Sherman Wildcat Reloading Data is Here!!!

[lpr3]

Just wanted to add a little more info:

6.5 SST
ADG Headstamped Virgin Brass
24" barrel / suppressed
Fed215
Berger 140 Hybrid
N565 60.3 - 60.5 right around 3000fps
3050fps starting showing slight pressure signs but its a new barrel and suppressed.

 

[Idaho Trecker]

It's been a busy fall so I got behind on adding data to the PDF. I appreciate the PM's with data. Keep it coming.
Updated today with 25sst, 6.5ss, 6.5sst, 338 max, and 338ss.
Thanks

 

[elkaholic]

It's been a busy fall so I got behind on adding data to the PDF. I appreciate the PM's with data. Keep it coming.
Updated today with 25sst, 6.5ss, 6.5sst, 338 max, and 338ss.
Thanks

Good job Ryan!

 

[elkaholic]

This might be a good place to mention that folks are getting false pressure readings at lower than max from firing heavy loads on Virgin brass. (x marks etc) You may want to cut back a little on the first firing even on the sst until the taper is blown out.

 

[Rhovee]

That's fire forming 101. Slight crush on close. Jam .015. Reduce powder. I usually go about 3-5 grains less than I shoot once formed. The walls have nothing to grab when taking taper out. It would be equal to shooting a case with water or lube still on it.

 

[elkaholic]

That's fire forming 101. Slight crush on close. Jam .015. Reduce powder. I usually go about 3-5 grains less than I shoot once formed. The walls have nothing to grab when taking taper out. It would be equal to shooting a case with water or lube still on it.

Thats a good way to put it and is why the Sherman cases perform better. LOW BODY TAPER GRIPS THE SIDEWALL REDUCING BOLT THRUST.
but not until its formed

 

[tdot]

This might be a good place to mention that folks are getting false pressure readings at lower than max from firing heavy loads on Virgin brass. (x marks etc) You may want to cut back a little on the first firing even on the sst until the taper is blown out.

I ended up backing off 8 grains from where I was expecting to see a max load. Too many pressure signs above that. Even at 8 grains I was seeing a heavily flattened primer, which I attributed to a primer seating issue from the CoAx press. But end result is that even the 2nd firing of the cases struggled to consistently reach high pressure. 3rd firing seems to be holding pressure better.

 

[elkaholic]

I ended up backing off 8 grains from where I was expecting to see a max load. Too many pressure signs above that. Even at 8 grains I was seeing a heavily flattened primer, which I attributed to a primer seating issue from the CoAx press. But end result is that even the 2nd firing of the cases struggled to consistently reach high pressure. 3rd firing seems to be holding pressure better.

8 grains is a Buttload!!!!

 

[Rhovee]

I ended up backing off 8 grains from where I was expecting to see a max load. Too many pressure signs above that. Even at 8 grains I was seeing a heavily flattened primer, which I attributed to a primer seating issue from the CoAx press. But end result is that even the 2nd firing of the cases struggled to consistently reach high pressure. 3rd firing seems to be holding pressure better.

are you jamming bullets?

 

[tdot]

are you jamming bullets?

Yes. .010" jamb.

I pulled the gun apart to clean the chamber, lugs, bolt a 2nd time after breakin, to ensure there weren't oils present. Wiped cases down. Double and triple checked everything, thru the reloading process and kept getting the same results. I was getting a nice crisp shoulder and the cases were consistent. So I stopped trying to go higher.

Tried one at .020" jamb and it was identical as far as pressure signs and the datum points I could measure reliably, so I didnt bother reseating any more rounds.

Any other tips/suggestions? It definitely had me scratching my head and just couldnt obtain different results.

 

[Buska]

We'll have 25 sst head stamped brass in May with the next run. 7sst and 338 SS will also be added at that time.

Any plans on 270 brass? I just posted a thread a few minutes ago asking if anyone had tinkered with lighter bullets in the 270 Sherman. Rich do you have a velocity estimate for the 130 grainers in your 270 Sherman? You think 3500 range in a 26" barrel or is that way off base. It would be a fun point and shoot load to about 400 yards or so! 3700ish in the 110 monos?? What do you think

 

[elkaholic]

Any plans on 270 brass? I just posted a thread a few minutes ago asking if anyone had tinkered with lighter bullets in the 270 Sherman. Rich do you have a velocity estimate for the 130 grainers in your 270 Sherman? You think 3500 range in a 26" barrel or is that way off base. It would be a fun point and shoot load to about 400 yards or so! 3700ish in the 110 monos?? What do you think

I think at least 3400'. Might reach higher

 

[Buska]

I think at least 3400'. Might reach higher

Could someone shoot standard 270 win factory ammo through a "Shermanized" chamber like an AI? Same concept but more horse power right

 

[elkaholic]

Could someone shoot standard 270 win factory ammo through a "Shermanized" chamber like an AI? Same concept but more horse power right

You could not. The shoulder is moved forward and it wouldnt head space.