Gunsmithing Throating .308 win

[l115a3]

One of mine rifle was chamber with Palma 95 Reamer which has .050 fb

In case that I need the longer throat to shoot the heavier bullet,

How many tools that required for throating?



I know that I have to buy Throat Reamer but not sure about specific tool that use to control the lenght. I read some forum and found that some smith using Adjusting Micro Meter Reamer Holder. Where I can buy those things?

 

[Aeon1]

PTG (Pacific Tool and Gauge) has multiple types of throat reamers available and also makes the Lambeth/Kiff micrometer reamer stop. With a PTG uni-throater you can lengthen the throat without any other tools. Uni-throaters have an adjustable stop built into the design. I have made nylon/delrin guide bushings when lengthening the throat on a barreled action with a uni-throater to help guide the rear of the reamer.

A Palma 95 reamer is typically ground with a .3083" throat diameter and a standard uni-throat tool will be setup with .3085". Most other match type throaters will be .3085" as well. PTG will grind any dimension. The reason I mention this is depending on throat diameter tolerances of your particular reamers you may not be able to easily insert a throating reamer with a .3085" diameter and be able to easily feel the lands to find your starting point.

 

[l115a3]

Dear sir



Thanks for your comment.

Could you please list me the tools that I have to order for throating out my F-TR Chamber. Can I done this process without remove my barrel from action? Any special tools?


I firstly chamber my new barrel with PTG F-TR Reamer (.342nk, .168fb with 1-30 as Dave recommend. But this barrel was tight bore (.299/.308) which affect the seat depth shorter than my previous barrel (.300/.308)


Could you please review my seat depth of PTG FTR Reamer .342nk, .168fb, 1-30.


• Previous Barrel (Cut and rechamber)
Factory Remington 700 XCR Barrel 12"tw (.300/.308)






• 168 SMK
COAL : 2.900"
CBTO : 2.325"

• 175 LRBTHP
COAL : 2.990"
CBTO : 2.329"




• New Barrel
Bartlein 5R M24 11.25"tw (.299/.308)



• 168 smk
COAL = 2.770"
CBTO = 2.195"

• 175 smk
COAL = 2.775"
CBTO = 2.200"

• 175 LRBT
COAL = 2.890"
CBTO = 2.226"


Both Barrel were chamber with the same Reamer but the seat Depth were differ so much.

I may need to throating out my new chamber to the same throat as my previous barrel. (Throating out around .100")

 

[LRI]

Don't forget a set of pilots for the throating tool. Variances in bore ID from one barrel to the next make this a good investment.

Runs around $100 for a full set of 30 calibers.

Good luck.

C.

 

[Aeon1]

One of mine rifle was chamber with Palma 95 Reamer which has .050 fb

Could you please list me the tools that I have to order for throating out my F-TR Chamber. Can I done this process without remove my barrel from action? Any special tools?


I firstly chamber my new barrel with PTG F-TR Reamer (.342nk, .168fb with 1-30 as Dave recommend. But this barrel was tight bore (.299/.308) which affect the seat depth shorter than my previous barrel (.300/.308)


Could you please review my seat depth of PTG FTR Reamer .342nk, .168fb, 1-30.


• Previous Barrel (Cut and rechamber)
Factory Remington 700 XCR Barrel 12"tw (.300/.308)


• 168 SMK
COAL : 2.900"
CBTO : 2.325"

• 175 LRBTHP
COAL : 2.990"
CBTO : 2.329"

• New Barrel
Bartlein 5R M24 11.25"tw (.299/.308)

• 168 smk
COAL = 2.770"
CBTO = 2.195"

• 175 smk
COAL = 2.775"
CBTO = 2.200"

• 175 LRBT
COAL = 2.890"
CBTO = 2.226"

Both Barrel were chamber with the same Reamer but the seat Depth were differ so much.

I may need to throating out my new chamber to the same throat as my previous barrel. (Throating out around .100")

First you said one of your rifles was chambered with a Palma 95 reamer, you now say they were both chambered with the same PTG FTR reamer. A .299 bore will not make a .100" difference in OAL if chambered with the same reamer. The rifle with the 168 SMK and 2.77" OAL is consistent with a Palma 95 .050" freebore reamer. A reamer with .168" freebore should not have an OAL as short as what you say you have. Did you chamber these yourself or someone else? My guess is someone else did the work and either two different reamers were used or one was throated deeper at the time it was chambered.

With a uni-throater you can lengthen the throat on a barreled action.

Uni-throat tool $95
9pc HSS bushing set $75

Edit: After looking at this again are you sure one barrel is not chambered with the FTR reamer and the other the Palma 95 reamer? There is only .118" difference in freebore dimensions between the reamers and .130" difference in OAL between your two barrels (comparing 168 SMK). There are reamer dimensions (other than freebore) that can/will affect final OAL dimensions as well.