RCBS 30-180 question

[tinhorn97062]

I'm loading this boolit (first cast load in this rifle) in my .30-06 and am a little confused on the COAL. As I do with most other loadings in this rifle, I seated it way out, put it in the chamber, and let the bolt seat it the rest of the way. Doing this, it's hitting the lands but leaving the upper grease groove exposed. Is this normal? The OAL is 3.13, if I remember correctly.

http://images.tapatalk-cdn.com/15/09/08/5add830817d4968f192fded790a25636.jpg

[Yodogsandman]

Lots of my loads leave the top lube groove exposed. Try shooting it with and without any lube in the groove and see which way you get better accuracy or if there's any difference. I normally just wipe the lube out after loading the case with a paper towel.

[Tatume]

It appears that your bullet was engraved by the rifling all the way down to that grease groove. In my opinion two things are happening here. First is your bullet is probably undersized, or you wouldn't be able to extract it without pulling the bullet from the case. Second, you are seating it out too long.

If you are using a 0.309" sizing die, try a 0.310" or even 0.311" die. Then seat the bullets until they do not touch the rifling, or if they do, they just barely do so. I suggest trying some seated with the crimp groove is level with the case mouth. You might be surprised!

[tinhorn97062]

Thanks guys!

I make those adjustments and will be shooting them this weekend.

[Scharfschuetze]

Wherever your final OAL ends up at, I wouldn't worry about grease groove exposure unless the ammunition is for field use. I like my cast boolits to touch the rifling and to also keep the gas check out of the powder chamber, thus an exposed groove is inevitable at times.

A couple of my rifles with very short necks (308, 7.65X53, etc.) all end up getting shot with exposed grease grooves for target shooting, even out in the field. I just store such ammo in zip lock bags or other dust and dirt proof container until I fire them.

By the way, I've had good results with your RCBS 30-180-SP boolit in my 30/06 rifles.

Here's an example for the 7.65X53 Mauser. Boolit is the Lyman 314299.

[tinhorn97062]

Wherever your final OAL ends up at, I wouldn't worry about grease groove exposure unless the ammunition is for field use. I like my cast boolits to touch the rifling and to also keep the gas check out of the powder chamber, thus an exposed groove in inevitable at times.

A couple of my rifles with very short necks (308, 7.65X53, etc.) all end up getting shot with exposed grease grooves when shot at the range. I just store such ammo in zip lock bags or other dust and dirt proof container until I fire them.

Here's an example for the 7.65X53 Mauser.

Well that makes me feel quite a bit better. I've only loaded cast in a .45-70 prior to this, so the exposed grease groove kinda threw me off last night. That dummy round I made fits in the mag well just fine and chambers like butter. I'm gonna load a few up with IMR 3031 to try out this weekend and adjust accordingly.

[wmitty]

Remember, there are two versions of the RCBS 30-180-SP.

[Leadmelter]

That does not look like my vintage 180 gr RCBS. Mine has a flat nose.
Leadmelter
MI

[tinhorn97062]

This boolit shot very well today over 33gr of IMR 3031. I wasn't able to chronograph the loads, but the accuracy was right on par with my 180gr Hornady Jacketed load. I was extremely impressed with it. I have a couple more styles to try out, but I anticipate the accuracy will probably be similar.

I loaded (5) each of 31gr, 33gr, and 35gr. The 31gr load grouped about 2" at 75yds. The 33gr load grouped right around an inch, and the 35gr load went to non-existent. Those rounds were just all over the place.

So it seems that my rifle likes this boolit over 33gr of IMR3031, with it seated to the lands. I'll tweak it a bit from there, but a group like that, with the first ever cast lead shot from it, makes me happy.

[Scharfschuetze]

That does not look like my vintage 180 gr RCBS. Mine has a flat nose.

I should have been more clear in describing the photo. It's an example of an exposed grease groove per the OP's original question of same, not of the RCBS boolit. Sorry about the confusion.

The boolit shown is actually the Lyman 314299. I have several 10 shot groups measuring in at 1 1/2 MOA with this boolit and it is now my boolit of choice for the 31 calibre military rifles. Here is that same round shown in the first photo as fired from an 1891 Mauser.

You can see from the original photo of the 314299 and this photo of the RCBS 30-180-SP mould, that the two boolit designs are miles apart, yet they both shoot quite well from the same rifles. I don't have any of the RCBS cast right now, but you can see it pretty well from the cavity in the mould block.

[MT Gianni]

That does not look like my vintage 180 gr RCBS. Mine has a flat nose.
Leadmelter
MI
RCBS has a 180 FN and a 180 spitzer in their catalog.