Page Index Toggle Pages: 1 Send TopicPrint
Hot Topic (More than 10 Replies) Need 32/40 bullet choice help (Read 1126 times)
SBoomer
Senior Forum Member
****
Offline



Posts: 374
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Need 32/40 bullet choice help
Mar 16th, 2019 at 8:50am
Print Post  
I pulled out my Stevens Tip Up New Model Range Rifle (No. 10), deciding that I need to shoot it. The chamber cast shows a slightly long 32/40 Win. chamber with a .313" groove. I am guessing that this might have been a rechambered 32/20, as the twist is 1:20". My question is what is the longest/heaviest bullet that this twist will stabilize at a lower velocity mode. Unfortunately, my range is only 100 yards long, so that is the limit of my shooting. Intent is breech seated offhand practice.
  
Back to top
 
IP Logged
 
Schuetzendave
Frequent Elocutionist
*****
Offline


Tune Your Rifle: Make
Her Sing

Posts: 3555
Location: St. Albert
Joined: Jan 28th, 2005
Re: Need 32/40 bullet choice help
Reply #1 - Mar 16th, 2019 at 11:55am
Print Post  
Gyroscopic Stability Factor (Sg):

Caliber      0.313      Inches            
Bullet Weight      84      Grains            
Bullet Length      0.52      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1400      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      2.51                  

Caliber      0.313      Inches            
Bullet Weight      100      Grains            
Bullet Length      0.619      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1400      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.92                  

Caliber      0.313      Inches            
Bullet Weight      120      Grains            
Bullet Length      0.743      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1400      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.42                  

Sg shouldn't be less than 1.4 (not spinning fast enough - use shorter bullet).  If Sg is greater than about 2.0 (overspinning bullet) you MAY gain some accuracy by going to a slower twist barrel or using a longer bullet.                        
  
Back to top
 
IP Logged
 
frnkeore
Frequent Elocutionist
*****
Offline



Posts: 6904
Location: Central Point, OR 97502
Joined: Jun 16th, 2010
Re: Need 32/40 bullet choice help
Reply #2 - Mar 16th, 2019 at 12:28pm
Print Post  
There are 3 common Lyman molds that will work for your twist rate but, may cast slightly small.

3118 or 311008

311359

311410

If they cast a little small, you can ream the base band or GC area, to .315 - .316 and it will cast .314 on the base band and shoot well.

I did this for my 8.15 x 46R rifle, using a 311413, that cast .314. My groove was .315 and I reamed the GC area, to cast .316. I've shot many 3/4" groups with that rifle/bullet combination @ 100 yd.

The only other easy option, is 32 pistol bullets, in WC and SWC. I've never seen that type bullet produce accuracy at 100 yards and beyond.

Frank
  

ASSRA Member #696, ISSA Member #339
Back to top
YIMAIM  
IP Logged
 
SBoomer
Senior Forum Member
****
Offline



Posts: 374
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Need 32/40 bullet choice help
Reply #3 - Mar 16th, 2019 at 2:13pm
Print Post  
Thanx for the input guys.
About a year ago, I ordered a dual cavity Accurate mold in a modified 31-125C and 31-125M. My hope was that this rifle would handle the 125gr bullets. A while back while casting, I cast up a bunch of the 31-125C and pan lubed with Pope lube. I was very happy to see perfectly stable bullets at 100yds today. Believe it or not, this group was shot with a buttstock fully broke in half at the wrist and only held together with the rear tang screw. It felt like I had a garden hose in the rest. There was only faint visible rifling lat the muzzle so I pushed the muzzle back 3/8" and recrowned with an 11deg. Cast showed excellent rifling now. The rest of the bore and chamber look new. Fun day!
  
Back to top
 
IP Logged
 
SBoomer
Senior Forum Member
****
Offline



Posts: 374
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Need 32/40 bullet choice help
Reply #4 - Mar 16th, 2019 at 2:23pm
Print Post  
Dave,
Bullet length shown is .694". I was going to modify an Accurate 150gr design, but now think I may just be happy with the 125gr. Mods being tapered bands to suit breechseating as were the 31-125's.
  
Back to top
 
IP Logged
 
Schuetzendave
Frequent Elocutionist
*****
Offline


Tune Your Rifle: Make
Her Sing

Posts: 3555
Location: St. Albert
Joined: Jan 28th, 2005
Re: Need 32/40 bullet choice help
Reply #5 - Mar 16th, 2019 at 6:03pm
Print Post  
Bullets above were round nosed and longer than flat nose versions of the same weight.

For your flat nose 125 grain:

Caliber      0.313      Inches            
Bullet Weight      125      Grains            
Bullet Length      0.694      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1400      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.78                  

Projections for a 150 grain flat nose:

Caliber      0.313      Inches            
Bullet Weight      150      Grains            
Bullet Length      0.833      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1400      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.30                  
  
Back to top
 
IP Logged
 
SBoomer
Senior Forum Member
****
Offline



Posts: 374
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Need 32/40 bullet choice help
Reply #6 - Mar 16th, 2019 at 7:47pm
Print Post  
So a 150gr at .805" long might be a decent option? I was thinking of having the gas check removed off this design and then tapering lands for breechseating.
  
Back to top
 
IP Logged
 
argie1891
Full Member
***
Offline



Posts: 220
Location: selah, washington
Joined: Jul 8th, 2010
Re: Need 32/40 bullet choice help
Reply #7 - Mar 17th, 2019 at 2:12am
Print Post  
I have a Ubirti in 32-20 with a 1 in 20 twist. it will stabilize a 140 gr. bullet I bought the mould from accurate moulds. cant remember the exact mould number. it is a flat point and shoots well. That said the lyman 3118 shoots the best and most consistent.
  

if you need me i will be at the range
Back to top
 
IP Logged
 
Schuetzendave
Frequent Elocutionist
*****
Offline


Tune Your Rifle: Make
Her Sing

Posts: 3555
Location: St. Albert
Joined: Jan 28th, 2005
Re: Need 32/40 bullet choice help
Reply #8 - Mar 17th, 2019 at 6:25am
Print Post  
Caliber      0.313      Inches            
Bullet Weight      150      Grains            
Bullet Length      0.805      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1400      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.43                  

Caliber      0.313      Inches            
Bullet Weight      150      Grains            
Bullet Length      0.805      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1200      fps            
Temperature      50      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.36                  

Caliber      0.313      Inches            
Bullet Weight      150      Grains            
Bullet Length      0.805      Inches            
Barrel Twist      20      Inches/turn            
muzzle velocity      1400      fps            
Temperature      32      degrees Fahrenheit (59 is standard)            
Pressure      29.92      inches of mercury (29.92 is standard)            
                       
Sg =      1.38      

The 150 grain bullet would be at the edge at normal conditions; but would fall below 1.4 if you reduced velocity, if the temperature dropped, or if you had a high pressure system - and more so if you had a combination of these conditions.

A 140 grain flat nose would probably be the heaviest bullet you could use wisely.
« Last Edit: Mar 17th, 2019 at 6:33am by Schuetzendave »  
Back to top
 
IP Logged
 
SBoomer
Senior Forum Member
****
Offline



Posts: 374
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Need 32/40 bullet choice help
Reply #9 - Mar 17th, 2019 at 8:56am
Print Post  
Thanx for the added info Dave, I really appreciate the help. I will look at something around 140gr. in the near future. Going to shoot some more with the 125's today after it warms up. Its -7 right now Huh
« Last Edit: Mar 17th, 2019 at 11:12am by SBoomer »  
Back to top
 
IP Logged
 
SBoomer
Senior Forum Member
****
Offline



Posts: 374
Location: Michigan's Frozen North (U.P.)
Joined: Jan 28th, 2010
Re: Need 32/40 bullet choice help
Reply #10 - Mar 31st, 2019 at 5:20pm
Print Post  
For anyone looking for light bullet 32-40 loads, below are the results of todays chrono work. Stevens Tip-Up New Model Range Rifle. 32/40 with .313" groove. 28" bbl. 1:20" twist. Accurate Molds bullets 31-125C & 31-125M. Cast at 122gr. in 17:1. Pan lubed with a modified Pope Lube. I used Gredag in addition to the graphite. Breechseated. Same case. Rem 9 1/2 primers in all loads listed. Unless noted, velocities are the avg. of 5 shots.

31-125C   14.0/Re7       1432fps
31-125M   14.0/Re7       1410
31-125C    15.0/Re7       1467

31-125M   11.5/4227   1352fps
31-125M   12/4227      1428
31-125M   12.5/4227   1493
31-125M   13.0/4227    1519
31-125C    12.5/4227   1465

31-125C     9.5/2400     1402fps
31-125M     9.5/2400     1407
31-125C     10.0/2400    1466

31-125C     9.0/AA9        1398fps (10)shot SD 13
31-125C     9.5/AA9        1474fps (10)shot SD 18
31-125M     9.5/AA9        1458



« Last Edit: Mar 31st, 2019 at 10:00pm by SBoomer »  
Back to top
 
IP Logged
 
Page Index Toggle Pages: 1
Send TopicPrint