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Post by epanzella on May 26, 2015 18:59:30 GMT -5
I have a 458 McSavage with a Savage plug. I installed a bushing for headspacing and left a 1/8 inch channel. Primer didn't stick at first but after 10 shots they started bulging and sticking. I noticed the PFC was quite fouled (FED209A). I drilled the PFC out to 3/16 and now it's good for 20 shots before fouling and sticking. What I didn't do is make the channel any longer. There seems to be about a half inch of small channel between the end of the vent liner and the bottom of the drilled out PFC. What should be the dimensions of the flash channel? Should I drill it deeper? I'm using 60 gr RL7, Harvester blue sabot & 200 gr xtp.
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Post by bestill on May 26, 2015 19:17:36 GMT -5
Imo .140 x .800 is a good start. Then if needed go to .156 x .800
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Post by Deleted on May 26, 2015 22:13:42 GMT -5
I drill my PFCs from the primer side in.
I leave a .200 "shelf" of metal for the bushing to sit on.
I'd start by opening the PFC by 1/64" bigger at a time.
As soon as the primer bulging goes away, stop drilling.
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Post by epanzella on May 27, 2015 9:11:20 GMT -5
Thanks.
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Post by bestill on May 27, 2015 9:54:14 GMT -5
I believe different lengths and i.d. of flame channel can be used as long as volume is equal.
Imo. .0150 cu. In. Is a good place when using.030 flash hole
.0295 cu in with .040 flash hole
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Post by jims on May 27, 2015 11:36:18 GMT -5
Bestill: What size for a .035, saves me from doing the math? Thanks
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Post by edge on May 27, 2015 13:55:40 GMT -5
Just curious, if you are using a bushing why not go larger?
In the past the only problem I had noticed was increased vent liner wear and I thought the pure carbide bushings eliminated that as an issue for you.
edge.
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Post by epanzella on May 27, 2015 14:57:40 GMT -5
Just curious, if you are using a bushing why not go larger? In the past the only problem I had noticed was increased vent liner wear and I thought the pure carbide bushings eliminated that as an issue for you. edge. I'm prolly not using the right lingo. My plug is a factory Savage with a vent liner. I couldn't stop the primers from jamming in the bolt because there was no ledge to headspace against. Turning in the barrel just seemed to push the primer deeper into the plug. I drilled out the primer side of the plug to .242 and pressed in a bushing that would provide a ledge to headspace against. That was the bushing I was referring to. I originally drilled the bushing to 1/8 but then drilled it to 3/16. I'm gathering from other posts in this thread that I need to extend the 3/16 portion of the PFC deeper as I don't have enough volume. Right now the PFC is .187 x approx. a half inch. |
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Post by bestill on May 27, 2015 17:34:14 GMT -5
Bestill: What size for a .035, saves me from doing the math? Thanks [br Imo .187 x .800 be very close .0213 cu. In. Volume |
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Post by edge on May 27, 2015 17:35:08 GMT -5
SNIP. Right now the PFC is .187 x approx. a half inch. No stop and wait for answers I do not use a standard plug so others using them will have better info than I do! edge. A sketch of the breechplug with some dimensions:  A sketch of a badly fouled breechplug. If the fouling becomes bad enough the carbon crud will take on the shape of the primer and the bolt will become very difficult to close:  A sketch of the relationship between the Boltface, Primer, and Breechplug :  Here is a sketch showing the relationship between the Savage Barrel, Breechplug, and Barrel Nut:  |
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Post by Deleted on May 27, 2015 23:08:23 GMT -5
SNIP. Right now the PFC is .187 x approx. a half inch. No stop and wait for answers I do not use a standard plug so others using them will have better info than I do! edge. A sketch of the breechplug with some dimensions: A sketch of a badly fouled breechplug. If the fouling becomes bad enough the carbon crud will take on the shape of the primer and the bolt will become very difficult to close: A sketch of the relationship between the Boltface, Primer, and Breechplug : Here is a sketch showing the relationship between the Savage Barrel, Breechplug, and Barrel Nut: If you get too large on the pfc volume then you start lacking on the ignition pressure ,imo and from others testing it here...... |
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Post by edge on May 28, 2015 5:52:53 GMT -5
I believe different lengths and i.d. of flame channel can be used as long as volume is equal. Imo. .0150 cu. In. Is a good place when using.030 flash hole .0295 cu in with .040 flash hole Does this include the volume taken up by the primer? The Original unmodified Savage BP would have a volume of 0.031 ^3 in. ( excludes primer and vent liner volume ). edge. |
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Post by bestill on May 28, 2015 6:17:31 GMT -5
Does not include primer pocket.
Flame channel volume is only that. Back of vent to primer face.
What dimension are you using for savage volume?
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Post by bestill on May 28, 2015 7:11:01 GMT -5
Radius x radius x 3.1417x height=volume
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Post by edge on May 28, 2015 7:27:17 GMT -5
SNIP. What dimension are you using for savage volume? I am basically using the volume of the "White cross hatched area in the lower picture ( including the hole ). The Vent liner takes up 3/8 in length, the primer takes up approx. 3/16 inside the BP leaving about 1.3 inches. The primer occupies about 0.0085 in^3 The BP is threaded for a 10-32 for some length more than the vent liner needs and I did not account for that minor amount. edge. PS The dimensions are approx.: 0.241 dia x 0.258 l= 0.01177 in^3 0.230 dia x 0.192 l= 0.00798 in^3 0.156 dia x 1.018 l= 0.01946 in^3 ======================== = 0.03921 in^3 including the primer occupied space but excluding the Vent Liner space. |
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Post by bestill on May 28, 2015 10:11:46 GMT -5
Your dead on so without primer pocket which is not part of flame channel. The flame channel volume is .02744 cu in. And if bushing and retaining screw is installed will reduce volume by .0047 leaving volume at .02267
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Post by edge on May 28, 2015 10:22:51 GMT -5
I used a primer depth of 3/16 which is about the most engagement you can get with a Savage ML-II for a volume of 0.0085 in^3 A break action or other than Savage bolt may get more. Based on this relationship: edge. |
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