Thread: The adventure begins, Ist question on compressing black
Retrieved: 12/23/2014
Last Post: 03/21/2015
The adventure begins, Ist question on compressing black.
I get the compression plug thing, my first questions are.
1- does the cartridge case need side support while compressing?
In other words is the required compression enough to bulge the case or not?
I can make a compression plug easy enough if it wont squish the case out.
2- what determines the required amount of compression? Is it the amount needed to get the boolit sitting tightly on the wad/powder at the OAL or do you compress a certain amount then adjust the wad(s) to get the assemble length, or something else?
I found an old fat aluminum arrow shaft at the archery store for free yesterday to make my drop tube.
bigted
03-16-2014
Usually the correct amount of compression is dictated by the cartridge/rifle combo you use it in. Generally the need is to compress different powders a different amount to make them... or allow them... to function in a correct fashion. GOEX for example will... again "generally"... like from .100 inch to .350 inch compression to ignite and function in a repeatable way for accuracy. There are different amounts compression for each load however that dictates by the efficiency of the fouling and accuracy as to what it wants.
This is what is so fun with this style shooting. it has tons of different paths to go down to reach the utmost in what you desire of your rifle. compression is just 1 thing that is needed to be experimented with to arrive at your optimum load.
There is a train of thought here that seems to work well for most;
1- put together a load [just a starting place] with 20 rounds loaded
2- shoot 2 groups of 10 rounds each at 100 yards to find out how it groups
3- now bracket load... [load 5 rounds each with 5 grain increase then 5 rounds in 5 grain decrease and so on]... and shoot again for group with each 5 round load while cleaning between groups for a spotless bore.
4- after finding the sweet load for your rifle... now do the increase bracket and decrease bracket... using 1 grain differences in the load.
5- now that you have found the best group load for your rifle... try changing primers from manufacturer and large rifle to mag large rifle to find out which primer is going to give the best group at the 100 yard range.
6- NOW you are ready for the compression changes... [do slight differences in compression so as not to change the final load column]... to find out what your powder combo is needing for the best accuracy. also be careful not to provide an air pocket in the column.
7- now that you have arrived at the best of the best for your rifle... now it is time to change in small differences the amount of "air" between the first drive band and the beginning of the rifling. change this from kissing the rifling with the drive band to loading further into the case by around .020 inch max.
8- now you can begin the search for the best boolit that will compliment all above... or destroy it... along with doing all these things again with the different boolit. WHAT FUN!
so for every change you make... be mindful of the change that is thrust on other components of your load column. this is the fun of chasing the accuracy bug. you must write down in a log what you have done in an account style so as to not repeat your findings with a particular load/column/compression/case/primer/boolit. without these notes in a shooting log you are bound for disappointment as you repeat failures from the past. don't ask me how I know this one.
good luck and have fun with your experiments and quest.
montana_charlie
03-16-2014
It is unlikely that you will reach that level of compression if you follow normal load development procedures.
2- Compression provides two things... a.) an increased amount of 'fuel' to reach a given speed - b.) a pressure characteristic that increases the efficiency of the burn.
Sometimes you get those at different levels of compression. If you get them both at the same level, you are onto something.
If you start with just enough powder to fill the case to the depth of your seated bulet, that is a 'no compression' load.
If that powder charge gives you the accuracy and speed you desire, there is no reason to increase it.
If you do increase the powder charge, you will begin to add 'compression' as you keep the powder column at the correct height to seat your bullet.
When you have passed the point where you got the best accuracy... or the correct speed... you go back to the amount of powder (and resulting compression) that gave you the desired performance.
With luck, that is also the load that gives minimum fouling in the bore.
smoked turkey
03-16-2014
I don't want to hyjack this thread. But I think my question could be related in a round about way. My question concerns the compression die. To compress the powder in a 45-70 case, can either a bullet seating die or an expander die from another die set be used? I am thinking of something like a 416 Remington or 41 magnum? If a dedicated compression die is used where would you go to purchase one? If this has been covered in another thread kindly direct me there and I will research it.
Lead pot
03-16-2014
Like what has been answered above; if you compress to the point that it bulges the case most generally your past the point of accuracy.
Nobody can give you a load that will shoot accurately in your rifle that is something you will have to find all they can do is suggest a starting point. There are just to many variables that will make your accuracy, like compression, wads stack, primers, bullets, I think you know what I'm getting at. One step most overlook is case prep.
The best way to get a load your looking for is start with zero compression and increase it at first by two grains with three loads each. This will usually show a pattern within 24 rounds fired. with the best three shots you can refine it by dropping a grain or increasing it. Then you can change your wad stack or type of wad as well as your primers. Just do one step at a time and keep good records.
Lead pot
03-16-2014
You can use a expander die for what ever caliber as long as the case fits the die and the plug you need for your caliber. I would not use the expander plug with it's round bottom. It's best that the base of the plug is flat.
country gent
03-16-2014
Smoked Turkey, Buffalo arms company has expanders that will work in the expander dies of most die sets. You want a "close' fit on the case id. I thumb the first wad in place then compress with the die to depth needed.
montana_charlie
03-16-2014
Originally Posted by smoked turkey
If a dedicated compression die is used where would you go to purchase
one?
Generally, you use an expander die body just like the one in your three die set.
BACO sells them, or you can by just the expander die body (and a lock ring) from Lyman, RCBS, whatever...
MikeT
03-17-2014
If you are trying to load 40 grains of powder into a 44-40, the case will bulge!
03-17-2014, 06:20 PM #14
Nobade
Originally Posted by Jim Flinchbaugh
Two hints: if you think you will ever contemplate shooting paper patched
boolits, do not use a regular throater on that chamber. The other is, if you
want to shoot heavy grease groove boolits, use a bore rider design like a
Postell or #457125. The case will hold plenty of powder to give you all the
recoil you care to experience in that rifle, once you get that compression
die.
I like bore riders, I've had my best success in all calibers with them.
I like the idea of paper patching, but my failing hand dexterity leaves me
with doubts about ever doing it.
A simple hole/leather punch of the correct dia (mine cuts .465 dia) can be
made to cut wads from gasket material, cork, playing cards, coffee can lids
whatever material you decide on. I bought General brand in 7/16 and ground out
to .465 for 45s and 3/8 to open up for 40s. I've been considering one to run
in a drill press for felt. Using a block of firewood end grain to punch into
will keep the punch sharp a lot longer.
Awfully hard to beat this wad punch. I have one for every caliber.
http://www.buffaloarms.com/
Originally Posted by MikeT
I have loaded 40 grs. by weight into 44-40 cases and compressed it with no
case expansion. I was using a Lyman "M" die to compress the powder.
Rifling starts at the case mouth. A throating reamer may be
in my future for some of the heavy weights.
Jim Flinchbaugh
03-18-2014
country gent
03-20-2014
Lead pot
03-20-2014
w30wcf
03-21-2014
If you are trying to load 40 grains of powder into a 44-40, the case will
bulge!