6.5x47L reloading and freebore question?

[nhshooter]

Having a barrel chamber in 6.5x47l and was planning on using 130's. I noticed at the 2.800 over all length half of the boat tail is in the neck. Should the gas seal of the boat tail be at the very end of the neck towards the primer or is it better to have the added case capacity? I would appreciate suggestions for free bore using the 130's and maybe lead angle.
ward

 

[RonAKA]

I think the ideal position is with the base of the bullet at the bottom of the neck. However if you want to shoot different bullets, like the 140 you will have to compromise somewhere. Perhaps it would make more sense for the 140 grain to be even with the bottom of the neck, and then seat the 130 a little further out. What that means for freebore, I will leave to others. I am struggling with that issue too!

 

[savagedasher]

I think the free bore should be where the boat tail is forward of the shoulder where the donut could be .
Every bullet fired the free bore increases .
Larry

 

[gotcha]

Though well meaning the above answers aren't giving you the information you want. Which is an actual free bore measurement for the bullet weight and style (shape) you intend to use. Contact a reputable reamer maker and they can advise you as to proper free bore. .......... And Savagedasher is correct, you want the heal of the bullet to be a minimum of .030" above the neck/ shoulder junction. If you intend to shoot both 130's and 140's you'll have to settle for a compromise. Best to pick a bullet for the type of shooting you intend to do and stick with it. My .02 FWIW

 

[Jeff A]

<Snip> And Savagedasher is correct, you want the heal of the bullet to be a minimum of .030" above the neck/ shoulder junction.<Snip>

What are the consequences for those who cannot, for one reason or another, achieve this?

 

[savagedasher]

What are the consequences for those who cannot, for one reason or another, achieve this?

You better find a way of dealing with the donuts try's haveing coffee isn't the answer .
Larry

 

[SheepDog]

There are old stories about bullets seated too deep actually going backwards and ending up in the case after firing. I have never personally seen this happen but those old stories came from somewhere. The theory is that the gases from firing can get ahead of the bullet before it can start to move and build enough pressure ahead of the bullet to push it back into the expanded case.
Whether or not I believe this I have never used a bullet long enough in a short chamber to necessitate seating a bullet too deeply.

 

[gotcha]

There are old stories about bullets seated too deep actually going backwards and ending up in the case after firing. I have never personally seen this happen but those old stories came from somewhere. The theory is that the gases from firing can get ahead of the bullet before it can start to move and build enough pressure ahead of the bullet to push it back into the expanded case.
Whether or not I believe this I have never used a bullet long enough in a short chamber to necessitate seating a bullet too deeply.

So, if you have no experience why bother commenting. go wrap some Christmas presents or something that might actually be productive

 

[Jeff A]

You better find a way of dealing with the donuts try's haveing coffee isn't the answer .
Larry

I'm sorry, but you have me stumped here. I don't know what you mean by this.

 

[savagedasher]

I'm sorry, but you have me stumped here. I don't know what you mean by this.

If you don't seat the bullet forward of the donut area you have the wrong free bore. The donut is going to be a problem The donut is not the kind you eat so coffee won't do anything . lol Larry

 

[SheepDog]

The "donut" that they are talking about is a ring of brass that forms at the base of the neck in a cartridge that has been neck turned without going into the shoulder enough. If you were to seat a bullet down on a donut it would cause high pressure.

 

[ShootDots]

If you are looking for the ideal freebore for the 6.5 x 47 for getting the bearing surface of the bullet above the neck shoulder junction, I can help. For the 130 Berger VLD, a .140 freebore is the ticket. For the Berger 140 LRBT, the same .140 freebore. For the 136 and 139 Scenars, the 140 VLD and the 140 Hybrid, a .165-.170 freebore is ideal.. If you are going to shoot from a magazine, then I can't help..

 

[savagedasher]

The "donut" that they are talking about is a ring of brass that forms at the base of the neck in a cartridge that has been neck turned without going into the shoulder enough. If you were to seat a bullet down on a donut it would cause high pressure.

It does make any difference if the neck is turned or not it when the brass flows foward Turning the neck helps but doesn't cure . Larry

 

[Jeff A]

If you don't seat the bullet forward of the donut area you have the wrong free bore. The donut is going to be a problem The donut is not the kind you eat so coffee won't do anything . lol Larry

I don't have any donut issues since I don't use bushing dies. I full length resize with dies that have custom honed necks. My chambers have a freebore for a particular bullet but sometimes I may try another bullet which may not be perfectly suited to my freebore. Although not optimum, what issues can develop by shooting a bullet that extends a little bit into the shoulder area?

 

[gotcha]

Does your alternate bullet have a pressure ring? If it protrudes below the shoulder it will change neck tension possibly changing tension to a Slip fit. ........Even if using an expander with your honed die you can't stop the migration of brass from the shoulder into the neck area. An AI cartridge would cause little to no migration of shoulder material into the neck. A cartridge with 30 * or more shoulder angle would be advantageous but will eventually require trimming which is one indication that shoulder material is moving into the neck area................. Even if you're using an expander the fatter area of the neck will have more resistance to movement by the expander and result in a small donut eventually

 

[ASbobcat]

I don't have any donut issues since I don't use bushing dies. I full length resize with dies that have custom honed necks. My chambers have a freebore for a particular bullet but sometimes I may try another bullet which may not be perfectly suited to my freebore. Although not optimum, what issues can develop by shooting a bullet that extends a little bit into the shoulder area?

There is no way to avoid a donut. Bushing dies make it more visible because it's on the outside. Non-bushing dies put it on the inside. This is a natural consequence of thicker shoulder brass flowing into the neck. You can slow it down with light loads or a 40deg shoulder, but you can't eliminate it.
If you intend to seat bullets below the neck/shoulder junction you have a choice of outside or inside turning. Otherwise be prepared for VERY erratic neck tension and chamber pressure. I have personally blown extractors because of this very effect.
This is especially true of 6.5x47L cases because thickness of shoulder brass is significantly greater than in the neck.

 

[nhshooter]

how many firings before the donuts start to appear and cause problems

 

[SheepDog]

You know, it has been my experience, that the only time I've seen donuts inside or out resulted from turning a case neck but not going far enough. This is something I have never heard of or seen and I do a lot of neck sizing. Interesting...