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GS Custom bullets my first time loading them

Grimstod

Machinist, Designer, and Shooter.
Here is what I purchased.
100 of the 165gr HP expand bullets for hunting.
50 of the 186gr HP expand bullets for hunting.

So I feel way out of my league loading these. They are monolithic so pressure and powder choices are way dif. Not to mention they are molly coated and I have never tried a molly coated bullet before. So here are my questions. Hope I am not asking to many, I just feel a little intimidated by these.

1. What sort of powders should I use? I have a list from there website for these bullets. I would like a powder that burns pretty clean and is reasonably temp stable.
2. How do they tend to take to pressure. A reloading buddy of mine used some Barns Monolithic bullets once and even with book minimum he was getting 2900fps with a 200gr bullet over just 46gr if IMR 4350. Needless to say those were dangerously hight pressured and I don't want to blow my head off.
3. How about cleaning routine? GS Custom also sent me some of there M98 bore cleaner. By the label it appears to be a coper fowling remover.
4. I can't even think of how to start with these. Really any experience you could share with me would be greatly appreciated.



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Grimstod,

Everyone I know who has started to load with Gerard's bullets has been at least slightly intimidated at first. But once you've achieved some experience with this style of bullet, you become more comfortable.

First of all please note that these are drive band bullets. The lands only engage the drive bands so the contact with the lands is minimal when compared to the standard cup and core bullets or the Barnes monolithic solids. The rest of the bullet is bore diameter or less.

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The problem with your buddy's overpressure situation was most likely their reloading manual which was printed without a proper proof reading. This manual was recalled and reprinted at great expense with the right information in the proper places. This falls in the category of 'measure twice and cut once'... Barnes took a lot of grief over this.

From the GS Custom website:

http://www.gsgroup.co.za/loaddata.html

Drive band bullets are different from standard bullets and easier to reload.

Follow the guidelines below, it differs from the procedure you would follow with other monometal bullets or jacketed lead bullets.

Please read all of it to save you time and money.



Do not use the data below for any other type of bullet.
This data only applies to GS Custom HV, FN and SP bullets with drive bands.

For load guidelines with old style GSC HP Bullets without drive bands, click here.


And from the same page but below the above warning:

RELOADING GUIDELINE

Procedure:

Drive band bullets are different from standard bullets and easier to reload.

If you follow the procedure below, you should complete your load development for speed and accuracy in the minimum of shots. If you need to fire more than 21 shots, something is wrong and you are welcome to contact GSC so that we can help.

Always use a magnum primer with drive band bullets. Do not crimp drive band bullets. See the reason.

Prepare cases properly. Do not expect good results with bad preparation. See our loading tips.

Start-loads may produce maximum speed in some rifles. The start loads in our tables are safe loads in our experience but not minimum loads. Start loads can be reduced, if required. Develop loads with a chronograph.

Develop speed first by loading one or two cartridges at the start load and one or two each increasing in half grain increments. Use one grain increments if the bullet is over 100 grains.

The indicated maximum speed in the tables, after adjustment with the FPS/INCH number, will closely correspond to the maximum pressure allowed for that caliber. The indicated speed is the maximum speed, it is not the recommended speed.

In your rifle, the load that gives the maximum indicated speed is also the maximum powder load and it must not be exceeded. The indicated speed is the maximum speed, it is not the recommended speed.

The powder load required to reach the MAX FPS will differ from rifle to rifle and the suggested start load will give varying speeds in different rifles.

Do not try to adjust grouping by varying speed. Drive band bullets are relatively insensitive to tuning with speed. Groups are tuned by varying cartridge overall length (c.o.l.). See the notes on cartridge overall length.

It is therefore best to separate the two processes and to develop speed first with no regard to what grouping is.

Using the start load, load the bullet with two drive bands into the case neck.

Check if this cartridge overall length (c.o.l.) will fit in the magazine box of the rifle. If it does not, seat the bullet deeper until the cartridge fits the magazine.

Check if the c.o.l. will allow the cartridge to chamber. If it does, continue with speed load development.

HV and FN bullets do not cause pressure spikes when loaded touching the rifling. See the reason for this.

Once the desired speed is reached, load 15 rounds with that powder charge and at the maximum cartridge length possible in the rifle. We recommend to load 50fps to 100fps from the maximum speed for general use.

Fire three for group. Run a dry nylon brush through the barrel and allow it to cool while the group is measured. Seat the next three rounds 0.5mm (0.02") deeper and fire for group. Repeat the process until it is established what the ideal c.o.l. is for the rifle. Use 1.0mm (0.04") steps if the bullet is over 100 grains.

Troubleshooting:

The signs for pressure and the signs for excessive headspace caused in the loading process, are virtually identical. If headspace/pressure signs occur at substantially lower speeds than the maximum speed indicated, make sure a magnum primer is used. If headspace/pressure signs are still present at low speeds, check that the sizer die is correctly set, according to the procedure described at this link.

As Gerard states, you can always contact them during their operation hours in their time zone (South Africa). Be sure to check the time differential first before calling.

Regards.
 
Ok here is a summery of my GS Custom 165gr bullet test.
The Gun I chose is one that has NEVER shot very well. It slugs at .313 on one side of the slug and .3135 on the other. So the bore is oval shaped. It isn't centered either. The freebore is really good though. I can seat bullets at just 3.308in to the bearing surface of the bullet. It was probably a gun that never left the arsenal. It was mint condition in every way.
I have tried many bullet and factory loads in it. SMK 174 shot ok at about 1.5moa. I also tried 150gr Sp Sierra and they shot a little better at 1.25moa. This was after a lot of testing and load development though. I have been feather frustrated with this guns poor performance as it shot factory ammo at about 3moa. So the gun just doesn't shine even though the bore was in like new condition.
Today I tried some of the new GS Custom 165gr bullets that are designed just for the Mosin. I got to say it is an amazing bullet. In this disappointing gun they can still shine. Like the sun! Even though not one of these bullets was the same powder charge, I was doing my ladder test, they still made one hole!
So here is how I loaded them.
I used CCI 250 large magnum primers.
Brass was once fired PPU
For powder I got some Vt N530 the stuff burns supper clean. I love it so far.
Then I loaded 12 rounds. Each in 1gr increments. I started at 41 and worked up to 52gr. I only shot five of them because at 45gr is was beginning to see plenty of pressure signs. When you the reader start doing this I recommend starting at 40gr and working up no higher then 45gr, some barrels may be able to handle 46gr but work up 1gr at a time. I chronographed them and only got reading on the first three bullets. Here they are.
41gr 2458
42gr 2523
43gr 2588
44gr -
45gr -
Unfortunately my Chrono failed the last two but I think if they were continuing to increase in speed like the first three then 45gr was running at 2718fps. I have a very short 22in barrel and thats pretty fast. My PPU 150gr soft tip bullets only get 2678fps.
I think with some Lapua brass I may be able to get a little faster of MV, but for now this gun is in every way ready for hunting season.
To summ it up. Always start your load development at the bottom of the recommended charge list. For this one I recommend 40gr. Check for pressure with ever new and bigger charge. When you see pressure signs STOP. Pull your bullets that are loaded to hot and live to kill that trophy deer.

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Thanks Jon I am going to stick with the 43gr load for now. It has no pressure signs and I want this guns barrel to last as long as I can make it. I will load up 12 bullets here soon but wont be shooting them again for a little while since I am moving to PA. They POI is the same as my PPU so I think I can sight in with that but wont be shooting to far.

I also did my ballistics calculations and even with the light load I will get supersonic out to 1150 yards. I will have enough energy to take a deer out to 750yards. There my lbs of energy is still at 840 so that would be plenty to take a deer. Not bad for a short 22in barrel that is not even chambered in a magnum sized shell.
 
Thanks. the barrel on it looks factory new. I used a Rock Solid Indd, scope mount. Its one of the two that I will recommend for the Mosin. All the other ones, except reproduction ones are junk.
 
Grimstod said:
...I also did my ballistics calculations and even with the light load I will get supersonic out to 1150 yards. I will have enough energy to take a deer out to 750yards. There my lbs of energy is still at 840 so that would be plenty to take a deer. Not bad for a short 22in barrel that is not even chambered in a magnum sized shell.


That is impressive! Looks like you have prepared quite well. I envy having your own range out back...perfect!!
 
I settled on a load of 43gr of the N530. At that level I get 2588fps. Not bad since that powder is pricy. I have about twelve loaded up for hunting season but I just moved to PA so I may not get to use them this year.
 
Yes I am. It's a 34 Izzy. Very off center. With all the other bullets I have tried I have had terably results. These though have been totally different. I think the greater fact they are a perfect fit for the bore and maybe the vibtori powder has a lot to do with it.
 

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