Gas check?

[STIHL]

Ok, I’ve been getting some 150 grain 7mm bullets ready to test, I’ve seated the checks with a .286 die and the checks feel solid, but I have 1 heard snd there that feel a little play in after seated and sized the mold casts small at .285-.286 the checks feel secure.

My question is, do the checks need to be firmly seated with absolutely no wiggle? If that’s the case I need to seat and crimp the checks to .285 then powder coat and resize. I haven’t done a pound cast in the rifle, just trying to get some bullets ready. If the checks have a little wiggle will they still shoot ok? By a little wiggle I mean they feel fine, and I can’t pull them off by hand. But occasionally I get one that the check just has a hair of a wiggle to it. Is that ok, or should I try to PC then seat the Checks, the powder will give me .002-.003 in added thickens to the shank.

I know this may sound stupid, but I guess I’m just needing a sounding board to what to do.

 

[Ian]

Any variance between bullets can affect accuracy. Can. The effect could be so small that you might never notice it.

Primer and powder are VERY effective at making gas checks and shanks intimate with one another.

Diagnostics is most effective in the event of an actual problem, not a perceived one. Faintly loose checks aren't typically of any danger, so proceed to see what Dr. Target has to tell you.

 

[Rick]

Couldn't begin to guess how many checks I've fired with them just barely loose enough that if you try you can turn them., gotta be many thousands. Not falling off, just barely loose. Far more important than they aren't crimped on cockeyed. They need to be flat and flush to the bullet base.

As I read somewhere very recently . . . Proceed to see what Dr. Target has to tell you.

 

[fiver]

back in the old days gas checks had a habit of flying off after coming out of the barrel.
then super glue was invented.... LOL

anyway check, coat, and size,,,, you'll be fine.

 

[Rick]

For decades Lyman's were about the only checks and they were designed to fall off.

 

[462]

I bought some .30 caliber gas checks from Sage's -- either theirs or Gator's -- and when pulling bullets an occasional gas check will remain in the case. I reckon, then, that sometimes the gas check and the bullet will leave the barrel and go their separate ways downrange.

Obviously, they are not a crimp-on design like Hornady's.

 

[STIHL]

Ian hit it in the head it’s more of a, this just doesn’t seem right, but it’s probably ok. Just me over analyzing something that isn’t an issue. I’ll carry on with my current process and get these ready to go. I am more or less just processing some projectiles to ultimately size appropriately after all my due diligence is done with the 7mm-08 cast project I have going. After powder that should give enough diameter to size to what I will ultimately need. I haven’t shot many gas checked rifle bullets. All my GC stuff has been in handgun. And I haven’t ran into this with those as all of my handgun molds throw fat boolits.

Thank you all for the input.

 

[Ian]

One thing that can matter a lot when loading for a rifle, and usually matters more the smaller the caliber, is having fully-filled, square, sharp, non-porous bases. If you have the occasional shrunken shank due to a spot of porosity or hidden void, it will likely cause a significant flyer.

 

[Bret4207]

Chances are "a little wiggle" will be fine. If it isn't it will show up on your targets. Once you touch off the powder charge things change anyway. Gotta shoot n see.

 

[STIHL]

One thing that can matter a lot when loading for a rifle, and usually matters more the smaller the caliber, is having fully-filled, square, sharp, non-porous bases. If you have the occasional shrunken shank due to a spot of porosity or hidden void, it will likely cause a significant flyer.

I understand, I have been very diligent in my keepers, all have very sharp driving bands, bases are filled out clean and sprue cuts are kept clean. these 7mm are probably some of the nicest bullets for a rifle i have ever cast. and gotten few rejects after the RCBS was up to temp and cooking.

Chances are "a little wiggle" will be fine. If it isn't it will show up on your targets. Once you touch off the powder charge things change anyway. Gotta shoot n see.

Think I was more worried about them coming off going down the barrel, which should be very hard with all that hot gas pushing it down the pipe.

 

[358156 hp]

Segregate the bullets with loose checks and fire them for group in batches to see if this condition is significant in this case. Lyman mould by chance? I only ask because tapered gas check steps seem to be a design feature for Lyman. I suppose it has something to do with their slip on gas check design that they no longer use. The taper would make it easier to slip the checks on (and off!). I really don't mind slip on checks, I tumble my bullet in powder, then seat the slip on check over the step squarely before baking. The powder coat glues the check on permanently, plus the check itself doesn't get coated this way. My OC side insists that I ream the gas check step to square so checks will fit properly, but I still don't do that.

 

[popper]

Loose is kinda ok. Several yrs ago (on a forum from a distant galaxy) older guy had trouble in 06 with un-crimped GC. Everybody said it was ok, until he looked down the barrel and found one stuck there. Then he ordered a Lee sizer.

 

[STIHL]

Segregate the bullets with loose checks and fire them for group in batches to see if this condition is significant in this case. Lyman mould by chance? I only ask because tapered gas check steps seem to be a design feature for Lyman. I suppose it has something to do with their slip on gas check design that they no longer use. The taper would make it easier to slip the checks on (and off!). I really don't mind slip on checks, I tumble my bullet in powder, then seat the slip on check over the step squarely before baking. The powder coat glues the check on permanently, plus the check itself doesn't get coated this way. My OC side insists that I ream the gas check step to square so checks will fit properly, but I still don't do that.

Its an RCBS 7mm-145SIL.

 

[fiver]

I like that mold.
I have a hard time getting the old Ideal slip on checks to go on.
I have to press them in place with the press before sizing.

 

[Rick]

Great bullet. I shot a lot of perfect 40x40 scores with that bullet in a 10 inch TC Contender 7TCU.

 

[STIHL]

I like that mold.
I have a hard time getting the old Ideal slip on checks to go on.
I have to press them in place with the press before sizing.

I have to do the same thing with the hornady checks.

 

[Bret4207]

I understand, I have been very diligent in my keepers, all have very sharp driving bands, bases are filled out clean and sprue cuts are kept clean. these 7mm are probably some of the nicest bullets for a rifle i have ever cast. and gotten few rejects after the RCBS was up to temp and cooking.



Think I was more worried about them coming off going down the barrel, which should be very hard with all that hot gas pushing it down the pipe.

That's what I was referring to when I said things change once you light the powder. In most cases you are going to have enough pressure behind the bullet to push the check firmly in contact with the base, and a good chance the check will be further reduced, (to a varying degree), once it', in the rifling. If it is going to be a problem it will show up on your targets pretty quickly. May even get those funny looking saucer shaped holes from the check hitting the paper all by it's lonesome.

 

[358156 hp]

Gas check expanders work well too. Once I started using them, I couldn't understand how I made it so long without them.