Long story short, due to pressure rings at the top of the case head - that won't iron out w/ a full length sizing, I have begun measuring the case heads on all my 25-06 brass.

Chamber is OK, & the loads are right out of the Nosler manual. Problem is of course, much worse on max book loads.

My Lee & Lyman manuals both show the correct case head (just above the extractor groove)measurement, to be .470"

I have 120 pieces of new RP that all measure .4635" - .464". Got some once fired FC, that comes in at .465". Nickle plated WW is .467".

Above the case head, the brass expands normally to about .469" - .470". Leaves a nice little .006" pressure ring that if you think about it, has got to weaken the brass at that point. A case head separation waiting to happen, if you will...

Out of curiousity, I measured the case heads on some Lapua .308 brass, & (BIG SURPRISE) it was right on the money at .470" - w/ a smooth / no ridge transition up the side of the case.

One little problem: It appears that no one sells 25-06 brass, but Remington & Winchester.

My 1 x fired RP brass is going back to Remington for inspection & comment, so we will see what they have to say. I can't help but think that this would not be an issue, w/ SAAMI spec formed brass.

It was suggested that a possible solution would be match grade 30-06 brass, formed down to 25 & trimmed to length. Never done it before, & seems like a bit of work, but then again...

Thoughts and / or suggestions would be greatly appreciated. I'm actually starting to lose sleep over this. Thanks in advance!

gcf

When you say "under spec", what spec are you referring to? I think you'll find that the base diameter of brass varies quite a bit from one brand to another. I don't think that '06 based cases that measure .465 are uncommon. Most loading books will show a diameter of .470 but that's because that is the SAAMI max cartridge, I believe. Min chamber is probably .471. For the 308W I believe the dimensions are min chamber .4715 and max cart is .4705.

I have a custom 280AI and the chamber butt is cut .4650" to fit Remington brass. I also have a 244AI with the same tight butt.

What you're dealing with is a normal factory chamber/cartridge fit. That's why so many shooters go custom.

As long as you don't keep trying to size your fired brass back down every time you re-load you should be OK. Neck size or partial body size and don't worry about that bulge.

Or get a custom barrel with a chamber to match the brass you are using.

JMHO

Ray

quote:

Originally posted by Cheechako:
...I think you'll find that the base diameter of brass varies quite a bit from one brand to another. I don't think that '06 based cases that measure .465 are uncommon.
Ray

Thanks for your response on this. I'm sure you are correct in your assessment. Just strikes me as a sorry state affairs, to have either inconsistent brass - or consistently undersize brass, be the load limiter.

Guess life can be a bitch, huh?

As RP & WW appear to be the only two choices for bulk brass in this caliber, the 30-06 neck down idea is starting to grow on me.

Of course finding some consistent SAAMI max brass will still be a requirement. I'm thinking maybe Norma or Lapua. Any thoughts on these two?

Thanks - Gary

I just measured some .25-06 brass that I've had since the 1980s, and both WW and Rem measured .465 right above the groove, and .468" at the rim.

So, I guess it's been like this for a very long time. This brass is nearly 30 years old.

Gary

I have some fairly new FC 25-06 cartridges, so just out of curiosity I measured a few of them and they are .4655". I also measured some 30-06 National Match cartridges and they were very uniform at .466"

If you can talk your local gun store into letting you measure different brands you might find one that is close to your goal of .470. If you do, buy a bunch of it.

Good Luck

Ray

GCF,

Here is my saga with undersized 25-06 brass:

Recent rebarrel now with brass bulge

I have loaded the pictured Winchester brass about 5 times now without incident.

I recently started a new batch of Remington brass. Despite very simular sizes, I do not get bulge.

quote:

Originally posted by jtinidaho:
GCF,

Here is my saga with undersized 25-06 brass:

Recent rebarrel now with brass bulge

I have loaded the pictured Winchester brass about 5 times now without incident.

I recently started a new batch of Remington brass. Despite very simular sizes, I do not get bulge.

JT -
Thanks for throwing in on this, but how in the heck did you get pictures of MY brass??

You mention that you have loaded this brass 5 times now. Did you go to neck sizing, or continue FL sizing.

Also, w/ your new RP brass, have you made any changes to your standard load that would account for reduced pressure?

I'm trying to find some .469 - .470 brass, but it ain't looking good. Also thought I'd switch from the IMR4831 to a slower powder such as RL22, as a possible work around.

I'm also wondering how much effect seating depth, might have. I seat Nosler BT's (100 & 115)at the same depth as WW Supreme BT cartridges, that group well in this rifle - 3.185"

GCF,

I do the partial full length resizing thing, just bumping the shoulder back a bit.

Closer inspection of the once fired Remington brass reveals just a slight bulge at the web, nowhere near as bad as the Winchester, which continue to shoot fine.

I did most of the load development with the Winchester brass and the Remington brass recieved the worked out load. All powder charges were well within published data. My final load is 52 gr. RL19 with a 100 gr. Barnes TSX. I haven't chrono'd it yet but it is in the middle of the range as far as Barnes data goes (~3,100 fps MV). Ran up the scale with the Winchester brass trying 110 gr. Nosler AB's with IMR4350 and RL 19 but couldn't get very good groups. I also ran it up the scale using the same powders and 85 gr. BT's, with adequate accuracy. The 100 gr. TSX shot extremely well and will fulfill all the needs for this rifle (coyote, deer, antelope). But, yes, the Winchester brass has seen higher pressures than the Remington brass.

As for seating depth...all the AB and BT loads where .03" off the lands and the TSX loads are all .05" from the lands.

The only brass I have found in 25-06 is either Winchester or Remington. Both of which are undersized in my chanber. If you are dead set on finding some .469-.470" brass, I would suggest finding some 30-06 brass with that spec and necking them down in your resizing die and then trimming.

I don't know why no one has mentioned this, but has anyone considered that the so-called under spec brass is actually not under spec? SAAMI has a maximum and mimimum spec forthe chamber of rifles and handguns for that matter. cartridges that may seem to be under spec also have to be able to fit in a minimum chamber as well. Without having the particulr max and min specs for the 25-06 round on hand, I'd have to venture a guess that most likely that brass really is within specs.
Paul B.

Paul

That's exactly waht I was trying to say in my first post. I guess my wording wasn't as clear as yours.

I don't have SAAMI drawings but I have several of the CIP drawings which is the European version. They have only min chamber and max cartridge dimensions. I don't think I've ever seen a min cartridge number anywhere.

I believe that the max cartridge SAAMI dimension for the '06 is .470. The CIP max cartridge is 11.96mm. That's why you will see that number in most loading manuals and on most drawings. It's also why you will probably not find any brass that measures that big.

Ray

All points well taken.

I think what we have here is ammo manufacturers producing min SAAMI spec brass, that will work w/ Legal Dept. approved factory ammo - and fit in any factory rifle.

The thing that hacks me off, is that up until a few years ago at least, it was possible to find brass that was closer in size, to what (at least in my opinion) it should be.

I'll again offer the example of my Lapua .308 brass, w/ .470" case head diameter.

At the risk of repeating myself, SAAMI does not have a minimum cartridge spec. The size of any brass case is determined by the manufacturer. And as GCF hinted, they are not going to make any case that is so undersize to be potentially dangerous.

While it may seem that cases have gotten smaller, it's not necessarily true. I measured some 30-06 cases going all the way back to the 1930s and most of them measured .465 to .466 at the base. The largest (and there were very few of them) measured only .468.

Today's LAPUA cases do seem to run higher than those in the USA, but .468 is probably the largest you will find. I would guess it has a lot to do with the CIP max cartridge spec being higher than SAAMI.

GCF's 308 brass with a .470 case head would be the biggest I have ever seen. My 243W Lapua brass measures only .468.

As I said earlier, the best way around all of this is a barrel with a custom chamber. Or, simply ignore that bulge. It's normal and won't hurt a thing.

JMHO

Ray

quote:

Originally posted by Cheechako:
Ray

PM sent. roger

Hey guys

It's .468

I corrected my post. One time is a typo. Twice is a screw-up. But three times!

Lucky for me that Roger was reading it.

Ray

quote:

Originally posted by Cheechako:
...Lucky for me that Roger was reading it.

Ray

A little off line reminder is the sign of a true gentleman. Ya know, the sort of guy who diplomatically takes you ASIDE from the crowd - to mention that your fly is open...
;=]