Gunsmithing Ordering a reamer. Making sure I get what I need.

[Wheres-Waldo]

Hi again gentlemen,

Ive decided to invest a bit of my tax return on setting back and rechambering my rifle, which is currently a spec chamber without too much freebore.

Ide like to have it set back and rechambered in the same cal. (300WM)
Yet with a tighter neck.


Correct me if I'm wrong here, but this is my train of though.

I need only a finish reamer to have my barrel set back and rechambered?

First off, I'll need a dummy round on which to get the reamer fabricated? If so, I'm neck and F/L sizing right now, with much better results F/L sizing as far as run-out is concerned. This makes me think I should submit a dummy round which has been FL sized, turned neck to the Dia. I will commit to once rechambered, and seat my bullet to magazine length.

I'm also thinking that purchasing a FL bushing die would be the best bet, as i seem to have my best luck w/ FL dies, yet I would still be able to control neck tension.....sound logical?

Am I correct so far?

OK, now....

What kind of clearences should I specify I would like on my neck, shoulder, body of the chamber?

.001" - .002" on the neck?
.001" - .002" on the shoulder?
.002 on the body?

I'm running trued necks that measure .330" currently.
Would turning down to .326" and running .327" - .328" necked chamber work, or is that too tight?

Would a request to have ZERO free-bore for the seating depth I've chosen be wise?

Thankyou for your time and advice.

 

[GasLight]

Re: Ordering a reamer. Making sure I get what I need.

I would call PT&G and talk to Dave Kiff about what reamer you need to accomplish the goals you are setting out for. He is very knowledgable and will know what neck diameter and free bore will get you where you want to go...

Dave

 

[Victor N TN]

Re: Ordering a reamer. Making sure I get what I need.

Boots Obermeyer designed a series of chamber reamers that are as tight as you can go and still shoot factory ammo. The military used to use them for "match" chambers. I'm sure either ptg or jgs can tell you what you want to know over the phone.

Do yourself a favor and order your go no go guages at the same time and from the same company when you order your reamer.

Good luck.

 

[Wheres-Waldo]

Re: Ordering a reamer. Making sure I get what I need.

I talked to David at Pacific.

What I was looking for is commonly refered to as a 300WM Match chamber/reamer, with a .335" neck. SAAMI is .340"
I told him I was running .330" at the moment, and asked if it was recomended or advisable to drop down to a tighter necked chamber than .335"
He said he wouldnt advise it, but if thats what I wanted, he'd make it for me.

Im thinking about requesting a .333" or .332" necked 300WM Match.
About 3-4 weeks turn around time.

 

[9H_Cracka]

Re: Ordering a reamer. Making sure I get what I need.

"He said he wouldnt advise it, but if thats what I wanted, he'd make it for me."

I'm with Kiff on this one. About the only reason for choosing the 300WM chambering these days in a match rifle is the ability to shoot factory ammo, so once you remove that possibility you have a real purple elephant of a rifle made with that reamer.

 

[FCS]

Re: Ordering a reamer. Making sure I get what I need.

What is an unturned neck diameter for a loaded round.

I see no reason to go smaller than 0.335 neck diameter on the reamer.

Out of box, no neck truing I'm guessing you'll be in the 0.333" or so range for loaded round neck diameter. 0.001" clearance a side is tighter than I'd suggest but will work w/o turning necks.

Even at 0.330" diameter neck for brass with turned neck, you have a whole 0.0025" / side clearance.

There are advantages to having a no turn neck.

Go 0.335 and be happy. You can always have it reground to 0.333 if you really want, hard to put material back on.

 

[Wheres-Waldo]

Re: Ordering a reamer. Making sure I get what I need.

I dont have anything on-hand thats unturned. (I'm just that motivated)

I just dont want to wind up with more neck clearance than I want.

EDIT: If the only reason for me NOT to go with a tighter reamer is to retain the ability to shoot factory ammo, I havent put a factory round in the rifle since a few days after I got it.

Well hell, what else is out there in .30 cal long action that will surpass the 300WM substantialy enough to rechamber to a new cartridge?

 

[FCS]

Re: Ordering a reamer. Making sure I get what I need.

How much clearance is too much? What are you basing this value on?

I've not shot a factory round in some time. However, knowing what I know now....I'd NEVER spec a 300WM reamer that was too tight for factory ammo.

Your $, your reamer, your specs....

 

[GasLight]

Re: Ordering a reamer. Making sure I get what I need.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wheres-Waldo</div><div class="ubbcode-body">I dont have anything on-hand thats unturned. (I'm just that motivated)

I just dont want to wind up with more neck clearance than I want.

EDIT: If the only reason for me NOT to go with a tighter reamer is to retain the ability to shoot factory ammo, I havent put a factory round in the rifle since a few days after I got it.

Well hell, what else is out there in .30 cal long action that will surpass the 300WM substantialy enough to rechamber to a new cartridge?</div></div>

.30-375 Ruger, can push slightly faster than the .300 Win Mag, but still fit in the AICS with some nice seating benefits.

.30-338 Lapua, faster and puts the .30 to the upper end and nearly maxes out the long action platform.

.300 RUM, factory available, and pushes the pills faster than the Winny.

Just 3 for starters... If you are not going to use factory ammo ever...

Dave

 

[Clark]

Re: Ordering a reamer. Making sure I get what I need.

I have paid for custom reamers in .223 [.250" neck] and 6mmBR [.272" neck], but I use standard reamers in 17M2, 22LR, 243, 257RAI, 30 Mauser, 308, 300WM, 7.62x54R, 338WM, and 9x23mm.

The reason is that if I only shoot 20 rounds a year of a cartridge, I can live with the SAAMI neck size in the chamber. My brass will never wear out.

If I am going to shoot 2,000 rounds/year, then I pay extra for the no turn neck reamer.