The Firing Line Forums

Go Back   The Firing Line Forums > The Skunkworks > The Smithy

Reply
 
Thread Tools Search this Thread
Old January 22, 2015, 11:57 PM   #1
mmwb
Junior Member
 
Join Date: November 12, 2004
Posts: 7
Parker Hale, jamming

I've a Parker Hale, .243. I believe it is the 1200 super. I am rather ignorant of the details of firearms (so please excuse any misuse of terminology), but the cartridges are short relative to the action and when the bolt is cycled, the cartridges tend to creep forward. If they creep forward, then the next cycle will usually cause a jam. It is my understanding that there may be a magazine box or some kind of keeper that can be installed to keep the cartridges snug to the back of the action. Thoughts/ideas/recommendations will be appreciated!
mmwb is offline  
Old January 23, 2015, 12:22 AM   #2
gunnut69
Member
 
Join Date: June 23, 2013
Posts: 40
I don't know much about the P-H's but if the magazine follower is shorter front to back than the magazine box is then it's likely there is supposed to be a filler block behind the follower. These are usually made from folded sheet metal.
gunnut69 is offline  
Old January 23, 2015, 06:01 AM   #3
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,063
Numrich shows the Parker Hale 1000 and 1200 rifles used one magazine for 243 Win and 308 Win and 30-06 and 270 Win. That's why it's long.

What's the nature of the jam? Is the nose of the cartridge not rising to exit the magazine? Usually a long magazine releases a short cartridge early. It makes me wonder if the magazine spring has taken a set and isn't pushing up hard enough?

You might try putting a short piece of Popsicle stick under the front half of the first cartridge in the magazine to lift its front end a little. See if that feeds. If so, and if the spring can't be replaced, a metal replacement for the Popsicle stick can be fashioned an permanently installed.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old January 23, 2015, 09:08 AM   #4
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
I had a similar problem with a 7x57 FN Mauser. Rebent the follower spring to put more pressure up at the front of the follower to fix it.

Some magazine followers' ridge on their left side doesn't push fatter cases against the right side rail at the best angle to let them feed reliably compared to skinnier ones. This was often a problem with pre-'64 Win. 70 actions with .308 Win. magazines and barrels. When the bolt was cycled fast in rapid fire matches (about a 1/2 second cycle time) the top round would pop out of the magazine as it started forward. Filing the follower rib's right edge to a steeper angle put the force axis on fatter .308 cases more horizontal so the round stayed against the left rail until it's tip started into the chamber and its head slid up into the bolt face with its rim behind the extractor claw. .30-06 rifles never had this problem; their case diameters in the front half are smaller than .308's.
Bart B. is offline  
Old January 23, 2015, 09:18 AM   #5
jimbob86
Junior member
 
Join Date: October 4, 2007
Location: All the way to NEBRASKA
Posts: 8,722
Quote:
it's likely there is supposed to be a filler block behind the follower. These are usually made from folded sheet metal.
His problem appears to be the cartidges are creeping forward ..... a block behind would have them start in a forward position ..... foward seems to be "bad" for feeding in his rifle.... How is putting the block at the back going to help?

How much more taper do the Mauser cases have than the .308 based ones?
jimbob86 is offline  
Old January 23, 2015, 10:00 AM   #6
Bart B.
Senior Member
 
Join Date: February 15, 2009
Posts: 8,927
Go to

http://www.saami.org/PubResources/CC...0-%20Rifle.pdf

get the cartridge drawings, calculate the case body taper per inch for the cartridges then compare them. A 7mm Mauser or .30-06 case had more taper than a .308 Win. case.
Bart B. is offline  
Old January 23, 2015, 05:04 PM   #7
Unclenick
Staff
 
Join Date: March 4, 2005
Location: Ohio
Posts: 21,063
Taper per inch of length from SAAMI drawings:

Code:
7mm Mauser:  0.0273 in/in
8mm Mauser:  0.0239 in/in
30-06/270 W: 0.0165 in/in
308 W/243 W: 0.0120 in/in
The above is why a .308 won't chamber in a .30-06 without enough push to chamber-size the front of the .308 Shoulder down. (Though I have seen it done, and see the neck-less case that returned from the firing.
__________________
Gunsite Orange Hat Family Member
CMP Certified GSM Master Instructor
NRA Certified Rifle Instructor
NRA Benefactor Member and Golden Eagle
Unclenick is offline  
Old January 24, 2015, 02:06 AM   #8
Scorch
Senior Member
 
Join Date: February 13, 2006
Location: Washington state
Posts: 15,248
There are two ways I have used to solve problems of this nature:
1- silver solder a piece of steel wire/welding rod to the inside of the magazine box on each side directly in front of where the cartridge's shoulder would sit. This will keep the cartridges from moving forward while in the magazine from either recoil or friction from cartridges above them.
OR
2- make a spacer and place it at the back of the magazine box to move the cartridges forward. This keeps the cartridges stacked up straight and eliminates the staggering of the rounds that allows the upper cartridges to nosedive and jam.
__________________
Never try to educate someone who resists knowledge at all costs.
But what do I know?
Summit Arms Services
Scorch is offline  
Old January 24, 2015, 06:16 AM   #9
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,286
Scorch:An Old Master told me to use a cotter key for the solder-in trick.Nice flat side for the solder joint.His name was Ben.

On the mag stack thing,ideally the mag box width /taper is such that the cases will stack as an equilateral triangle at both the casehead and the shoulder.

It has been my experience putting a 308/243 in a mauser box that,due to the straighter case,the shoulder will stack to a tight triangle between the box.follower,and rails while while back at the case head,the stack is loose.Its not tight up against the rails,and the brass at the case head sags down.

Then the bolt coming forward over rides the case head,but digs into the case body,crushing the case as it pushes the cartridge forward.The case head is not on the bolt face,its under the bolt,and the bullet/neck are jammed into the feed ramp.

You don't have this option,but,IMO,the best way to put a.243 in a Mauser is to use a 6mm Rem chambering reamer and make it into a necked down 7x57 Mauser(which is what the 6mm R is)

They really should alter the mag box to be a little wider at the shoulder for the .308 cartridge family to stack properly if they are going to chamber these cartridges in a Mauser.

I'd have to do some number figuring to see how much material would need to be milled off the boxwall to make a Mauser box correct for a .308 parent case.
HiBC is offline  
Old January 24, 2015, 11:01 PM   #10
mmwb
Junior Member
 
Join Date: November 12, 2004
Posts: 7
Appreciate the replies guys. Some good ideas to follow through on. I also found this thread: http://thefiringline.com/forums/showthread.php?t=388790
Looking at it, it appears clear that it had a block in the back of the magazine box that had been removed (perhaps taken in an out a few times per wear marks). It may be a combination of things. It does seem to cycle better if the top cartridge is to the far back, but the follower sits forward in the box. The spring also seems a bit weak to me, relative to my other bolt action long guns.

I picked this rifle up several years ago with a Weaver scope, for a great price, but just haven't done much with it. It is in beautiful shape and my understanding that these older ones that were still made in England were fairly accurate. I will get to work on it and see if I can get this problem fixed.
mmwb is offline  
Old January 26, 2015, 04:10 PM   #11
HiBC
Senior Member
 
Join Date: November 13, 2006
Posts: 8,286
I do not recommend this as a permanent,or even temporary fix,but for an experimental remedy,try degreasing the rear mag box metal and double stick taping a thin wood strip in place.Screen molding or a bit off a yardstick or? whatever is a good thickness.
See if it solves the problem,and you can follow up with something well made.
HiBC is offline  
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 12:48 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
This site and contents, including all posts, Copyright © 1998-2021 S.W.A.T. Magazine
Copyright Complaints: Please direct DMCA Takedown Notices to the registered agent: thefiringline.com
Page generated in 0.06901 seconds with 8 queries