35 XCB bullet mold design.

[MBTcustom]

2550 not bad, just not what you were hoping for. I've only been able to get about 2200 fps from my existing boolit designs so 2550 would be a big step up for me. If a 30 caliber XCB boolit can make it to 3000 fps I'd expect the 35XCB can make it as well. I'm suspecting it will take a purpose-built rifle to get you there but I think you already know that.

Well as far as that goes, for all intents and purposes, I was using a purpose built rifle. The Felix rifle was built to be a solid test bed of known accuracy that I could use to prove the accuracy of barrels that I install on rifles. If I build a rifle and it does not deliver the accuracy I expect, it's just really handy to be able to screw the barrel into a solid bench rifle and see if the problem lies in the barrel or in something else. For the record, if a rifle does not shoot, it has never failed to be the barrel that is the guilty party. Every time without fail. A good barrel gets you sub MOA no matter what. All the other stuff matters if you want to shoot tighter than that.

Anyway, I wanted to dip my big toe in the 35XCB, so I figured I would just screw my 30" medium Palma barrel into the Felix rifle and voila!
The thing is, I'm not so sure about the results now. Yeah I was hoping for better, but there were several things about this last outing that were severely sub standard when compared to the typical XCB process that the other members of the team and I adhere to. Here's a list of things that could have made it shoot less than it's potential:
1. I was using an unproven barrel. This was the first time I have shot this Shilen barrel, so I really don't know what its accuracy potential is. I need to fix that.
2. The bullets were my very first run with the new mold, and I shot all of them with no culls. Typically, I have no problem doing this if I have run the mold through several bell curve exercises and I know precisely how to cast with it for optimum results. As it is, I didn't weigh but maybe 5-6, and I saw over a grain of differance in that handful. I know I wasn't running it the best way, but I didn't have time to really rag it out properly like I have all my other molds. It could be that I had voids, or the bullets were being dropped too hot causing them to be warped etc etc etc. Who knows?
3. I reloaded the brass that had been formed and fired in a rifle I previously built for Bjornb. I have not pulled the funds together for my own 35Whelen set of dies that I can modify to 35XCB, so all my loading was done with my 358 WCF set. This is no problem for neck sizing, but the bullet seater was definitely not able to insert the bullets into the necks with the same precision that I can achieve with my inline seater made from a piece of barrel blank that I made for the 30XCB. I think that seating the bullets in a more supported scenario will improve things greatly. There is absolutely no guarantee that my bullets were getting started straight into the barrel. I need to find a better solution for that.

I think I need to take a step back and work on holding the same standard for excellence that we have developed for the XCB project. I keep hearing my old boss's words ringing in my ears: "we have a very good system for success here. Don't defeat the system!"

Tonight I cast another run of 35XCB bullets. The mold has calmed down and is throwing very well. In the coming weeks, I'll learn what it needs to produce superb results as I demonstrated in the "consistency applied" thread. I cast exactly the same way I did last time, but this time I'll measure and make one correction at a time and pull the accuracy together in a scientific manner.

Also, I will find a better solution for seating the bullets correctly.

Once I get the new 35XCB rifle built correctly, I'll prove it's practical accuracy with jacketed bullets and continue on, armed with that information.

As it is, I really have no business being disappointed with the design till I have given due diligence to loading it correctly.

The good news is that I gathered a plethora of load data with yesterdays range session, so next time I can cut right to the chase and start working up from there.

The last thing that I considered is the fact that even though I only shot 2MOA at 2550 FPS, the fact is that I actually shot 2MOA at 2550 FPS!!! if you had told me that a couple years ago, I wouldn't have believed it. I think it's a good practice to do a sanity check once in a while and keep in mind that it wasn't too long ago that I was spraying the target backer with holes at less than 2400FPS with the 358 Winchester. If I make a few small logical changes to my loading procedure, I might very well be able to take the groups to less than 1.5MOA @ 2600FPS with this bullet design. Time will tell.

[TXGunNut]

Point is you haven't given this project due diligence yet, no one has. It's not a failure, it's a work in progress. You're on solid ground, just need to build from there.
Can't fault you, my mould sits unused and I've been no help at all. I have the correct dies, powder, brass, mould and quite possibly the rifle but they all sit idly by. Hope to remedy that soon but life gets in the way.

[Elkins45]

Tried again today with water quenched alloy. I loaded some with 7383 and some with BLC2. At 1950 fps with the 7383 they were OK, not great but OK. At 2500 fps with the BLC2 they wouldn't stay on the paper.

[MBTcustom]

Tried again today with water quenched alloy. I loaded some with 7383 and some with BLC2. At 1950 fps with the 7383 they were OK, not great but OK. At 2500 fps with the BLC2 they wouldn't stay on the paper.

Sorry you're having so much trouble Elkins! I wonder what alloy you are using? Mine is nothing wild and crazy, just COWW + 2.2% tin water dropped. I wasn't exactly shooting aspirins off a plank, but I was definitely on paper I'd say. Groups didn't open up till I crossed 2600FPS, but that's approaching ludicrous speed with a 14 twist, and I never have been able to get any cast bullet up that fast.

[Elkins45]

The alloy is those big round medical isotope cores that Muddy Creek Sam sold here a couple of years before he died. It's somewhere around 96-2-2 IIRC. It hardens very well when water dropped.

I'm going to try again with my 358 Win next. Maybe the Whelen just isn't a good match. I'm also going to try another lube. Today's test was with 666+1 and I think it ran out of lube before the end of this 26" barrel.

[dragon813gt]

The large isotope cores are 96/3/1. Not much of a difference from the smaller containers but there is a higher antimony content.

[MBTcustom]

The alloy is those big round medical isotope cores that Muddy Creek Sam sold here a couple of years before he died. It's somewhere around 96-2-2 IIRC. It hardens very well when water dropped.

I'm going to try again with my 358 Win next. Maybe the Whelen just isn't a good match. I'm also going to try another lube. Today's test was with 666+1 and I think it ran out of lube before the end of this 26" barrel.

I suppose that's possible. Bjornb and Larry Gibson did a pretty epic lube test in which they tested most of the available lubes for HV shooting. It was found that there were only a small handful that could deliver at 2500FPS or more. Oddly enough, two of these lubes are made by the White Label Lube company. Seemed like sometimes 2500+ was the magic pill, and sometimes 2700+ was it. I usually defer to 2700+ for many reasons other than the way it shoots. Lets just say the two lubes are good to try, and "if the right one don't getcha then the left one will" but I always hope 2700+ will be the right lube because it's so nice to work with.
I am good friends with the owners of the WLL Co. and I have a few sample packs here to send out. If you would like to try it, shoot me your address and ill get one in the mail to you. it comes with four half sticks of their lube and two of them are what I just mentioned. It might make a difference for you and it might not, but it's worth a try.
I like the stuff so much, I talked Glenn out of a block the size of an Acme brick in both flavors. LOL!

[Yodogsandman]

The alloy is those big round medical isotope cores that Muddy Creek Sam sold here a couple of years before he died. It's somewhere around 96-2-2 IIRC. It hardens very well when water dropped.

I'm going to try again with my 358 Win next. Maybe the Whelen just isn't a good match. I'm also going to try another lube. Today's test was with 666+1 and I think it ran out of lube before the end of this 26" barrel.

I tried 666-1 just once in the 35 Whelen with the NOE RD 360-230 at about 2500 FPS and like you, it wouldn't keep all the shots on the paper.

[TXGunNut]

Hmmmm.....my "smokeless" 4500 has BAC (with a good supply on the shelf) and not looking forward to changing lubes so I'll see if my shoulder gives out before the BAC does, lol. BAC seems to be doing fine up to 2200 with the RD and that's a pretty good thump with a benched sporter rifle.

[MBTcustom]

I really need to try BAC in my 45-70. Lubes seem to have a range they are effective in, in certain rifles. I was trying 2500+ in my 45-70 because it seems like such a do it all lube, but the 45-70 didn't like it as much as olive oil/beeswax (smokeless, not BP).

Come to think of it, I really need to shoot the 35XCB with 2500+ to see if it likes it better.

[runfiverun]

try modifying the BAC with some lanolin or a little neets-foot oil. [3-4% is enough]
it helps it fling from the lube grooves better, and also helps the first shot stay closer to the group.

[TXGunNut]

Lubes are a bit of a mystery to me, my SP 45-70 is quite happy with RD boolits and LLA so it doesn't concern me much. My lube adventures start when LLA doesn't quite cut it and BP lubes are not appropriate. I used to think any lube that got the boolit to the end of the barrel without leading was a good lube but a few projects have caused to me rethink that. NRA 50/50 seems to be quite good but I still had some nagging fliers that I wasn't able to explain. BAC seems to be helping to reduce that number. I agree that lubes seem to work better under certain conditions but I'm just starting to understand that. Looks like the 35XCB just like anything else; when you start pushing the envelope everything has to be right.

[runfiverun]

and you gotta start at the bottom and move ahead one step at a time to get things to the 'just right' part.
this ain't as easy as the 30 xcb makes it look [is it?]
tuning a lube to a 20-f window is easy after you spend a couple of years and @40 pounds of powder figuring it out.

[TXGunNut]

Seems we're on the same page, R5R. Picked up 8# of IMR4350 this week. I don't think I'll be able to get enough of it into a 35 Whelen case to get past 2500 fps but as you say, it's all an educated guess...

[Larry Gibson]

Managed to finally get a test in of the 35 XCB cast bullet. I've received numerous requests to test this bullet in my M91 Argentine rebarreled with a 26" Shilen barrel with a 14" twist and chambered in 35 Remington, especially using LeveRevolution powder. Here's how she shoots with the RCBS 35-200-FN at 2150 fps; there's two 5 shot groups there as I was refining the zero.

Attachment 186882

The 35 XCB bullet test was done yesterday. The day here (Lake Havasu City, AZ) was a nice sunny day with temperatures running 60 - 65 degrees during the test with little wind. The M91 Argie has a Lyman SME receiver sight and a M98 front sight band I modified for and M14 front sight. In years past I could hold moa with such sights but these days with my eyes having gone south I can hold 1 1/2 - 2 moa. I have a strain Gauge attached to the barrel so complete internal ballistics can be measured along with chronographing velocities via an Oehler M43 PBL. Here's the set up yesterday.

Attachment 186884

As a "reference" before testing the 35 XCB I shot a 10 shot test string of my practice load with the 35-200-FN. These were loaded 4+ years ago. The 10 shots went into a 2.15" group right at point of aim......About what I figured my tired old eyes were good for. Muzzle velocity was 2162 fps at 41,100 average psi.

NOTE: These loads all exceed the SAAMI MAP (Maximum Average Pressure) for the 35 Remington. These loads are for bolt and single shot actions only. They should not be used in any lever, slide or semi auto (exception being the Remington 760/7600 series).



The 35 XCBs were cast of COWWs + 2.2% tin and WQ'd. the BHN according to my tester was 27 +/-. The bullets were sized .360, GC'd with Hornady GCs and lubed with 2500+. They were loaded over 39, 40, 41 and 42 gr LeveRevolution powder in W-W 35 Remington cases primed with WLR primers.

The 39 gr LvR load; 2.75" group

Attachment 186885

The 40 gr LvR load; 2.15" group

Attachment 186886

The 41 gr LvR load; 2.18" group

Attachment 186887

The 42 gr LvR load; 1.58" group

Attachment 186888

In the 42 gr LvR load under the 35 XCB bullet really came into it's own. If you compare the "ES" of the five measured categories (Vel, Prf, Peak, Area, Rise) in the "Summary" section between the four loads you'll note the consistency of the 42 gr load. Additionally the accuracy speaks for itself. The 10 shot group is 1.58" (pretty darn close to 1 1/2 moa) and 8 fo those 10 shots went into .95".....a little less than moa. At a muzzle velocity ( The M43 PBL auto corrects the screened velocity to muzzle and it's listed in the "Standard Atmosphere Ballistics" section) of 2314 the 231 gr 35 XCB bullet should be a real "thumper".

Absolutely nothing wrong with the 35 XCB when a correct alloy, load and barrel twist are used.

Larry Gibson