Unique and the 32 spl.

[RU shooter]

Can someone tell me what the max load is for the 32 spl. using the RCBS 170 and Unique?. Ive been shooting 10 gr with so so results, so I slowly worked up to 12.0 and accuracy was excellent with no pressure sighs .Just wondering how much more if any I could go or am I already over listed data.


Thanks,Tim

[Rico1950]

The RCBS Cast Bullet Manual #1 (and only). lists 10.5 grains of Unique as max.
8.5 Unique 1191
10.5 Unique 1468
Win. 94
20" bbl.
1-16 twist

[Rocky Raab]

The Lyman #3 Cast manual shows max of 10.6 (1550 fps, 35,700 CUP). I use Unique only with the 100 Speer Plinker half-jacket in the 30-30, and even with that bullet, I stop at 10 grains.

Except for very reduced loads, I use nothing faster than 2400 in the 30-30 with cast bullets; 16.0 is a great load with that 170-gr bullet.

There is no significant difference between the 30-30 and 32 Special with these loads, except that there are more loads and bullets listed for the 30-30.

[RU shooter]

Eeeek! I guess I will need to back off or find a different load. I never would have thought it would be almost 2 grs over published data as the primers looked fine with still rounded edges and no other signs of excess pressure in that carbine. A shame though since it shot the best groups by a good margin of any load I have tried so far.
Thanks for the help.


Tim

[Papa smurf]

Hay RU shooter-----Rocky Raab is on the money with the 30-30 and 32Spl are all the same or darn near. I load 10.2gr Unique for 1400fps in my 30-30 with 170gr Lee. Also 20.5 gr IMR 4198 for 1710fps and 23.0 gr IMR 4895 for 1550 fps . You may want to try the last two powders at the amounts I list in your 32 Spl.
Good Shooting----------------Papa Smurf

[madsenshooter]

Eeeek! I guess I will need to back off or find a different load. I never would have thought it would be almost 2 grs over published data as the primers looked fine with still rounded edges and no other signs of excess pressure in that carbine. A shame though since it shot the best groups by a good margin of any load I have tried so far.
Thanks for the help.


Tim

Each rifle is an entity onto itself when it comes to a max load. If you're not seeing any pressure signs at the 12gr level and it shoots good, I'd go with it. There would be some difference between the expansion ration of a .308 bore vs a .321 bore, maybe enough to allow the 2gr difference. In fact, my old 3rd ed Hornady manual shows a 1-2 gr difference in the max loads of various powders between the 30-30 and 32 Win with the same weight bullet going the same velocity.

[Bass Ackward]

I have an older Lyman manual that lists 12 grains max with that bullet weight, but not that slug.


Personally, I would .... search for another way to determine pressure besides observation on a case like this in an older firearm. Pick up a set of mics.

[madsenshooter]

An excellent suggestion Bass Ackward. Expansion of the solid portion of the casehead is a much more reliable method of pressure estimation than observations of primer condition, though it would still be an estimate due to varying hardness of cases used. A blade type micrometer would be best, and new cases should be used as fired cases have been worked and thus hardened. Maximum expansion of the casehead in a low pressure cartridge such as the 30/30 and 32 Win Spc should be .0003" to .0004". That's ten thousandths, not thousandths, just wanted to make sure everyone noted the number of zeros.