Page Index Toggle Pages: [1] 2  Send TopicPrint
Hot Topic (More than 10 Replies) Undersize .38 Green Mountain Barrel (Read 6879 times)
Nickle
Newbie
*
Offline



Posts: 4
Joined: Jan 16th, 2018
Undersize .38 Green Mountain Barrel
Jul 15th, 2018 at 12:26am
Print Post  
Hey Folks,
I've been pulling my hair out trying to get a .38-55 to shoot. It's an original Ballard action with a new recently-installed Green Mountain barrel. After trying a bunch of load that didn't work, I  finally slugged the barrel and think I found the problem.The specs for .38-55 have a bullet diameter of .3775". This barrel has a .372" groove diameter and .367" land diameter.  So standard .38-55 molds like the one I have, won't work (Buffalo Arms .378" and 360 grs).

What would you do?  Order a custom mold? from where?  Size the bullets from the mold I have down? That seems like a lot of sizing - so much that I'll probably loose my grease grooves.
Have the barrel lined?

This is for BPCR silhouette, so out to 500 meters. 

Thanks,
-Nick
  
Back to top
 
IP Logged
 
Schuetzenmiester
Frequent Elocutionist
*****
Offline



Posts: 6707
Location: Cool Wet Side of WA
Joined: Apr 27th, 2008
Re: Undersize .38 Green Mountain Barrel
Reply #1 - Jul 15th, 2018 at 12:31am
Print Post  
Is it within Green Mountain 's stated specs?
  

"some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence
Back to top
 
IP Logged
 
marlinguy
Frequent Elocutionist
*****
Offline


Ballards may be weaker,
but they sure are neater!

Posts: 18036
Location: Oregon
Joined: Feb 2nd, 2009
Re: Undersize .38 Green Mountain Barrel
Reply #2 - Jul 15th, 2018 at 1:12am
Print Post  
Considering it's all mounted and finished, I'd have a custom mold made for it. Hate to say this, but I always slug a new barrel when I get it, before fitting it. Just in case there's an issue like this.
  

(You need to Login or Register to view media files and links)
Back to top
 
IP Logged
 
Schuetzenmiester
Frequent Elocutionist
*****
Offline



Posts: 6707
Location: Cool Wet Side of WA
Joined: Apr 27th, 2008
Re: Undersize .38 Green Mountain Barrel
Reply #3 - Jul 15th, 2018 at 4:01am
Print Post  
Why would a GM be that far off?
  

"some old things are lovely, warm still with life ... of the forgotten men who made them." - D.H. Lawrence
Back to top
 
IP Logged
 
Hiwall55
Senior Forum Member
****
Offline



Posts: 468
Location: west central Illinois
Joined: Jun 30th, 2012
Re: Undersize .38 Green Mountain Barrel
Reply #4 - Jul 15th, 2018 at 6:39am
Print Post  
I would double check your measurements and have Steve Brooks make a 360 grain money to fit the barrel.
  
Back to top
 
IP Logged
 
Cat_Whisperer
Frequent Elocutionist
*****
Offline


No 1, 9.3x74R

Posts: 3987
Location: Mountains of Virginia
Joined: Apr 17th, 2004
Re: Undersize .38 Green Mountain Barrel
Reply #5 - Jul 15th, 2018 at 9:00am
Print Post  
Know also the alloy you're using.  Which blend you have WILL make a difference in the size (as will temperatures of alloy and mold).
  

Cat Whisperer (trk)
Chief of Smoke
Pulaski Coehorn Works and Skunk Works
Drafted May 1970, Retired Maj. U.S.Army
assra #9885
Back to top
WWW  
IP Logged
 
marlinguy
Frequent Elocutionist
*****
Offline


Ballards may be weaker,
but they sure are neater!

Posts: 18036
Location: Oregon
Joined: Feb 2nd, 2009
Re: Undersize .38 Green Mountain Barrel
Reply #6 - Jul 15th, 2018 at 11:26am
Print Post  
Schuetzenmiester wrote on Jul 15th, 2018 at 4:01am:
Why would a GM be that far off?


That's a great question, as I've never found their barrels to ever be off in those I purchased.
  

(You need to Login or Register to view media files and links)
Back to top
 
IP Logged
 
beltfed
Frequent Elocutionist
*****
Offline



Posts: 1824
Location: Central Wi
Joined: Dec 20th, 2007
Re: Undersize .38 Green Mountain Barrel
Reply #7 - Jul 15th, 2018 at 12:07pm
Print Post  
Nickle
As said, recheck that bore and groove measurement.

What twist is that GM barrel? 
The 12 twist or the other. 
Perhaps your problems are with too short or too long a bullet.
beltfed/arnie
  
Back to top
 
IP Logged
 
.22Hepburn
Oldtimer
*****
Offline



Posts: 844
Location: Pennsylvania
Joined: Feb 18th, 2008
Re: Undersize .38 Green Mountain Barrel
Reply #8 - Jul 16th, 2018 at 2:00am
Print Post  
Probably your best bet would be going with a custom mold, made to fit the barrel. I ordered a mold for my 38-50 from Steve Brooks a while back. I specified a .375 diameter to fit the groove diameter of my Douglas barrel. Because my Hepburn has a tight chamber I can't use an over size bullet. What I got from him was a mold that measured .378. I ended up getting a .375 sizing die from Lee and I was in business. Lee makes custom sizing dies in pretty much any diameter you want.
  
Back to top
IP Logged
 
bruce moulds
Senior Forum Member
****
Offline



Posts: 290
Location: the antipodes
Joined: Mar 14th, 2015
Re: Undersize .38 Green Mountain Barrel
Reply #9 - Jul 16th, 2018 at 2:00am
Print Post  
that would mean that your rifling is only 0.0025" deep.
keep safe,
bruce.
  

ventum est amicus meus
Back to top
 
IP Logged
 
bruce moulds
Senior Forum Member
****
Offline



Posts: 290
Location: the antipodes
Joined: Mar 14th, 2015
Re: Undersize .38 Green Mountain Barrel
Reply #10 - Jul 16th, 2018 at 5:48am
Print Post  
any new barrel is like the lottery.
only thing is bartlein, krieger, ron smith, have a greater chance of winning.
douglas look ok, but next step down from above.
a few more choices are available for rimfire, including lilja and shilen.
when you consider all the expense of getting a gun shooting, not to mention the time and work, better barrels are cheaper.
it is now known what to do to make barrels that shoot, and those makers that go the full mile are becoming well known.
they also warranty their product well.
keep safe,
bruce.
  

ventum est amicus meus
Back to top
 
IP Logged
 
.22Hepburn
Oldtimer
*****
Offline



Posts: 844
Location: Pennsylvania
Joined: Feb 18th, 2008
Re: Undersize .38 Green Mountain Barrel
Reply #11 - Jul 16th, 2018 at 7:06am
Print Post  
A friend has a 15 twist GM .22 barrel on his Ballard silhouette rifle. This was one of several that my gunsmith ordered. He made it a practice of checking/slugging every barrel that came thru the door. The others measured correctly at 16" twist. My friend wanted the faster twist and it is a tack driver. The 14" twist .40 barrels that GM offers started out as a mistake. This same gunsmith ordered two .40 barrels for customers guns. After slugging/scoping, one turned out to have 14 twist, the others were all correctly 16 twist. He decided to keep the 14 twist barrel and put it on his own BP silhouette rifle. It shot so well he suggested to GM that they make more and sell them as an optional twist. I have one of the first production 14 twist GM barrels on my 40-82 Hepburn and it's a tack driver. I also have a .22 GM barrel that shoots just "OK" (after testing with all manner of Lapua, Eley, and RWS ammo) and a .45 barrel that is an outstanding shooter. So my experience is that some GM barrels are great and others not so much. I'm not sure if this is the result of poor manufacturing or sketchy quality control.
  
Back to top
IP Logged
 
Red Cent
Senior Forum Member
****
Offline



Posts: 316
Location: Benton, KY byway of WV, VA, NC
Joined: Dec 25th, 2016
Re: Undersize .38 Green Mountain Barrel
Reply #12 - Jul 16th, 2018 at 4:41pm
Print Post  
Recently, I had an e-mail discussion with Don, manager at C. Sharps. My Hi Wall is .375 and .368 and is a very recent GM #4 octagon. 

"....372" groove diameter and .367" land diameter....."

What reamer did they use? Cool
  

Life is too short to argue with stupid people
and/or drink cheap booze
Back to top
 
IP Logged
 
bruce moulds
Senior Forum Member
****
Offline



Posts: 290
Location: the antipodes
Joined: Mar 14th, 2015
Re: Undersize .38 Green Mountain Barrel
Reply #13 - Jul 16th, 2018 at 8:32pm
Print Post  
or the spotter was making poor wind calls Wink
keep safe,
bruce.
  

ventum est amicus meus
Back to top
 
IP Logged
 
Jeff_Schultz
ASSRA Board Member
*****
Offline



Posts: 1659
Location: Ransomville, NY
Joined: Apr 25th, 2004
Re: Undersize .38 Green Mountain Barrel
Reply #14 - Jul 16th, 2018 at 8:34pm
Print Post  
  Who made the reamer with a pilot small enough to enter the bore?
  

"We have met the enemy and he is us." Pogo

“There is no situation so bad that it cannot be made worse."

  Confidence- The feeling you get before you fully understand the situation.
Back to top
 
IP Logged
 
Page Index Toggle Pages: [1] 2 
Send TopicPrint