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Post by rustystud on Mar 19, 2012 20:21:14 GMT -5
I am having a reamer made to cut a chamber in a breach plug. This reamer will cut a chamber for the last .700" .308 Winchester SAAMI spec. I will have a hollow vented center post for the primer to ignight the powder. It will go from .100" to .031. The diameter of the post will expand the carrier to the front of the chamber wall. There will be six .050 vent holes in the post allowing returning gases to expand the carrier into the chamber wall. The end of the post will be chamfers so the carrierwill feed over the post. The carrier will headspace simultaniously on the post and case walls. The carriers will be made out of Lapua brass cut and chamfered at .690" . This will be set up on a .450/.458 7R RockCreek 28" Palma contour in a Savage PTA. I will ise a Kevin Rayhill Varmiter stock set up for a ram rod. I plan to shoot 285 or 325 sized Parker bullets (sabotless) Any ideas aor suggestions. Nat Lambeth
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Post by Jon on Mar 19, 2012 22:16:08 GMT -5
Sounds interesting. I'm assuming you will use lrp what is the distance from primer to powder? What, if any vent are you going to use? I'm thinking you have plenty of brass but if it would help I have some extra Lapua 308 brass. Arn't you worried about loosing too much primer heat and power through the 6 .050 holes before it gets to the powder?
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Post by rossman40 on Mar 20, 2012 11:18:46 GMT -5
Awful lot of work on the breechplug. Pretty much the same as Ken Johnston's design for the BP Express (US patent 6385887) but the 6 extra holes also worry me. You want to direct as much of the primer gas to the vent. Since your building on a Savage target action (love the dual port solid floor) it would be a piece of cake to use one of Dave D's boltheads for a 209 and use a factory Savage breechplug.
The Rock Creek 7R barrel would be great for sized sabotless (hope your getting a full form die). You may get a slight MV gain with a 5R. The drawback would be if you wanted to try sabots, it might not work too well. Indexing the sabots would be tough and with the canted lands they might allow sabot slip
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Post by Jon on Mar 20, 2012 18:14:50 GMT -5
Ken thank you for the update I didn't know that BP express used a nipple. I have to agree on the 6 .050 holes unless they are after the .031 vent ( going from the powder side )? 5R sounds interesting I need more info. Is there a sight I can look at?
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Post by rustystud on Mar 21, 2012 15:29:53 GMT -5
Rock Creek barrels goes from 5R to 7R in calibers larger than 35.
The reason for the vents in the carrier post is to prevent the gasses from cutting through between the casehead and the post.
I am confident enough fire from the primer will reach the powder. The side vents are for the blow back. I was tol by another smokless builder to put at least 6 ports in the post. Hope fully the flow from the primer will run past the ports until the presure is builds up and by then the powder will be lit up.
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Post by Jon on Mar 21, 2012 18:14:59 GMT -5
Rusty. Watching with great interest. To me the weakest part of present b/p's is the vent I feel it contributes a lot to consistancy. What I'm working on I'm trying to get away from the post. I figure if bass can handle 60k in a center fire why totally try to invent the wheel. That is one less thing I have to worry about? Most people are satisfied with what is now available. Which is to me great at this time but when you want to go to the next level you have to change your thinking or at least modify it a little. Keep up the work and please keep us informed.
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Post by spoonover on Mar 25, 2012 17:15:00 GMT -5
Rusty, need some photos of your chamber/breech plug when you get it figured out.
Cecil Epp (http://www.prbullet.com/700.htm) has BP that sounds close to what you are working on. Have one of his BP's and use Savage vent liners in it with success. My loads are not very hot, the most pressure has been RL7 65 grains and 300 grain REMINGTON in the 50 ML, not sure of pressure but kicks way to hard for me.
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Post by Jon on Mar 25, 2012 18:26:39 GMT -5
Spoonover. Again I'm confused I thought Cecil wasn't using a nipple in his B/P. I need enlighting, the pic's I see look like They are using a chamber for the brass? I thought that was a great way to go? Would some one up date me on what they are really using? I feel the nipple and the vent are the weak points.
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Post by spoonover on Mar 25, 2012 19:17:48 GMT -5
You are rite Jon, mine is hollow with a 10X32 vent liner. Yes "chamber" for the brass is correct. Head space is not to hard to achieve and cases seem to last a long time. Had a few cases that were not long enough (mixed up from another action) and had some blow by without any damage to the BP, seemed only to turn the cases black.
I like Pete's BP better after I got the bugs worked out with 209 mod!
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Post by Jon on Mar 26, 2012 2:28:25 GMT -5
Watching with interest on the 209 mod. also. I have a couple of Pete's plugs. If you don't mind me asking on Cecil's plug does he have a taper on the chamber to keep the brass snug and you headspace the brass to the depth of the chamber?
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Post by smokeless77 on Mar 26, 2012 14:53:31 GMT -5
Jon, They don't have a taper they just head space to the bottom of the plug with the bottom of the brass. It is very tough to ignite Straight H-4198 with that plug, always needed a booster powder like N-110 etc.
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Post by Jon on Mar 26, 2012 16:34:10 GMT -5
Smokeless thank you. I've been under the impression if you stay under 1.2" from primer to powder with lrp's you should be good to go?
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Post by dannoboone on Mar 26, 2012 16:46:44 GMT -5
Cecil's plugs ARE tapered/funneled to assist the flame through the front of the BP. But the taper begins where the case end stops. Don't know about others' experiences, but with mine, it was necessary to use magnum LRP's, even with N110 as a booster.
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Post by smokeless77 on Mar 26, 2012 17:19:05 GMT -5
Jon there is way too much empty space in the breech plug. What I did was make a module that fit the taper from the drill used to drill the plug. I think 118 degrees, To direct the flame to the very bottom of the plug and that worked pretty good. Here is a pic of the modules I made. The other brass are powder funnels. John
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Post by Jon on Mar 26, 2012 18:09:24 GMT -5
Smokeless very interesting. As I under stand you are no longer using brass but the module? If that is the case we are getting back to the original ml1. Bill Ball (may he rest in piece) that is pretty much what he originally designed luckly his son is here to carry on. Between the two of them sml would not be what it is today.
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Post by smokeless77 on Mar 26, 2012 18:37:01 GMT -5
Jon, I actually made another plug that takes 6mm cases but uses 209s for ignition. Works great and it has Zero leakage. I really do not use the modules no more. This Is for a M77 short action Ruger center fire. John
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Post by Jon on Mar 27, 2012 5:11:11 GMT -5
John. The 209 sounds interesting. Are you using a post that the 209 fits into or just a open case? If I stay with Petes plug I would probably modify the case and the nipple to take 209 primers. Some one else on the board is doing it with success. He had quite a good write up on it.
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Post by smokeless77 on Mar 27, 2012 9:14:14 GMT -5
Jon, Here are some pics of the plug and cases. The other board member that did this was spoonover. These pics are going to be huge, forgot how to shrink'em
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Post by rustystud on Apr 12, 2012 7:48:36 GMT -5
I have begun to receive the tooling I ordered for this project. I have received my piloted range rod, piloted counterbore, piloted centerdrill, piloted 79 degree crowning tool, and 24 pilots in .0002" increments above and below .450". I still have not received my reamer. I have 6 feet of 1.", 416 SS stock to turn my breech plugs and Muzzle brakes from. I have also ordered 6 feet of 416 SS 7/16" hex stock to make my nipples from. My stocks have a 3-4 month delivery time and have been ordered for 2 months now. My barrels should be here in 2-3 weeks. I will order my sizing dies to make my bullet sizers. Spin jags and bullets. I can get the actions in 48 hours. Things are moving along nicely. Nat Lambeth
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Post by Jon on Apr 12, 2012 17:11:06 GMT -5
Rusty looking forwards to up dates.
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Post by rustystud on Jul 29, 2012 8:36:11 GMT -5
For the last 6 months I have been collecting the components and tooling to build my smokeless muzzleloaders. I have received, my spin jags, spin jag starters, ramrods, Parker bullets, 416 SS 7/16ths hex stock, 416 SS round stock to make breech plugs, PT&G .715 308 body reamer, paper wads, wonder wads. Still waiting on my two RockCreek 7R, 1:20, 45 caliber barrels, two Stockade stocks, and two Savage SS Target actions. I have decided to make my breech plugs with both an exterior chamber and a center nipple to headspace off. The nipple will be made from the 7/16ths hex stock turned and tapered to fit inside the cut off 308 Lapua brass. I will try with and without a gas vent as I don't think it will be necessary to use one since the nipple will be over .300" thick where it contacts the brass and the brass will be supported exteriorly also. Guess the first trigger pull will be with a string behind a big tree. ha ha
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Post by jims on Jul 29, 2012 9:09:05 GMT -5
Keep us posted on the project.
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Post by Deleted on Jul 29, 2012 21:19:00 GMT -5
sounds very interesting... will be watching with interest
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Post by willbird on Dec 7, 2012 8:49:43 GMT -5
Jon there is way too much empty space in the breech plug. What I did was make a module that fit the taper from the drill used to drill the plug. I think 118 degrees, To direct the flame to the very bottom of the plug and that worked pretty good. Here is a pic of the modules I made. The other brass are powder funnels. John I really like that setup :-).
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Post by willbird on Dec 7, 2012 9:03:13 GMT -5
Jon, Here are some pics of the plug and cases. The other board member that did this was spoonover. These pics are going to be huge, forgot how to shrink'em Is it very difficult to fiddle that short little case remnant into the receiver ring and onto the post...just wondering about how that all works out up inside the receiver ring ? Bill
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Post by edge on Dec 7, 2012 13:01:55 GMT -5
Some like a LRM but I am very partial to the 209 since you can use it to seal a less than perfect headspace! My BP is actually 3 pieces. The outer threaded potion is taper bored to fit either a cut down 308 or 30-06 or a 45 ACP that I run through a 30-06 die to get taper. I then drill and bore for a snug fit on a 209 primer. The primer protrudes through the case by about 0.100 making headspacing less critical. The center nipple section is press fit or threaded through the outer section and is threaded for a vent liner and usually a bushing too. The assembly is completed when the vent liner is installed. The vent can be omitted if the center section is threaded, but it protects the center section from excessive pressure. If you have an EDM machine then a single piece would be ideal edge. Here is an assembly sketch:
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Post by willbird on Dec 7, 2012 14:26:17 GMT -5
Sounds like a GREAT use for 45 GAP fired cases :-). Is the 209 in your design actually sealing on the BP ?? The edm finish on steel is a bit "wierd"....and getting down in there to polish would be a PITA :-).
I bet the part could be investment cast though, and be very nice....one place I used to work we had one part made that way and the 5/8" or so hole in it was nice enough you could just case harden the parts and lap the hole and have a really nice end result.
Bill
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Post by edge on Dec 7, 2012 14:52:07 GMT -5
The 209 is a snug fit in the nipple. The snout is a couple of thousandths short from bottoming on the inside of the case so the 209 is inside the nipple by about 0.075 -0.100 depending on what the case web thickness is on the case you choose.
Pete at PA Machine makes a very similar plug for the Remington. Dave D. can probably give you the specifics on that.
IIRC he does not taper bore the outer portion so a straight case works in his, the nipple is designed for a LRM so it does not fit a 209 primer.
Modifying a case for a 209 is not a big deal especially if you have your own lathe that you can set up and leave it that way while you do all of the cases. One at a time is a real pain.
edge.
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Post by willbird on Dec 7, 2012 15:15:58 GMT -5
I can imagine one at a time is "trying" :-).
Bill
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Post by denphillips2 on Dec 8, 2012 20:07:06 GMT -5
Hey Nat, I tried to send you an email off your website, but that got rejected. Was wondering how you were coming out on this project. Very interested in your breech plug!!
Thanks! Denny
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