PRC bullet seating depth

[quandary]

As for the literature stating "the PRC specs are much more stringent", that is hype from Hornady. There is still a SAAMI spec. It is no more or less stringent than any other cartridge. Especially when the best reamer design for the 7PRC is the 7PRC AW reamer...

Not to speak for the OP...... SAAMI specs for a chamber are precise regardless of cartridge. I think what he meant to refer to is the fact that the SAAMI chamber specs for the PRC to the SAAMI specs for the cartridge provide for much smaller space between the cartridge and the chamber wall than traditional cartridges. Which is true.

 

[lancetkenyon]

Not to speak for the OP...... SAAMI specs for a chamber are precise regardless of cartridge. I think what he meant to refer to is the fact that the SAAMI chamber specs for the PRC to the SAAMI specs for the cartridge provide for much smaller space between the cartridge and the chamber wall than traditional cartridges. Which is true.

I agree with that.

 

[cajun]

I agree with that.

Lance I know you have a prc. Have you had the sticky extraction issues?

 

[lancetkenyon]

Lance I know you have a prc. Have you had the sticky extraction issues?

I had a 6.5PRC, cut with the AW2 reamer. Used Lapua brass, had 14x firings on it with zero issues. Smooth like butter.
I have a .300PRC, again, cut with a modified AW reamer, just a touch less FB. I have up to 3x firings on Lapua brass. No issues. Very smooth, and it is running on the "warm" side. 230s @ 2995fps.
I have loaded for a few different 7PRCs now. When using Peterson or ADG brass, no problems. When using Hornady brass....yes. Clickers and bolt lift. I think a lot has to do with garbage brass.

 

[quandary]

I have a large base reemer for my 6.5PRC, Lapua brass, no issues. My 7PC and 300PRC are SAAMI reemers. On those I double size. First with the Forester FL bushing dies, than the Cortina mandrel sizing die made to deal with the clicker issue. It puts my brass back to .532 at the .200 datum line. So far so good but kind of a PIA. Will likely rent some AW reemers at some point to clean up the chambers.

 

[Taylorbok]

Not to speak for the OP...... SAAMI specs for a chamber are precise regardless of cartridge. I think what he meant to refer to is the fact that the SAAMI chamber specs for the PRC to the SAAMI specs for the cartridge provide for much smaller space between the cartridge and the chamber wall than traditional cartridges. Which is true.

That's not true. I'm really not sure where that myth ever came from.

Anyone can look at the drawings on the SAAMI website. There's no real difference when compared to anything else

 

[charlie 7]

The OP already noted he used to measure to the lands,
and your question was not definitive if you are asking as to "how-to" and that you are needing the information. If not, my apologies for trying to help out.

It was actually good idea to post the Gavin video as it answered the blackfoot95 question how others are doing it.

All good and no apology is required.

 

[charlie 7]

I was mostly interested in finding out if anyone was eliminating this step with PRC cartridges as the literature I've read states the specifications for the PRC cartridges are much more stringent than standard cartridges which if maintained would mean all ammo could be safely produced at one "custom" length.
As for my method I've always used a cleaning rod to measure to the bolt face then push a bullet into the bore for the 2nd measurement. Subtract. 020" off the measurement then double check by chambering a bullet colored with a sharpie to ensure the bullet isn't touching.

Keep doing what you do as your method is not inferior to any modern one and does not require any super-duper tools.

If you use two close fitting discs that can be fixed to the cleaning rod this system is at least as precise as that shown in the FEENIX video.

Do not relay on any COAL shown anywhere, it is your magazine
and your chamber.

 

[quandary]

That's not true. I'm really not sure where that myth ever came from.

Anyone can look at the drawings on the SAAMI website. There's no real difference when compared to anything els

The tighter chamber is what causes problems that creates the clickers, further the throat is also tighter.

Modern Cartridge Design: Why New Rifle Cartridges Are Superior to the Classics

Modern Cartridge Design has revolutionized how we build cartridges, leading to hunting and competition rounds that outperform the classics.

www.outdoorlife.com

 

[quandary]

That's not true. I'm really not sure where that myth ever came from.

Anyone can look at the drawings on the SAAMI website. There's no real difference when compared to anything else

Here is another article that will help your understanding.

Is 7mm PRC Best 7mm Ever? — Ron Spomer Outdoors

New Hornady 7mm PRC Cartridge promises best of all worlds .

www.ronspomeroutdoors.com

 

[Taylorbok]

The tighter chamber is what causes problems that creates the clickers, further the throat is also tighter.

Modern Cartridge Design: Why New Rifle Cartridges Are Superior to the Classics

Modern Cartridge Design has revolutionized how we build cartridges, leading to hunting and competition rounds that outperform the classics.

www.outdoorlife.com

The clicker problem is more of an issue between the sizing die and chamber dimensions but can also be rectified by expanding the chamber at the .200 line. This doesn't really have an affect on accuracy. Many other chambers have the same relation ship between the chamber and ammo spec but the mfg's corrected the issue with the brass and dies so it doesn't cause a problem.

The SAAMI drawing shows the throat has about .0008" clearance over bullet diameter (which is pretty common), but that spec also has a +.002" tolerance so depending on how the reamer was made it can vary.

7mm Rem Mag according to SAAMI drawings actually has just as tight of base and actually a tighter throat.
The angles are a bit different in the throat, also the steeper shoulder on the PRC will help case efficiency.

 

[quandary]

300PRC .0008, 300WM .007, 7PRC .0006, 7RM .0005, 6.5PRC .0005, 264WM .004. Throat on 7RM and 7PRC are virtually the same. This can't be said for most of the older catridges. But as you said a lot more goes into the "inherent" accuracy of the newer catridge designs than just throat tolerances. This is all well laid out by Snow and Spomer I won't reiterate it. But fact is fact. Of course with a custom reamer you can achieve the same results. However, as I am sure you know, that was not the objective of the PRCs. The objective was to make it available to the masses as a SAAMI spec design.