Cartridge Conversion 7.62x39 to 6.5 Grendel

I am starting a small series on converting brass. I am converting the 7.62x39 small primer pocket cases to the 6.5 Grendel small pocket cases. From my understanding by alexander arms, 7.62x39 will start having the small primer pockets. Remington has already started coming out with them.

I will have some pics to put up in a few. These pics will be of the 6.5 Factory brass from Hornady and Lapua, as well as a 7.62x39 case before conversion and after conversion with an unaltered case to compare. I am also in the process of uploading a video to youtube that you can check out in the youtube member section.

OK Day truly I'm not being obstinate i just really don't know why it would matter if you have a large primer pocket or small. please explain. For me the large would certainly be handier? If this would in anyway subtract form you thread just delete it. its ok with me.

nope that is a good question. Just uniformity. All of the 6.5 Grendel brass from the factory are all small primer pockets. Since I have about 200 factory new brass, all the primers I have purchased thus far is for the small primer pocket of the Grendel. This helps me keep everything organized. When I go to the grendel, I know that I will be using the small magnum primers and not trying to remember, but wait, I converted some brass that has the large. My load data might be a bit different with the large non magnum v/s the small magnum primers.

Plus, information from Alexander Arms, the 7.62x39 will be utilizing the small primer pockets. Remington has already started making the move to making them with the small primer pockets.

Just orginization on my part I guess..

just curious inquiring mind need to know kinda like the national enquirer
thanks for sharing that I have converted some brass just to say i could do it but have never had an excotic round that i had the need to do it on. lol I have converted 270 brass to 3006 nothing major there until i got a 270 and i took some 6mm rem and turned them into 243 but now that i can say i did it I dont need to. but now if you were to part with that grendel

LOL, don't think I will be parting with it anytime soon. Ammunition for the grendel is hard to come by. Powder and primers and bullets are better found. I am just getting as much brass together as possible so that I am not one of the few that has such a great rifle and round yet can't shoot it. I already did that for oh what, 7 months before I got to shoot it for the first time? I ordered the ammunition in Feburary when I built the rifle. It finally got here June July, maybe a little later. Then I got to shoot it..

The small primer use is to help in accuracy and to strengthen the case. A smaller primer has less influence on the overall charge and firing pressure which can make them more accurate.They did the same in the 6.5x47 Lapua.

Here are some pics.....

Hey Dw, How is the neck wall thickness after converting as compared to the factory brass? Will they need to be trimmed/turned?

I am going to measure that here in a bit. I was told by Alexander Arms that nothing would have to be turned. I was also told that when I fire form these for the first time, in order for the case body to blow out to the right diameter, I will notice that the oal of the case will actually be shorter because when the body "fattens", the Neck gets sucked in a bit. So I may wait and see if these will chamber as is, fire form, then look at trimming to length. Also if you notice, right now, the shoulder still isn't fully formed as well. All of that will work out during the fire forming. Let me do a measurement and I will get back to you...

Ok according to my measurements, there isn't any difference at all. The factory case, I got readings from .014-.015 measuring in different areas. Measuring the converted 7.62x39...

well that's great news! No need for a high dollar neck turner yet.

Exactly... Neck turning isn't something I was wanting to venture into anyhow. I have came across some plans on how to use the lathe for neck turning, but I think it would be easier to buy a handheld one..

....

you now, tears are usually preventable when you go by the rule that, what they don't know don't hurt them??


Oh well LOL, thats ok. I did not know Lapua made 7.62x39 brass!! Prob a bit pricy too...

Thanks anyhow...

kcatto wrote:dang tommy..... I wish I had seen this thread.... I just sold about 5000 laupa cases in 762x39 this weekend at the gun show.....

dang for sure! I would have picked some of them up for my AK....next time you get some reloadable brass in 7.62x39 please post some of it in the FS/trade section.

Daywalker wrote:Exactly... Neck turning isn't something I was wanting to venture into anyhow. I have came across some plans on how to use the lathe for neck turning, but I think it would be easier to buy a handheld one..

my understanding is when you do a conversion more times then not you have to ream the inside to remove some sort of "doughnut", not necessarily the outside. I haven't done any conversions so I don't know all the details, can someone elaborate?

also, neck turning usually isn't a good idea for semi autos, so I would assume the same would apply for the Grendal in an AR platform. any concerns there that the cases might prematurely split or cause any other potential issues?

you may have to remove some of the material from inside the case where you moved the shoulder, that is what I had to do when I converted 308 to 260 plus I had to trim the neck, I can't even put a bullet back in the shell casing after it has been fired.

While I have not done a 6.5 Grendel, I have done several other calibers.

My .225 Win AI barrel for the Encore was made with a tight neck so I have to turn the neck a little and also I have a .220 Wilson snipe reamer to thin the inside.

Another that requires a bit of neck turning and inside reaming is when I swage .240 Weatherby from .25-06 brass. The ones that I really have to work on is when I use old LC .30-06 brass (or other WW2 .30-06 brass) that I reduce to .25-06, trim and then swage to .240 Wby.

Sometimes I have to anneal the brass to get it soft enough so that it does not split or crumple when forming the belt. While it is a lot of work, the WW2 .30-06 brass seems to work the best and last longest.

If you ask the manufacturer of the 6.5 Grendel, they will probably tell you how to make the brass. I have heard good things about Alexander arms but have not dealt with them myself.

I have became great friends with Jacob who works there as a gunsmith and does alot of their builds and repairs. Alexander Arms is about a 10-15 min drive from the house. It is ashame they are on the Radford Army Ammunition Plant which is off limits to civilians. Alliant Powder is also made here as well.

I did get to meet the creater Bill Alexander at the eye dr while my kids was getting a check up. He was in there getting his glasses fixed. He will talk your ear off that is for sure...

Alot of my information is comeing from my talks with Jacob. He has been helping me with this rifle every step. I had bought the wrong bullets once, could not get it to chamber. We have done everything until Bill came to Jacobs work area as Jacob was lost. It took him like a couple seconds to tell Jacob, yea the Hornady 120 grain amax wont work because of the ogive is too far forward. Hornady had to stretch the bullet and make it heavier at 123 grain in order to move the ogive back far enough to chamber into the rifle. So I traded jacob 2 boxes of 120s's for his swede and he gave me some Nosler 120 BT's...

I am glad to hear that the reputation of Alexander Arms seems well deserved.

You need to find a military buddy to get you on that post. When I was at Ft Useless there in VA, we sometimes had to go down to Radford for ammo run. Nothing like driving a deuce and half with a few millon rounds of small arms ammo.

BTW I love the Hornady 120s for my Swede and for my 6.5x284 Win, although my 6.5x284 Win likes the heavier 140s better.

Cartridge conversions are a lot of fun and are time consuming. But I enjoy working with different calibers and something that is not usual.

When I burn the barrel out of my 7mm STW its going to Fred to become a 6.5 STW with a 28" tube. It still wears the Ruger stock barrel that I had Fred bore out to 7mm STW and recrown. Groups shrank dramatically.

I have seen some neat wildcats based on the 7.62 Russian short (7.62x39 for you civies). Not surprised someone necked it down to 6.5 and blew the shoulders out.

I still lean towards the old original 6.5x308 with 40 deg shoulders. But like the numbers of the 6.5x300 WSM too.

hey you might just ask if you can come there on a civilian guest pass.....

They allow that at the McAllister ammo plant here in Oklahoma... they make all kinds of boolits there from big howitzer stuff to small arms stuff.....

but if you just ask they will do a background on you and let you know before you drive over if you are allowed, and let you come in for a tour???? just a thought... heck we can hunt on the ammo plant property with permission of course... they hold shoots here at the ammo plant as well.... from archery to blackpowder and everything in between.

9-11 changed a lot of things for civies on military posts.

If you can get cleared for a pass, or take the post hunter safety course that puts you in the "system" and it should make it easier to get on post later.

Of course this means "the man" may know a bit about you, and that you like to enter military posts, but this is not all bad IMHO.

Unfortunately, the days of civies coming on post and shooting with us are rapidly ending. We used to host shooting matches out to 600 meters and was one of the few places that civies could shoot their .50 BMGs on post whereas most of the outside ranges here specify no .50s.

Somebody got nervous about the civies coming on post with weapons, so it was curtailed. We used to love it when the Squid reservists would come shoot for their quals, because they never took the brass. The Army counts every piece of brass, stripper clip, crate, and box.

When the Squids shot we used to divy the brass among the shooters who reloaded, civie and military.

Our post here lets civies hunt on post but they have to take a hunter's safety course, and they have to check their weapons in with the Provost Marshall. The PM takes the serial numbers for the records and a lot of guys do not like that as they feel it is a violation of rights.

Same if you lived on post and had personal weapons, the PM had to know the make, type and serial numbers.

For many of the conversions I prefer military brass as it holds up better for the most part. But sources of military brass are getting scarce and pricey.

I still prefer surplus 7.62x51 NATO for my .22-243 AI. I usually anneal the cases, blow them out to 35 cal and then reduce them in gradual steps to .224. The shoulders are the hard part as the sharp 40 deg shoulders are farther forward of the parent case.

First load is a fire forming load so I load the bullets so they are sitting against the lands when the action is closed. This raises pressures significantly so I load a 90% density load and have had great success with H4895, Varget, 4198, and Hunter.

I tend to prefer the slower powders since the tube is 28" and I have plenty of barrel to burn large charges of slow powder. The fireforming loads I tend to use a quicker powder sometimes like H322. Somebody recommended Benchmark but that is a small rifle powder, that I am not too familiar with.

If your 6.5 Grendel is in a semi-auto you may not be able to load past SAAMI OAL as it may not chamber or fit in the mag. You could single load, but I am not sure the pressure limits.

My single shot Encore is pretty stout and I am well within the pressure limits even loading the bullet to sit against the lands when closed.