284 SHEhane UNI-THROAT .188FB to.230 ??

[noload]

I have a PTG Shehane reamer .314NK (NO FB dim. marked on it). I think its a .188FB. I shoot Berg 180 VLDs and I have pressure issues with 56.4 grains of 4831sc on Hot Days. A forum member thinks its possibly my FB being too short and recommended a longer one. I do have to push the VLD deeper into the case than I like. Do you think about .230" FB would help? And would PTG have a UNI throater on the shelf ? I have a set of 9- 284 pilot bushings. I haven't done any throathing ...........nothing can go wrong right? I know the VLDs have more bearing surface than the HYBs could that be my pressure problem? I have both VLDs and HYBs but like the Vs better cause they are easier to get and group tighter for me. Suggestions........

 

[Erik Cortina]

Call PT&G. I called them last week and they had one on the shelf. Maybe they'll have another one.

.230" - .240" is good for 180 VLD's.

 

[Jay Christopherson]

Call PT&G. I called them last week and they had one on the shelf. Maybe they'll have another one.

.230" - .240" is good for 180 VLD's.

Ah, so that was you. They do NOT currently have one on the shelf... At least as of yesterday. And Erik is right on the FB for 180VLD's.

 

[Alex Wheeler]

I have a PTG 284 shehane reamer with .220 fb. With PTG you never know, but if it is really a .220 fb I would want .240-.250 fb with the 180 vld.

 

[Erik Cortina]

Call PT&G. I called them last week and they had one on the shelf. Maybe they'll have another one.

.230" - .240" is good for 180 VLD's.

Ah, so that was you. They do NOT currently have one on the shelf... At least as of yesterday. And Erik is right on the FB for 180VLD's.

LOL, yes, that was me! I called them Wednesday evening and they had one on the shelf. I rather be lucky than good!

 

[noload]

Do you guys think using the throater will cure my pressure problems that I have with my load of 56.4 4831, 180 Vld touching, ????? As of now... It will widen the base rim to .474 in 4 fires, and cause fart stains around primers (both BR2 and others). Also should I make a bushing of sorts to center and support Uni- throater. A member told me he had cut rifling off center when he used his UNI THROATER ?

 

[Jay Christopherson]

It's hard to say if lengthening the throat on your chamber will solve your pressure problems. There are a lot of different factors. But, it could definitely help. I'm planning to extend the throat on mine because the initial freebore recommended was too short.

FWIW, my original Shehane reamer had a .190" FB, for using with 180VLD bullets. I did not have any pressure issues with that, although that FB is definitely too short for the 180 VLD bullets if you want to stay above the potential "donut" area.

And as for off-center rifling, I expect that technique will have a lot to do with it. I've heard that particular issue reported with throating reamers, but not from anyone I know to be highly skilled. I have at least one friend who uses one for his 6 Dasher and it works out well for him.

 

[noload]

I will call PTG to see if I can get a UNI-throater Monday. I'd buy a new reamer but I have custom dies for that reamer already. It shoots well as is with the 180's. I got to try something to save the brass a bit better. If this plan goes well I'll apply it to a new blank I've been sitting on.

 

[Scott Harris]

I will call PTG to see if I can get a UNI-throater Monday. I'd buy a new reamer but I have custom dies for that reamer already. It shoots well as is with the 180's. I got to try something to save the brass a bit better. If this plan goes well I'll apply it to a new blank I've been sitting on.

Pushing the freebore out to .250 and then seating the bullet longer will definitely lower pressure/velocity. But you can achieve the same thing with a lot less hassle: use LESS POWDER. Your brass is telling you that you are using too much powder....listen to it.

As an experiment, I did some load testing with a short FB. I then used a throating reamer to push the throat out and seated the bullet further out. The shorter FB required less powder to achieve the same velocity, but max velocity was in the same vicinity. In short, I don't think you are going to change things much by throating .060 out other than getting the bullet above the neck-shoulder junction.

Just my .02.

 

[Jay Christopherson]

I will call PTG to see if I can get a UNI-throater Monday. I'd buy a new reamer but I have custom dies for that reamer already. It shoots well as is with the 180's. I got to try something to save the brass a bit better. If this plan goes well I'll apply it to a new blank I've been sitting on.

Pushing the freebore out to .250 and then seating the bullet longer will definitely lower pressure/velocity. But you can achieve the same thing with a lot less hassle: use LESS POWDER. Your brass is telling you that you are using too much powder....listen to it.

As an experiment, I did some load testing with a short FB. I then used a throating reamer to push the throat out and seated the bullet further out. The shorter FB required less powder to achieve the same velocity, but max velocity was in the same vicinity. In short, I don't think you are going to change things much by throating .060 out other than getting the bullet above the neck-shoulder junction.

Just my .02.

That (bold) is a fairly important point and a very good reason for extending the throat.