|
Post by rambler on Oct 1, 2014 16:20:57 GMT -5
If so can I have your new lathe??
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 18:44:17 GMT -5
Well I lived but not to tell great tales tonight. Had some ignition issues with straight charges of retumbo. At first I thought the muscle brake worked wonders as it only kicked like a .243 but I was having hangfires and ftf so after trying cci, win and fed LRMPs I drilled some brass to take 209's. The first one just popped, reseat, retry. The second primer did the job and I got my first taste of full power. Bounced a swfa off my head and thank god they are wide at the eyepiece. That shot flat out rocked! Next loading everything the same and three pops no ignition. Now I'm waiting to tear out the plug and drop the load cuz it's dark. So we will get her going strong soon but not tonight..... It was fun though and stubbornness is stupidness so watch me work! All bullets punched pretty little straight clean holes though.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 19:01:14 GMT -5
You'll get 'er no doubt. It's a learning curve/process. Once you get it dialed, it will be more than worth the time and troubles.
|
|
|
Post by 7mmfreak on Oct 1, 2014 19:11:01 GMT -5
You never know until you try. I bet you get it on the next try. I bet it did rock you though, the big capacity medium bores are awful. The .378 Wby is the most vicious medium I ever shot and you are front stuffing is twin.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 19:17:36 GMT -5
Pull the string man! If in doubt do it from a distance..LOL
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 19:30:38 GMT -5
I put my face down into the ground and laid a duffle bag on my head...... Not the best way to do it but at least it went off! All digits and still as ugly as my momma made me!
|
|
|
Post by ET on Oct 1, 2014 20:22:49 GMT -5
Myers129
Now you know why I asked about that large powder chamber. I suspect it will give you headaches for consistent ignition with really slow powders. Good luck with finding a viable solution to overcome this.
Ed
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 20:31:08 GMT -5
I think it's a little early to blame the chamber but I hope to find a solution soon.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 20:43:16 GMT -5
Would 4198 be too fast as a primer in a duplex....?? Uncharted ...
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 20:45:48 GMT -5
I believe 4198 will be a fast primer but within my needs. I'm hoping to find a useable load and definitely chrono it before I start mixing in a duplex. Hoping....
|
|
|
Post by hankinsrfls on Oct 1, 2014 21:10:17 GMT -5
Myers.. That is a lot of powder to ignight but it can be done. It's done in the. 375 Cheytac and other large capacity cartridges so why not a rifle without the brass.. It will work but you need your powder right next to your primer flame. If it has to travel very far at all it will hang fire, and the LRMP's are much hotter than the 209's so try to figure out why it's not igniting with the LRMP. Drill your flash hole out some and see if that helps.. I have gotten 100% ignition with my 416 using up to 125 grains of H4350 and 350 grain CEB...
You have a 50BMG,,, why not modify a primer carrier to hold a 50BMG primer. That might be the ticket..
Jeff.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 1, 2014 21:22:04 GMT -5
Jeff I have mentioned the bmg primers to guys in private but they are a spendy primer so if i don't have to I don't want to. I think I know what I need to do to make it work well with the Dave D. plug. Some guys see it differently than I do and that's fine that's why this is all fun. There is still stuff for all of is to learn from each other. Incase you've never seen one it uses cut off 45 or 308 style brass about .450" long so there is a chamber inside that brass behind the vent very similar to the savage plugs. I think I need to minimize this volume and get all the pressure directed into the vent before it dissapates into the space behind the vent. I am going to turn down some inserts and put them into the brass to take up that volume and try that. Thanks for your interest on this build, I'm gonna get it going and we will tear up that river bottom and have one heck of a time doing it.
|
|
|
Post by markb317 on Oct 1, 2014 22:24:39 GMT -5
I think a booster would probably take care of your hangfires and help get better ignition of the Retumbo.I know it helps ignition in my 416 with the slower powders , I can tell a difference in how hard the gun recoils between a straight load and a boosted load .
|
|
|
Post by 7mmfreak on Oct 2, 2014 5:22:38 GMT -5
Myers,
Why did you choose Retumbo? I have noticed guys (Bad Bull, Earnhardt, etc.) choose much slower powders for some of the high performance SML than I would choose myself. I would have thought H/IMR 4350 to H/IMR 4831 (SC) for your .375 build.
|
|
|
Post by 7mmfreak on Oct 2, 2014 5:23:18 GMT -5
I guess if I were shooting the 350gn bullets I might look as slow as RL22.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 2, 2014 6:10:08 GMT -5
7mmfreak, my end result load for this gun, which no one should ever try to duplicate, is 130-132gr of retumbo. Pressure will be up where it should be for retumbo and it is straight up a .375 chey tac load. I am going to try some h1000 on the next outing and see where that gets me. 120grs of retumbo was a low end load for my expectations and should have been in the low 50kpsi range.
|
|
|
Post by 7mmfreak on Oct 2, 2014 6:47:24 GMT -5
Cool. I was just curious. I just always wonder if the slow loads don't build pressure as expected since upon ignition the bullets don't engrave into the rifling since there is not a throat/leade transition like a metallic chamber has. I guess I just assume a load with a faster rise time would help since the bullet's inertia is overcome more quickly since there is somewhere between a slip fit and mild interference fit required in order to load from the muzzle vice a chamber loaded gun where there is no way you could run a bullet more than say .020" to .030" into the rifling at the leade.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 2, 2014 7:07:21 GMT -5
myers129, do you have Quickloads? Since you have a 120 grain powder chamber, you're somewhat painted in a corner for what you use as a main powder charge. Right now Quickloads says your load is 56,000 psi, with Retumbo as your powder. Yes that pressure is with a center fire rifle that does not have full formed bullets, but...
DO NOT USE 120 GRAINS OF A 4350 or 4831 POWDER!
PM me if you need some help.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 2, 2014 7:31:39 GMT -5
Earnhardt, thanks for the offer of some help. I will probably get in touch with you for some of your experience igniting these slow powders. I do have quickloads and as crazy as it sounds the pressure you calculated is correct and is also right where I intended to be. The Dave d plug is awesome as far as strength goes. The same threads, in size and quanity, as the savage plug but much shorter nose and the ears surround it mate up exactly to your bolt on a lugged action. Metal to metal where it really counts. Even with the loads I have chosen the "plug thrust" is relatively low compared to the thrust generated by fat magnum cartridges in a 700action. I put a lot of thought and calculations into this rifle and I don't recommend anyone else pursue it but it will be a one of a kind, only one in the world front stuffer.
|
|
|
Post by linebaugh on Oct 2, 2014 7:43:01 GMT -5
Myers129,
I have a plug in use very similar to what you are wanting to run. If there is a retumbo load I can run in my .458 I can give it a try after work.
My plug uses hornet modules at .400 and has the .040 x .250 tungsten bushing. I have a total flame path of .700-.710 and am running mag large rifle primers.
I made a FF die but can't get my press to play with the 350gr .458 bullets so I am stuck with running FF on .451 bullets. I do get a good tight fit and use a wad so I should be able to ignite Retumbo... maybe.
|
|
|
Post by 7mmfreak on Oct 2, 2014 7:57:18 GMT -5
DO NOT USE 120 GRAINS OF A 4350 or 4831 POWDER! PM me if you need some help. I was not advocating an equivalent charge of those powders, just that I would have chosen those powders. I would think about 100gn of 4831 would work in an appropriate powder chamber.
|
|
|
Post by rambler on Oct 2, 2014 8:22:17 GMT -5
DO NOT USE 120 GRAINS OF A 4350 or 4831 POWDER! PM me if you need some help. I was not advocating an equivalent charge of those powders, just that I would have chosen those powders. I would think about 100gn of 4831 would work in an appropriate powder chamber. How does Bad Bull get away with using 140GR of IMR4350. I have a friend in Iowa with a Bad Bull and that's all he uses with a 275BE that has been sized by Bad Bull
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 2, 2014 8:24:46 GMT -5
Different bore sizes react very differently to pressure generated by certain doses of powder. 90grs of 4350 is a swing lock load for a .416, in a .45 it's like a 28,000psi pea shooter
|
|
|
Post by 7mmfreak on Oct 2, 2014 8:38:27 GMT -5
I don't understand the choice of powder by Bad Bull either but it works for him. When you start looking at yield in energy per grain it seems inefficient to me.
|
|
|
Post by dave d. on Oct 2, 2014 8:47:58 GMT -5
Cole you are plenty close enough to the powder with my plug and I have to agree with Jeff the slow powder along with hefty load is your issue. Throw alittle booster in there and see what happens it will probably go boom every time. Give me a shout.
|
|
|
Post by Dave W on Oct 2, 2014 12:15:19 GMT -5
I was not advocating an equivalent charge of those powders, just that I would have chosen those powders. I would think about 100gn of 4831 would work in an appropriate powder chamber. How does Bad Bull get away with using 140GR of IMR4350. I have a friend in Iowa with a Bad Bull and that's all he uses with a 275BE that has been sized by Bad Bull Short and large flame path.
|
|
|
Post by linebaugh on Oct 3, 2014 10:47:44 GMT -5
I did some minor testing with Retumbo this morning in hopes that it helps Myers129 and perhaps others. Please do not repeat my test as it is not intended for the masses, more to help a fellow smokeless shooter in his efforts.
Rifle is a Howa 1500 with a 23" PacNor .458 1:22 I think. (Whatever Luke recommended for twist) Bullets, 300BE Powder XXXgr of Retumbo. .060 veggie wad Federal 215M primer in .22 hornet carrier 45 degrees outside - small hurricane type winds
First shot loaded loose, perhaps 10-15#, and I figured I would be pulling my plug. To my surprise it fired but recoil was percieved low and things felt like I did not get full ignition. Shot two loaded tighter as they usually do, 20-30# is my guess. Ignition felt fine and the report was much better than shot one. Recoil was low but I fully expected that with this load. I am not sure what the velocity would be but I would guess I'm breaking over the 2,000fps at least. Shot three was a duplicate of shot two in all aspects.
I did not chrony nor shoot groups. I simply shot into my backstop freehand leaning into my bench. First shot was left and low of my gong and the next two were just under it. I assume I could shoot a group and confirm ignition potential but at present I have 37 bullets to get me into season... waiting on a MH order like many on this board.
My plug is a modified savage with Fishawk's .040x.250 bushing. Some exceptions to my plug are that I am getting 100% seal and I have converted the plug to accept a 22 hornet module that is cut to .400 in length. I also counter bored my plug with a taper burr so that it holds 22gr of H4198, non compacted. Flame path from the face of my primer to the powder size of my bushing is approximately .710. More importantly, in my opinion (only opinion) is that I left approximately .200 of an inch forward of the retainer at a threaded .250 diameter prior to beginning the taper.
Why I believe this to be important is it leaves a small volume (surface area) of compacted powder at the face of my bushing instead of using a flat cut which would increase the surface area and lower initial pressure and heat from the primer on the powder. Is this concept correct, heck if I know? It sure made me feel warm n fuzzy inside but in reality it may not make a bit of difference. I just personally feel I get better powder compaction on the bushing face and more heat and pressure to a smaller area of powder on ignition.
I hope this helps Myers129 and any others in some way. I appreciated just testing it as it proves to me that my ignition system is pretty sound.
|
|
Deleted
Deleted Member
Posts: 0
|
Post by Deleted on Oct 3, 2014 12:42:30 GMT -5
I did some minor testing with Retumbo this morning in hopes that it helps Myers129 and perhaps others. Please do not repeat my test as it is not intended for the masses, more to help a fellow smokeless shooter in his efforts. Rifle is a Howa 1500 with a 23" PacNor .458 1:22 I think. (Whatever Luke recommended for twist) Bullets, 300BE Powder XXXgr of Retumbo. .060 veggie wad Federal 215M primer in .22 hornet carrier 45 degrees outside - small hurricane type winds First shot loaded loose, perhaps 10-15#, and I figured I would be pulling my plug. To my surprise it fired but recoil was percieved low and things felt like I did not get full ignition. Shot two loaded tighter as they usually do, 20-30# is my guess. Ignition felt fine and the report was much better than shot one. Recoil was low but I fully expected that with this load. I am not sure what the velocity would be but I would guess I'm breaking over the 2,000fps at least. Shot three was a duplicate of shot two in all aspects. I did not chrony nor shoot groups. I simply shot into my backstop freehand leaning into my bench. First shot was left and low of my gong and the next two were just under it. I assume I could shoot a group and confirm ignition potential but at present I have 37 bullets to get me into season... waiting on a MH order like many on this board. My plug is a modified savage with Fishawk's .040x.250 bushing. Some exceptions to my plug are that I am getting 100% seal and I have converted the plug to accept a 22 hornet module that is cut to .400 in length. I also counter bored my plug with a taper burr so that it holds 22gr of H4198, non compacted. Flame path from the face of my primer to the powder size of my bushing is approximately .710. More importantly, in my opinion (only opinion) is that I left approximately .200 of an inch forward of the retainer at a threaded .250 diameter prior to beginning the taper. Why I believe this to be important is it leaves a small volume (surface area) of compacted powder at the face of my bushing instead of using a flat cut which would increase the surface area and lower initial pressure and heat from the primer on the powder. Is this concept correct, heck if I know? It sure made me feel warm n fuzzy inside but in reality it may not make a bit of difference. I just personally feel I get better powder compaction on the bushing face and more heat and pressure to a smaller area of powder on ignition. I hope this helps Myers129 and any others in some way. I appreciated just testing it as it proves to me that my ignition system is pretty sound. Sounds interesting....I've kind of been thinking along those lines ....inverse chambering....4198 is a main in the 45 and 50 cals but acts as a booster in .416 and smaller calibers....so confine it in a smaller volume closer to ignition point and it should react the same...?
|
|
|
Post by ET on Oct 3, 2014 19:51:52 GMT -5
I also counter bored my plug with a taper burr so that it holds 22gr of H4198, non compacted. Flame path from the face of my primer to the powder size of my bushing is approximately .710. More importantly, in my opinion (only opinion) is that I left approximately .200 of an inch forward of the retainer at a threaded .250 diameter prior to beginning the taper. Why I believe this to be important is it leaves a small volume (surface area) of compacted powder at the face of my bushing instead of using a flat cut which would increase the surface area and lower initial pressure and heat from the primer on the powder. Is this concept correct, heck if I know? It sure made me feel warm n fuzzy inside but in reality it may not make a bit of difference. I just personally feel I get better powder compaction on the bushing face and more heat and pressure to a smaller area of powder on ignition. Linebaugh If I read your post correctly it seems to describe a recessed BP that produces a smaller pre-chamber before bore size chamber for ignition. If so I agree with your concept assessment. Ed
|
|
|
Post by linebaugh on Oct 3, 2014 19:59:56 GMT -5
Yup. I guess you could say it's a pre-chamber or something like that. If I was going sub bore I personally think I would run a taper on my plug and on my powder chamber. Only reason would be to induce more back pressure. Again this is theory... I for sure don't know.
|
|