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I want to build a 375 max on a martini cadet action. For cast only, the boolit of choice will be RCBS 180gr Sil. Any advice on barrel length twist or problems to overcome would be much appreciated. It is my hope to be able to push these pills close to the limit if I wish, I only want to build it once, and you guys surely have all the info I need to do so. thanks in advance.
Standby for info from 357Maximum. He'll be here later today and I'll mention this thread to him. BABore uses 300MP and 357 uses N120 to drive 180s of different configurations to near or at max velocities. Several people I know have 20" or so long barrels. I doubt that you'd want to go shorter than 18" in a rifle, Mine is an H&R from the early 80s and has a 20" barrel and balances well. Hope you find this info useful.
Edd
Agree. Both folks are wringing the max out to it's max potential. One is opting for the lighter boolits and slower twist in a bolt gun. Barrel starting at 22 inches, and then incrementally cutting it off to find the middle of a node where the most consistent boolit exit point exists. Assumption is 21.75 inches. On the other hand, my cowboy guns are stock 20 inches because of balance. Marlin's octagon barrels should be at 18.5 inches for the same balance as the round barrels at 20. ... felix
Stephen, I have one, 24" barrel, 1 in 16" twist. I tried some Hornady 180HP and got good accuracy, then changed my mind and now shoot nothing but cast. I will say that you may note some difficulty with certain nose profiles causing problems with chambering, easy to figure that out tho. Right now I'm shooting a Ranch Dog 359190GC boolit, sized .359 for my .358 bore and getting excellent accuracy with 28gr of A1680 powder in the 2000fps category. I have some of the boolit you mention but don't have my book in front of me to quote figures, but being a tapered nose you won't have any difficulties. You can pm me any time if need be. Goatwhiskers
I would think it would work well. My 357 max. rifle is a Ruger #1 CHP 357mag, that I rechambered to 357max. Not sure what twist is factory, but the SIL boolit shot very well, as did others, even up to 260gr. Noted that the 357max Thompson/center carbine barrels are 1-14" twists
The 38-180sil should be able to be pushed to around 2300-2400fps using WW680 powder.
If you have a reamer made up, be sure to watch the front driving band. Too short a throat and you will jam the front driving band into the throat and cause difficulty chambering. I had a custom reamer made up for the 358627 lyman design and it took this into account. Gives it kind of a Weatherby freebore, but maybe thats why I get the velocities I do, although my gun dislikes the 358627 boolit but loves the 35-200 RCBS design.. Go figure.
I size all my boolits to .360". I think the gun has a 20" barrel, but I would have preferred a 22" as it is a bit muzzle light.
Hope this helps
Thank you one and all, this has been on wish list for some years, I have done a good deal of study on net and advice varies from can do to cant do. I was aware of feeding problems as put foward by Goatwhiskers and may well take him up on Pm when this project is in full swing. again thank you all. Stephen
I've had my Cadet rebarrelled to 357 max for close to 20 years now...
The Max is probably the longest straight wall case that will fit past the breech block. Nose shape and seating depths definitely come in to play
When I put mine together it was for lighter J-bullets with a 1-22 twist, 20.5" barrel length.
That rcbs sil is a good accurate boolit....I prefer a larger meplate but my 357MAX was built for turning deer into steak.
As far as twist goes a 1in18 or 1in16 would be my advice. Any barrel length over 18 inches is a waste in the max but you also need to take balance into consideration. My 15 inch Bull Barrelled Match Grade Machine 1/18 twist Encore does things I never dreamed it would do and the longer 20inch barrel of a friends 20" MGM Encore carbine gains absolutely nothing on me velocity wise.
Now for chambering.....stay away from a stock saami reamer. You want a "rifle" reamer or have it done in a seperate operation with a piloted throating reamer. When MGM built my barrel I specified a rifle throat and sent him dummy rounds. I could not be happier with the results. Mine was set up to engage the rifling with my boolit. I have since lengthened the throat a little bit with many many "warm" loads with ball powders and it still shoots great.
My favorite load might be a bit warm for your cadet action but here it is.......tread carefully and sneak up on it.
180 Grain BRP 360-180 GC-RNFP
22.5 Grains Vhit N-120 (22-23 grains of ALLIANT MP300 will duplicate it)
Remington 7.5 Sparkplug
Remington or Federal brass
That load does 2150 to 2160 avg out of my max depending on boolit/composition and accounted for several nice bucks thus far. I have also killed quite a few with the Glen Larsen designed Lee C-258-180-FN and it is a stone cold hammer on deer. There is currently a group buy in the signup stage down in the group buy area for this boolit.
You will not be dissapointed with the 357MAXIMUM but I may be a bit biased in my opinion. ;)
Quote:
Originally Posted by 357maximum
would you mean the C-358-180-FN?
I sure would mean that. I would type that too if I did not have such fat finners.:roll:Quote:
Originally Posted by nanuk
Thank you Nitroproof and 357 maximum, I am now sold on this conversion, yes it seems one dont need a long barrel to gain the maximum from this cartridge, so I guess it will be all up to balance of the outfit. I was of the opinion that saami reamer was not way to go and my gunsmith has both reamers so that is covered, I like the idea of sending in dummy rounds as well. All good info thanks guys. Stephen.
http://357maximum.com/
My Max is 1-14, shoot great, if I were to do it all over again, I'd go1-18 twist . Davis White Gunsmith built one with 1-20, lot of information on his site.....Lak
http://www.gmdr.com/rcbs/rcbstext8.htm
thank you lak, yes good usefull info there.
I have one of the Lyman .358 214 grain SWC molds and use them in my Max pistols, 10" and Super 14 and my Max carbine.
The slightly heavier bullet works very well for me and it does turn deer in to steaks.
Jerry
here is a chart that may be usefull as im no help here
http://www.riflebarrels.com/products...wist_rates.htm
I realise this is an old post, but it has taken me a year to get the action of my dreams. The timber for stock is inbound now the problem is which Twist, I wanted 1in 18 but only have a choice of 1 in 14 or 1 in 20, which would be the better for my intended use, from what I have seen 1 in 20 will not be best choice for heavier boolits. Of cause I could get one from States but all the hoops to jump through to get it is way more than I want. Since the barrels are button rifled and have shallow rifling I was wondering if the 1 in 14 may be a little fast for cast.
I don't know how this got in testing, could one of mods move if need be , thank you.
When I had my Dan Wesson, I used the CBE 358-200 GC Sil boolit, in front of 19.5gns ADI 2205. The boolit actually drops at closer to 220 gns with my alloy, and I still use it in the FA .357 mag I bought to replace the flaky DW.
http://farm9.staticflickr.com/8516/8...a3aa3259d6.jpg
IIRC, the DW twist was 1:18, and I had a 1:16 barrel for it which I never fitted.
I think the FA is 1:14, but I'm not really sure. Shoots well, though; night and day between it and the DW!
If you are going for the heavier boolit, I'd go with the 1:14.
As you see from the pic, this boolit has a long nose, so takes up little space in the case. It may be a bit long to allow loading in the Martini, but I have also loaded it into 357 mag to std length and crimped on the nose. Of course you wouldn't need to do that in a single shot, although 2205 seems to like a good crimp to get it burning nicely. Again, maybe not an issue in a rifle.
If the nose is too long for your Martini, you could get one of the other CBE styles.
If you want some samples of the boolit, PM me and I'll get some in the mail for you.
Oh, BTW, I have a bunch of new .357 Max brass for sale!
If you intend to shoot something around 200 grains, I personally would go for the 1-14. I am a bit feared that 1-20 would be too slow to be useful with the heavies. my 2 cents.
Edd
Thank you Gents I think your right 1-14 is way to go, its a shame the firearm industry in this country is all but gone very few choices. I may well take you up on your kind offer Norbrat,