NOE 360160 SWC double crimp groove loaded as 38spl, 2 diff guns

[gefiltephish]

I purchased this mold with the intention of using it only for a new 686+. However, as things happen, yesterday I picked up a used S&W M64 38spl+.

For clarity, I'm going to call the canelure closest to the nose as #1 and the other obviously #2.

For the 686 I use #1 for 357's and #2 for 38spl. This works out great. However, those 38spl cartridges are too long for the 64's chambers. If I seat the bullet to #1 in 38 cases it drops in no problem.

I'd prefer to have only one 38 cartridge set up for both guns. Seating that bullet almost .100 deeper means working up new loads again. But this also means that the bullet now has .100 *more* free travel before it hits the cylinder throats in the 686. I'm thinking that this may result in a lot of lost pressure and velocity. BTW, I don't have access to a chrono.

So my question is, would I be better off making up separate cartridges for each gun or should I go ahead and use the shorter cartridge for both guns?

For data I'm looking at Lyman 49 pg 355, bullet #358665. Since the bullet weight and OAL work out to be nearly identical to my bullet seated to #1, I'm assuming this data is suitable. These cartridges would be primarily for my wife, so not looking to hotrod. I would appreciate any opinions.

http://castboolits.gunloads.com/imagehosting/thum_83024f3fd5329730a.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=4008)

[PacMan]

I would load the shorter length for both. The only draw back would be in the longer cylinder gun you may get some carbon build up that may cause problems at some point but a good cleaning should cure that.
If you want to shoot the same loads inboth work them up in the 38 and hope they shoot well in the 357.

[gefiltephish]

I did just that yesterday and took 'em both to the range. Bullseye @ 3.0, 3.2 and 3.4 worked well in both guns, but I'll likely stick with 3.2.

The 686 is definitely more accurate, or at least it's easier to be more accurate with. Even with the extra-short cartridges I was able to easily nail the bullseye (7yds offhand) 6 out of 7. #5 usually turns out to be a flyer for me. I guess it's just a concentration thing. I could hit the 25yd gong all day long though.

The 64 was ok and grouped fairly well, close enough for home defense, but the sighting is way off and nonadjustable. About 1 1/2 low and left for me. My wife was not liking this gun regardless of cartridges, said it had too much muzzle flip. I had her remove the wool gloves and worked on her grip, resulting in a drastic improvement.

For both guns, I was disappointed to see some leading at the forcing cone and for a short distance after. Nothing alarming, but I just wasn't expecting it. Both barrels slug to approx .357. Bullets are sized to .358. .359's won't chamber. The 686 has been fire-lapped, the 64 doesn't need it. I'll double check the BHN, but expect them to be 12-14. Still, maybe I need to go a little bit softer, say 8-10?

[C A Plater]

You might want to check the cylinder throats and see if they are undersized. I had a similar leading pattern on a Ruger .45 Colt. They were .447 originally and opening them up with a .451 reamer cured the problem. Not saying you have the problem but it don't cost anything to check.

[gefiltephish]

Throats are groove diameter.