BERTRAM BRASS FOR 6.5 SHERMAN SHORTMAG??

[elkaholic]

I am in the beginning stages of gathering parts for a 6.5ss build so count me in. How soon depends if I make my sako trg22 a 6mm based off a shortens 284 which takes only a barrel change or 6.5ss and open the Bolt up. The other will be a ground up build I am getting parts for presently. But for sure in on betram brass for sure.

I know it early but what price range are you hoping to come in at? I am guessing $3 per??

I am HOPING even less but not sure until I get things nailed down......Rich

 

[tim_w]

If it's less that would be terrific. I was just estimating based on the last time around. Well keep us updated and whT would be needed if any for a minimum order.

 

[kyron]

Would this extend to the 7mm ss also? The barrel on my rifle is now toast and I am planning to replace it with a 7mm ss. In fact I saw this post as I logged in to search for the post you put up earlier on which smiths are doing pre fits

 

[mhamlin]

Head Stamped Brass is what I've been waiting for. ..

-Mike

 

[elkaholic]

I am not sure that there would be anything right away with a 7 head stamp but it would be simply necking up the case to make a 7SS. Could be I could do a mixed batch of 6.5 and 7, but we are a ways from anything as yet. I am waiting for some sample Bertram 7 saum from Bruce Bertram and then we will start discussing the possibilities. Keep your fingers crossed as I REALLY want to make this work!......Rich

 

[tim_w]

Good luck. I have unusual build in mind for this and the brass would be a big help as I might not always be able to retreive all my fired cases.

 

[elkaholic]

Hmmmm? pop pop pop pop!

 

[tim_w]

Hmmmm? pop pop pop pop!

You sir are a wise man lol

Just waiting for the bolt face to be opened up. Bit of extractor work.

My hope is the new 155 eol will work inside a 2.86 - 2.87.

That at say 3100-3150 accurcay node out of a 24" would make this a dream come true.

 

[elkaholic]

You sir are a wise man lol

Just waiting for the bolt face to be opened up. Bit of extractor work.

My hope is the new 155 eol will work inside a 2.86 - 2.87.

That at say 3100-3150 accurcay node out of a 24" would make this a dream come true.

Well, it will make 3100 I am pretty sure. Feeding COULD be a problem with an auto, but I don't know for sure? The SST at 3000 plus might be a better option with the 30 degree shoulder. I run the 147's at 3100 at a coal of 2.770"....Rich

 

[tim_w]

I am wondering that myself. As a test I found a round off the 5.56 that had a 40 degree shoulder and even with a fairly tight chamber it was feeding fine. Now if I was looking to shoot as fast as when doing a mag dump or burst f/a I could certainly see an issue. I think it may come down to how I set the feed lips on the mag and the ramp angle in the reciever which I can adjust. If not I ca certainly set the shoulder back to create a 30 or 35 degree. I know 35 degree worked in a wsm for this so I am hopeful.

 

[elkaholic]

I am wondering that myself. As a test I found a round off the 5.56 that had a 40 degree shoulder and even with a fairly tight chamber it was feeding fine. Now if I was looking to shoot as fast as when doing a mag dump or burst f/a I could certainly see an issue. I think it may come down to how I set the feed lips on the mag and the ramp angle in the reciever which I can adjust. If not I ca certainly set the shoulder back to create a 30 or 35 degree. I know 35 degree worked in a wsm for this so I am hopeful.

It will be a good test!......Rich

 

[elkaholic]

I received some Bertram 7 saum brass from Bruce Bertram and have been playing with it it bit. It seems to form nicely into the SST case.
A few things of note:
The neck wall thickness is a little less than Norma which is not a problem and could bode well for the head stamped brass being on from the factory.
The capacity from (1 fire formed case) yielded 71.3 grains H20 capacity (Norma is 69.7) This could also be a plus as long as strength does not suffer, and I have heard Bertram brass is tough!
The flash hole is considerably larger on the Bertram? Does anyone have any experience with this? I don't really know what affect this will have?
Here are a couple pics of the flash hole and the formed case sequence from saum to ready to form, to formed......Rich

 

[tim_w]

Rich,

I would think over all larger flash hole would not be ideal. But looking at the edges it looks like someone chamfered the flash hole on the bertram. maybe its a play on the light but it seems clear when looking between the two.

Either way I would think that is something Bertram can easily make just about any size you want. Can you tell or do you know if they drill or punch the FH? I would rather it be a smaller just because we know the performance we are getting from the smaller dimension. I know I personally always tried to never open up the hole past making it even and clean. I beveled out and inside edge but that was it for total FH prep.

It should be tough brass though. You can never use capacity as a indicator of how much pressure the case can handle. I have had a number of cases that were way way tougher but also have a good bit more capacity. Good example is to compare hornadyy to just about any other brass. LOL That stuff is soft in my experience.

 

[elkaholic]

The pic does not represent the true shape of the hole. It is round, just larger. I am not sure how they from it yet, but I will look closer when I get a chance.....Rich