Gas Checks That Exceed Bullet Diameter

MacD

I was given some gas checked 140 and 180 grain bullets some time back which I pulled out the other day to give a closer examination. The bullets are. 308 but the checks measure.311-.312. They are tightly crimped on to the point I couldn't get one off without ruining the bullet. I loaded one of each into an empty, primerless 308 win case with the check base even with the bottom of the case neck. They fit the mag of my. Savage 99 and chamber easily. Was wondering if anyone has seen this before. Haven't decided whether I am going to shoot them or just toss them in the melter.

PaulS

I have never done it but I would be willing to shoot them. The cas checks will squash down to fit the grooves and shouldn't cause any problems at the pressures/velocity of lead bullets.

Elvis

Im guessing they should be fine and are probably meant to be that way.
the cast projectiles I have are .308 supposedly
they go fine in x39mm but look hory in 30/30 eg they expand neck of case..fire fine though ..maybe they are .310???

gelandangan

I believe they are fine to shoot.
If you are worried, lightly lube and run them through neck sizers without the decapping pin.

Aloysius

Mac, the main task of a GC is to scrape leading from your barrel, if it should occur. So don't worry, your's will even scrape better.

I would suggest to try and recover a bullet just to check that the GC remains on the bullet during the flight. It gives poor accuraty when it doesn't stay put.

MacD

Thanks, will load up a couple. It's minus 22C here just now and blowing so still no range time probable for me until it warms up.

slimjim

MacD wrote:

It's minus 22C here just now

Hmmm ... I should come up there to do my temperature sensitivity test!

Pumpkinslinger

Just FYI, there is an article about gas checks in the April 2015 issue of "Handloader" magazine.

res45

It sound like somebody just used a .311" push through sizer or one close to .311" to apply a gas check to a .308" dia. bullet, It's also possible the check sprang back out just as little as they often do if the checks haven't been annealed before applying them to soften them up so you get a better crimp.

It's not the most ideal situation as your cast bullet should be .001 to .002" over the groove dia. of your bore gas checked or not but you will probably be ok if you keep the velocity/pressure of the load on the lower side of things. Gas check do several things but the two main uses are they help seal the bore and protect the bullets base from the high pressure gasses. They also allow you to shoot a much softer alloy usually for expansion purposes at a much higher velocity and pressure than they softer alloy could normally withstand.

The check may have also have been sized down closer to the bullet dia. as well when your seated it if you used the factory expander which is designed for jacketed bullets, Cambering shouldn't be an issue either in the Sav. 99.

In my Sav. 99 in 300 Sav. I shoot a gas check .311" dia. bullet in it all the time with excellent results even using the thicker LC 7.62 x 51 mm surplus brass reformed to 300 Sav.

Here is a 5 shot group I consistently shoot in my 99 using the Lee .312" tumble lube gas check bullet sized down to .311" that I usually use in my SKS and Mosin rifles. Nice to have a bullet that works well in multiple rifles.

Elvis

yip thats a dead deer!!!!

MacD

Thanks for the info res45.

PaulS

That's not a bad five shot group considering that it is a lead bullet load. The comment was made, and rightfully so, "that's a dead deer" as true as that is it would also be a dead rabbit or even a squirrel with that group.

Good job! Great shooting!

res45 · Last edited by res45 on Sun Mar 22, 2015 7:47 am; edited 1 time in total

I have a special load for small game for all my US 30 cal. rifles as well as my Russian SKS and Mosin.

All the loads use the same little Lee tumble lube plain base 32 cal. .314" 90 gr. SWC For the Russian rifles that have .312" groove bores I size the bullet to .314" for the US 30 cal. rifles I size it to .311" I cast the bullet from pure lead as all the loads are subsonic and MV runs between 900 and 1100 fps. In the SKS there isn't enough port pressure to cycle the action so I just hand cycle those rds.

I use Alliant Bullseye for all the loads,in the X39 I use a Max. charge of 3.0 grs. In the 30-30,300 Sav. and 54r I used 3.0 to 3.5 grs. and finally ended up using 3.5 grs. for all those larger cartridge cases as they were very accurate out to 50 yds. and easy to just throw them with my RCBS Lil Dandy and a #5 rotor.

Here is a group I shot out of my old Sav. 170 30-30 pump rifle. They shoot a little high with my sights set up for 170 gr. cast loads. I chronoed these little plinker small game loads at just over 1100 fps. average with 5 shots.

Here is another 5 shot group I shot on the same day with the 99 using the Lee 150 gr. RNFP and the same load of 2400. I have some of the Lee 170 gr. RNFP bullets I use in my 30-30 that I will be shooting in the 300 Sav. as well in a few weeks. Plan to also work on getting the velocity up closer to the 2K fps. range over the summer.

Suzanne

Hey Res45! I've been tryin to develop a load for 8x58rDanish for an old rolling block. I was wondering if you use any filler.

Suz

res45

Suzanne wrote:

Hey Res45! I've been tryin to develop a load for 8x58rDanish for an old rolling block. I was wondering if you use any filler.

Suz

The powders I use in my cast rifle bullet loads like Alliant 2400,Red Dot,Unique and Bulllseye don't require the use of a filler. There burn rates which are in the fast to Med. fast burn rate or there bulky enough with a starting load as to not require a filler.

I've personally never used a filler up to this point but if I were going to use a Med to slower burn rate stick powder and the load density was 80% or under I would use a Dacron filler. I know about fillers and why they are used but I have no experience using them.

This post may help you with some load data for your rifle.
castboolits.gunloads.c...58R-Danish and castboolits.gunloads.c...Swedish-RB