6-284 /107SMK/Ramshot Magnum-Results

[RockZ]

I built up a 6-284 on a Savage target action and installed a 28" Shilen prefit barrel, put those in a Bell and Carlson Medalist stock(sorry no pics yet)

For load workups I loaded at the range with a load giving me 3250fps with the 107smk's,57gr Ramshot Magnum, and did a seating depth test. I used this velocity because I read it was a very accurate range for this cartridge.

After finding the best seating depth I did pressure workups.

I shot at each charge through the chrono until I reached 3450fps,61.5gr Ramshot Magnum , and still without any high pressure signs, but figured that was enough velocity.

I then worked backwards and shot loads of 2 more each through the chrono and watched for good ES. At the 3400 range, 60.5gr Ramshot Magnum I had a load that read 3392,3400,3395 fps.

Looked good to me so I loaded 3 more up and shot them at 565yds.

I also shot 3 rounds of 57gr to compare.

For the 57gr load, which by the way shot 3 shots into .25 at 100yds, shot a 5inch vertical at 565yds, with es being about 40fps.

Proving again that you need to shoot at long range to really see what a load does! Of course we all know that!

For the 60.5gr load:
Vertical was about 2 inches total, with 2 of the three shots being within one inch

I shot 12 more shots, for four -3shot groups.
The vertical was never more than 2 inches, and horizontal not more than 3 inches. A couple groups were 1.5"

As a note:

It seems like these charges are very high, but I noticed no difficult bolt lift, the Fed 210 primers all looked good, and the case web measured the same at 55grains -61.5grains., with no difference in expansion.
When I went back to reload the brass the primer pockets were still snug. I am using Lapua 6.5-284 brass necked down.
I was shooting in 95 degree heat with 90 percent humidity. Typical central FL summer.

Looks like a great load for my antelope hunt in a few of weeks.

The 6-284 with the 107smk's at 3400fps, looks awesome in the charts and has 1000ft.lbs energy at 800yds+/-. In fact not many rounds can stay with it as far as drop and drift.

Just will have to see how the 107 smk's perform on antelope!

Anyone with any exprerience with them please chime in.

Thanks

 

[Broz]

Just will have to see how the 107 smk's perform on antelope!

Anyone with any exprerience with them please chime in.

Thanks

The 107 SMK is the bullet of choice for my 6 br. My wife and I will be using on antelope out to 700 yards. I don't have any field reports for it on speed goats yet, but I did take a coyote with it. MV is 2775 and at 653 yards with the yote mostly straight on facing me. I put one in the front shoulder and it exited right under his tail with an exit hole of 1 1/2". Needless to say he dropped like he was lightning struck. I felt the exit proved expansion and I have no doubts with it for a well placed shot on a speed goat.

Jeff

 

[RockZ]

Jeff,
Thanks for the info.
The 107smk's should work great after hearing your results.
I am looking forward to giving this combo a try. I've mostly been working with the bigger rounds from 7wsm to 338 Lapua Improved.

Looks like the 6-284 can be awesome as far as ballistics and a light kicking round.
I'm very happy with the accuracy at the higher velocity as well.

I'm hunting in Wyoming from sep 25th -28th with Tyler Sims again and will let you all know how it goes.

 

[Broz]

Jeff,
Thanks for the info.
The 107smk's should work great after hearing your results.
I am looking forward to giving this combo a try. I've mostly been working with the bigger rounds from 7wsm to 338 Lapua Improved.

My 6mm BR use to be a 6mm-284 with a 26" 10 twist Shaw barrel. I used it on deer and antelope and a ton of coyotes and PD's. With the 10 twist I was limited to smaller bullets. It hated anything above a 85 gr. I used the 85 SGK for deer and speed goats and 70 gr Sierra HPBT for yotes and prairie dogs. She would really bust a PD into pieces with a 70 gr hollow point at 4100 fps.

But I would not push it to hard if I were you. The 6mm-284 can wear out a troat pretty fast.

Jeff

 

[RockZ]

I've been taking it nice and slow. That's why only 3 shot groups.
I'm also going to treat it with Gun Juice and see how that works out.

So, how many rounds did you get through it when it was a 6-284? Right now I only have about 50.

 

[Broz]

So, how many rounds did you get through it when it was a 6-284? Right now I only have about 50.

I built it to be fast, so the first barrel I loaded them that way... that barrel lasted 500 rounds and went from a .5 moa rifle to a 1.5 moa rifle. The second barrel was still shooting good at 500 but I took it off to go with a 8 twist for the bigger bullets and also opted for the 6br.

Jeff

 

[RockZ]

The 6br is a great round, I've had one for a while.
I figured I needed to try a burner so I am enjoying the 6-284.
Hopefully gun juice wll help a little

 

[Fiftydriver]

THe 107 SMK is better served on larger game such as pronghorn and deer then it is for lighter game as it will expand a bit better on the larger targets. That said, it is what it is an it tends to be a bit lacking in expansion even at best if impact is soft tissue.

The bullets perform very differently comparing shoulder hits compared to behind the shoulder impacts. On bone, they expand very well and do ALOT of damage for a 6mm bullet. In soft tissue, there can be very little expansion. The good news is that if you punch a hole through both lungs of a goat he will not go far at all. Pronghorns hurt easy if hit in the body. I have yet to see one take a solid body hit that was not recovered easily if some thought is put into the recovery. Now blow a leg off and they will run, VERY FAST for many miles but with a body hit, they will generally run a bit, then lay up rather quickly even if not a vital hit.

My point is not to say that you should not do everything in your power to put the bullet through the vitals, only to comment that in the event of a bad situation, if you use your head you will recover most any body hit goat.

I have used the 6-284 for years in a 30" lilja. When I started I ran it pretty hard, in fact my average load with the 107 gr SMK was 3590 fps, yep, hot load but still had good brass life.

Later in the rifles life I have decided to be a bit nicer to the rifle and backed down to 3450 fps. It has always shot very well, pushed hard or throttled back to more comfortable pressures but that SMK will take any velocity you can throw at it. Thats why it can be a bit tempermental as far as expansion however!!!

Have fun. ITs amazine what this big 6mm will do at long range.

 

[RockZ]

Kirby,
I appreciate the info. The 6-284 is pretty incredible as far as ballistics for the amount of recoil.
With my 28" barrel, 3400fps seems like the idea velocity.Very accurate and consistent.
I feel pretty good about it since it is pretty close to your ideal velocity of 3450fps.

It's awesome that the 107smk's held up when you pushed them to almost 3600fps!
Looks like I don't have to worry about the blowups I've heard of some lighter jacketed bullets.

I built this rifle just for antelope, it seems like a very good fit.

I'll take your advice and put it close, if not in the shoulder and not worry about a little meat loss.
This year I'm holding out for a B&C Antelope and I want to drop him on the spot.

I'll let you all know how it goes.

 

[Fiftydriver]

My barrel on my 6-284 is a Lilja 1-8, 3 groove, known very well to be one of the hardest barrels on match bullets and I have yet to see a bullet dust, at least no 107 gr SMK anyway, berger and A-max, thats a totally different story for sure. I started using this rifle back when I was just learning about long range rifles. Now, I recommend a Lilja 1-9, 6 groove for all my customers wanting a chambering in the 243 AI, 6mm AI, 6-284, 6-06 or 6-06 AI.

In my wifes pronghorn rifle, a fully built Sporter Win M70 in 6-06 with 27" barrel length, her standard load breaks 3500 fps and again has never had a single bullet failure.

YOu can also uniform the meplat on the 107 gr which slightly opens up the HP and will expand a bit better at longer ranges with soft tissue impacts but you will loose a very slight bit of BC.

That said, the BC you do have will be more consistant as well.

I have always found that sorting the bullets by baring surface length made the biggest difference to long range consistancy, especially vertical stringing. This becomes more critical the more extreme in performance you get. For example, it makes more difference in a large capacity chambering shooting heavy bullets in fast twist barrels then it does with the same capacity chambering with light bullets in slow twist barrels.

Also, bullet shorting makes the most difference past 800 yards. IF you do not plan to reach that far on big game, not really an issue, not enough to cause a bad shot in a good rifle anyway at closer ranges then 1/2 mile. Personally, I think 1/2 mile is about max I would use this chambering on big game, even pronghorns. I have taken a few at near 1000 yards with it but the retained velocity really gives inconsistant expansion, inside 1/2 mile it is much more consistant but even at its best, not great.

I would love to see Sierra put their Blitzking tip on their entire line of SMK bullets and we would then have some easy to get, BAD *** long range hunting bullets. I have told them this a hundred times and apparently I have alot of pull with decisions made at Sierra!!! LOL

Have fun.

 

[RockZ]

Kirby,
I'm going to shoot this Fri and will sort the bullets by bearing surface and see what kind of groups I can get at 565yds.
I won't shoot too many since I want to save the barrel life a bit.

I'm also going to verify my drops out to 1000yds.

I don't have a meplat uniformer so I won't be able to do that .

You are right, it would be great if sierra would put the blitz tips in their smk's. Maybe we should all call them !

Hopefully the conditions will be good for a little while. Down here is Fl with the heat and humidity the mirage is fierce.
Good news is that I get plenty of practice reading it.

Thanks again for the info

 

[Broz]

I can't add much info for the larger game other than what I had with the yote. But I remembered the pics I took of a few killer gophers. I have shot gophers with the 6br to 100~500 yards and have had mixed results with the 107's as far as expansion. Some simply pass through with not much carnage, but some do a pretty good job of exploding the little guys. Here are two examples.

Jeff

 

[Fiftydriver]

Broz,

My results pretty much echo your results using the 107 on lighter targets. I used them alot on rockchucks out to 1100 yards. Inside 600 yards you could get by with any solid body hit and anchor those tough vermin. From 700 to around 900 you better get a solid head or front shoulder hit or they would make it to their dens. Past 1000 yards, it better be a head shot or you would loose them. Witnessed this MANY, MANY times.

On yotes, very similiar, inside 600 yards, it was mostly bang/flops with front shoulder hits, past that, with the same hit you could see a bang flop or they could run for several hundred yards before giving up the ghost.

I have always commented that the 107 gr SMK is a better light, big game bullet then varmint bullet for long range hunting. Seems your results were the same.

 

[Fiftydriver]

Broz,

One more thing, have you ever tried the 105 gr A-max in your 6mm BR. I have shot this bullet in the BR with steller results, especially with increased terminal POP factor!!! They simply can not survive the top end launch speed of the 6-284 or 6-06 but they have been amazing in the smaller 6mms such as the BR, Dasher and 6-250.

You have have already tried them, if not, you may want to.