Plowing New Ground Here

[Pirate69]

Compared to most, I am still wet behind the ears with regards to shooting cast. In milsurp rifles, I have been content to shot low powder charges that I could get away without a GC. For the few calibers that I have used the GC, the base of the boolits stops in the neck where the GC is held firmly. For these two scenarios, loading is not very difficult and I have been getting pretty good results.

Ok, now enters a 8MM Mauser. Shooting without a GC, no issue. If I install a GS, the seating depth requires the GS to be below the neck, into the case. The GC, going through the neck, opens the neck to the point that the boolit is no longer held firmly by the neck.

Additional information. I am not sizing the boolits. I want to keep them as fat as possible. The unsized GC may be the problem since it is a larger diameter than the boolit.

How do you handle this situation? Do you just crimp the round at the proper seating depth, even though it has minimal neck tension? Or do I need to size the GC and boolit to a lesser diameter? Still think it will seal OK?

Need your experience please.

[paul h]

Neck tension can play a big part in accuracy, and a crimp is no replacement for a neck with proper tension.

Personally I'd use a sizer to get the gc to be sized to the same dia as the bullet.

[462]

The gas check needs to be crimped, not the case.

[badgeredd]

One can "size" the gas check with an over sized Lee push-through sizer honed out to your "as dropped" size boolit. A little hassle to hone out a sizer but likely to alleviate your problem.

Edd

[Tracy]

I haven't tried it myself, but have read (probably on this site) about the use of a Lee Factory Crimp die to crimp the gaschecks on the bullet. That would probably also size the gascheck, while leaving the rest of the bullet untouched. Just an idea. Personally, I size any bullet I use a gascheck on.

[Mk42gunner]

Neck tension can play a big part in accuracy, and a crimp is no replacement for a neck with proper tension.

Personally I'd use a sizer to get the gc to be sized to the same dia as the bullet.


The gas check needs to be crimped, not the case.

Listen to these guys, without the gascheck crimped onto the boolit it is likely to fall off at an inopportune time.

Robert

[UBER7MM]

Pirate69,

There are ways to seat a gas check without sizing the bullet. Lyman 45, 405 and 4500 models luber/sizers are one type of option. Other members might have other options for you as well.
What size are you attempting to achieve for your 8mm?

[Bret4207]

Way back in the day I didn't own a sizer, but I used GC's. Try taking a common slip joint pliers and lightly crimping the GC using the larger opening in the pliers more towards the joint. It's crude, but it works pretty well with the crimp on checks. Just sort of roll the boolit in your fingers while lightly pressing the GC crimp into the boolit. At least that will get you started.

The easier way is to get a sizer. With an RCBS or Lyman you can partially size the GC area. With a Lee you can hone it out or start the boolit base first and knock it back out with a rod from above. Use your imagination. worst case you lose a few GC's.

Oh yeah, and try annealing the GC's, just put some on top of your melt, let then turn black and skim them off and let them cool. They will be much softer and may not give you the opened necks you're getting.

[Pirate69]

It is a Turkish Mauser that slugs 0.325". Would like to seat a 0.327" boolit.

[Pirate69]

Thanks for the info everyone.

[Larry Gibson]

It is a Turkish Mauser that slugs 0.325". Would like to seat a 0.327" boolit.

As mentioned, the GCs need to be crimped on and sized to the diameter of the bullet. If you want to shoot "as cast" with your bullets then you preferably need a sizer of .327. However, if you have a .325 sizer for the Lyman or RCBS lubrisizer you can adjust the stop so you just crimp the GC on the base of the bullet and size it just enough so it won't size the case necks.

What cast bullet are we talking about? Most milsurps have a generous throat so most cast bullets can be seated out.

Larry Gibson

[Pirate69]

Larry,
It's a Lee mold. I need to go the garage to determine which one. However, it is dropping a 0.327" boolit which is great to shoot un-checked. Shot 10 rounds at 50 yards this morning that ran around 2"-2.5", as cast, with 1.3cc of Red Dot. I want to range out, so that is why I am looking to increase the load.

I guess the best option is to purchase the Lee 0.323 sizing die and hone it out to something that works with the GCs. Next Lee size up is 0.329" which is too big. Or, I could play at 50 yards and be satisfied. Nah!!

[Larry Gibson]

Larry,
It's a Lee mold. I need to go the garage to determine which one. However, it is dropping a 0.327" boolit which is great to shoot un-checked. Shot 10 rounds at 50 yards this morning that ran around 2"-2.5", as cast, with 1.3cc of Red Dot. I want to range out, so that is why I am looking to increase the load.

I guess the best option is to purchase the Lee 0.323 sizing die and hone it out to something that works with the GCs. Next Lee size up is 0.329" which is too big. Or, I could play at 50 yards and be satisfied. Nah!!

Sounds like you've got a decent unchecked load. Honing out the .323 Lee die to .327 will not be difficult, just go slow and size at least 3 bullets to measure when testing. That will then crimp the GCs on perfectly and you can switch to a medium powder like 4895 for top end loads (1800 - 1950 fps) and get good accuracy.

Larry Gibson