Some primers are harder than others. Soft ones will fire, hard ones won't.

 

Some primer's are harder than other's but what generally happens with soft primer's is that they look flattened out from pressure when it's not pressure but a soft primer cup. Once you see the difference between a soft primer flattened and a primer flattened by high pressure it's unmistakable!

 

Use the bolt action.

Been there, done that.

Btw, I appreciate your attitude regarding the young man.




P

 

I will leave that choice up to him.
I think he wants to kill his first buck with his grand dads old rifle, I like the idea of it all. The reload thing is all me, just trying to save him some coin and appearntly I like a challenge. It shoots good enough for killing deer with factory loads, we just need to keep the shots relatively close. No long range gunnin'.

 

Sounds like a good young man. Good luck to you guys, hope you get that big 190

 

Thanks, any decent buck will do.

 

Primer ignition issues... SB dies..... hummm....
Sounds like you could be sizing your brass too short.
Did you smoke a case to establish proper case shoulder length sizing?

For years I loaded for a 7mm mag Browning BAR.
Handloading for Semi-Auto's can be very frustrating.
Honestly you can't expect sub MOA accuracy, I was happy with 1.5moa after a LOT of work.

For the Rem742 I'd load 180s over a relatively quick powder and be happy with sub 2moa.

The other thing to consider with old semi-autos is...... rifling wear at the muzzle associated with cleaning rod wear. SA's generally were cleaned from the muzzle end and years of cleaning rods rubbing on the riflings will cause rifling wear which ruins accuracy. About the only thing you can do at that point is fire lap the bore. Air-gaging or slugging the bore should yield in tell on bore condition.

Hope this helps,
Hunt'nFish

 

With all the tips you guys have given we may get it figured out prior to his hunt. If not we do have back up plans. Thanks again everyone.

 

Don... On the money for sure. Don't know if there's any current data on primer hardness vs brand, maybe a Google search can turn something up for those interested? All sorts of things can cause primer metal to move that have little to do with pressure.

 

Make sure you seat your bullets a little more than normal so it will eject properly. I don't think my old 742 has ever seen a factory shell

 

It may take a while to get loading issues all sorted out. Maybe your best bet for this season is to use factory ammo. Regardless, with the semi-auto I'd be trying to duplicate factory parameters as much as possible. The action is designed to function with them. I've always like the old Remington 742 and 760. My Dad had the pump version, and killed many bucks with it over the years we hunted together

 

The gun probably needs a good cleaning. The area behind the trigger mechanism collects a ton of debris due to narrow opening in the metal along the receiver. I mean it collects a TON! It is surprising how many fir needles it can hold. The trigger mechanism probably needs to be taken off so you can effectively clean back in there.

The other areaS you should clean are the metal components under the forestock. The 742 is an old gun and if the metal under the forestock hasn't been cleaned you will have rust build up. Take care of that before it creeps into the barrel.

Those two measures will help prolong the life of the rifle for that young man.

Here is a video I found, it should help get the gun apart: https://youtu.be/Cm54Qj2ZGUA