I got a good deal on some PMC .375 ammo with 300gr. Barnes X bullets ($25 a box!) The ammo shoots real good out of my 1947 M70 but the problem is that the ammo is just a smidge to long to fit in the magazine.

I am a reloader but have never tried to re-seat factory ammo, is this feasible? I imagine that the bullets are crimped in from the factory so would it be possible to just run them though a seating die and push the bullets in 1/10"? THe powder is not compresed in the case.

I wouldn't do it. Most new era factory loads are close to max. If you shorten up the OAL then the bullet will decrease the case capacity, causing your pressure to go up. I can't say by how much or if will be dangerous but if it is too much, shooting it would be the wrong time to learn about it.

Heck, I'd be game to try one, a bit at a time to see how the bullet is slideing in, and any extra pressure you might get should be countered somewhat by the extra bullet jump.

Failing that, or after that, you could pull the bullets and take a grain or so out and reload.

One other thing I should mention is that the rifle has been rechambered to 375 Weatherby. How would that affect preasure?

If it's throated like a traditional Weatherby, I doubt it would hurt. Another thought, however, is most of the Weatherby ammo is tightly compressed to begin with.

tie you rifle in a car tire and get chu a loooong string...........

This is a note from the take it with a grain of salt department. I simply took a 414 load 300 grX 375WBY in Loadtech. At max if I shortened the OAL by .1" the program calculated a 1625 psi increase in maximum pressure. The 375Wby max is 63825. If is the pressure jumps by 3000 you are still not in dangerous territory. As stated you will increase the jump for the bullet as well which could offset some of the pressure.

Any way to pick up a little space front and rear?

Thanks for the info guys. This is H&H ammo, not Weatherby and there is quite a bit of "air" in the case that is obvious when you shake the shell. I am shooting it in a Weatherby chamber though.

I do not want to modify the magazine at all on this rifle. Before I did that I would just reload for it. Like I said I reload several other cartridges but I only plan on using this for one bear hunt this fall and then will probably never shoot it again so I don't want to invest roughtly $150 into a set of dies for it. If this doesn't work I would just buy different ammo.

I assume that this ammo is a little longer due to the use of the Barnes X bullets.

quote:

This is H&H ammo, not Weatherby and there is quite a bit of "air" in the case that is obvious when you shake the shell. I am shooting it in a Weatherby chamber though.

If this is H&H ammo and you are shooting it in a Wby chamber then I would just push the bullet back (assuming you can without damage) and fire. The Wby has 8% greater capacity. Using Loadtech again. If I take a max load in a H&H and put it in a Wby case the pressure drops 6-8000psi due to the larger capacity.

If the bullet is crimped then you might have problems pushing in. You can pull the bullet out a little just enough to bend the case mouth out of the grove then push the bullet in.

Well I tried it with 5 shells to make sure they would work through the magazine, which they did, and then took them to the range. No signs or excesive preasure, POI the same as before, and the powder is still loose in the case ie. when I shake the round you can still hear the powder move in the case.

Thanks for all the advice.

Am I the only one who caught on to the 1947 M70?! Oh, I bet that's a sweet rifle. I saw a pre-64 H&H at a gunshow recently in great shape going for $2800! I bet it could tell some stories....

I have the same problem with my '47 375. The magazine is right at the spec'd OAL for the 375. Mine will be making a trip to Mark Penrod to get the magazine opened up.

-Steve