The PRC die "problem"

[IHFarmer07]

.0045"-.005" is what I like

Thank you! It's a hard decision for me obviously lol!!! I think I'll do .005", more is better right?

 

[elkaholic]

Thank you! It's a hard decision for me obviously lol!!! I think I'll do .005", more is better right?

If you dont crack the sizer
You should be ok

 

[JPatzig]

If you dont crack the sizer
You should be ok

So the "proper" fix sounds like a wider chamber where the web hits. I've got a Defiance Proof pre-fit barrel. A gunsmith would be able to widen the chamber a few thousandths on an already cut barrel?

 

[IHFarmer07]

If you dont crack the sizer
You should be ok

Lol I guess I like to live life on the dangerous side!

The reason I think .005" is spring back, .5285 if it stays sized in the perfect world we live in and .5295 with a .001" spring back......correct me if I'm not thinking clearly, wild turkey in the system.

 

[Bob Wright]

Alex,

As someone who is literally just getting ready to get rolling with a .300 PRC project (as in the last part showed up a couple days ago)... and with dies from the manufacturer that I think y'all are hinting at, and 150 pcs of ADG brass... what's the best way for a lay person such as myself to check and see what the actual dimensions of that area of the chamber and die are? I'm assuming using the back side of a set of calipers isn't accurate/reliable enough for this?

Kinda wanting to get the project going... not excited about having to modify a brandy new barrel, or replace dies... but not thrilled at the notion of having to replace the brass early, either.

Monte

There are so many accepted ways that machinists and gunsmiths use to fix the problem today, I risk being considered as not in this universe with the following:
In Gage design (aerospace) we would use a precision gage ball in the tapered hole to define a size at a gage line. A "gage line gage". The ball diameter would be per the .200 line diameter.
You would be better to have the barrel off, but you could measure to the ball before and lightly polish the chamber and measure again.
You would have to be able to measure accurately/repeatedly.
But you could just send it to a really good smith and let him laugh at this one.....
But that's how we did it making parts.
Popcorn, Feenix. I'm going back to my cave now.

 

[Pdvdh]

If I had the problem, I'd be inclined to polish out the back 1" of the chamber the little bit it takes to eliminate the problem.

I'd chuck up a short section of cleaning rod on a battery operated drill, attach a slightly undersized bronze bore brush with some 400-600 grit taped/wrapped over it to make firm contact with the chamber, and polish it out free-hand style.

How much out of round could the butt end of the chamber become when only increasing diameter 0.0015". Not much. Barrel steel is soft. Wouldn't take much effort to polish away 0.00075".

Stop polishing as soon as the sticky casings are no longer sticky. And save the bore brush setup in case another polishing becomes necessary...

I've done this cleaning rod attachment method to polish shotgun chambers and even the entire length of shotgun barrels. Would be easy.

 

[PatriotHenry]

First you need to measure your fired brass just in front of the extractor groove to see what you have.

Alex,

I am getting lost in this thread now. Can I contact you directly or Elkaholic? I think Elk is closer to me in Idaho than you.

I am attaching pictures. Recap: Seekins Havak PH2 6.5PRC very noticeable bulge near web of Factory Hornady once fired Factory loading. ADG once fired at near max or max loads same thing, but not as bad. Did this from day one. After resizing in Hornady match grade bushing sizer maxed just before cam over in my Redding single stage press the ADG as well as Hornady brass will not go into my case gauge.

 

[elkaholic]

Lol I guess I like to live life on the dangerous side!

The reason I think .005" is spring back, .5285 if it stays sized in the perfect world we live in and .5295 with a .001" spring back......correct me if I'm not thinking clearly, wild turkey in the system.

It will spring back more than a thou; trust me. If it sizes under .532" and stays, you'll be ok.

Alex,

I am getting lost in this thread now. Can I contact you directly or Elkaholic? I think Elk is closer to me in Idaho than you.

I am attaching pictures. Recap: Seekins Havak PH2 6.5PRC very noticeable bulge near web of Factory Hornady once fired Factory loading. ADG once fired at near max or max loads same thing, but not as bad. Did this from day one. After resizing in Hornady match grade bushing sizer maxed just before cam over in my Redding single stage press the ADG as well as Hornady brass will not go into my case gauge.

Alex can help you but I cant!
I'm not a smith

 

[jrock]

I have a 6.5 PRC with ADG brass I have been trying to debug. It appeared to reach peak pressure a bit early and the first sign of an issue would be a light ejector mark and a stuck case. The cases sticking got worse with time. Replaced the Remington extractor with an M16 and can get the cases out but only with difficulty. I set the chamber back just enough to clean it up and that seemed to mitigate the stuck cases. I read this article and started taking measurements. The fired cases are 0.532" at the base and the chamber is 0.533". The Forster die sizes the base to 0.5315". The cases are on their 3rd firing and seem to have a snug fit now. Do you think this chamber needs to be enlarged?
I looked at the master list of SAAMI specs and 0.001" difference between case and chamber appears to be the norm. Why would the PRC need more than say a 28 Nosler

 

[Wind Gypsy]

Are there any smiths out there with reamers to address this you guys would recommend?

I'm looking to have a 300 wm havak rebarreled and chambered in PRC.

 

[PCF]

"I looked at the master list of SAAMI specs and 0.001" difference between case and chamber appears to be the norm. Why would the PRC need more than say a 28 Nosler"

This is my question also.

 

[mitebeck]

I just want to thank all of you here on this forum, and especially this thread for all the understanding you have brought out to the followers of this, Especially Alex Wheeler and Elkaholic as I'm just about to acquire a 6.5PRC and I don't mind problems as long as they can be resolved! Thank You, Mike

 

[mitebeck]

Here they are

Thank You Alex

 

[jrock]

ttt, any comments on other cartridges having a 0.001" difference?