Do I have to use a gas check with this bullet?

[Lovesbeer99]

I'm looking for a 170gr 30cal FN round for the model 94 30-30. I've been buying them from Laser-Cast, but now I'd like to cast my own. The only mold I see is from Lee (maybe lyman) but it says in the description to use a gas check. I don't use one with the laser-cast so my question is...

If the manufacturer of the mold list the round to use with a gas check, is it mandatory, or just recommended?

Thanks in advance.

 

[Seafarer12]

You dont have to run them but if your going to push them very fast you probably want to run them. I use them on my cast 7-30 waters loads. You can always try them load them up till they start leading then either back off or start running gas checks.

 

[highlander 5]

Check Redding-Saeco for the mold your looking for,I cast that type of bullet myself. You don't have to use a gas check if you keep velocities in the 1700 fps range.

 

[Lovesbeer99]

Actually, I plan to load 9gr of unique so I don't suspect I'll get above 1300 to 1400 fps. These are like .357 mag loads and are great for plinking and target shooting at 50 - 100 yards. (Although the velocities are low so you have to hold a little over). I've heard people hunt deer with these, but I just like to shoot.

 

[jjohnson]

GC Not Needed at Lower Velocities.

If you're loading even under 1500 FPS, you'd likely be wasting your time and money with the gas checks, if you're using any but really soft lead alloy. Regular "linotype" sort of mix should work without GC up to 1700 or so before you start leading much.

 

[Lovesbeer99]

I understand, but my questions was more around - if the bullet mold says I need a gas check should I use one? In other words, do I need GC based on the mold or are all molds the same and I just add a GC based on my velocities.

Thanks for the responses

 

[Walkalong]

Molds are made specifically for gas checks. You can look at the bullet design and tell if it is intended for a gas check. You can shoot a gas check designed bullet without a check and it usually works OK, but if you are not shooting at velocities that need a check, or do not want to shoot a soft alloy faster than it can handle, then just buy a non gas check design.

Here is a gas check designed bullet mold. Look at the base where it has room for the gas check to go on it vs a flat or bevel base bullet.

Found a good pic of an RCBS bullet with a gas check

And a flat based RCBS bullet without a check. This bullet can not use a check.