338-06 issues

[bigbrowndog]

I just took 3 of the sized cases that fed easily without bullets, placed bullets in them and purposely seated the bullets 1/10" further out than what the others were loaded at,......they fed with no change in resistance from having no bullets. This confirms for me that bullet contact is not taking place with the loaded rounds.
I still believe my problems stem from brass size or oversize,.... somewhere???
The load I'm using is 53.2 gr of powder and Hornady manual states 57.1gr is max, so again I do not think pressure is the issue.

Trapr

[Paden]

Well, I'm stumped. If a piece of sized brass chambers easily before being loaded, but offers resistance after being loaded, it has to be either bullet contact with the lands, or a neck dimension conflict. No other brass dimension should be changed as a result of filling the case with powder and stuffing a bullet on top of it.

[sixshot]

Is your seating die too close to your shell holder, that can cause a problem by bumping the shoulder out a bit. You might try backing the seating die off a full turn & see if that makes a difference. Had a couple of young guys show up here a couple years back with that problem & I could feel the difference as soon as they handed me the loaded case.

Dick

[Paden]

Hadn't thought of that. Seating die should gently cradle and align the brass, but shouldn't apply any downward pressure to the shoulder at all if properly adjusted. You can, without unlocking the ring, back the seat die off, put a prepped brass on the ram and run it up to TDC, then very gently screw the die down until you feel it just barely kiss the brass and back off half a turn, and see where you should be relative to where you have been. If the die kisses the cartridge before the lock ring bottoms out, you were too tight.

Have to admit, I've forgotten about this in the past too. Not long ago, I crushed the hell out of a couple 6.5x55 cases in a seat die before I got my head right.

[bradshaw]

bigbrowndog....
Details which may condemn this .338-06 chamber:
* "Neck diameter with bullet seated .361-inch.
Neck diameter, fired .369-inch.

Neck expansion of .008” on firing predisposes case neck to splitting; certainly condemn case to a short reloading life. May not adversely affect hunting accuracy, especially with flat base bullets.

* “Circular tool marks on fired case...”

Indicates rough chamber job, regardless of dimensions.

Good idea to do a Cerrosafe chamber cast. The casting should easily push out of the chamber. If it does not and you have to drive it out, look carefully for abrasion of Cerrosafe. To sort out problems requires a process of elimination. Right now, fingers point at the chamber. Also, check headspace if possible, and check for bolt setback. Hard bolt lift may indicate peening of locking lug abutments in receiver ring, although your notes don’t point in this direction.
David Bradshaw

[bigbrowndog]

David, I had noticed the difference in the neck diam. Measurements but wasn't sure if chamber dimensions and round dimensions would differ that amount normally.
The .369 measurement appears to be correct for the cartridge, so It does make me wonder if it's the dies???

I will also reset the seating die, and check for contact there.

Trapr

[bigbrowndog]

Perhaps it time to purchase another set of dies, or send these back.  At the time of collecting reloading supplies Lee dies were the only ones available "new".  I much prefer RCBS or Redding, so maybe my insistence of purchasing quickly has bitten me in the arse???
Paden, could you provide a neck diam. measurement from your loaded ammo or a sized case??
ill lay my hands on a go and no go gauge,  as well as make arrangements for cerrosafeing the chamber.
Trapr

[bigbrowndog]

I took some 338WM brass and sized it then measured neck diameter, as well as measuring previously loaded ammo, neck diam. It measures..........361to .360 without a bullet and .363 to .364 with a bullet.
So perhaps, this is a normal neck diam. measurement for a sized case?

Trapr

[bushog]

Put black sharpie all over the bullet and let it dry before chambering to see if you get rifling marks on it.

[Paden]

Nov 14, 2016 11:08:58 GMT -5 bigbrowndog said:

Paden, could you provide a neck diam. measurement from your loaded ammo or a sized case??

Winchester 30-06 brass necked up to 338-06, once fired, neck sized and reloaded with 210 Barnes TSX = 0.363

[bigbrowndog]

Thanks, Paden......I got Saami spec drawings of cartridge and chamber specs, without doing the cerrosafe casting it looks like the dies may be working the case a bit too much. I'll do the cerrosafe to verify what the chamber looks like.

Thanks, Trapr

[Paden]

I actually have the ability to measure my chamber neck as well... It runs 0.377 just above the shoulder, and tapers to 0.373 toward the throat. That's a direct measurement, not from a cerrosafe cast.

Additional trivia: I don't know who manufactured the reamer that was used to cut my chamber, but I can say it was purchased and used by my smith during the period of time when A-Square had recently begun producing 338-06 ammunition with their name on it (and had a reputation for poor quality control/dimensional consistency), but before they got SAAMI to standardize specs with their name attached. So, I consider mine an "original" real 338-06, and not a "338-06 A-Square". And for whatever it's worth, my FL Redding die purchased about the same time, measures as if cut by the very same reamer which cut my chamber; it's a dead match.

[bigbrowndog]

I prepped 6 cases of the A-square brass, 6 of the RP that chambered easily, and 6 of the RP that chambered with effort. All the while taking measurements of neck diam., shoulder datum line, and shoulder diam.
There were 2 cases from the easy group that after sizing the shoulder datum line was .002 and.003 taller off the base than all the others, all other cases from all three groups were within .001 plus or minus. Yet the taller datum line cases chambered with the same perceived effort as the other easy group cases???
The shoulder diameter of all the cases except the new unfireformed A-square cases measured .440 to .441.
Neck diameter of the A-square cases was .362, and all the fire formed cases measured .359 all without bullets.
I also measured fired neck diameters compared to loaded neck diameters of various caliber I had on hand to see if the jump from .361 to .369 was a normal jump, .008 .
My various 30's and 35's measured less difference, the jump was closer to .005 or .006 for everything from target precision rifle chambers to factory chambers.
I think the A-square brass may be the answer, but loading and firing that brass and re measuring will provide more info.

Trapr

[bigbrowndog]

In an effort to close this topic,.....I fired the 3 sets of six cases that were loaded. All of the fire formed R/P cases either required more than normal effort to extract or needed to be forcibly removed with a cleaning rod. The A-square cases went into the chamber easily and were extracted easily?? The only thing I can think of is that the extra .003 needed to seal the neck upon firing was enough to cause the cases to stick. The neck diameter measurement was the only thing really off between the cases, .361 vs .364 for loaded neck diameter, and .359 vs .362 unloaded diameter. The neck walls of the R/P brass were thinner, perhaps too thin for a good seal to the chamber.

It looks like I'll be putting the R/P brass in the recycling bin, and using the A-square from now on.

Trapr

[Paden]

Weird. I wonder if the RP brass is too soft (bad batch(?)). What's your load/bullet/primer?