7.62x39 to 6.5grendel issue

[jasonZ]

So I resizer and worked up some 7.62x39 brass to 6.5grendel and I went to fire form with a light load. All of the rounds that I tried to fire would not work. None of them would fire. There really wasn't any pin strike at all in the primer. A few had very light strike marks. My question is did I miss something? I haven't ever tried this before. I cleaned, resized, and loaded just as I read on. I don't recall anything special with the primer, but could of missed or forgot something.

I'm running an AR setup with Sabre Defense barrel/bolt. I put some reloaded that I worked up in Hornady brass. These fired just fine, each and every one of them.

Any help would be appreciated. Thanks Jason

 

[jasonZ]

Re: 7.62x39 to 6.5grendel issue

So nobody has any input. I'm wondering if the bolt is getting over the rim of the case. I didn't pay enough attention on the range, but the bolt looked to be fully closed and the trigger was allowed to be pulled and the pin fired. Guess I'm on my own here.

 

[gvanhyning]

Re: 7.62x39 to 6.5grendel issue

I have a 6.5 Grendel AA GDMR and I have only read about resizing the 7.62x39 in the Grendel forums. I'm not sure it's the best thing to do. The 6.5 Grendel was developed off the 6mm PPC cartridge because of the small primer and flash hole. The Grendel builds some very high chamber pressures that the 7.62x39 cases are not designed for. Hornady now makes the brass which is an alternative to the more expensive Lapua.

 

[jasonZ]

Re: 7.62x39 to 6.5grendel issue

I put a resized load and a factory hornady load in the chamber and it appears that the resized load sits deeper in the chamber. I let the bolt slam closed and it locked everything up solid. I mean I had to take the rifle apart and drive the bolt backwards to get the round out. Thinking the reloaded may not be a good idea, but still may explore into this more.

 

[leadbullet]

Re: 7.62x39 to 6.5grendel issue

I have fireformed hundreds of 7,62x39 case to grendel in a sabre defense barrel also, seems to me your problem is fron necking the 7,62 too low, you only need to size the case until the bolt closes, a 120 gr bullet with 24 gr of tac does a great job.
hope this helps.

 

[jasonZ]

Re: 7.62x39 to 6.5grendel issue

That could be the problem. I was just running the cases through my hornady dies. I'll have to check on that and see what happens. I didn't realize that I could size the case to far down. Thanks

 

[DRAM40A1]

Re: 7.62x39 to 6.5grendel issue

If the case is getting stuck to the point that you have to beat the bolt open you are not oversizing them. You might try and locate a Grendel case guage.

I have formed a couple hundred IMI cases into Grendel without a problem but I use Redding dies.

 

[bronzepig]

Re: 7.62x39 to 6.5grendel issue

your shoulder needs bumped back further, your bolt isnt closing (rotating shut) far enough to get a full firing pin strike but the bolt is closng far enough that it is difficult to open.

 

[jasonZ]

Re: 7.62x39 to 6.5grendel issue

I've got a hornady modified case that I ordered a while back. Forgot about it actually. I needed to see if I can get the case neck and shoulder to match that.

Yeah the bolt is only closing far enough to partially engage the live, which jams it up. I also noted that the shoulder of the case had markings on it where it was seating in the chamber. It appears that I need to neck it deeper on the case to get everything in check, but I need to verify this on some cases.
Thanks for the info guys