8x57 Gas Check Question

[SPRINGFIELDM141972]

A long while back I purchased a box of old 8mm Sierra gas checks to use with my old Mauser. I had not opened box or attempted to use them because I could never get my LEE Karabiner mold to produce acceptable boolits. I finally figured out what I was doing wrong and was excited to break out my checks and get some sized up. Well, they don't fit the shank at all. They are way to thick of material to go onto the shank, even when annealed.

Which leads me to this question; Can I load the check backwards into the neck as long as I am mindful not to let it push past the neck and has anyone had problems trying to do this.

Regards,
Everett

[Blammer]

get a steel ball bearing and use it the "flair" the GCs' some to see if they'll fit or just spend a few bucks and get some new 8mm GC's.

and to answer your question, no I have not inverted a gc then try to make sure it stays in the neck. To me that's just asking for trouble.

[UBER7MM]

SPRINGFIELDM141972,

32/8mm Hornady gas checks fit on my Karabiner boolits without incident. My guess is that it's your particular gas checks, if our molds are identical. Blammer's advise sounds like the quickest solution.

I hope this helps,

[oldarkie]

I also use hornady checks and they work great.hope you like this boolit as much as I do,shoots great in my old 98.

[Skunkworks]

Dont know Sierra gaschecks, but:
I know the difference between Hornady and Lyman is that hornady is "open" and Lyman is straight sided.

A hornay will crimp onto the boolit base
82352

And a quick google tour confirmed that i was lying!
The Lyman is also crimp on.

So maybe what i heard some/(long) time ago was that it was the Sierra checks that was "slip" on?

I was right after all!
The old Lyman checks they made themselves were slip fit, the new ones they sell are Hornady.

http://castboolits.gunloads.com/archive/index.php/t-23498.html
http://www.lasc.us/Brennan_4-2_GasChecks.htm

[Hardcast416taylor]

I`ve read that Hornady makes the gas checks that Lyman sells under their brand name.Robert

[gnoahhh]

I had the same problem with getting Hornady checks to fit a specific bullet. I turned a small punch, the end of which mimics the base of this bullet, and by using it in a small antique arbor press I 'squash open' the checks that will go for this application. It's a bit of a pain, but the results justify it. Perhaps you have a machinist friend who could make something similar for you?

[Char-Gar]

It is not uncommon to flair checks to get them on the bullet gas check shank. It is nothing I think odd or a reason for concern.

[45 2.1]

A little tip for those of you with out of spec gas check shanks......... you can use the next size (if they are the crimp on type) up usually if it is relatively close. 30 goes to 8mm/32 cal..... 8mm/32 cal goes to 338 cal........ etc.

[SPRINGFIELDM141972]

Thanks to all for the suggestions. I did as suggested and opened them up a bit and they work just fine.

Regards,
Everett

[338RemUltraMag]

A little tip for those of you with out of spec gas check shanks......... you can use the next size (if they are the crimp on type) up usually if it is relatively close. 30 goes to 8mm/32 cal..... 8mm/32 cal goes to 338 cal........ etc.

Or if you shoot me a PM with shank diameter and size diameter I can usually make a custom thickness check. you must be careful when using the next size up, for example if you use an 8mm check with an OD of .330 and then put it on a 30 cal that is sized to .309-.310 you are likely to get swaging of the check and it will look like you smeared it across the boolit.

[45 2.1]

Or if you shoot me a PM with shank diameter and size diameter I can usually make a custom thickness check. you must be careful when using the next size up, for example if you use an 8mm check with an OD of .330 and then put it on a 30 cal that is sized to .309-.310 you are likely to get swaging of the check and it will look like you smeared it across the boolit.

Not had a bit of trouble with any Hornady GC doing this. I've used 6mm on 22 cal., 25 on 6mm, 6.5 on 25, 7mm on 6.5, 8mm on 30, 338 on 8mm, 35 on 348, 375 on 9.3mm.... all with good results and no troubles. You will note I said "(if they are the crimp on type)".

[Three44s]

OK, thinking outside the box here:

Standard issue 7mm checks are a pain to find right now ......... the last time I looked, you could find 6.5 checks ....... are they going to work from .264 to .284?

I do have barrels and brass for .277 (but no molds) yet in case. Just don't have any mounted on an action right now.


Three 44s

[338RemUltraMag]

PM me, I have 7mm checks for $18/K

[45 2.1]

Standard issue 7mm checks are a pain to find right now ......... the last time I looked, you could find 6.5 checks ....... are they going to work from .264 to .284?

If you look at the Hornady GC dimension chart which lists all the supposedly pertinent dimensions of a GC, you will see that the shank diameter for those two are (6.5mm) 0.254" and (7mm) 0.253". Those seem compatible. Unfortunately, the outside diameter lists at the basic caliber dimensions. OF course you know that isn't right because they are larger than caliber on the outside.... So, it's one of those situations you just have to try it and see. Usually you use a larger one going down to a smaller caliber... as long as the GC fits in the sizer flat.

[Skunkworks]

This might help:

http://i295.photobucket.com/albums/mm153/Chickenthief/Skydning/Gas_Check_Dimensions_zps47f16de0.gif (http://s295.photobucket.com/user/Chickenthief/media/Skydning/Gas_Check_Dimensions_zps47f16de0.gif.html)