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Post by deadeer on Jul 28, 2010 19:13:38 GMT -5
I recessed my breechplug today. I saw where some guys are going about 1/2" deep. I may have went a little deeper, but with the vent screwed in, there are still threads left on the primer side, so I didn't compromise the thread count of the vent. My question is, I looked for an 82 degree countersink as was previously mentioned, but cannot find an angle number on any one. Are all countersinks the same angle? I drilled with a 3/8" bit, so do I need a 3/8" countersink? Thanks, Jay.
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Post by Richard on Jul 28, 2010 19:34:13 GMT -5
Yes........Get a 3/8" counter sink with an 82* angle. They can be had from any of the industrial suppliers such as MSC.com, Grainger, Mc Master Carr, Enco. Most counter sinks are 60* but if you look, you will see they also have them in 82*. Just make sure the "tip" is not a larger diameter than the 10/32 vent hole. Mine has a 1/8" tip. I recess my plugs with a 5/16" drill and then grind down the sides of the vent liner to fit. This keeps the walls of the plug .025" thicker. Is it necessary? In my mind it does Right ET? You simply take a piece of rod and Dill and tap it for 11/32"......put your vent liner in, chuck it in your hand drill, turn on your bench grinder and with the drill spinning, hold it against the grinder. Takes about 10 sec. to modify. Richard
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Post by deadeer on Jul 28, 2010 21:05:28 GMT -5
Richard,
What do you think about the 3/8" recess then? Too much? I shoot mid to upper end loads mostly (300 or 325 gr bullets and either 70 gr H4198, or 5/65 duplex n110-H4198). Do you think that the breech plug is compromised for strength? I would like to get the new hex head factory plug and do the same, but wanted to try with this 4 prong original one to see how it turned out. Thanks, Jay.
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Post by ET on Jul 28, 2010 22:15:26 GMT -5
Richard
Yes I personally prefer and feel more comfortable with the additional re-enforcement/safety factor a 5/16” recess provides especially having experienced a double load once. And you’re right about making a simple adjustment to fit. I use a 5/16” rod, drilled and tapped 10/32” to house the vent liner exposing the head. Put it in my drill press and used a coarse file to reduce the head size. Once you started to touch the supporting rod you were usually there for the correct size head diameter.
Deadeer
Many who have modified the breech plug in the past for a recess have used 3/8” for recess hole diameter and have never heard of any failures or problems yet and that’s with a deeper recess than ½”. Here you have to decide how comfortable you are with less or more BP wall thickness when doing the recess. My comfort is with the 5/16” diameter recess.
Ed
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Post by Richard on Jul 29, 2010 13:56:49 GMT -5
What ET said! Richard
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Post by deadeer on Jul 29, 2010 17:18:40 GMT -5
Enough said!
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Post by Jon on Jul 29, 2010 19:33:55 GMT -5
+1
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Post by boarhog on Jul 29, 2010 23:49:02 GMT -5
I have recessed 3 plugs. All with 3/8, but I didn't know any better. No sign of a problem with loads hot enough to bulge and blow a primer. The Pete's Stainless bushing plug has a smaller diameter recess, but is almost 1" deep.
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Post by Richard on Jul 30, 2010 20:14:09 GMT -5
There may not be any problem at all?? If I was a mechanical engineer and could figure these pressures and strength of the steel used in the plug and how thick the walls are, then I might have a better idea? Since I do not have that information, I would rather err on the "thicker wall" side I bulged my barrel with a double load and the plug held up fine..........Thats good enough for me! Richard
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Post by edge on Aug 1, 2010 13:39:13 GMT -5
The "Original" recessed plug back when Doug's was a 5 page message board.... probably in 2003 was made by drilling with a "V" drill ( 0.377 ) and then I think that I bored it to 0.380 but too many brain cells have bit the dust to remember to 100% certainty The depth was just about 0.850 and about to the threads...but you should stop short of them. Here was the sketch that I posted of the BP in 2004...I don't think the original board had pictures, but they would have been lost anyway. edge.
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Post by Jon on Aug 1, 2010 15:35:00 GMT -5
Edge. you have a great memory I remeber the post. Keep up the good and informative info Jon
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Post by deadeer on Aug 2, 2010 12:44:12 GMT -5
I hit the plug with a drill/countersink bit and went a little deeper than I wanted . It looks like 3-4 threads of the vent are past the end of the plug threads, so that was a learning experience. I have a hex plug coming from Savage. Does anyone know how Savage ships a plug, USPS, FX, or UPS? Thanks. Jay
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Post by Richard on Aug 2, 2010 19:41:29 GMT -5
I just got two firing pin supports (somewhat smaller than a BP) today from Savage and they came in a soft padded envelope via USPS! Richard
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Post by edge on Aug 3, 2010 5:41:13 GMT -5
I just got two firing pin supports (somewhat smaller than a BP) today from Savage and they came in a soft padded envelope via USPS! Richard No fair without Pictures edge.
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