+P Throating

[Rum Man]

I've used the +P type throating in chamberings that were mild to begin with to allow a step up in velocity while retaining some barrel life. 100% of the RUM and Lapua class cases I've seen with the +P were done extremely fast. When you think about it why do you need an extra 100 fps on the most aggressive chamberings any way, you only see 50-100 yards of gain on the extreme other end before going transonic, not worth it!!

Thanks !!
Would you recommend just throating for the bullet intended?

Rum Man

 

[bigngreen]

Thanks !!
Would you recommend just throating for the bullet intended?

Rum Man

Absolutely, there are some specs that take your from generic to ideal like neck and throat diameter, not too tight but not factory slop, those are worth perfecting as a small detail to make your whole process ideal but there are a plethora of ways to take a gun from a hammer all day every day to you never knowing when it's going to change next.

 

[Rich Coyle]

This is a heated debate and has caused some very hurt feelings. PM if you really must know. But there is no pressure testing data from those guys making+P chamberings!!!! Show me the data...

The owner of Bartlien Barrels even chimed in and said, " stay away"

I wouldn't do it, yes you can get more velocity, but at what cost?

The cost of the reamer. Nothing more.

 

[waveslayer]

The cost of the reamer. Nothing more.

Meaning?...

 

[stazmania]

Years ago I read something about this and came to the conclusion that my ultimate barrel/chambering would have a decent lead/freebore/jump to the the lands, "maybe .060" Then the lands would have a tapered lead in/beveling over say maybe .40 then if i wanted to have say an 1:8 twist barrel. It would start off at an 1:10 and gain twist to an 1:8. My theory was it would eliminate some of the pressure at these bottle necks allowing a gain in volocity. Of course, long barrel, large case capacity and over bore.

 

[Rich Coyle]

Meaning?...

For those wanting maximum velocity they don't lose anything they own a gain.

 

[waveslayer]

For those wanting maximum velocity they don't lose anything they own a gain.

Why not just AI it at that point . Issues are the pressures, no one can provide actual testing

 

[Rich Coyle]

starzmania,

I hit "like" but that doesn't convey my enthusiasm for your idea. Lately my finances live on hopi-u-m. (Spell corrector wouldn't allow the spelling.) If that changes I will borrow your idea for my next wildcat. Thank you.

 

[Tumbleweed]

Years ago I read something about this and came to the conclusion that my ultimate barrel/chambering would have a decent lead/freebore/jump to the the lands, "maybe .060" Then the lands would have a tapered lead in/beveling over say maybe .40 then if i wanted to have say an 1:8 twist barrel. It would start off at an 1:10 and gain twist to an 1:8. My theory was it would eliminate some of the pressure at these bottle necks allowing a gain in volocity. Of course, long barrel, large case capacity and over bore.

This is essentially what I did with this RUM. 34", 1:9 to 1:8 transitional twist. I have decided to have a local friend/smith re-chamber with a reamer I already have that was used in my last barrel. It has a .3084" throat at .500" long. That's long, but with a 250 Atip seated just above the donut area, I'll only be jumping .100" or so which is what the Atips prefer anyway. This was a spendy little experiment. Live and learn