Slugg'n Barrels

[wildchild]

Not real sure were this thread will go, but whats the general ideas and thoughts behind this?
Seems like the ones ive done seem to have no consistancy with brands. Wouldnt the dude lappen be trying to duplicate a specific taper? ???
Seems like 2,3 or 4 barrels ya get and slug each one ya get differant results, some are straight then tight at the last 1" and some are concistant taper all the way to the muzzle, some are tapered for 4" then straight then pinch at the crown.
Maybe its just too costly and time consuming for barrel makers to get consistant results. ???
Does anyone have a specific taper they prefer like 2 tenths,3 or none at all?
Could it be bullet specific, maybe bergers like 2 tenths and seirras like 3 tenths taper and thats why some barrels only shot one brand?
Feel free to add questions and or experiances 8)

 

[Eddie Harren]

How are you taking your measurements?

 

[wildchild]

How are you taking your measurements?

Tape measure ;D na a swiss mic measured 3 ways groove to land. Also by pushing the slug in say 4" then pushing it back out and measuring then pushing it bach in say 12" then pushing it back out a repeat til your at the crown, this may be wrong but is how we did it.

 

[wildchild]

It was brought to my attention today that BENCHMARK barrels engrave the letter either A,G or N in the end of the breech end as to WHO lapped the barrel. 8) 8)

 

[jonbearman]

How do the barrels shoot.If they shoot outstanding why worry about it.Some barrel makers put a slight taper(choke) at the muzzle.I wouldnt get to technical as it only matters if the barrel shoots bad.

 

[gmitchell]

Jonbearman, it matters if you want benchrest quality you can slug and maybe send back for something you want like the proper amount of taper and no loose spots. The barrel wildchild is talking about is mine there is .0001-.0002 taper for 24" then the last 8" has .0003 for a total of .0005 I talked to barrel maker they informed me that should not have left the shop and send it back they will fix. That said it matters, differnce between a barrel that coppers up or shoots great

 

[Bob3700]

I think that you need to differentiate what the bbl application is. If it is a rimfire, then you are dealing with a bullet that is made out of dead metal. The internal variations in dimensions of a RF bbl would be more critical than a centerfire.

The centerfire bullet is deformed by higher pressures within the bbl and provides a better gas seal. The RF bullet cannot do this so the choke or taper is more critical. A tight spot in the RF bbl in front of the chamber would be the kiss of death for a lead bullet.

That said, I would want my CF bbl to have the same choke at the muzzle so that the last few inches of bbl have a tight seal.

If you slug enough bbls you can certainly feel the tight and rough spots in the bore.

Slugging certainly allows you to verify the quality of the bore diameter and smoothness of the lapping on a new blank. For the time and money spent on these tubes, it is well worth the effort.

Bob

 

[gmitchell]

Bob your exactly right rimfire and centerfire are differnt, rf needs way more taper than cf. Sound like rf around.0005, cf not over .0003. This is something that anybody san do if you have a vise,cleaning rod, and some lead slugs