Gentlemen,

I am going to order two reamers from PTG and need opinions and measurements.

My tools: two brand new Brown & Sharpe (Swiss, not Taiwanese), calipers, an 6" and 8", and a calibrated Starrett No.436 0-1" mike. All agree exactly.

The necks of new factory loaded .223 WSSM from two different lot numbers show 0.266" - 0.2665", with nickle cases 0.267". My fired cases show 0.275" which jives with the SAAMI chamber drawing. The fired bases show exactly 0.556".

I am thinking of ordering a finish reamer with a 0.270" neck and 0.2242" leade diameter. The SAAMI leade is an incredibly generous 0.2266". These would be the only changes.

My intention is to have a set-up to use box ammo in a pinch, but that would benefit from cleaning up ~35% to ~45% of the neck; just enough to remove any high spots.

I need measurements for the .243 WSSM. I will buy a couple boxes of ammo from different lot numbers, but need fired measurements too. If someone could make some measurements for me it would really help; I wouldn't have to buy a rifle just to fire some rounds.

I need the following:
New factory neck diameter just below the mouth (to avoid the factory crimp)
New factory base diameter.
Fired case mouth diameter, again just below the case mouth.
Fired case base diameter at the largest diameter. It should be about 0.150" above the extractor groove.

I am open to any opinions, and for anyone taking the time to give me measurements, thank you.

Roger,

Why do you need to know what the "fired" dimensions are when you are ordering new reamers?

I want to compare the fired case dimensions to the chamber dimensions in the reamer drawings. I have looked at the SAAMI site which shows max cartridge/min chamber dimensions. I guess just to know.

I have a great print for this set up and also a idea of how you can double your barrel life . Call me 541-826-5808. Thanks Dave

My personal opinion is that there are three ways to do it. The Saami spec, a tight factory chamber, but much more room for error than you are talking, and a tight neck with turned cases. Trying to do what you are doing will eventually lead to a problem. Murphy will insure that the one time you need to use factory rounds, they will be a thick neck batch.

You didn't mention, but are you by chance looking at an AR platform? If so, I suspect there are a lot of knowledeable people who have already worked out the optimum on this.