Effects upon seating cast bullet into the rifling?

[Thomas Krupinski]

I have a Lee Custom .358 260 grain RF mould that I would like to use in my .35 Whelen.

This bullet has a really straight side almost all of the way to the front.  This results in the forward portion of the bullet substantially engaging the rifling upon chambering the cartridge even when seated to the same length as my 200 grain cast round nose loads.  The 200 grain bullets do not engage the rifling.

What I am wondering is how much of an effect involving increased pressure, or anything else detrimental, would be experienced?  I have talked to my gunsmith about enlarging the throat to accomodate this bullet, but I would like to hold off on that in the event that it would negate any desired effect shooting more tapered cast bullets or jacketed bullets.

I am planning upon using a compressed charge, near maximum, of Accurate Arms 4350 powder.

Any ideas?

Thanks,

[Paul H]

I have that same mold, and same problem in my 350 Rigby.  I don't mean to insult the designer of the mold, but he obviously made a big oops in the design by not making a longer ogive, or the front section bore rider dia.  Anyhow, too late now.

So far I've been using 40 gr of RL15 for ~1900 fps, and accuracy is fair ~2" at 50 yds for 5 shots.  I want to use the bullet for hunting, and the extensive nose engraving is unacceptable for a hunting bullet.  I did try seating them deep enough so that they didn't ingrave, but groups opened up to 4" @ 50 yds.

I plan on making a nose sizing die to draw the nose down to .350", and see how that works.

I have no worries about pressure, as the bullet shoould be driven around 2000 fps, which is several hundred fps slower then what a whelen can do with a jacketed bullet of this weight.

[Thomas Krupinski]

Paul,

Why did you consider the nose engraving unaccepatable on a hunting bullet?

On my Whelen when I seat that 260 grain bullet to the length of the 200 grain, the gas check is just even with the bottom of the cartridge neck where it begins to spread.  It's a compressed load with that AA4350 and I don't think I can really get it down much further.  I anticipate that it will be pushing it a bit more than your load for Rigby.

Although it engraves the rifling on the bullet at that length, it does not bind nor grab when the cartridge is being extracted.  I have detected no pulling of the bullet from the case as a result of the throat engraving.

I am just wondering how much of a pressure increase would be anticipated because there is no gap between the bullet facing surface and the throat.

[Paul H]

Tom,

On my chamber, the bullet engraves from the ogive all the way to first lube groove.  It takes a good deal of force to chamber such a round, and I want reliable feeding on my hunting ammo, especially as everywhere I hunt is bear country.  

I don't think there will be a signifigant in crease in pressure from the engraving and lack of jump, and as I said, opperating at 2000 fps from a whelen won't be at max pressures.

[Thomas Krupinski]

Thank Paul,

My Whelen barrel is a sportized 23" on a Model 1903 Springfield action.  The engraving when seated deep is as I mentioned to the length of the 200 grain cast round nose is only about half way to the first lube grove.

The alloy is straight wheel weight and lubed with Lee Liquid Alox and in talking to the Accurate Powder tech, I should be looking at about 45,000 psi and a velocity of almost 2,400 fps with their XMR-4350.  Haven't fired it through the Chrony yet, so just thinking about it now.  Might take it out in the desert early next week and give it a try.  If it shoots well and I don't show signs of excessive pressure it could be pretty handy.

With that amount of engraving, it chambers easily with no extra pressure felt closing the bolt and I feel no unusual pressure extracting the unfired cartridge.

Just haven't had a cast bullet yet push that far into the throat.

[Turbo]

Thomas, I am interested in getting one of the Lee Custom .358 260 grain RF moulds. Could you tell me where you purchased it? I didn't think it was a regularly listed mold.

I have a 35 Whelen and have been having rather poor luck with an RCBS 200 grain bullet.  I shoot at rather low velocity and believe a longer bullet might be more accurate.

Thanks!

Jon

[Thomas Krupinski]

Jon,

That 6 cavity mould was a special production run arranged by one of the Mr. Porterfields at Midway.  I did not hear about them until they were on clearance and they sold out now, and I don't know if they will be available again.  

I was hoping that Lee would begin that 260 grain design and the 200 grain round nose as a regular production product, but have heard nothing from them.

That 6 cavity 260 grain mould is a real easy mould to use and one of my favorites for casting.  Maybe if you could also contact Midway and Lee and see if they can get something going on some more of these heavier weight 35 caliber moulds.

[Turbo]

Thomas,

Thanks for letting me know where you bought the Lee mold. I will contact Midway to see if they can acquire more 35 caliber molds for rifle shooting. I really like the 6 cavity Lee molds, but have been frustrated because they don't list them for rifle sized bullets.

Jon

[Thomas Krupinski]

Turbo,

Send me an e-mail with your address and I will return an attached .bmp file of a photo of that mould that I copied from the Midway website when they had it listed.  It gives a pretty good view of the cavities and what the bullet looks like.

[waksupi]

Resurrecting an old topic here.

I had my rifle throated to accept the heavy Lee custom. The bullet meets the lands perfectly on this bullet. Accuracy is about an inch at 1500 fps. at a hundred yards It goes to about 2 1/4" at 2100 fps at a hundred yards. I believe it has potential for more speed.

[Thomas Krupinski]

waksupi,

Have you tried any spitzer style jacketed bullets after the throat modification for that Lee cast bullet?  

I am wondering how much if any effect upon other bullet styles is the result from increasing the throating for that straight bullet.

[waksupi]

I wouldn't know about jacketed bullets. Don't own any, and can see none in my future. This rifle was built specifically for cast bullets. I am going to have a mold cut by Dan at Mountain Molds for the rifle soon, with a longer ogive, and reducing the meplate to a flat .250, most likely. I believe the larger meplate on the big Lee may have actually cut down on penetration on a buffalo I shot a couple weeks ago, so am thinking of going with something slightly smaller.

[Johm D M]

I am considering sizing the nose on my LEE 260 to .354 and see if it chambers better in my Whelen.  Has any one tried this? Gianni.

[waksupi]

It seems I have seen reference to two diameter sizing on Accurate at one time, but don't remember the details.
On the heavy Lee's, I have had trouble with the nose bumping up a bit in sizing, causing short seating, until I caught on to what was happening.
Try seating an unsized bullet in the case, and chamber it, to see if it will go in. You may be suffering from the same affliction I had.

[Cat Whisperer]

I posted the question on Accurate (about page 6 or 7ish if the link doesn't do it):

http://www.nookhill.com/cgi-bin/ubbcgi/ultimatebb.cgi?ubb=get_topic;f=19;t=001189
 
and regarding making a die on the Swaging Forum (here on GBO)

http://www.graybeardoutdoors.com/phpbb2/viewtopic.php?p=100533&highlight=#100533


There were some exellent responses in both postings - worth looking at both of them.