View Full Version : 7mm Contender load problem.
12-31-2007, 03:42 PM
I'm not new to reloading: I started in '47, but I am fairly new to cast boolits in rifle calibers. So far I've been lucky with the boolit loads for the M1 and the L/E #5. But boolits in my 7mm barrels for my Contender have me stumped. J-words, no problem. LEE "130 gr." no problem. It's the RCBS 165 SIL that is driving me nuts. I have a 10" 7mmTC/U, and a 14" 7-30 Waters. Testing so far has only been in my basement at 7 yards, but no matter what I try after reading all your wonderful pointers, that damned boolit still keyholes at even that short range. My Lyman #47 says the 10" TC/U is twisted 1/10", the 14" 7-30 at 1/9", which seems odd: I would have thought TC would just make a common 7mm barrel and chamber as req'd? Both std. bull barrels have 8-groove rifling, TC factory iron sights. Everything shoots to POA, but that RCBS hits skewed every time.
Both boolits cast quite heavy in my WDWW alloy, and neither nose will enter either muzzle. I stuck them into the throats until they contacted the rifling and they are oversize, in fact as-cast, the cartridges won't chamber unless boolits are sized .284. That "165" RCBS weighs in at about 185grs.!
I have sized/lubed/GC'd in the Lyman lubrisizer, and then applied a coating of mule snot LLA. Boolits were seated so as to just clear the rifling. I have tried loads using 700x (bad), 296 (good), SR4759 (huge blue flash), 4227 (good), etc. I have avoided Unique simply because I can never get it to meter reliably. Maybe I should weigh some charges and try that? The TC/U doesn't care whether I use Standard Small Rifle or Standard Small Pistol primers, and I used Standard Large Rifle in the 7-30. NONE of the loads tried produced undue fouling or any leading whatsoever.
Does anyone out there in Boolitland have a load in either or both of these calibers that produces good results with that particular RCBS boolit? So far it works OK in my 7x57 98 Mauser 29" 'sniper toy', and in my pre'64 7x57 Win. 70 24" Douglas, but those developments have a happy way to go yet. It's the Contender that is giving me fits! I had hoped for a good hunting load to have on hand if I ever wanted/needed it. The LEE does just fine for fun.
12-31-2007, 04:24 PM
never could get a good load for 7mm tcu with cast
139 hornadys was almost hole to hole with h-4227
12-31-2007, 04:56 PM
Habcan what town are you close to on that side of the province?
I am no expert on cast bollits by any stretch of the imagination, but I have fire a few Contenders over the past 25 years. They can be the most ornery critters that have ever been built; at least that is what I have discovered!!!
When I first tried cast in my Contenders, the 30-30 was the initial candidate—to this day, accuracy is mediocre at best—but I am going to get it back out this year sometime…
Then I went to the 7-30 Waters. I really didn’t have any slug weight in mind so several of the posters on this great website sent me a few samples. The silhouette boolits you mention was a disaster in my Super 14 also, as where all heavy bollits. They simply would not shoot—Period. I didn’t get keyholes, but 3+ inch groups at 100 yards were the best the ol’ girl would do.
I then thought that lighter boolits might be better so, not wanting to spend lots of $$$$ as I really didn’t have much confidence in this barrel ever shooting cast, I purchased a Lee C285-130R (130+ grains with WW). This little slug showed potential and I was able to get 1.5” groups most of the time. So, I splurged and purchased a Lyman 287346 (135+ with WW). This is the boolit that made the Waters shoot. It will mostly stay at 1.0 inch or a bit better at 100 yards. I have a life-size groundhog made of steel that I can place at various distances on my shooting range and it will get rattled every time at 300 years with the 287346 and a good rest. The Burris 4x-12x ‘scope is required for me to shoot these long distances.
Now to the powders that I have found to be the best. Every powder you listed in your 3rd paragraph did not work for me either!!! Powders of the same burning rate as the ones you listed also failed!!! SO, I immediately went to the slow burners—the also failed!!! Well, that left one other group of powders, the middle ones!!! I now shoot H-335, WC-844 (a grain or 2 slower than my H-335), and Win-748. The best accuracy is with the WC-844 at an average velocity of 2044 fps and the second best is H-335 at 2141 fps.
Other things that I do—I heat treat my boolits by heating them in the oven to 400º+ (not sure of the exact temp, but I know where to set the dial!) and then water quench. Recently, I have been trying to shoot boolits that have not been heat treated. In all actuality, the heat treating may not be necessary—we shall see later on. All boolits are shot as cast—only the check is sized to seat it. AND, the Contender barrels that I own have all been “rough” internally. That is, they require excessive cleaning. Almost to the extent of brutal or extreme. My Waters will shoot bunches of boolits and then all of a sudden, accuracy starts down hill. Clean, clean, clean, clean, and clean again. Accuracy will again return.
I don’t know if any of the above info will help you or not—I hope so. I really like my Waters and enjoy shooting at plastic soda bottles filled with water at various ranges. Trouble is those dang cast boolits just punch a hole through them and the pee themselves to death! Good-luck…BCB
The 10" 7TCU will be blasty with some flash, not much way around it from the one I had and shot a lot, FLGC's in those days. WW748 or AA2015 was my go to powder with FLGC's, it will work with your CB's. H335 will work, but will be blasty as the same with BLC2.
I have not loaded any for my 7-30 for quite a while, but was using VV powder. Sub groups at 100, FLGC's again with this one. I had tried 748 and H322 with this one, shot OK but not great.
4895 and AA2520 works well in both of these cases. I would advise to stick with the rifle primers in the TCU. Pressures get up there a bit for pistol primers and the long powder column seemed to like a rifle primer.
I would suggest a chamber cast on most any factory TC barrel. Others will disagree with me, but I must have the worst luck with them. My 7TCU 14" barrel I had was a shooter for sure and wish I had kept it. However I had to swap, sell and barter a half dozen or more barrels to find one that would shoot to make me happy.
01-01-2008, 07:24 AM
BCB, that LEE 130gr. is the one I have that works fine in both barrels. I have used J-words in the 7-30 with match-winning success using 748. I was trying for a less-than-fullbore blast with the heavy RCBS so did not go to that powder : I will use it for full load trials. JSH, I did not think to try it in the TC/U thinking it might be too slow, but will soon. Thank you both for your replies.
I'm still asking if anyone has developed a 1000/1200 fps. fun load with the RCBS boolit in those calibers.
I'm still asking if anyone has developed a 1000/1200 fps. fun load with the RCBS boolit in those calibers.
Hmmm, maybe try some trail boss if you can get your hands on some. I doubt there is any load data, but about 3/4-7/8 of a case full may give you what you want. BTW, concerning the TCU, never had any luck with it until I got the case pretty full of what ever powder I was using. That is why I thought maybe TB.
Don't fall into the old myth that you have to use pistol powders in a pistol length barrel, when using rifle powders.
I have a 6-223 rifle and use the same bullet, powder, primer and case with my XP 6-223 with almost the same results. Powder is H335 btw. Yup a bit blasty, but how can a fellow argue with accuracy. Sorry boys, FLGC's in this one as I push it pretty hard.
Speed is money, how fast do you want to go,lol. So I still shoot the FLGC in this one.
01-01-2008, 09:44 AM
"Don't fall into the old myth that you have to use pistol powders in a pistol length barrel, when using rifle powders."
Nope, never had that problem, but thanks JSH for reinforcing the point.
I'll see if I can chase down some of the TB you suggest. Working on 748 trails right now. Will advise results here.
01-01-2008, 10:35 AM
Habcan, what is the chronographed velocity of these loads? You said keyholes, which means the bullets aren't stable. Possible that a shorter bullet requiring less rpm would work better, and this long RCBS bullet isn't being spun fast enough because it's going too slow?
How about trying the 1600 fps range to see if accuracy improves, and working downward to see if it begins to deteriorate?
Sometimes very fast powders aren't the answer since by the time you reach velocities high enough to stabilize a long, heavy bullet pressures become excessive for cast.
01-01-2008, 11:18 AM
35Rem, exactly! Again, thanks for reinforcing the point. I can't chrono until spring weather, so am just working now to get something that reasonably delivers what I'm looking for.
I'm just out of the basement, and 748 is a winner in the TC/U with that RCBS cruise missile. Shoots POA, no keyholes, and the unburnt powder barrel residue and dirty cases from the 12.4gr. charge should disappear if I increase the charge judiciously.
Now I gotta go change barrels. Can you tell I live alone?
THANK YOU(SE)! [It's OK to say 'youse' if there's more than one of 'youse'!]
01-01-2008, 11:40 AM
OK guys, the results in the 7-30 were identical to the results posted above for the TC/U!
I will now happily play with increasing charges slightly, and chronographing on the PACT when the weather is more salubrious. I'll come back then and report accuracy/velocity results, K?
Thank you all so much. WTH didn't I think of 748, since it worked already with FLGC's??? Just shows to go ya even 'experience' needs a jog from 'other experience' once in a while, eh? (That's Canajun for 'hunh?'.)
01-04-2008, 09:24 PM
Things are looking up! I claim dim lighting and a slight flinch in the second pic. But look, no keyholes! 7-30W tomorrow. IMR#4227 burns a LOT cleaner than 748 in these tests.
01-05-2008, 11:04 AM
This is comfy!
01-08-2008, 04:44 PM
We have had very good results using unique in the 7tcu with cast bullets.
C A Plater
01-08-2008, 05:13 PM
My 6.5 TCU does very well with H322, Reloader 7, IMR3031 and IMR4064. Cast and "J" as long as it is 120 grains or less.
I have the 14 inch 7mm TCU shooting the rcbs 145 gr bullet actual weight is 156 with wwwd shooting H322 22.6 gr. and rem. 7 1/2 primer average 10 vel. is 1685. With a 2X7 scope I am getting a 2 inch group 5 shots at 100 yards. recoil is med but accurate for me.
01-09-2008, 06:04 AM
Thanks Kirb, that's exactly the sort of info I'm chasing.
01-09-2008, 06:49 AM
I have had several 10 & 14 inch, and still have 1 10 inch 7TCU, kirb's boolit is about as heavy as that T/C will handle and be easy to find a load to shoot well. My RCBS drops the boolit and fullly dressed at 154 gr. 4227, Unique, 2400, 5744, 4759, 322, RE-7, 748 will all do good with the RCBS 145 Sil or the Lyman 135, in speeds 1200-1700 fps. It is not hard to get single digit SD. The barrels all differ because T/C chamber length is all over the map. Try to seat the boolit as far out as possible, and try not to let GC seat below the neck.
A pleasant accurate load I use for close eye relief scope is 8 grains/Unique 1300-1400 fps, 9 sd speed depending on barrel.
7-30 Waters, now that's another story, finicky and tempermental. I have tried 2- 10 inch, 1- 14 and 1- 24. I spent countless trips to the range w/chrongraph and loading equipment. Never had on I was happy with, couldn't sell them fast enough. My guess is that the boolit has to seat below the neck, because of the short throat, and that is upsetting something. J-bullets will shoot great, the faster the better, but cast boolits?????????
12-03-2012, 02:55 PM
I cast 120 gr. w/ gas check. Is old Lyman Ideal mould. Favorite load in 7mm TCU is 5.2 grains Unique behind the 120 grain cast GC bullet.In 7-30 waters use 10 grains Universal, 7 x 57 use 14 grains 5744. I like the 120 grain cast GC bullet as some cases , 7 mm TCU has a short neck. The old Lyman Ideal mould in 120 grain GC is hard to find. I have been able to have two for faster casting.
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