Hi - I am building a 284 win f class rifle and was reading something about throating a barrel for a specific bullet. I presume this means the barrel is reamed out so it optimizes a specific bullets dimensions, but not too sure about that. Can someone explain throating, and is it a good idea? I would probably not be changing bullets very often.
what is 'throating' a barrel? good idea or not?
- Thread starter MJT
- Start date
Keith Glasscock
Gold $$ Contributor
The throating can be simplified down to how far in front of the chamber neck that the rifling starts.
One would want that distance to match up with the size and shape of the intended bullet. In many cases, the throating is correctly designed into the chamber reamer For example, my 284 reamer has the correct (in my opinion) throating for the 180 hybrid bullets.
If the chamber reamer used for a barrel has a throating shorter than desired, a special throating reamer can be used to make it longer. As with all things cutting metal related, judicious use of caution is advised to not take too much off.
One would want that distance to match up with the size and shape of the intended bullet. In many cases, the throating is correctly designed into the chamber reamer For example, my 284 reamer has the correct (in my opinion) throating for the 180 hybrid bullets.
If the chamber reamer used for a barrel has a throating shorter than desired, a special throating reamer can be used to make it longer. As with all things cutting metal related, judicious use of caution is advised to not take too much off.
^^^^^^^^ this is why. After multiple firings the neck/shoulder junction thickens (donut) and will create a pinch point on the bullet. This creates a pressure problem that will vary with each casing depending on number of firings. It's easy to detect by trying to put a bullet in a fired case by hand.
Northridge
Gold $$ Contributor
Throating a barrel is simply the task of advancing throat forward to accomadate different bullet configurations. Reason or purpose for advanceing throat is typically to get bearing surface of bullet away from neck shoulder junction and the potential donut area which can degrade rifles performance down range on brass with some firings on it. The task is very basic, duplicatable and repeadable in the hands of a seasoned rifle smith but can easily be botched in the hands of the careless. If set up is loose or off set you can oversize a throat & blemish what otherwise was good even with proper bushing sizing etc. If throating reamer has side load at bushing end the bushing has a affinity to slightly drop into the groove and not ride soly on face of land therefore oversizing the throat.
Shawn williams
Shawn williams
No it doesn't change neck size.
You can get a Remer to open up necks. After metal is removed, you can't put it back. The only way to make it smaller is rechamber. Matt
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