Primer question

Silentstalker · May 16, 2009

Hey guy's,

I am in the process of working up a load for my 7mm WSM. It is a Winchester M70. I am using IMR 4350 right now and have a problem with cratering at low to medium loads. Even factory Winchester ammo craters just a bit. My loads were enough to cause me to stop until I get some advice from you guy's. I have been told by a few guy's to try different primers due to differences in primer jacket thickness. I am shooting Federal primers right now.

Is this a good idea or should I just switch powders? The loads I shot grouped as well as 1" but none tighter. The brass as it comes out of the rifle is fairly tight whether it is factory or reloaded. I am thinking it was a tad tighter with the reloads.

What are your recommendations?

RELH · May 16, 2009

I use IMR-4350 in my 300 mag loads and it seems to be a powder that does it's best at or near max loads.
If you are sure that your loads are not near max, it could be your brand of primers. CCI is a good primer with a heavy metal cup. Try finding a 100 of them and try it to see if it cures the cratering. Your rifle may also just have a very heavy firing pin spring or a pin that protudes enought to cause cratering.

RELH

Hardway · May 16, 2009

What bullets are you using? If they are nosler etips or another solid copper bullet you may be at max pressure. Nosler recomends using a lighter charge than you would with the accubond or ballistic tip.

"A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms shall not be infringed."

Silentstalker · May 16, 2009

I am using 160 grain SST's. My plan is also to build a load for the Accubond.

I will try the CCI primers. Any other ideas?

How do I tell if my rifle has a heavy firing pin or it is cratering?

ELKOHOLIC · May 16, 2009

LAST EDITED ON May-16-09 AT 06:17PM (MST)[p]LAST EDITED ON May-16-09 AT 05:53?PM (MST)

I have a gun that the firing pin causes minimal cratering. I asked the same thing a while back. If its not that bad I wouldn't worry about it. And, if it does it with factory ammo I would say its just the gun. Do you have any other pressure signs?

Are you full length sizing every time? Whats throwing me off is you said the factory ammo is even tight. Hope someone has an answer for you. Maybe the chamber tolerances are just tight on that gun? Have you looked into the chamber to see if its dirty?

ps. By the way, Good luck finding any Primers. Let me know if you find any.

Silentstalker · May 16, 2009

Yeah, I am full length sizing every time. I am new to reloading but as far as I can see I don't see any signs of over pressure. My gun is pretty clean but I will touch up the chamber again. Lucky for me, my 7mm Rem takes the federal primers just fine, and my Dad has a pile of CCI's. I will try those and cross my fingers that I can find some more to replace those for him! I will let you know if I find some too!

Thanks guy's.

ELKOHOLIC · May 16, 2009

Silentstalker, You say that your 7mm Rem mag takes the primers just fine? Are you using the magnum primers for your 7mm WSM? I am pretty new to this too, but I noticed it don't call for a magnum primer for 7mm WSM. Just wondering if your using that because thats what most use for the rem mag. I don't know if that would cause you problems or not. Just a thought. I have heard people use the large rifle primers for the rem mag so maybe its not a big deal?

Silentstalker · May 16, 2009

LAST EDITED ON May-16-09 AT 10:00PM (MST)[p]Yes, I did use the magnum primer. Maybe I better look at that again! Hope I did not make a mistake! Thanks for the info. I will go look that up right now! I bet that is my problem. What a moron I am!!

Edit:

I made a mistake. I will switch to the large rifle. I bet that fixes it! Thanks for helping me.

REDDOG · May 16, 2009

Hope it works out for you, but i bet not. I load for a 7wsm and cant recall using anything but mag primers.

if the load was developed using standard primers, the old rule of thumb is to back off 2 grains if you plan on running magnums.

you also said that factory ammo gives it a stiff bolt? i know its rare, but i have had to send a factory gun back because it had excessive head space.

I have another factory gun that the chamber is so tight in, that if i fire factory ammo it will blow the primer! how this happned to me i dont know, i have never heard of it before in a mass produced gun. but this rifle with the neck's reamed and some carful hand loading is one of the best shooting guns I've ever owned!

huntindude · May 16, 2009

A WSM not using a magnum primer? that seems odd.

It wouldn't surprise me if your cratering is worse with a standard primer, the 215 is a thick cup and the difference in pressure between it and a standard may not offset the metal thickness , but you never know.

I use a magnum primer in my 270 Win all the time, don't worry about using a magnum primer in a WSM if it was me I would anyway, just adjust your load to work. don't rule out a poor firing pin fit as your problem , many guns crater even with factory loads and most of the time that's the problem.

BuckSnort · May 16, 2009

Since you stated....."The brass as it comes out of the rifle is fairly tight whether it is factory or reloaded"

My suggestion to you would be to take it to the a smith and have him measure the headspace...

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ELKOHOLIC · May 17, 2009

Like I said. It probably don't matter. I'm still new to this just trying to help him out. I was surprised as well when I looked in the book and it called for a standard large rifle for the wsm.

Not to hijack the thread, but I have a lot of large rifle primers. Has anyone had good luck using them in the Rem mag?

Silentstalker · May 17, 2009

Okay guy's,

It sounds like the primers are not the real issue. Perhaps a jacked up firing pin or a gun with out enough head space?? This gun has less than 100 rounds through it.

Is this something I should contact Winchester about? Any good gunsmiths in the SLC area you recommend?

RELH · May 17, 2009

Seeing the primers would be of more help on what is happening. I would find a good riflesmith in your area and take the gun in to him along with about 4-5 fired cases, factory and handload if you have both. He may be able to determine if you have a problem you need to worry about or you may not.

If there is a problem with the rifle due to poor workmanship, then you need to decide to leave it with that gunsmith for repair or see if Winchester will repair under warranty.

RELH

Coach Hunt · May 17, 2009

LAST EDITED ON May-17-09 AT 09:01PM (MST)[p]Howdy,

Ok, here is what is happening. Winchester made a lot (several hundred) actions both Stainless and blued that had bolts fitted to them with over-size firing pin holes. I know because I bought one and returned it to Winchester before the New Haven plant shut down. The problem is that your primer is flowing around the firing pin and slightly into the hole. It is not unusual for a WSM to be "tight" to eject... reason being the lack of taper to the sides of the cartridge. I wasn't concerned with the primer crater as much as I was with the scope holes being drilled 10 degrees off center!!! That was the reason for the rifle being returned.

I don't think you should worry all that much about it. Be sure to use INTELLEGENT loads in your 7WSM, and your 4350 should be fine. I use it, H4350, to get about 3100 fps with the 140 accubond and have killed deer up to 486 yards away... in front of witnesses. The primers I use are Winchester. I use the magnum primers for hunting and the regular primers with reduced loads for practice.

Hope this helps.

Coach

REDDOG · May 17, 2009

I think in this case coach is 100% correct. and is not a winchester thing, alot of late model remington and savage's have the same problem, oversize pinhole.

so your wondering why we didnt just come out and say it? cause back when they used to build rifles, if one had this problem the culprit was high pressure. so just FYI, it can be other things, but likley just shotty workmanship.

Silentstalker · May 18, 2009

Thanks guy's, One last question for now. IS there a website where I can view pic's of "signs of pressure". I have read many descriptions of signs, but never really seen pic's. Any useful websites with that type of info?