First build : 7 mm rem mag

I promised I would post results of my new rifle. It started out a 111 rem mag, I found on the internet. I ordered a Mcgowen 27" 1:9 twist, full bull barrel and had a certified gun smith slap that bad boy on the 111 action. I also ordered up the Boyd's tacticool stock to replace the factory stock.

I have been reloading for 5 years now, so I decided to test the Berger 168gr Vld. I like the. IMR 4831 powder so I started with 60 gr of that. I measured the OAL of my rifle to be 3.425inches.
Here are the results;

6 shots 60 gr IMR 4831
http://img.tapatalk.com/d/14/04/30/5u5u6a3a.jpg
5 shots 61 gr IMR 4831
http://img.tapatalk.com/d/14/04/30/demetuge.jpg
5 shots 62 Gr IMR 4831
http://img.tapatalk.com/d/14/04/30/qe4equse.jpg
6 shots 63 gr IMR 4831
http://img.tapatalk.com/d/14/04/30/y8yqa7uv.jpg

It's a very accurate, but here is my question... Would the heating of the barrel shrink the size of the shot groups?

Shoot your groups slow, like 3-5 min between shots. When the barrel starts to get hot accuracy will more than likely go with it. If that occurs trying to find a good load or test accuracy will have you chasing your tail so to speak.

With my Savage barrels I usually shoot 5-6 fouling rounds then shoot 3-5 slowly to test each load. My Magnums and '06 in sporter barrels require more time between shots. Smaller calibers and heavy barrels get away with quicker succession.

My Browning a-bolt will shoot 2 tight, then walk 1 inch right each shot thereafter if I don't let it cool completely between shots. (they will hit further and further to the right, right off the paper!)

I did shoot slow, maybe 2-3 min apart, looking for signs of over pressure. I did not use a rear bag, but I am sub MOA without the rear bag.....

those are good, especially without a rear bag... hard to tell if your load is right, though, if you don't use a rear bag. You want to be sure you are not holding high/low. One of the key indicators of a good load is how little your shots string vertically. Without a rear rest, its hard to say if it's you or the load, even when groups are tight.

I will use a rest next time.

A few photos from today's shoot.
http://img.tapatalk.com/d/14/04/30/za9y4aha.jpg
http://img.tapatalk.com/d/14/04/30/sybase5a.jpg
http://img.tapatalk.com/d/14/04/30/hy9uqy9a.jpg

Rifle looks really good, groups look like they are quite promising...what kinda speed were you gettin with the 168s?

Velocities 7mm rem mag 4/29/2014

60 gr
2880
2860
2877
2879
2890
2865
Avg----2875

61 gr
2957
2834
2961
2926
2945
Avg---2924

62gr
2910
2891
2910
2904
2906
Avg--2903

63 gr
2951
2969
2967
2989
2968
Avg--2968

When you finish with this powder you might want to go to a slower one, 63gr in a magnum round is on the low side volume wise, especially with a 27" barrel you are losing efficiency, you seem to like IMR powder so for my first choice, I would go with IMR7828 you would be in the 70gr range, or my 2nd choice would be IMR4831 that would put you in the 67gr area, alot more efficient you would most likely end up with more velocity and tighter groupings, carry on

Dean

I am using the IMR4831, and my book says max load is 64 gr. Next I will try the IMR7828.

Sorry I misread, but what I said still applies at 63gr of IMR4831, with a tight new chamber & barrel you are well under max, and will see improvements with the IMR7828.

Dean

63.1gr of Reloader 19 with a 168gr Sierra Matchking is an awesome load.

Quote:

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Originally Posted by scope eye

Sorry I misread, but what I said still applies at 63gr of IMR4831, with a tight new chamber & barrel you are well under max, and will see improvements with the IMR7828.

Dean

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Hi, Dean. Are you saying that because IMR7828 will better fill the case?

Quote:

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Originally Posted by foxx

Hi, Dean. Are you saying that because IMR7828 will better fill the case?

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Yes magnum cases more than any, benefit from more volume of a slower burning powder, hence the longer barrels, and you don't necessarily need to use mag primers either,

Dean

+1 for Dean....magnums seem to like a full case, I dont think you will go wrong with IMR7828, keep us posted on your results.

Now I need to find where they are selling this rare powder you are talking about!

RL25 has the same burn rate as IMR7828, which I prefer anyway, even H1000 would be a viable option.
Dean

We liked h1000 best in our 7mm but I hear it is still hard to get these days.

Also try neck sizing your fire formed brass and don't rely on the belt for headspace, use shoulder to base for overall better accuracy and case life.