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View Full Version : Let's talk gas checks.........



pa.frank
11-24-2018, 07:05 PM
some bullet designs have a groove for a gas check but it seems most do not.

Is a cast bullet (38/357) REQUIRED to have a gas check groove in order to use a gas check or not?

I'l be using a Lyman 450 to size and seat the checks
thanks!

Rcmaveric
11-24-2018, 07:51 PM
No. You can buy plain based gas checks. Using plain based gas checks in 9mm Luger i noticed a better cluster grouping. I also had random leading problems. Those went away. For once I didn't have to clean my 9mm after some range fun.

For .357 Mag and .38 Special I hear tell that some can push those bullets harder with plane based gas checks. I am not speed deamon though with my cast bullets. I am looking for the most consistent accuracy. Gas checks help that.

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RogerDat
11-24-2018, 08:45 PM
Check out plain base gas checks. Pat Marlin's sells dies to make them, I don't know about commercial sellers, I think they exist but haven't bought any. If you post in the swapping and selling forum you might get someone to sell you some, or provide a few to try. They are really thin metal. You can make them from beverage cans.

One thing that you can't really expect to work well is gas check base without gas check. I have read a few who said some bullet or another worked ok without the gas check covering the inset base and grove but I would expect it to not work more often than it works.

Some molds can be ordered that will have some cavities plain base and some gas checked. I have an NOE mold for .303 British that is like that. Four cavity, two plain, two GC. Bolt action so don't need the high volume and like having plain base for mild loads without needing to deal with gas checks or use the gas check cavity for when I want to have a stouter load.

BallisticExpansion
03-26-2019, 02:10 PM
No. You can buy plain based gas checks. Using plain based gas checks in 9mm Luger i noticed a better cluster grouping. I also had random leading problems. Those went away. For once I didn't have to clean my 9mm after some range fun.

For .357 Mag and .38 Special I hear tell that some can push those bullets harder with plane based gas checks. I am not speed deamon though with my cast bullets. I am looking for the most consistent accuracy. Gas checks help that.

Sent from my SM-G950U using Tapatalk

How do you crimp the plain base gas checks on the 9mm bullets? Any idea of max velocity? I've been thinking about doing PC bullets with a gas check for a 9 major open gun. Talking about a 124gr going 1375FPS

stubshaft
03-26-2019, 04:56 PM
I drive plain based .357's faster than that with just PC.

RED BEAR
03-26-2019, 04:58 PM
Well this is a new one on me as i rarely use gas checks. You really can learn an old dog new tricks thanks.

Rcmaveric
03-26-2019, 07:21 PM
How do you crimp the plain base gas checks on the 9mm bullets? Any idea of max velocity? I've been thinking about doing PC bullets with a gas check for a 9 major open gun. Talking about a 124gr going 1375FPSInstall the check and run it through the sizing die. They crimp on just fine and hold. I don't push the envelope but a few of my friends say they push them to normal 9mm velocity. I need to chrono my 9mm and. 357 mag

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Petrol & Powder
03-27-2019, 05:06 AM
I don't like gas checks on handgun bullets - period.

You can push a plain base bullet plenty fast without a gas check and it's just so much easier to avoid the things to start with.

Now rifles are a different story.

BallisticExpansion
03-27-2019, 09:14 AM
I don't like gas checks on handgun bullets - period.

You can push a plain base bullet plenty fast without a gas check and it's just so much easier to avoid the things to start with.

Now rifles are a different story.

For me its about keeping the compensator from getting gunked up. Some shooters are pushing the coated 9mm bullets that fast without gas checks no issue in the bore, but the comp cleaning/maintenance is more burdensome. I still have a half a mind to just buy FMJ bullets and shoot plain base coated bullets for my lighter steel plinking loads or practice ammo.

BallisticExpansion
03-27-2019, 09:16 AM
Install the check and run it through the sizing die. They crimp on just fine and hold. I don't push the envelope but a few of my friends say they push them to normal 9mm velocity. I need to chrono my 9mm and. 357 mag

Sent from my SM-G950U using Tapatalk

A lee push through size die will work? Do you run the bullet through backwards or anything or just set the GC on the stem, set the bullet and ram it home?

I was looking at getting some of those sage gas checks.

Rcmaveric
03-27-2019, 05:31 PM
My 125 gr bullets seat fine either way through a lee sizer. I do like to push base first just because it makes a nice flat, square base. Nose first leaves the base rounded (still shoot fine though).

The 105g bulllets are tinny and its just plane easier to push them through base first.

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RogerDat
03-27-2019, 06:18 PM
I do base first because I think it does a better job of seating the gas checks. Most of my cast bullets are a RNFP design so the ram pushing on the tip isn't a problem. Almost all the rest are a broad rounded point where a little metplat is not a problem it's a feature :-)

I sometimes use a tiny amount of Lee sizing lube to lubricate the bullet nose so it doesn't leave excessive lube before the check goes through the die base first. Lee sizing lube cleans off with hot (tea kettle hot) water very well and has given no indication of contaminating the surface so PC won't stick. Dry with towel and time or hit with a blow dryer to speed the drying process along.

BallisticExpansion
03-28-2019, 10:16 AM
Sweet... I'm going to order some checks from Sages. Thanks for the info guys! Hope I can make this work and save some dollars!

Boolseye
04-01-2019, 05:36 AM
I tried PB gas checks and found them to be a PIA–incredible force was necessary for me to apply them, and they didn't always stay on very well. I really wanted to like them, but I gave up on the concept. Seems others have much better luck with them, hopefully you do, too.

BallisticExpansion
04-01-2019, 02:35 PM
I tried PB gas checks and found them to be a PIA–incredible force was necessary for me to apply them, and they didn't always stay on very well. I really wanted to like them, but I gave up on the concept. Seems others have much better luck with them, hopefully you do, too.

Got any extra you want to send me for testing :) ?

Boolseye
04-01-2019, 04:09 PM
just looked, no dice. Don't know what I did with them.
They're pretty cheap from Sage–he's definitely a good guy, I just couldn't find a system.

beagle
04-01-2019, 11:01 PM
Ballistic Expansion. You have a PM./beagle

osteodoc08
04-03-2019, 01:54 AM
I don't like gas checks on handgun bullets - period.

You can push a plain base bullet plenty fast without a gas check and it's just so much easier to avoid the things to start with.

Now rifles are a different story.

Same here for the most part. I do notice a bit more uniform groups at longer distance when pushed hard with GC magnum pistol rounds, especially when shot in rifles.

rintinglen
04-25-2019, 11:30 AM
All things being equal, I have always found that gas checked boolits were more accurate in magnum revolvers than similar plain based. In the special cartridges, particularly the 38 special, plain based work so well that there is no benefit worthy of the time it takes to fiddle with them.
In rifles, however, save for "cat's sneeze" or similar loads, gas checks are essential for adequate accuracy, if more than a few cartridges are to be shot at a sitting. Once you get much past 1500 fps, especially in "fast " twist bores 1-10", 1-12" etc, leading becomes a real problem.

gwpercle
04-25-2019, 02:57 PM
All things being equal, I have always found that gas checked boolits were more accurate in magnum revolvers than similar plain based. In the special cartridges, particularly the 38 special, plain based work so well that there is no benefit worthy of the time it takes to fiddle with them.
In rifles, however, save for "cat's sneeze" or similar loads, gas checks are essential for adequate accuracy, if more than a few cartridges are to be shot at a sitting. Once you get much past 1500 fps, especially in "fast " twist bores 1-10", 1-12" etc, leading becomes a real problem.

Well said ! My experiences have shown the same .
I've never been reluctant to use gas checks when the boolit had a place for one and I thought it might help .
Gary