Thread: Substituting projectiles

Hi guys I am relatively new to reloading centrefire rifle rounds and I was contemplating pulling projectiles from F4 7.62 ball ammo and replacing it with 150 gr SSTs and it would be great to get your input as to the suitability of this task

Cheers Kylie

People have been doing this forever
I’d suggest you necksize before seating the SST’s

Just be aware that some of the military surplus 7.62x51can be quite hot and I have found that I get significant over pressure doing this.

I would suggest starting off a few grains lighter than what's in there and working your way up.

That ammo is fairly warm. Would pay to follow the old recommendation of substitution of same weight or next weight down. Eg. either 145 gr or go down to 130gr. Been doing it with this ammo, MEN and Norinco for a few years now, generally use Hornady 130 sp. Good practice would be to knock powder back a few grains, test in rifle and maybe work back up. You’re going up in projectile weight remember.

Cheers guys I was looking at doing maybe 400-500 once I have settled on a load as I have heaps of the MEN 85 ammo that I want to re-purpose

My suggestion would be that it would be better in terms of results vs time invested to get 100 new cases, and start loading from there. If you have surplus F4 ball, sell it off and use the funds to reinvest. Remember, military ball ammo does not have a 'recipe' like sporting own-reloaded ammo. They use a bulk lot of powder during each lot number run, and test each lot of powder to get the amount required for the performance they need with each lot number of primers, bullets and case runs. This means that there could quite likely be variations between different lots of ammo, and worse case scenario is that over the subsequent years that ammo might have been mixed and blended so several different lot numbers might be in the same package. The best option you can get is like the MEN or the South African sealed plastic packs so you know it's most likely all the same recipe. But then you don't know if the factory has used several different bulk powder lots and the change over just happened to be in the same ammo lot number in the bag you've just opened... Military ammo is loaded to achieve safe reliable operation with 'X' weight of projectile travelling at 'Y' velocity with a specification for critical dimensions. Peak pressures and in-chamber performance can vary over the various lots.

Originally Posted by knightshade

Hi guys I am relatively new to reloading centrefire rifle rounds and I was contemplating pulling projectiles from F4 7.62 ball ammo and replacing it with 150 gr SSTs and it would be great to get your input as to the suitability of this task

Cheers Kylie

The projectiles in F4 7.62x51 are .3075" not .308", so lowering the powder charge is a good idea,
On the other hand factory ammo is loaded to higher pressure than NATO spec 7.62 these days
Recently I pulled down 30 rounds of .308 Federal Match reputed to be the Gold standard of factory .308
powder weight varied by 4.0 grains,
So if nothin else pulling the F4 and reloading will give you more consistent ammo,
Pull them and weight the powder charges work out the average charge and load a test batch at that weight see what you get.

Wow , I have never heard of this being done before .

You maybe swapping bullets of the same weight but there will be a significant difference in length which in turn will effect internal case capacity and pressure characteristics . I can't imagine pulling all those rounds will be an easy task , especially if they're crimped .
As has been suggested the necks will require sizing and you'll need to establish the average charge weight within those rounds before attempting any kind of load development . I would suggest a starting charge of 10% under and working up , especially since the propellant is unknown .

This isn't something that is commonplace over here in the UK or if it is I've certainly never come across it . It makes absolute sense from an economic standpoint to repurpose those rounds , especially if you guys are experiencing the same supply issues as we are .
I'd be interested in your results , if you wouldn't mind posting them ?

Did it in the states years ago probably up till present day.
Mexican handload I think. Usually 308
Used for military matches. Pull the FMJ pills and use appropriate target loads. Cheapest way at the time to get reasonable ammo

Do it. You'll be fine.
After you pull them, neck size the case before seating the new bullet.
If you get a sticky bolt drop two grains off the load and try again.

This is all very interesting. I've got some greek 303 ammo which may too hot and have been contemplating pulling the bullets, dumping a few grain of powder then reseating bullets.

I must admit I had neglected to neck size rounds I have done this to.
Am I correct in thinking that if I was to remove the deprimer in a standard lee die then it would only neck size?

Originally Posted by PeteD

I must admit I had neglected to neck size rounds I have done this to.
Am I correct in thinking that if I was to remove the deprimer in a standard lee die then it would only neck size?

Yes, but….
You’ll have to set up the die to only necksize, if that makes sense ?

You may not want to remove the deprimer, but raise it in the die body enough so the pin doesn't contact the base. You'll likely need the expander to set the neck to the right diameter for seating. For neck sizing as opposed to full length resizing, try a thin 16mm washer under the locking ring so you don't stuff up the die setting for FL sizing. I've done this with a seating die when I don't want it to crimp projectiles. Can't see it wouldn't work for a resizing die too. Be aware that some Lee resizing dies have longer neck expanders than other brands so don't back it off more than necessary.

As has been previously pointed out , the expander is what sets the final neck tension in a full length sizing die so again as has already been said , the decapping rod can be lifted to prevent popping the primer out .
Lee f/l dies are suitable for bump sizing , but you'll need to check cases will chamber before recharging and seating. If the die engages the case body without having sufficient shoulder contact the cases may grow as a result and not chamber .
It's a little thing, but worth bearing in mind.