USAMU and the 7MM

[JOHN708]

I heard that the US Army marksmanship unit was experimenting with a 7mm short mag. for their long range target shooting. I also heard that they abandoned this project and went back to the 6.5-284. Is this true, and if so why?

 

[FatBoy]

John,

I shot next to Emil a few years back, when he was working with the 7SAUM. Sam Tedders was also working in tandem with them, on a 7WSM project. Sam abandon the project, only after trying three or four barrels, several chamber, bullet, brass and powder combinations. He said it would shoot bugholes one day, and crappy the next.

Emil shot the 7SAUM in a regional with us at ORSA. His 19th shot of his last match never made it to the target. That dropped him from a comfortable lead, to 2nd place. I haven't seen him use it again.

The team shooters I see on the line have one of three calibers, 6.5x284, 308,palma shooters) or 5.56 in LR SR's. That's not to say they don't have something up their sleeves,, but I think their record with the FagMags pretty well speaks for itself.

That said, I got my first 7mm back yesterday,284Lapua match). I'm gonna give it a go, in hopes that sierra has the bullets worked out. We'll see how it works.

Chris...

 

[chrisj]

Chris....do you know what bullet Emil was using when it didn't reach the target. It sounds like the bullet may have been the problem. I don't see how the cartridge could have been at fault for a bullet not hitting the target.

Chris

 

[FatBoy]

Chris,

Emil said he was using a Berger 180 when it let go. He used both Sierra 175's,he was testing them for Sierra) and Berger 180's during the match. Brass was sorted and prepped Remington SAUM brass. Not sure about powder or primers.

I like the look of the chamber, but I'm going to see how the 284Win works before trying it.

Chris...

 

[Wild_Bill]

If they pull the 7mm's out of the closet and use the 175gr Sierra's they will all make the target also what twist were they using a 9 twist is all that is needed as i use one in a 284 also the 175gr Sierra stabalises at 600 yards out of my model 7 in 7mmSAUM 22" barrel and shoots sub MOA.

I think with the new Sierra the Rem SAUM loaded with 175gr Sierra'a and H1000 would be an awsome target round and would give all the 300 mag target loads a run for their money.

Cheers Bill
Australia

 

[AlanWarner]

You fellas are relating to some very old info. Why don't one of you ask them now what direction they are looking to??

Just a passing thought

Alan

 

[FroggyOne2]

Alan.. that info may be found out this weekend.. we'll see what we can find out.

FO

 

[chrisj]

6mm?

 

[FroggyOne2]

6mm, nope, i probed Don this week end about that.. He said that they are planning on sticking with the 6.5 x 284. And when I mentioned the 243 with a 115 was inside the 6.5 x 284, Don said that they were not going to go that route. But then, he was smiling when he said that. But what he did tell me is that he has been doing a lot of testing with the 6.5 Grendel. And is very pleased with its performace.. "Great centered groups and very consistant, not getting the velocity that that I would like. We are using approx 21 grains of N-540 with the 123's at Six and shooting the 107's at 2 and 3." Don continued, "I have shot some high X count groups with it at 2 and 3 and I am very please with it!"

 

[RickB]

I would be rather surprised if they do not at least run some tests with the 6.5x47L, and possibly some variations on it. In bolt guns it should be able to outperform the 6.5 Grendel at 600 with only a bit more recoil and still have very good barrel life.

I should think the 6.5x284 will remain a specialized tool for those occasions where the barrel life is not a particular consideration when shooting longer ranges.

 

[FroggyOne2]

Rick, they are shooting the Grendel round in the AR platform.

 

[RickB]

Thanks Froggy, that is what I would have expected. In the AR the 6.5 Grendel is a very interesting cartridge. As the lead article on the 6 AR illustrates there are a number of useful possibilities on the case.

 

[rcw3]

6mm, nope, i probed Don this week end about that.. He said that they are planning on sticking with the 6.5 x 284. And when I mentioned the 243 with a 115 was inside the 6.5 x 284, Don said that they were not going to go that route. But then, he was smiling when he said that. But what he did tell me is that he has been doing a lot of testing with the 6.5 Grendel. And is very pleased with its performace.. "Great centered groups and very consistant, not getting the velocity that that I would like. We are using approx 21 grains of N-540 with the 123's at Six and shooting the 107's at 2 and 3." Don continued, "I have shot some high X count groups with it at 2 and 3 and I am very please with it!"

21 gr of N540 has got to be way too light of a load out of a Grendel with the 123 Lapuas. Maybe 31 gr, if you can get it all in the case and seat the bullet on top of it. In competition I was running 30 gr of AA2520 with the 123 Lapuas which yielded around 2600 - 2625 fps,deadly accurate I might add).

Robert Whitley