AMT Guns forum

Forum Home Forum Home > Auto Mag Pistol > Pet loads
  New Posts New Posts RSS Feed - 41 JMP LOADING HELP NEEDED
  FAQ FAQ  Forum Search   Register Register  Login Login

41 JMP LOADING HELP NEEDED

 Post Reply Post Reply Page  123>
Author
Message
buckstix View Drop Down
180 Auto Mag
180 Auto Mag
Avatar

Joined: 09 Sep 2012
Location: Wis
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote buckstix Quote  Post ReplyReply Direct Link To This Post Topic: 41 JMP LOADING HELP NEEDED
    Posted: 23 Sep 2012 at 5:54pm
I just purchased an original unfired 6-1/2" Lee Jurras 41 JMP barrel and have a few reloading questions. 
 
Does anyone have any dimensions for the case?  It seems that the chamber of this barrel is a little deeper than I expected.  Any idea of variations throughout production?
 
I've formed a few cases and headspaced them off the shoulder and fired a nice 1-1/2" 25 yd group with 25.5g H110 w/ 170 JHP but they seemed a bit light and although they ejected, feeding was poor.
 
Any help would be appreciated.
"..You never pay too much for someting, you only buy it too early.."
Back to Top
Auto Mag View Drop Down
Callahan's Auto Mag
Callahan's Auto Mag
Avatar

Joined: 08 Mar 2008
Location: MA
Status: Offline
Points: 1662
Post Options Post Options   Thanks (0) Thanks(0)   Quote Auto Mag Quote  Post ReplyReply Direct Link To This Post Posted: 23 Sep 2012 at 6:35pm
Hummm,,,
 
Not 100% sure by any means, but I thought the 41 JMP headspaced against the case mouth not the shoulder???
 
LEJ what say you?
 
gh
Who was that masked man,,,
Back to Top
curmudgeon View Drop Down
Callahan's Auto Mag
Callahan's Auto Mag
Avatar

Joined: 08 Mar 2008
Location: hagerman,NM
Status: Offline
Points: 747
Post Options Post Options   Thanks (0) Thanks(0)   Quote curmudgeon Quote  Post ReplyReply Direct Link To This Post Posted: 23 Sep 2012 at 7:58pm
Shoulder, check magazine for rough follower or burrs on lip edges, then check feed ramp to chamber, have you cleaned inside magazine?
Back to Top
buckstix View Drop Down
180 Auto Mag
180 Auto Mag
Avatar

Joined: 09 Sep 2012
Location: Wis
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote buckstix Quote  Post ReplyReply Direct Link To This Post Posted: 23 Sep 2012 at 8:22pm
Oh yes, everything was checked.   The only reason I mention that there is a feeding issue is that I think the load is a bit light.  It seems to short-strokes the bolt, not grabing the next round and not locking open when shooting last shot.  I'm going to "up" the load 1/2 grain to 26.0 and try again. 
 
I haven't been able to locate ANY information on loads or case dimensions.  Can you point me in the right direction on these?
"..You never pay too much for someting, you only buy it too early.."
Back to Top
BEEMER1 View Drop Down
Callahan's Auto Mag
Callahan's Auto Mag
Avatar

Joined: 06 Jan 2010
Location: iowa
Status: Offline
Points: 616
Post Options Post Options   Thanks (0) Thanks(0)   Quote BEEMER1 Quote  Post ReplyReply Direct Link To This Post Posted: 24 Sep 2012 at 3:26pm
I have no idea on where to find load data or chamber drawings other than Lee or Bruce Stark.
 
If you have your fired brass you can measure these as that is your "true" chamber dimensions.  If no dies are available, they can make dies from these.
Back to Top
buckstix View Drop Down
180 Auto Mag
180 Auto Mag
Avatar

Joined: 09 Sep 2012
Location: Wis
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote buckstix Quote  Post ReplyReply Direct Link To This Post Posted: 24 Sep 2012 at 5:43pm
Well I've got a set of CH dies coming, so that's taken care of. 
 
I actually formed 5 cases with my RCBS 44AMT form dies, and swaged a 41 neck on these using 41 Rem Mag dies. 
 
Even with this Laborious seat-of-the-pants method, I was able to obtain a 1-1/2" 5-shot group at 25yds.   I used 25.5g of H110.
 
I sure would love to have someone Else's "load" data to build on.
 
thanks
"..You never pay too much for someting, you only buy it too early.."
Back to Top
Auto Mag View Drop Down
Callahan's Auto Mag
Callahan's Auto Mag
Avatar

Joined: 08 Mar 2008
Location: MA
Status: Offline
Points: 1662
Post Options Post Options   Thanks (0) Thanks(0)   Quote Auto Mag Quote  Post ReplyReply Direct Link To This Post Posted: 25 Sep 2012 at 12:22am
Originally posted by buckstix buckstix wrote:

Well I've got a set of CH dies coming, so that's taken care of. 
 
I actually formed 5 cases with my RCBS 44AMT form dies, and swaged a 41 neck on these using 41 Rem Mag dies. 
 
Even with this Laborious seat-of-the-pants method, I was able to obtain a 1-1/2" 5-shot group at 25yds.   I used 25.5g of H110.
 
I sure would love to have someone Else's "load" data to build on.
 
thanks
WOW, never heard of that one.
 
Unless you are 100% sure your method is producing brass to the proper specs I would suggest you wait until you get a set of 41 JMP dies or you risk destroying your Bbl and bolt and possibly damaging your frame,,,
 
Sorry for the doom and gloom but these guns can be broken easily.  Used properly they are solid, but improper ammo is a sure fire way to ruin an Auto Mag.
 
LEJ, any words of wisdom???
 
Good Luck either way.
Who was that masked man,,,
Back to Top
buckstix View Drop Down
180 Auto Mag
180 Auto Mag
Avatar

Joined: 09 Sep 2012
Location: Wis
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote buckstix Quote  Post ReplyReply Direct Link To This Post Posted: 25 Sep 2012 at 1:05am
"... WOW, never heard of that one.
 
Unless you are 100% sure your method is producing brass to the proper specs I would suggest you wait until you get a set of 41 JMP dies or you risk destroying your Bbl and bolt and possibly damaging your frame,,,
 
Sorry for the doom and gloom but these guns can be broken easily.  Used properly they are solid, but improper ammo is a sure fire way to ruin an Auto Mag. ..."
 
 
Yes, this is not a practice for a novice.  One must get the headspace correct.
 
Having said that, I've used this method many times in the past to get brass ready for dies that have been ordered.  I've got about 220 sets of reloading dies and if you mix & Match, you can just about load anything. 
 
I just wouldn't want to use this lengthy time consuming method more than required for run-of-the-mill reloading.  That's where the factory dies will come in.
 
I even modified a 40-65 bullet swage die to swage some mean looking  .41 cal 170g jacketed bullets.  They look real nasty with their little points.  They feed very good and they seem to shoot well too.
 
 
 
 
Still looking for some reliable loading info of the .41 if anyone out there can help with that.
 
"..You never pay too much for someting, you only buy it too early.."
Back to Top
jurras View Drop Down
Callahan's Auto Mag
Callahan's Auto Mag
Avatar

Joined: 24 Sep 2012
Location: Hagerman,NM
Status: Offline
Points: 463
Post Options Post Options   Thanks (0) Thanks(0)   Quote jurras Quote  Post ReplyReply Direct Link To This Post Posted: 25 Sep 2012 at 8:26pm
Still looking in the archives, have you checked the AM newsletters???
Back to Top
buckstix View Drop Down
180 Auto Mag
180 Auto Mag
Avatar

Joined: 09 Sep 2012
Location: Wis
Status: Offline
Points: 20
Post Options Post Options   Thanks (0) Thanks(0)   Quote buckstix Quote  Post ReplyReply Direct Link To This Post Posted: 25 Sep 2012 at 8:33pm
I've got 14 of the AutoMag newsletters, but they end with the announcing the availablility of the new Lee Jurras 41.  But no loading data in that one.
"..You never pay too much for someting, you only buy it too early.."
Back to Top
 Post Reply Post Reply Page  123>
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.055 seconds.

 - amtguns.info All rights reserved