dummy round question

[balloonpilot9513]

Hey guys,

I am building my first custom.
I have done a lot of research and many smiths want dummy rounds to use to reference chamber sizing.
I understand how to make the dummy round, my question is:
If I have not fired the rifle, how do I know what bullet will work the best for it? IE, Berger, Lapua, Sierra??? What grain bullet???

I appreciate any input I can get,

 

[MGYSGT]

Just a guess, but perhaps your smith has more than one reamer with different throats and leads for the different projectiles.

 

[tenring]

Load the dummy round with one of the bullets you prefer, seated just where you want it. The smith will cut the chamber to fit that OAL and most bullets of that approx weight will work OK.

 

[carlsbad]

Can you tell your smith what freebore you want?

If you don't know what freebore you want, don't know what bullet you want to shoot, then you aren't ready to build. Each barrel has a freebore and somebody has to choose it.

So if you're asking for help figuring out what freebore to use, then I'm sure there are people here willing to do that.
--Jerry

 

[clowdis]

Hey guys,

I am building my first custom.
I have done a lot of research and many smiths want dummy rounds to use to reference chamber sizing.
I understand how to make the dummy round, my question is:
If I have not fired the rifle, how do I know what bullet will work the best for it? IE, Berger, Lapua, Sierra??? What grain bullet???

I appreciate any input I can get,

A good question and at this point you really aren't ready to tell your gunsmith anything except what case and what bullet you want to use. If you can take him a .308 case for instance and a 175 bullet seated about where you'd like it he probably has a reamer to get you close to what you need. If you're shooting benchrest he'll need to know if your going to turn case necks and how much or he can tell you how much to turn them. I don't want to be varying chambers and throat depths to any number of imaginary dimensions thought up by someone who has no experience or has never shot the cartridge he's requesting. Your 'smith is a great consultant and his info is probably free.

 

[okie]

Your 'smith is a great consultant and his info is probably free.
clowdis is right---ask the guy doing the work
he should steer you right---reamers and rifles like anything else---no single one can do it all.
but some can do more...

 

[cahunter805]

What cartridge are you looking into?
What barrel and twist rate?
What action and magazine setup?

All these factors will help you determine your dummy rounds also.

 

[philip brousseau]

google gre-tan dummy cartridge. on u-tube and on accurate shooter site. good explanation.

 

[balloonpilot9513]

I appreciate the input guys, but that is exactly my issue.
I have a factory 223 that I have tried different bullets and weights and have found a good combination for it through trial and error.
How do I figure that out for a gun that I am not able to fire until this is done?
Do I go with the heaviest bullet possible? Heaviest I see others loading with for this caliber? Do I go middle of the road with weight, Most common brand of bullet?...

I am so confused!!!

I am building a 6.5x47, Bat B action and Krieger 8 twist barrel for those interested or if it helps your answering.

 

[carlsbad]

1. Tell your smith you want your freebore to be .175".
http://forum.accurateshooter.com/threads/6-5x47-freebore-for-140-bergers.3758466/
2. Relax.

--Jerry

 

[butchlambert]

Funny story, When I first started shootin BR I was told by the reamer maker to seat a bullet and send it to him. At this time I was concerned with the height of seated primers and other useless things, because I was part of the great unwashed. No internet at the time. I slammed a bullet into a case not knowing the seated length was important. My bullet had the base way below the neck shoulder juncture-that is very short OAL. I shot a lot then and not knowing that I screwed up I probably won more compressed wood than later in my career when I had learned everything. chuckle chuckle Morale of this story, shoot a lot and learn to read your flags. Not saying the other things are not important, but.

 

[cahunter805]

Seat some 140 bergers to where the base of the bullet is right above the neck shoulder junction or about .015-.020 short of magazine length. Whichever is shorter OAL.

Also most custom barrels and guns will shot lots of different bullets accurately so don't stress on picking just the "one" bullet.