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Post by artjr338wm on Mar 13, 2011 20:36:04 GMT -5
I have not seen or at least not noticed this talked about for a long time, so I need some help educating myself.
As it applies to the flash hole in the vent liner what is the accepted maximum size it can be and still be capable of delivering excellent accuracy? IIRC I think I read the max ID is between .033 and .035" anything above .035" ID and usually accuracy begins to seriously degrade. But I could be totally wrong about that.
Now about Lehigh vent liners. Does anyone know approx how many shots you should get when using near max charges of H-4198 and RL-10X, before they are trash?
I am asking these VL questions because I was just served a rather hard learning experience today and would like some info before I give a accounting of it here, as I feel sharing my experience/screw-up here most likely will prove beneficial to the newer/newest members of our site.
Short version is this, groups went from sub MOA to 1.5-3.5" for a 3-shot 100yrd group, replaced vent liner with new, groups instantly went back to MOA to sub-moa.
Will elaborate in detail once my questions are answered and I have the info I need.
Thanks,
Arthur.
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Post by Deleted on Mar 13, 2011 20:45:01 GMT -5
Art, my lehighs have went about 70 shots ea. I have used two since I got them. i am shooting some pretty hot loads in the pacnored savage behind 200 grn ssts. I change out when they reach .035 as the groups will open over .035. my group size will also open after about 30 shots on the plug with 4198, the verdict is still out on the vv110/vv120 loads as far as shot numbers on plug cleaning....Bill
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Post by mdgroundhogger on Mar 13, 2011 23:50:33 GMT -5
This probably won't help but, I don't check mine. But I do change them regardless after 40-50 shots. I'd rather just spend a couple bucks and be done with it, personally. This practice along with cleaning regularly has helped me maintain consistant accuracy in mine. I've been getting 1 1/2in 5 shot groups @ 100yds while following this practice along with 41gr of 5744. Not bad in my opinion  |
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Post by mountainam on Mar 14, 2011 6:53:40 GMT -5
Art, I'm not sure that I agree about the accuracy degrading after .035"with Lehigh vents anyway. I do recall that being said in the Savage manual. With factory Savage VL's and AA5744 I believe it's true. I shoot 10x in my .45 exclusively and was well into my 2nd box of bullets and started to notice a smudge on my .32ACP cases, but my accuracy was spot on as when I worked up the load initially. I sluffed off the smudges due to having over 50 firings on them. I then checked the Lehigh's flash hole with an .035" mig wire. I could see light all the way around the wire while it was in the hole. Dia. was well over .040". No degrade in accuracy. I had over 150shots through it. I didn't even check it before because the ancedote of "ACCURACY DEGRADES" was stuck in the back of my mind. I figured THAT would let me know. So, I still really don't know when the Lehigh started to go South. Anyhow I got the ACCURACY DEGRADES thing out of my head and check after 20-30 shots and it's a part or my regimen. It may be that the 10x is easier on the vents. I know AA5744 is not. Good Shooting!
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Post by rossman40 on Mar 14, 2011 11:25:35 GMT -5
It seems to me to be a balancing act of vent size, primer choice, type of powder, charge weight and even bullet weight. From my experiance with N110 and the hotter primers a tight vent works better. I even seen that if the groups start to open up with the CCI 209Ms I could switch to WW 209s and get the accuracy back for a few more shots. We even seen this in the old days when guys with SMIs would try 10ML loads. With the larger SMI vent back then Savage loads would not work.
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Post by bigmoose on Mar 14, 2011 17:51:38 GMT -5
I seem to be at odd's with conventual thinking, I use no fouling shot, the first shot is among the best of the group.
With vent liners, I find .27 and.28 the best, when they get to .31, I pitch them. I gave up on drill bushing and use only Vent liners.
I haven't counted but I have obout 50 to 70 shot fired with with 70gr of H4198 with Barnes 350gr X bullet and 71grs of Benchmark with the 400gr Barnes Buster bullet, those load must not to as hot as some of the high velocity some folks are using.
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Post by Jon on Mar 14, 2011 20:48:32 GMT -5
Bigmoose. I'm think you mean .027 and .028? My question is where do you get vents that size or do you make them yourself? That along with a 1/2 in. long plug if possible might be a help with the high pressure loads that some are shooting now and the vents dont even last through one session? Trying to remember back I think you had posted where you get the vents. A small amount of booster and a heavy main may get rid of or atleast help control That second high pressure spike the traces are showing. Sorry to get off the subject but it brought it to mind.
Jon
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Post by bigmoose on Mar 14, 2011 21:40:30 GMT -5
From Cecil in Canada. I bought some Lehigh vents they start at .031, I spoke to the gent that makes them, asked if he would consider making them smaller, but I guess he's happy with his current size, since most folks speak well of them, why change.
I have yet to try the Lehighs.
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Post by Jon on Mar 14, 2011 21:54:37 GMT -5
Dave at Lehigh has a big calling with the b/p people and I guess his vents work for them. I have them in all my guns now. I havn't got into the heavy loads that some are using yet But I'm trying to plan ahead. Thank you for the info. I will have to get ahold of Cecil in Canada and order some. Is that a standerd or a special order? I'm assuming that is Cecil from Precision?
Jon
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Post by GMB54-120 on Mar 14, 2011 22:23:38 GMT -5
Lehigh liners are probably still back ordered because he has a contract with Knight and the next 400 are going into 200 of his NFPJ conversions for Knights. 2 come with each NFPJ. He is swamped atm with other obligations too.
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Post by rossman40 on Mar 14, 2011 22:33:57 GMT -5
How is he getting around Henry Ball's patent on the replaceable vent? Henry is a good'ol boy but for another manufacturer to start using the system something might be said. Same way with the bolt carrier for the primer which has Henry's and Ron Coburn's name on that patent.
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Post by GMB54-120 on Mar 14, 2011 22:57:53 GMT -5
How is he getting around Henry Ball's patent on the replaceable vent? Henry is a good'ol boy but for another manufacturer to start using the system something might be said. Same way with the bolt carrier for the primer which has Henry's and Ron Coburn's name on that patent. In the Knight plugs he makes FOR Knight they are permanently installed in the breach plug. The upgrade plugs for older Knights are the last run i know about. |
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Post by bigmoose on Mar 15, 2011 9:37:28 GMT -5
The one I got from Cecil are 5 to 7 years old
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Post by Jon on Mar 15, 2011 10:45:28 GMT -5
Bigmoose thank you I'm going to get ahold of Cecil and ask him if they are still avaliable?
Jon
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