Trouble loading 7mm mauser

[DRM7997]

Hi guys, fairly new to the site. Hoping someone answer a few questions for me. For a little background I currently reload for 9.3x57 mauser, 35 whelen, 35 remington, 308 win, and 30-06.

My issue is I'm getting pressure signs with mid-level loads (flattened primers) in my 7mm mauser. No issues moving the bolt. I've tried 3 different powders, 3 different bullets, and 2 brands of brass. Also tried changing seating depths and trimming brass to min overall length. Tried adjusting my sizing die as well.

Any advice would be greatly appreciated.
Thanks

 

[troy fairweather]

Need info what rifle and the loads, some load data like nosler is modern loads.

 

[bummer7]

DRM7997,
Would you be able to post pictures of the cases?
Also what rifle are you shooting these loads from?

 

[DRM7997]

The rifle is a 98k mauser with a sporter barrel. Don't know make or twist rate of the barrel. I picked it up at an estate sale a year ago.
Unfortunately I've already deprimed and resized the brass. Did that before I decided it'd be a good idea to get some more input before continuing.

 

[troy fairweather]

What's the powder charge and bullet.

 

[Bill M.]

Put in less powder?

 

[DRM7997]

Bullets 140gr nosler ballistic tip, speer 140gr sp, and 139gr interlock sp. Powders used rl15 36.5grs, 748 37grs, and imr 4895 38grs. I worked up to these loads starting at min according to hornady and Lee manuals. Stopped when I saw flattened primers. I do have h4895 and I'm 3031 I can still try

 

[DRM7997]

Brass is ppu and rem umc. I know the rem umc is older brass

 

[troy fairweather]

Get some imr 4350,

 

[troy fairweather]

Brass is ppu and rem umc. I know the rem umc is older brass

The rem and ppu brass I got have a huge difference in case capacity stick with one.

 

[tightgroup tiger]

You may want to slug your barrel to see what the actual diameter is. This doesn't sound right.

 

[DRM7997]

The barrel on the rifle is stamped 7x57. I know that doesn't mean its right.
I'll try and find some imr4350.
Thanks

 

[troy fairweather]

What are you using the gun for, with imr 4350 it's about impossible to put in to much powder.

 

[DRM7997]

For now mainly target. I primarily hunt heavy timber in Northern Wisconsin. So 35 rem and whelen are my go to.

 

[DRM7997]

What I usually do when starting out is load 4rnds starting at min and work up in 1 gr increments till I get an accurate load or hit max. If I don't get what I'm looking for i try a different powder or bullet.

 

[troy fairweather]

1 grain jump is more then enough to miss a good node I do half grain at most and start in the middle on the data, if on a strong modern action.

There are some times were a charge that's to light can show pressure could be what happened to you.

 

[AJC1]

If you have access to a bore scope look for carbon ring....if not you should be able to feel it with a brass brush.

 

[DRM7997]

Thanks for your help guys. Especially you Troy. I'll look for imr4350. I'll also try those powders again starting in the middle and work up from their in 1/2gr increments.

 

[troy fairweather]

Excessive headspace can give faults high pressure to. Or even a chamber that's to polished. I agree ajc1 give the barrel a good cleaning to.

 

[AJC1]

Excessive headspace can give faults high pressure to. Or even a chamber that's to polished. I agree ajc1 give the barrel a good cleaning to.

See people get rid of rifles because it doesn't shoot like it used to. The easiest fix is always the best.

 

[DRM7997]

I will also be thoroughly cleaning the rifle.

 

[PWC]

I guess this is new estate sale aquisition. Does it do it with comm'l ammo? Have you checked headspace? If both of these are good, start over on load workup.

 

[DRM7997]

Accuracy was ok with commercial ammo. Their were no pressure signs with it. It really disliked anything heavier than 140gr. I have not had head space checked yet.

 

[bummer7]

Accuracy was ok with commercial ammo. Their were no pressure signs with it. It really disliked anything heavier than 140gr. I have not had head space checked yet.

But how was the accuracy of your reloads? And how was the accuracy of the commercial ammo? Was it better, worse, or the same as your reloads? I'm not making light of the pressure signs such as flattened primers, but sometimes accuracy gets lost in the shuffle.

 

[AJC1]

Accuracy was ok with commercial ammo. Their were no pressure signs with it. It really disliked anything heavier than 140gr. I have not had head space checked yet.

There is no need to pay to have it checked. You can measure your brass or buy a go guage and add tape to the back. Either way you end up with a tool and a measurement vis just money spent.