 45 grain bullets that are short enough to stabilize well in a 12" twist barrel.

-BCB

Bullet weight is the indicator, because if you increase the bullet weight, the piece of lead that you cut off will be longer for a 40 gr bullet than a 32 gr....but all stuff neatly in the same jacket.

The "bearing surface length" should be the indicator of what twist rate is needed.

Should also be some physics included so that the bearing surface length multiplied to the n'th degree of core weight....provides a magic number of twist rate needed.

acloco wrote:Bullet weight is the indicator, because if you increase the bullet weight, the piece of lead that you cut off will be longer for a 40 gr bullet than a 32 gr....but all stuff neatly in the same jacket.

The "bearing surface length" should be the indicator of what twist rate is needed.

Should also be some physics included so that the bearing surface length multiplied to the n'th degree of core weight....provides a magic number of twist rate needed.

Its hard to argue about the length of the lead core not being longer in a heavier bullet with both bullets having the same length jacket.... But, that has nothing to do with barrel twist rates.

If you swage bullets with enough lead ("all stuffed neatly in the same jacket") to bring the lead weight + the jacket weight (all equal in length and hence, weight) to 32, 35, 38, 42, and 45 grains, none of the bullets will stabilize in a 12" twist barrel if the overall bullet jacket - and hence the overall bullet length - is too long to stabilize in a 12"twist barrel.

However, they will all stabilize in a 12" twist barrel if the jacket length - and hence the overall bullet length - is short enough to stabilize in a 12" twist barrel.

I'm guessing from your prose that "all stuffed neatly in the same jacket" means all the jackets are the same length and hence the same weight...

Again....spelled out a little plainer from the link.....

Define the Variables:
T = Twist rate in 1 turn per inches.
L = Bullet length in inches.
V = Muzzle Velocity
D = Diameter of the bore grooves in inches.
Constant = 3.5

Find the optimum twist rate from velocity, bore size and bullet length:
T= ( 3.5 * SqRt( V ) * D² ) ÷ L

Notice there is no mention of bullet weight in the mathematical formula....

Sorry that things aren't as they "should be", but they are in spite of what we might incorrectly think....or wish...

-BCB

"Its hard to argue about the length of the lead core not being longer in a heavier bullet with both bullets having the same length jacket.... But, that has nothing to do with barrel twist rates."

Actually, this has EVERYTHING to do with stabilizing a bullet.

We are spinning bullets at 10's of thousands of RPM when they exit a muzzle.

If the weight of a bullet is spread out over the length of a lead core that is 1" long....versus a lead core that is 1/2" long.....there will be a drastically different twist rate required.

My example is extreme, but this does play a part.

acloco wrote:"Its hard to argue about the length of the lead core not being longer in a heavier bullet with both bullets having the same length jacket.... But, that has nothing to do with barrel twist rates."

Actually, this has EVERYTHING to do with stabilizing a bullet.

We are spinning bullets at 10's of thousands of RPM when they exit a muzzle.

If the weight of a bullet is spread out over the length of a lead core that is 1" long....versus a lead core that is 1/2" long.....there will be a drastically different twist rate required.

My example is extreme, but this does play a part.

acloco:

First off: the "weight of a bullet is spread out over the length of a lead core that is 1" long" is not a true statement....the weight of the bullet is spread out over the entire length of the bullet which includes the core weight and the bullet jacket weight. And the length of the lead core in the bullet does not affect required twist rates.

I'm going to stick with what ballisticians have known for years and let you believe what you want....bullet length and not weight is the variable bullet characteristic within a given caliber that affects barrel twist rates..

That's what all the bullet twist rate formulas show..... Hence, as I said, I think I'll stick with proven ballistic knowledge and the math involved rather than an individual's incorrect assumptions or theories... Sorry....

Come down and visit and I'll swage you some 32,34,35,36 37,38 39 and 40 grain 20 caliber bullets that will not stabilize in a 12" twist barrel because the jacket I used is too long. In essence, the 12" twist is not spinning the long gyros (bullets) fast enough to make them stable in flight. But they will all stabilize in a faster twist 9" or 10" barrel.

And then I'll swage you some bullets with the same weights as above which will all stabilize in a 12" barrel because the jacket used is not too long to make them unstable in a 12" twist barrel. I'll even make you a 43.5 grain lead tipped bullet off the same length of jacket and it too will shoot fine in the 12" barrel. They will all be stable because the gyros (bullets) are shorter and do not require as much spin to make them stable in flight. And you can shoot all these same bullets in a tighter twist barrel and they will stabilize there also...

Your argument about bullet weight maybe holds water around the camp fire, but its not correct from a practical ballistic point of view...anywhere on Earth anyway.... If you were to cram an element which is much denser than lead (hence much heavier) into the same length bullet jacket, the bullet may not be stable because the velocity is lowered by the ]hugely increased weight of the bullet and hence a major reduction in velocity - which is a variable in the twist rate formulas. This is all mathematically possible because velocity is a part of the rate twist formulas, but it is not a practical mathematical possibility with lead core bullets in the same bore diameter. Hence bullet weight is not a variable important enough to be included in mathematical formulas to determine rates of twist used in real life on earth. Maybe it is in the world you live in, but its not in my world (Earth).

Now, keep in mind that velocity is part of the math. So....I can easily shoot a 38 grain 20 caliber bullet of a certain length at a velocity that will stabilize the bullet in a 12" twist barrel. I could also (theoretically, but not practically) lower the powder charge of the cartridge and in effect lower the velocity of the same length and weight bullet to the point that it may not be stable in a 12" twist barrel because it is not spinning fast enough. Here, the length of the bullet along with the bullet velocity is what determines if the gyro (bullet) is stable under a condition of greatly reduced bullet RPM's..... That's why bullet length and velocity are both part of the formulas... The weights of the bullets used are the same and are not a part of the math..... And please note that the velocity I'm talking about here will be only a fraction of the velocity capability of the cartridge and generally not in an area where gun powders are safe to use. So, it can be created mathematically, but it's definitely not safe for you or I to try creating the scenario using conventional gun powders.

If you still want to diagree, PM me. I'm getting writer's cramp saying the same thing several times....

-BCB

BCB - lol (on the writer's cramp)


It would be too much typing to provide the info....


I will let it be..........