7x61 SHARPE & HART

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Just bought a Schultz & Larsen chambered for this cartridge. I have a part box of Norma 160 gr factory stuff I picked up at a gun show several years back. The original Norma loading was supposedly 160 gr @ 3100 fps!! I know Norma stuff is hot but that seems a little over the top. The 7mm Rem. Mag. is a bigger case and I have trouble getting 3100 FPS with a 140 without pushing the pressure envelope. I know there were 2 versions; the later one marked "Super". I seem to remember reading that the Super version was on a thinner case that held a little more powder to get higher velocity. I have cases for both versions but no empties of one version to weigh.

Anyway, anybody ever fooled around with this cartridge?

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Any pet load information? I've just acquired a Custom Mauser in 7x61 with 26 inch barrel. I'm guessing it's 1-12 Pitch as it appears slower than a 1-10 barrel I examined.

charliemeyer007

I like full or lightly compressed case full loads of slower burning powder in my 7mm Rem Mag. The Hornady 162 BT is my all time favorite bullet on top of a full case of H870 or just above the top of shoulder with T870.

Candle soot black is better for marking bullets for seating depth than Sharpie black.

http://www.chuckhawks.com/7x61_SH_Mag.htm

62fuelie

Mine liked 62 grains of IMR4350 with the 154 Nosler partition and the Federal 215 primer. You can check the twist with a cleaning rod with a tight fitting bore brush. Put a piece of masking tape around the shaft of the rod so it forms a "flag" insert and put a Sharpie mark on the shaft when the brush has engaged the rifling. Push slowly until the flag makes one rotation and mark again. Push on through and measure the distance between the marks, that's your twist.

XXCross

A one in twelve twist would be a little slow in any 7mm.
MAYBE a one in ten, or even a one in nine.

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I put masking tape flag on my Dewey Rod. I then used white-out to mark as the rod is covered with black plastic coating. Using the rear of rcvr. tang as reference point I marked and repeated twice one rotation and arrive at 1-10 twist. I'm happy to now know I have a 1-10. I just assumed it'd be a 1-12 because they were using this twist back in the day for this cartridge. Thank You 62 Fuelie!
I've loaded some rounds to try out using 120, 139, 154 grain bullets over 53 grains of H-380 using a standard large rifle primer. I had acquired some reloads and I pulled them down to see 63 grains of stick powder that looked like IMR-4350. The bullets here were 175 grain bronze tipped silver jacket spitzer that compressed the powder to the point I had to break it apart. The other re-load was 63 grains under a 162 grain spritzer. I reduced both of these hand loads to 56 grains each.
I really don't like compressed loads. I have also on hand besides H-380, IMR-4831, IMR-4350, IMR-4320, Reloader 22.
Is the 154 grain bullet over 62 grains of IMR-4350 near max? I've read that this cartridge was designed to work with IMR-4350.

62fuelie

The 62 grains of 4350 and the 154 is very close to max, so you may want to start a few grains back and work up. The 26 inch tube will give you plenty of time to build velocity.

Ambrose

Be advised that Norma made two different cases for the 7x61. The older, original cases were head-stamped "7x61 S&H" while the later ones are head-stamped "Super 7x61". There is a considerable difference in capacity: The older cases hold 70.3 gr. of water to the junction of the neck/shoulder while the later "Super" cases hold 75.3 gr. If you're using Norma cases, don't mix the "Super" cases with the "S&H".

My rifle is a Schultz & Larsen and has the early super-slow 1-14" twist (It is so marked on the barrel) and will not group decently with bullets longer than the 140 gr. Sierra flat base but it groups under an inch with that bullet and 67.5 gr. of H4831 and WLRM primer (velocity is 3143 fps). The 120 gr. Sierra flat base also shoots very well. I am using Norma "Super" cases.

In re-reading the above, it looks like I stated there were two different 7x61 Sharpe & Hart cartridges and that's NOT what I meant! The exterior dimensions of the "Super" and the "S&H" are the same and the cases are intended for the same rifle. The "Super" cases have greater internal capacity to allow for more powder and thereby get a little more velocity.

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Thanks for the detailed info on case capacity differences. I did read about this change was done later to gain more fps.
I have also re-formed cases from 7mm Rem Mag. & 270 Wby Mag. to try yet. If I anneal cases first the 7mm Rem Mag have less dents in shoulder. The 270 Wby Mag reform perfect. Both Rem. & Wby. are then trimmed to length. It appears the Weatherby Mag. cases are a smoother transition to become 7x61 S&H.

sandwarrior

Speaking of slow 7mm twists, I have a 7x57 custom Mexican 1910 that was re-barreled to a 1-12" twist. The heaviest bullets I can stabilize through it are the 154 Hornady's. It will not stabilize either 160 RN or spitzers. I imagine then the 154's are right on the verge.

Ambrose,

good to know there are two different chamberings for this. I wonder if there were any European differences in Nomenclature that picked this up? I know many people here in the U.S. don't know there is a difference between .30-338 and .308 Norma. In fact, two reloading books I have write that they are the same. And, they are not! One could get away with putting a .30-338 in a .308 (vice-versa won't fit) and firing it, but you are trashing your throat. Not to mention the excess space the case has to fill takes up a lot of useful pressure and you don't get much velocity.

richarda

One additional thing to note - back in the day, many 7x61s, like the Weatherbys also, hade chambers w/freebore in front of the neck , so as to permit loading to higher pressures to obtain maximum velocity.

Ambrose

sandwarrior: Please understand, there are NOT two different chamberings for the 7x61 Sharpe & Hart. There are, made by Norma, two different cartridge CASES. The ones with "Super" in the head-stamp are lighter, thinner, and hold more powder (see my post above).