Just brought my new Mdl 70 375 H&H home from the gunsmith after bedding and some other work. I had loaded some ammo while the rifle was away, and I cycled each round through the magazine, into the chamber and out. On two of the rounds, the bolt would close, but was very difficult to push down in to the final downward position.

What would cause this?

I have had this happen when brass cases became too long for the chamber in Model 700 in 25.06.

Marv

Don't fire the hard to chamber rounds. If they are long pressure could go thru the roof. On the other hand the shoulder/neck could be pulled forward due to lack of lube on the neck sizer.
Good luck!

The cases had been trimmed and the overall length is the same as the rounds that chambered. What do I look for on the shoulder/neck?

Improper die adjustment or not lubing the necks can pull the shoulder forward, making them tight. I would lean toward the first as the second problem is more likely with a cartridge with a longer bottleneck, like a .243 not a .375 H&H. Of course bullets could also be seated out too long, hitting the rifling, but you can mark the bullet and make sure that's not happening. That's also not likely with a .375, since almost all of them will be too long for the magazine before they bump the rifling, at least in my experience it would be rare for a .375 to fit the mag. and touch the rifling. If you can close the bolt, you can probably shoot them and readjust the die. Marking the shoulder with a magic marker will tell you where the contact is occuring.

You said you just got bedding done and some other work. Don't assume your gunsmith is perfect. It may be possible that the problem is not the brass.

If you want to really check, blacken the bullets on the long rounds with a sharpie and cycle them thru the rifle. If there are no rifling marks on the bullets, load 'em up and shoot 'em. Sounds like you kinda short stroked a couple of the cases when you resized. No biggie.

It is never advisable to fire hard chambering rounds unless you know for certain the cause.

Pull a few bullets and resize the cases full length and see if the case alone chambers easily. Double check the length while you're at it.

You might check the measurements on the belt and just forward of the belt. That is where the belted mags go out of spec. Makes them hard to chamber and hard bolt closing. If this is the case and you can still close the bolt you won't create any high or higher than normal pressures
due to the belt being out of spec.

The front screw on M-70's goes through the lower lug recess in the action. Check to see if there might be a little piece of bedding material stuck in the lug recess that would cause the bolt to bind. Or, as the gun is newly bedded, see if the front screw might be rubbing on the bolt lug and binding it slightly. If so, shorten the screw a little.

I would recommend trying some factory ammo to determine if the brass or the chamber is your problem.

If factory ammo is tight you should then check headspace.

Regards,

Dan

The 375 H&H headspaces off the belt, so most likely the shoulder is not too far forward but the case has gotten bulged just ahead of the belt.

This is what that 2 piece magnum resizing die that you see in the reloading catalogs is for. If you have a lathe with collets, or a friend who has, you can also use that to get rid of this bulge. I haven't had coffee yet, but I think the #5 (??) collet is the proper one to use.

quote:

You might check the measurements on the belt and just forward of the belt. That is where the belted mags go out of spec. Makes them hard to chamber and hard bolt closing. If this is the case and you can still close the bolt you won't create any high or higher than normal pressures

This is commonly a problem w/ belted brass. You will see the bright marks just above the belt where it's rubbing.

It's not dangerous to fire these or other tight brass AS LONG AS you know the bullet is seated at the proper depth and the brass is trimmed to the correct length. Brass that is tight at the belt or tight at the shoulder will often expand to your chamber when fired and then contract and come out much easier than it went in.

Good Luck

Reloader

quote:

Originally posted by Mark:
The 375 H&H headspaces off the belt, so most likely the shoulder is not too far forward but the case has gotten bulged just ahead of the belt.

This is what that 2 piece magnum resizing die that you see in the reloading catalogs is for. If you have a lathe with collets, or a friend who has, you can also use that to get rid of this bulge. I haven't had coffee yet, but I think the #5 (??) collet is the proper one to use.

Are these handloads on fired or new brass? Did you FL size or just neck size? An out of round chamber could cause the problem too.

I would never cut metal away from a cartridge case there! It could weaken and thin the most vulnerable spot on any case. Don't do it.

Instead blacken the cartridge and see where it's hanging up. Go slow on this with the firing pin removed. If you don't find the problem take the gun back to the smith.

If you can get one try a small base die. Also are you trying Nickle Brass? I had a problem with new Nickle Remington Brass with my 300 Win mag with the bolt closing hard. I went back to regular brass (non Nickle) and have not had anymore problems.

A friend bought a few hundred 300WSM once fired off E-Bay and a lot of them wouldnt fit even after they were full length resized and trimmed for length.

Lot of great suggestions here, thank you. They are nickel cases and it was only two out of 10 that I had a problem with.

Savage99,

Thank you for bringing that up, that was not what I meant to imply but I could see how it might be misinterpreted.

What I meant to say more clearly was the case needs to be squeezed down right next to the belt. You can buy a 2 part die to do it:


Now if you do not have one of these, and have a lathe or mill with collets you can put a case in the collet and squeeze it to get the same result. Again, I see how it could be interpreted to mean turning the bulge off which as you said is a recipe for disaster.

And also, as many have mentioned the first thing to do is color a case with a magic marker to find out exactly where it is binding.

Mark:
Where do I find one of those dies you have shown in the picture above?

midsouth shooters supply has them, that is who I linked the picture to.

http://www.midsouthshooterssupply.com/item.asp?sku=203-...search=yes&submit=GO

The company is Innovative Technology, google that and magnum resizing die.

quote:

Originally posted by Mark:
midsouth shooters supply has them, that is who I linked the picture to.

http://www.midsouthshooterssupply.com/item.asp?sku=203-...search=yes&submit=GO

The company is Innovative Technology, google that and magnum resizing die.

Thanks Mark I went to there sight they are on order but I added it to my wish list. I want to try it on my New resized Rem Nickle brass that wont fit.

I marked the bullets and shoulder/neck of the two rounds with a magic marker and chambered each. They came out with no marks on the areas marked. Now what?

One more thing to check. If you don't clean primer pockets, you may have a primer not fully seated. If that's the problem it will be easy to tell as you'll see a half circle mark on the outside of the primer(from the bolt turning down). Take a look at them, you may see a light mark on the ones that chambered.

Jstevens,
That was a good idea. I checked, but there wasn't any mark. I'm leaning towards the theory that I didn't size them properly, although I don't know how that would happen as I always use a full stroke.

Swede44,

I just looked at midway and they are discontinued there, and went to the website larrywillis.com, they say they are out of stock too and are looking for someone else to make a run. So you may have a wait here.

Set your shoulder back on your case just a tad by adj your sizer die down a additional 1/4 Turn or until your brass chambers smooth.