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Post by deertroy1 on Sept 19, 2014 18:26:56 GMT -5
I have a stainless laminate thumbhole Savage ML-II 50 cal. with a new McGowen barrel and I really enjoy shooting it. The one thing I do not like is that in my one year of hunting with it (with the factory barrel) in cold temperatures my accuracy went south as soon as the temperatures went much below 32 F. I also noticed the consistent velocities I had obtained in warmer weather also become very erratic as the temperatures dropped. I've had no problems with misfires however. It seems from reading here that most feel a good part of the problem is related to the Savage breech plug and in particular the length of the flame channel.
My question is:
Is there an after market breech plug available that improves cold weather performance?
- I've read about a modified recessed breech plug. Are these available and do they improve cold weather performance? Has anyone actually proved this?
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mtecs
Button Buck
Posts: 23 
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Post by mtecs on Sept 19, 2014 20:01:11 GMT -5
My solution is 10 grains of IMR SR4759 under 60 grains of 4198. No issues down to -10. Don't know about the modified breech plugs.
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Post by dannoboone on Sept 19, 2014 20:21:52 GMT -5
About all I can give you is theory, along with a bit
(hopefully) of common sense. Shorter the flame
channel in a Savage type BP, the more flame gets to
the powder. Sparks cool off the further they have
to go. I'm a believer that modified BP's help in
several ways, but cannot prove it. I have several
BP's, and the only one that has yet to be modified
is one with a bushing.
Pete (PA Machine) makes after market modified BP's.
With the right equipment (a lathe, a 3/8 drill bit
and a countersink) it is easy to modify the stock
BP.
What powder are you using? Some are more effected
by temperature swings than others.
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Post by ET on Sept 20, 2014 7:05:26 GMT -5
Deertroy1
I can’t guarantee what will work in much colder weather but can pass along my experience like Dannoboone.
Recessing the plug will aid in ignition. Smaller flame path creates more pressure and heat being fed to the powder. Less exposure to cold steel also means less heat loss from cold walls of flame channel.
Larger orifice opening will allow more thermal energy at a quicker rate to access powder. So don’t put in a newer vent with a smaller opening before hunting.
The recess being a short powder chamber keeps thermal energy from dispersing more widely when it reaches the powder and probably aids in pressure buildup when powder begins to ignite.
Don’t overlook that a good snug fitting load will help powder ignition and compressing the load will help reduce space between powder granules so less heat migration throughout the powder load when thermal energy is introduced.
In much colder weather if possible a hotter primer should help. Duplex would probably be another asset but having no real experience with duplex I can’t really comment as to how beneficial it would be.
Ed
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Post by deertroy1 on Sept 20, 2014 7:55:03 GMT -5
Thanks for the input guys. The powder I was using at the time was a lighter charge of AA5744 with a 250gr bullet. It seems like the light charge coupled with the light bullet also aggravated the situation. I am now experimenting with SR4759 and 300gr bullets but want to have as many things working in my favor as possible.
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Post by deertroy1 on Sept 20, 2014 7:57:19 GMT -5
I have a few more questions about Pete's recessed breech plug.
1. Does it have a vent liner?
2. Does it have a hex head?
I found some older threads on it but the only photo I found was from 2008.
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Post by jims on Sept 20, 2014 8:06:11 GMT -5
I have never had a misfire with 4759 and a 300 grain bullet and a CCImag primer or 209Feda primer. The bullet should fit snugly in the sabot however, there are different sizes of sabots.
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Post by Dave W on Sept 20, 2014 9:19:32 GMT -5
I am also of the mindset that a recessed plug is better for ignition, only type of plug I have used in my .50 for years. Unfortunately, powder/loads still show temp sensitivity with a recessed plug. I believe Pete did away with the bushing plugs.
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Post by lakeplainshunter on Sept 20, 2014 10:07:07 GMT -5
I have a few more questions about Pete's recessed breech plug. 1. Does it have a vent liner? 2. Does it have a hex head? I found some older threads on it but the only photo I found was from 2008. They are hex head and use a vent liner. It is a well made breechplug. |
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Post by cr500afx on Sept 21, 2014 19:54:49 GMT -5
A few years ago, I had the exact same issue with AA5744 in my Savage 50. At 45 degrees it was dead on. When the temp dropped below 35, the poi rose six inches at 100 yards. I switched to RL7 and never looked back...
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Post by deertroy1 on Oct 6, 2014 14:19:11 GMT -5
Which would be better for use in cold weather to reduce temperature sensitivity, the recessed plug as offered by Pete or the LRVF kit as offered by PRBullet?
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Post by GMB54-120 on Oct 6, 2014 17:32:04 GMT -5
Oh wow. i never saw those on PR website before. Has anyone got a chance to try these yet?  |
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Deleted
Deleted Member
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Post by Deleted on Oct 6, 2014 17:53:40 GMT -5
  PA Pete recessed Savage plug with vent liner. Ohioguy has this great plug now. |
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Deleted
Deleted Member
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Post by Deleted on Oct 6, 2014 18:27:31 GMT -5
PA Pete recessed Savage plug with vent liner. Ohioguy has this great plug now.  |
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Post by letemgrow on Oct 6, 2014 19:40:53 GMT -5
Oh wow. i never saw those on PR website before. Has anyone got a chance to try these yet? I bought this kit from pr Be prepared to re headspace if you get one. |
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Post by smokelessindian84 on Oct 6, 2014 21:40:35 GMT -5
I have the PA Machine recessed plug like Ohio guy and so far I enjoy how clean it is after shooting it in my Savage .45 Pacnor. I have fired 25 shots of 10/50 duplex charge of 4759/4198 and had no more than a smoke film in my flame channel.
This is a huge improvement over my factory BP in my factory .50 barrel which would clog my flame channel in 5 shots.
I havn't had a chance to test it in cold weather yet but I expect good things. It will get tested this winter.
Another thing I think will help is a tightly headspaced plug with a shoulder in the primer pocket to seal the primer against to virtually eliminate blowback by the primer. You will still get a slight blow by through the anvil and cup of the primer itself but everything going out the muzzle end is a good thing. This will help with ignition by keeping heat and pressure in front of the primer on the powder charge.
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Post by deertroy1 on Oct 7, 2014 16:34:34 GMT -5
I'm contemplating on which plug to get but was just curious as to which one may be the best in cold temperatures? Also, I'm not sure if Pete will ship to Canada?
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Post by slammer on Oct 7, 2014 17:18:35 GMT -5
who is Pa Pete  ? |
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Post by deertroy1 on Oct 7, 2014 17:46:34 GMT -5
Oh wow. i never saw those on PR website before. Has anyone got a chance to try these yet? I bought this kit from pr Be prepared to re headspace if you get one. I guess that makes up my mind. I'm having my sights and ramrod thimble installed on my new McGowen. Re-headspacing is out of the question. Thanks for the heads up! |
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Post by lakeplainshunter on Oct 7, 2014 19:51:59 GMT -5
I have a PA Machine recessed breechplug you can have if you can tell me how to ship it to Canada without going to Jail.
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Post by deertroy1 on Oct 7, 2014 20:13:46 GMT -5
Thanks lakeplainshunter but I'm not to familiar with US laws. All I know is that they have become much stricter than ours since 9-11. The breech plug may be considered just a machine part but it may not as well! Canada Customs has no problem with me importing up to 8 lbs of smokeless powder from the US. However, US Customs informs me that I'm not allowed to export it from the US and anyone selling it to me from the US is in big ka ka also!
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