HuntingNut
HuntingNut
   Login or Register
HomeCommunity ForumsPhoto AlbumsRegister
     
 

User Info

Welcome Anonymous


Membership:
Latest: Bobbo68
New Today: 0
New Yesterday: 0
Overall: 12628

People Online:
Members: 0
Visitors: 117
BOT: 1
Total: 118
Who Is Where:
 Visitors:
01: Forums
02: Forums
03: Forums
04: Forums
05: Forums
06: Forums
07: Forums
08: Forums
09: Forums
10: Forums
11: Forums
12: Forums
13: Forums
14: Forums
15: Forums
16: Forums
17: Forums
18: Forums
19: Forums
20: Forums
21: Forums
22: Forums
23: Forums
24: Forums
25: Forums
26: Forums
27: Forums
28: Forums
29: Forums
30: Forums
31: Home
32: Forums
33: Forums
34: Forums
35: Forums
36: Forums
37: Forums
38: Forums
39: Forums
40: Forums
41: Forums
42: Forums
43: Forums
44: Forums
45: Home
46: Forums
47: Forums
48: Forums
49: Forums
50: Photo Albums
51: Forums
52: Forums
53: Forums
54: Forums
55: Forums
56: Forums
57: Forums
58: Forums
59: Forums
60: Home
61: Forums
62: Forums
63: Forums
64: Forums
65: Forums
66: Forums
67: Forums
68: Forums
69: Your Account
70: Forums
71: Forums
72: Forums
73: Forums
74: Forums
75: Forums
76: Forums
77: Forums
78: Forums
79: Forums
80: Forums
81: Forums
82: Forums
83: Forums
84: Photo Albums
85: Photo Albums
86: Forums
87: Forums
88: Forums
89: Photo Albums
90: Forums
91: Forums
92: Forums
93: Forums
94: Forums
95: Home
96: Forums
97: Home
98: Forums
99: Forums
100: Forums
101: Forums
102: Forums
103: Forums
104: Forums
105: Forums
106: Photo Albums
107: Forums
108: Forums
109: Photo Albums
110: Home
111: Forums
112: Forums
113: Forums
114: Forums
115: Forums
116: Forums
117: Forums
  BOT:
01: Forums

Staff Online:

No staff members are online!
 

Coppermine Stats
Photo Albums
 Albums: 305
 Pictures: 2362
  · Views: 459184
  · Votes: 1311
  · Comments: 86
 

Support our Advertisers

PC'ed bullets for the Mosin
Discussion regarding the reloading of ammunition and tuning of loads for accuracy
Go to page Previous  1, 2
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition

View previous topic :: View next topic  
Author Message
res45
Member
Member


Joined: Jul 09, 2007
Posts: 67
Location: China Grove North Carolina

PostPosted: Sun Feb 25, 2018 6:18 am    Post subject: Re: PC'ed bullets for the Mosin Reply with quote

Elvis wrote:
you got to be happy with that.....

I am, but I'm not done pushing the envelope. The original load using a similar weight jacketed bullet is 41.0 grs. of H4895 but I want ever get there as I will be pushing the cast bullet to fast to be stable / accurate at that velocity in a 1"10 twist bore.

However I should be able get up around 1900 to 2K fps. with good results so we will see how that goes on the next outing. I have to load up some test loads using 35.0 and 36.0 grs.
Back to top
View user's profile
slimjim
Super Member
Super Member


Joined: May 16, 2009
Posts: 7620
Location: Fort Worth TX

PostPosted: Tue Feb 27, 2018 4:36 am    Post subject: Re: PC'ed bullets for the Mosin Reply with quote

I wish all my loads grouped that well. I stop when I get one like that.

Better is the enemy of good enough.

_________________
"To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein
Back to top
View user's profile
res45
Member
Member


Joined: Jul 09, 2007
Posts: 67
Location: China Grove North Carolina

PostPosted: Thu Mar 01, 2018 8:42 pm    Post subject: Re: PC'ed bullets for the Mosin Reply with quote

slimjim wrote:
I wish all my loads grouped that well. I stop when I get one like that.

Better is the enemy of good enough.

That load will go in the load book for sure, I have to load up another batch of the same load both with traditional lube and my clear powder coat, 1. To see what the velocity of the load is and 2. to see which shoot the most accurately.

I still want to push the load up a couple grs. higher if possible, it really just depend on what the velocity of the 34 gr. load ends up being as eventually the velocity/RPM/stability threshold will meet and accuracy will go south.
Back to top
View user's profile
slimjim
Super Member
Super Member


Joined: May 16, 2009
Posts: 7620
Location: Fort Worth TX

PostPosted: Thu Mar 01, 2018 8:46 pm    Post subject: Re: PC'ed bullets for the Mosin Reply with quote

res45 wrote:
eventually the velocity/RPM/stability threshold will meet and accuracy will go south.

Do you have a formula for this?

_________________
"To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt

"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein
Back to top
View user's profile
res45
Member
Member


Joined: Jul 09, 2007
Posts: 67
Location: China Grove North Carolina

PostPosted: Sat Mar 03, 2018 10:22 am    Post subject: Re: PC'ed bullets for the Mosin Reply with quote

slimjim wrote:
res45 wrote:
eventually the velocity/RPM/stability threshold will meet and accuracy will go south.

Do you have a formula for this?

This article basically pertains to jacketed bullets, I'm sure you have heard on occasion where someone having bullets shot from an AR with fast twist barrels blew up the bullet before they barely made it no more than past the muzzle.

www.accurateshooter.co...stability/

As to cast lead bullets it's a whole different animal. This post by Larry Gibson who has done extensive test covers the main point. The subject has been argued back and forth on many forums but it's been my experience that it's more true than not. It not impossible to shoot cast lead bullets at factory jacketed bullet velocity but it requires using the right combination of bullet design, alloy hardness an good casting, proper powder and correct bore twist so that the forces imparted on the bullet by the velocity / twist rate ie RPM's doesn't accentuate the defects of the cast bullet and cause instability and tear it apart due to the weaker structure of the bullet.

Quote::
The RPM threshold is area of velocity where the RPM created by the twist accentuates the defects in cast bullets creating excessive yaw, wobble and pitch of the bullet during flight. Defects in cast bullets are caused by imbalance due to out of round casting, other casting defects, or unwanted obturation during acceleration. Exactly where that threshold is depends on numerous things but those that mostly affect the threshold are; burning rate of powder, quality of cast bullet, design of cast bullet, alloy, fit of bullet to throat/leade and twist of the rifling. I've found over the years that with normal commercial moulds generally available (what most of us use), casting quality bullets of WWs or harder, with proper lube and fit to the throat when using medium to slow burning powders the threshold is in the 125-140,000 RPM range. If we are using the old '06 with a 10" twist and 311291 then the threshold translates to somewhere between 1735 fps and 1944 fps we will find the best accuracy when using 4895 or a slower burning powder.

With a faster powder such as 2400 best accuracy will come at a little slower velocity as the faster powder has a faster acceleration. This means unwanted obturation will occur at lower velocity so accuracy will deteriorate quicker than when the medium/slower powders are used.

Quote::
The cast bullet bench rest boys really slow twists down which does help considerable. If one is building a special purpose cast bullet rifle then twist is of major importance. My 14" twist Palma barrel (27.5" long) in .308 Winchester shoots regular cast bullets (30-15--FN, 311291, 311041, 311299) with excellent accuracy in the 2400+ fps which is 125,000 RPM, right at the beginning of the threshold. Really, really best accuracy comes down in the 21-2200 fps range which is around the 110,000 RPM area Junior1942 talks about. Same bullets in my M70 target with 12" twist 26" barrel loose accuracy at the same RPM as the 14" twist barrel. My M788 with a 10" twist 22" barrel does exactly the same. With the 12" twist that is in the 21-2200 fps range and with the 10" twist it is in the 1740-1940 fps range.

I've found that most regular heavy for caliber cast bullets shot out of regular rifles shoot best in the 125-140,000 RPM range with medium to slow powders. One merely must know the twist of the rifle to figure what the velocity range for best accuracy will be.


Basically I have several know conclusions. With my current molds, alloys an casting techniques and powders putting together the best loads I can with the equipment I have I can pretty much match the above results in my 1:12 twist 30-30 an my 300 Sav. and all my 1:10 twist 30 cal rifles like my Mosin and SKS rifles.

Good article here as well goodsteelforum.com/for...-accuracy/
Back to top
View user's profile
Display posts from previous:   
Post new topic   Reply to topic   Printer Friendly Page    Forum Index » Reloading Ammunition
Page 2 of 2
All times are GMT - 7 Hours
Go to page Previous  1, 2



Jump to:  


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


Advertisements
 


Valid CSS! Valid HTML 4.01!
Click to check if this page is realy HTML 4.01 compliant for speed :)

All logos and trademarks in this site are property of HuntingNut.com.
The comments are property of their posters, all the rest © 2011 by HuntingNut.com
Interactive software released under GNU GPL, Code Credits, Privacy Policy

.: Upgraded to DragonFly 9.2 by Dizfunkshunal :.