30 cal Uni throater angle?

[Tac-O]

I am thinking I'm going to either buy or rent a 30cal uni throater. I want to lengthen my chamber throat to try some longer bullets. I'm also thinking it will reduce pressure of my current load so I can fill the remaining case capacity with powder.

Anyone know what the freebore diameter and leade angle is for the ones available for rent from 4D rentals? Anyone know the numbers for the ones PTG sells? I assume they're the same.... The description and instructions on both web sites are the same.

 

[Coyote Shadow Tracker]

I am thinking I'm going to either buy or rent a 30cal uni throater. I want to lengthen my chamber throat to try some longer bullets. I'm also thinking it will reduce pressure of my current load so I can fill the remaining case capacity with powder.

Anyone know what the freebore diameter and leade angle is for the ones available for rent from 4D rentals? Anyone know the numbers for the ones PTG sells? I assume they're the same.... The description and instructions on both web sites are the same.

First make sure that you need more Throat. Have a good gauge and measure several times to see what needs to be cut. If you need technical question contact PTG or 4D. Just be aware that best results come if you use a Lathe, but if doing by hand be very careful and SLOW. These Uni Cutters are very sharp (if new or in very good condition) and will cut fast with you hardly noticing. You don't want to cut too much!!! You can't replace what you take out. I have heard some DYI damaging their barrels.

 

[xr650rRider]

If you have a Teslong borescope, you can watch the throater from the other end and know exactly where your cutting.

 

[Coyote Shadow Tracker]

If you have a Teslong borescope, you can watch the throater from the other end and know exactly where your cutting.

Yes you can watch, but you need to properly gauge your depth of the cut - we are talking thousands of inches. I would be more focused on the UniThroater than anything. We have 1/2 dozen Throaters and would measure on our Lather with Electronic DROs.
You can do by hand. Take it slow and measure. If you have a friend with a Lathe or a GS Shop that won't charge much go that route.

 

[Mike D Texas]

First make sure that you need more Throat. Have a good gauge and measure several times to see what needs to be cut. If you need technical question contact PTG or 4D. Just be aware that best results come if you use a Lathe, but if doing by hand be very careful and SLOW. These Uni Cutters are very sharp (if new or in very good condition) and will cut fast with you hardly noticing. You don't want to cut too much!!! You can't replace what you take out. I have heard some DYI damaging their barrels.

I can vouch for everything said here. At least the new ones from PTG are very sharp. I would expect the rental units to not be as sharp, but you can still easily over do it if not careful.

 

[Tac-O]

Yup, I've got a base to give comparator that I'd be using, doing it by hand.

I do have a smith that would do it in a lathe. Not sure what he charges for that. But I thought I wanted to try my hand at learning to do it. Sounds pretty easy long as you go really slow and measure a lot.

 

[MagMan]

I've Uni throated with actions on. It's not that bad just be smart about it. You'll spend more time checking and rechecking than you will cutting. Lol
I was able to get one within .001 of where I wanted. I use the "Wheeler" method of finding lands so it took me longer.

 

[Tac-O]

For anyone else that wants to know, the 4d rental 30 cal Uni throater is made by PTG. I emailed 4d and they said they have no print don't know the dimensions. Well that's silly.

Called PTG and and they said their 30cal uni throater has a .3085 freebore diameter and a 1.5* leade angle.

 

[BillLarson]

Be VERY careful with a throater.......make sure you can feel contact.....
go slo.... and take measurements...

 

[FEENIX]

For anyone else that wants to know, the 4d rental 30 cal Uni throater is made by PTG. I emailed 4d and they said they have no print don't know the dimensions. Well that's silly.

Called PTG and and they said their 30cal uni throater has a .3085 freebore diameter and a 1.5* leade angle.

Is this for your .30-.284? I know you want to try it yourself, but there are some uncertainties. If your goal is to reduce chamber pressure for your current plan, +P throating is what people I know are doing. However, it is not for everybody. I would contact Shawn at DE to make sure. If you are not at maxed load capacity (have more room for additional powder), you can also gain more velocity in the process. Good luck!



ADDED: I am not sure if you saw this thread, https://www.longrangehunting.com/threads/a-moron-and-his-uni-throater.306122/

 

[Tac-O]

Is this for your .30-.284? I know you want to try it yourself, but there are some uncertainties. If your goal is to reduce chamber pressure for your current plan, +P throating is what people I know are doing. However, it is not for everybody. I would contact Shawn at DE to make sure. If you are not at maxed load capacity (have more room for additional powder), you can also gain more velocity in the process. Good luck!



ADDED: I am not sure if you saw this thread, https://www.longrangehunting.com/threads/a-moron-and-his-uni-throater.306122/

Yes it's for my 30-284. Thanks for the advice. GRT tells me I'm at 93% case fill for h4350 with my 185jugg (55.5gr current load and 68.75gr H20 cap). I thought about a +P or bore rider throat, but part of it is that I want to try some 200eldx or similar. Looking at my 185jugg load, I have about .210 bullet bearing in the neck and I'm jumping about 0.020. I know if I increase COL for that load, it would decrease pressure but I certainly don't want any less than 0.200 of bearing surface in the neck. So the question would be is if I throat it to seat some 200gr bullets (probably would be 0.070 more freebore), would that decrease pressure of the current 185 load to be able to use more powder. I think that might only be answerable by trying and it might be better to test this on another barrel after I burn this one out unless I want to gamble.

I did see that thread but haven't read through it yet. I planned to do so before renting or ordering a throater. The title sounds like it could scare me off trying it myself.

 

[xr650rRider]

I have a lathe but used a 4D reamer rental Uni-throater on 2 different 28 Noslers by hand. Wanted ability on a 1:8 to be able to shoot 195 Bergers that weren't stuffed in the case. Rifle was ordered that way and when picked up was told we only do SAAMI reamers. I did take fired cases and cut them off right at the web and bored them out to be tight fit on back of reamer shank. Creates a stabilizing bushing so everything stays on center. The uni-throater has 40 TPI threads, so 1 revolution is .025" depth. Easy to control the depth. Rough set it with a dummy round, make a pass, then pull and inspect with borescope. You can feel when it starts cutting. At least I did. Used the Wheeler method and had dummy rounds made up. When the bolt handle closed most of the way easily, I stopped. Other rifle was a Christensen 1:9 and reamed so that 175 Nosler LRAB seated pressure ring above neck/shoulder junction. Both rifles had Wyatt extended boxes, bolt stops and port clearance so that this worked. Christensen action was milled for Wyatt box.

 

[ARlife4me]

I have uni-throaters in 24,26,30 and 33 (maybe 1 other) from pt&g. I think the cut angle is 1.5* and YES, very sharp!

 

[Tac-O]

I have a lathe but used a 4D reamer rental Uni-throater on 2 different 28 Noslers by hand. Wanted ability on a 1:8 to be able to shoot 195 Bergers that weren't stuffed in the case. Rifle was ordered that way and when picked up was told we only do SAAMI reamers. I did take fired cases and cut them off right at the web and bored them out to be tight fit on back of reamer shank. Creates a stabilizing bushing so everything stays on center. The uni-throater has 40 TPI threads, so 1 revolution is .025" depth. Easy to control the depth. Rough set it with a dummy round, make a pass, then pull and inspect with borescope. You can feel when it starts cutting. At least I did. Used the Wheeler method and had dummy rounds made up. When the bolt handle closed most of the way easily, I stopped. Other rifle was a Christensen 1:9 and reamed so that 175 Nosler LRAB seated pressure ring above neck/shoulder junction. Both rifles had Wyatt extended boxes, bolt stops and port clearance so that this worked. Christensen action was milled for Wyatt box.

What did you use to bore out the back of your fired case bushing? I have a drill press, but it's terrible so I don't think I'd have the tools to bore one out concentrically