338 SS split dies and fired ADG brass measuring .006 at the web

[lancetkenyon]

I only know of two dies cracking. Both were Hornady dies.

One was unknown reasons, as I know the shooter, and he is a world class F Class shooter, so I can't see any user error on his behalf.

The other was definitely user error. He did not set up the die correctly and was camming over the ram and shell holder way too much and cracked the die body.

You failed to give any load data or testing info, so hard for me to guess the culprit of anything.

 

[MAD10]

I only know of two dies cracking. Both were Hornady dies.

One was unknown reasons, as I know the shooter, and he is a world class F Class shooter, so I can't see any user error on his behalf.

The other was definitely user error. He did not set up the die correctly and was camming over the ram and shell holder way too much and cracked the die body.

You failed to give any load data or testing info, so hard for me to guess the culprit of anything.

Thanks Lance … I'm being vague simply because I want to learn how many guys have split dies specific to the 338 SS and have seen .006 expansion on the 338 SS ADG brass while following normal reloading procedures and known load data.

 

[lancetkenyon]

Thanks Lance … I'm being vague simply because I want to learn how many guys have split dies specific to the 338 SS and have seen .006 expansion on the 338 SS ADG brass while following normal reloading procedures and known load data.

"Known load data" varies greatly. What works for one rifle might not work for another. Too many variables.

A tight spot in a barrel will show early pressure long before it should. I had a tight spot in a 26" 6.5mm Proof, and it would pressure out way before it should. I had a 20" chambered in the same cartridge by the same gunsmith with the same reamer with a different Proof with the same groove count and twist rate, and could get another 5gr of powder safely without pressure and more velocity than the 26" with the tight spot would allow.

I pulled the 26" Proof 5R 1:7.5" that had the tight spot and installed a new 26" 5R 1:7.5" Bartlein and with my max loads in the old barrel, gained 60fps with a brand new barrel with 0 rounds down it. Upped the powder charge slowly to where the 20" was shooting, and gained over 200fps over the 26" Proof load.

I also have a slow Proof 7mm on another rifle. My max speeds are a good 100+fps slower than a lot of other load data in the same cartridge with identical components. Stupid accurate, but way slow. And it is not the powder lot causing it. I have tried 4 powders. All are consistently slow. So I deal with it for the accuracy I am getting.

 

[Phil Rizzo]

I have been there myself. Unfortunately.
Proof Research replaced mine, after I fired too many rounds trying to force it.
A most appreciated gesture, on their behalf, though.
Not picking on Proof here, I've had slow barrels from other manufacturers.
Including one that mic'ed WELL under spec.

 

[MAD10]

"Known load data" varies greatly. What works for one rifle might not work for another. Too many variables.

A tight spot in a barrel will show early pressure long before it should. I had a tight spot in a 26" 6.5mm Proof, and it would pressure out way before it should. I had a 20" chambered in the same cartridge by the same gunsmith with the same reamer with a different Proof with the same groove count and twist rate, and could get another 5gr of powder safely without pressure and more velocity than the 26" with the tight spot would allow.

I pulled the 26" Proof 5R 1:7.5" that had the tight spot and installed a new 26" 5R 1:7.5" Bartlein and with my max loads in the old barrel, gained 60fps with a brand new barrel with 0 rounds down it. Upped the powder charge slowly to where the 20" was shooting, and gained over 200fps over the 26" Proof load.

I also have a slow Proof 7mm on another rifle. My max speeds are a good 100+fps slower than a lot of other load data in the same cartridge with identical components. Stupid accurate, but way slow. And it is not the powder lot causing it. I have tried 4 powders. All are consistently slow. So I deal with it for the accuracy I am getting.

Yeah I'm with ya on what you've experienced …

I had the barrel bore slugged the entire 22" to confirm if it had any tight spots causing pressure - no issues

Then had the action inspected by Zermatt to ensure proper fit with barrel and bolt face ( head space) - passed with flying colors

Had a third party measure the "B" reamer and chamber with their very high end equipment … about as perfect with respect to machining a gun smith can get when comparing the fired brass against both.

I'm getting the velocities I want in a 22" barrel ie 2700- 2800 and beyond 54-58 grains of Varget at 7,000 ft but even at 2600 fps I'm getting .006 expansion at the web and in turn cracking dies because of it in the resizing process

I did a lot of research and spoke with Rich at length no reason I can't get 2750 without pressure running 230 ELDXs in a 22" barrel.

 

[lancetkenyon]

What brand barrel?
Did they measure the actual bore diameter?

230 @ 2750-2800 in a 22" from a .338SS sounds like a fairly tall order in my opinion. But I don't run my stuff on the edge of pressure usually. Give me accuracy over raw speed all day long.

I have several Shermans. None are run at max. And none have given me troubles.
26" 25SST 133 Elite @ 3240 w. H1000
22" 25PRC/SI 133 Elite @ 3170 w. RL23
20" 6.5SS 130 OTM @ 3084 w. RL23
26" 6.5SS 156 Elite @ 3034 w. H1000
25" 6.5SS 140 Hyb @ 3190 w. RL26 (sold to a buddy)
26" 6.5SS 156 Elite @ 2930 w. H1000 (had a tight spot in the Proof barrel that pressured early, so I pulled it)
22" 6.5PRC/SI 140 Elite @ 3100 w. RL23
24" 7SS 184 Hyb @ 2886 w. N565 or 2835 w. H1000

I have shot probably 30 other Shermans in one chambering or another. Again, no issues on them either.

You might just have a one-off issue.

 

[Beluebow]

I want to learn how many guys have split dies specific to the 338 SS and have seen .006 expansion on the 338 SS ADG brass while following normal reloading procedures and known load data.

I've seen plenty of RCBS small base dies split, specifically 284SB dies. No help with 338SS.

How much bolt nose clearance do you have? Plastigage is your friend.

 

[MAD10]

What brand barrel?
Did they measure the actual bore diameter?

230 @ 2750-2800 in a 22" from a .338SS sounds like a fairly tall order in my opinion. But I don't run my stuff on the edge of pressure usually. Give me accuracy over raw speed all day long.

I have several Shermans. None are run at max. And none have given me troubles.
26" 25SST 133 Elite @ 3240 w. H1000
22" 25PRC/SI 133 Elite @ 3170 w. RL23
20" 6.5SS 130 OTM @ 3084 w. RL23
26" 6.5SS 156 Elite @ 3034 w. H1000
25" 6.5SS 140 Hyb @ 3190 w. RL26 (sold to a buddy)
26" 6.5SS 156 Elite @ 2930 w. H1000 (had a tight spot in the Proof barrel that pressured early, so I pulled it)
22" 6.5PRC/SI 140 Elite @ 3100 w. RL23
24" 7SS 184 Hyb @ 2886 w. N565 or 2835 w. H1000

I have shot probably 30 other Shermans in one chambering or another. Again, no issues on them either.

You might just have a one-off issue.

I made my decision off of numerous posts including Rich talking directly to me on a 22" barrel and the 338 SS

Preferred barrels and yes they measured the bore it met tolerance…I'm told the industry term is "slugging the barrel" where they use a specific diameter slug and send it through the bore looking for abnormalities or tight spots

 

[tim_w]

I have used gauge pins many times to get check the minimal bore diameter as a quick check. I can not tell you how many times in building customer ARs, where they sent me barrels, that the minimum gauge pin would not pass thru. Getting stuck at certain points when passed from muzzle or breech. Indicating a fluctuating bore size.

The issue with using a gauge pin is it only measures the bore not the groove diameter. For that to get the minimum of the entire length you need to pour a lead slug and then push it thru the remaining bore. The issue there is if you are not careful how you push the slug or it does not use a ball bearing rod that spins the force can obutrate the slug hiding the tight spot. You can many times feel it as the force needed changes. If the groove is consistent and tight its easier.

Some of the soft turned copper bullets with the multiple pressure bands can be soft enough to manually push thru the entire bore with a dowel rod. I use to use gs customs hv bullets for this as they were soft and small bearing surface bands. They tend to hold their size once engraved and sized to the groove as well.

When they slugged the barrel was it a poured lead slug or a gauge pin?

0.006 is such an extreme amount of web growth for an ADG 65k mag case pressure has to be quite up there. I can see why your scratching your head on what's causing the issue. That would frustrate me as well even more so cracking custom dies.

I figure you have already considered it but have you been using the same lot of powder? Maybe an off batch? Measured bullet diameter etc



@lancekenyon,

I personally stopped using proof barrels a number of yrs ago for that very reason. Just not worth the chance and then the time and cost of fitting a new barrel.

 

[MAD10]

I have used gauge pins many times to get check the minimal bore diameter as a quick check. I can not tell you how many times in building customer ARs, where they sent me barrels, that the minimum gauge pin would not pass thru. Getting stuck at certain points when passed from muzzle or breech. Indicating a fluctuating bore size.

The issue with using a gauge pin is it only measures the bore not the groove diameter. For that to get the minimum of the entire length you need to pour a lead slug and then push it thru the remaining bore. The issue there is if you are not careful how you push the slug or it does not use a ball bearing rod that spins the force can obutrate the slug hiding the tight spot. You can many times feel it as the force needed changes. If the groove is consistent and tight its easier.

Some of the soft turned copper bullets with the multiple pressure bands can be soft enough to manually push thru the entire bore with a dowel rod. I use to use gs customs hv bullets for this as they were soft and small bearing surface bands. They tend to hold their size once engraved and sized to the groove as well.

When they slugged the barrel was it a poured lead slug or a gauge pin?

0.006 is such an extreme amount of web growth for an ADG 65k mag case pressure has to be quite up there. I can see why your scratching your head on what's causing the issue. That would frustrate me as well even more so cracking custom dies.

I figure you have already considered it but have you been using the same lot of powder? Maybe an off batch? Measured bullet diameter etc



@lancekenyon,

I personally stopped using proof barrels a number of yrs ago for that very reason. Just not worth the chance and then the time and cost of fitting a new barrel.

 

[MAD10]

Tim you have said all that has gone through my mind and discussed with many of the experts I consulted.

I'm gonna have a third party confirm the bore is in tolerance and not just take the manufacturers word for it especially when nothing else has been discovered.

Derek the new owner of sherman wildcats wants my rifle to run some brass tests between various ADG lots and a few other things knowing very precise machines have already inspected the reamer chamber and fired brass

It's definitely a puzzle

I'll post when I learn something new

Appreciate your time and effort

 

[tim_w]

I sure hope it works out for you. Having to deal with the time and cost to refit a new barrel sucks. But you do this long enough it will happen.

I can tell you a properly functioning 338 be it an SS or my mega gets it done with authority on any NA game. Its going on my east coast Candaian moose black bear hunt this winter.

I wish I could use varget like you do on the SS with the mega as its such a great powder and can find it. The best powders for the mega are the unobtainium RL26 and then N560 for vel.

Again, good luck, sorry I could not be of more help to you.

 

[Lefty7mmstw]

Dang, the only time I split a die was when I had a m700 in 7rum with a fat chamber. I zipped open a RCBS AND a Redding sizing die, then the gun shop took the rifle back... It's been around 20 years since I zipped a die open..

 

[lancetkenyon]

Obviously, if you are getting .006" expansion and cracking dies, something is wrong. Could be barrel (more than likely in my opinion), could be the chambering job (another huge possibility and still part of the barrel problem), could be reloading issues (I don't know you or your experience so don't take offence), could be a brass lot issue (but even then, to get that much expansion would still seem to be a chambering issue).

My suggestion: Bite the bullet and rebarrel. Buy another die. Call it a day and leave the frustration behind. Not worth it.

Or accept the fact you are not going to hit 2800fps in your configuration and load it lighter. I don't think any animal is going to know the difference between 2800fps and 2650fps MV when a 230gr .338" bullet freight trains them.